Patent Publication Number: US-2009228100-A1

Title: Methods and Devices for Heart Valve Repair

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. patent application Ser. No. 11/014,273, filed Dec. 15, 2004, entitled “DEVICE FOR CHANGING THE SHAPE OF THE MITRAL ANNULUS”, which claims priority from U.S. Provisional Patent Application No. 60/530,352 filed Dec. 16, 2003 titled “Device to Change the Shape of the Mitral Valve Annulus” and U.S. Provisional Patent Application 60/547,741 filed Feb. 25, 2004 titled “Methods and Apparatus for Treatment of Mitral Insufficiency” and U.S. Provisional Patent Application 60/624,224 filed Nov. 2, 2004 titled “Device for Changing the Shape of the Mitral Annulus”, the entire content of which is expressly incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to devices and methods for heart valve repair and, more particularly, to endovascular devices and methods for improving mitral valve function using devices inserted into the coronary sinus. 
     BACKGROUND 
     Heart valve regurgitation, or leakage from the outflow to the inflow side of a heart valve, is a common occurrence in patients with heart failure and a source of morbidity and mortality in these patients. Usually, regurgitation will occur in the mitral valve, located between the left atrium and the left ventricle, or in the tricuspid valve, located between the right atrium and right ventricle. Mitral regurgitation in patients with heart failure is caused by changes in the geometric configurations of the left ventricle, papillary muscles and mitral annulus. Similarly, tricuspid regurgitation is caused by changes in the geometric configurations of the right ventricle, papillary muscles, and tricuspid annulus. These geometric alterations result in mitral and tricuspid leaflet tethering and incomplete coaptation in systole. 
     Mitral valve repair is the procedure of choice to correct mitral regurgitation of all etiologies. With the use of current surgical techniques, between 40% and 60% of regurgitant mitral valves can be repaired depending on the surgeon&#39;s experience and the anatomic conditions. The advantages of mitral valve repair over mitral valve replacement are well documented. These advantages include better preservation of cardiac function and reduced risk of anticoagulant-related hemorrhage, thromboembolism and endocarditis. 
     In current practice, mitral valve surgery requires an extremely invasive approach that includes a chest wall incision, cardiopulmonary bypass, cardiac and pulmonary arrest, and an incision on the heart itself to gain access to the mitral valve. Such a procedure is associated with high morbidity and mortality. Due to the risks associated with this procedure, many of the sickest patients are denied the potential benefits of surgical correction of mitral regurgitation. In addition, patients with moderate, symptomatic mitral regurgitation are denied early intervention and undergo surgical correction only after the development of cardiac dysfunction. 
     More particularly, current surgical practice for mitral valve repair generally requires that the posterior mitral valve annulus be reduced in radius by surgically opening the left atrium and then fixing sutures, or sutures in combination with a support ring, to the internal surface of the annulus. This structure is used to pull the annulus back into a smaller radius, thereby reducing mitral regurgitation by improving leaflet coaptation. 
     This method of mitral valve repair, generally termed “annuloplasty,” effectively reduces mitral regurgitation in heart failure patients. This, in turn, reduces symptoms of heart failure, improves quality of life and increases longevity. Unfortunately, however, the invasive nature of mitral valve surgery and the attendant risks render most heart failure patients poor surgical candidates. Thus, a less invasive means to increase leaflet coaptation and thereby reduce mitral regurgitation in heart failure patients would make this therapy available to a much greater percentage of patients. 
     Several recent developments in minimally invasive techniques for repairing the mitral valve without surgery have been introduced. Some of these techniques involve introducing systems for remodeling the mitral annulus through the coronary sinus. 
     The coronary sinus is a blood vessel commencing at the coronary ostium in the right atrium and passing through the atrioventricular groove in close proximity to the posterior, lateral and medial aspects of the mitral annulus. Because of its position adjacent to the mitral annulus, the coronary sinus provides an ideal conduit for positioning an endovascular prosthesis to act on the mitral annulus and therefore reshape it. 
     One example of a minimally invasive technique for mitral valve repair can be found in U.S. Patent Publication No. 2003/0083,538 to Adams et al. (“the &#39;538 publication”). The &#39;538 publication describes a balloon expandable device insertable into the coronary sinus to reshape the mitral valve annulus, the device taking the form of a frame structure having an elongated base and integral columnar structures extending therefrom. The columnar structures form the force applier to apply force to discrete portions of the wall of the coronary sinus. 
     Another device is described in U.S. Pat. No. 6,656,221 issued to Taylor et al. (“the &#39;221 patent”). The &#39;835 publication describes a substantially straight rigid elongated body including relatively flexible portions to help better distribute the stress exerted on the walls of the coronary sinus. 
     U.S. Patent Publication 2002/0183838 to Liddicoat et al. (“the &#39;838 publication) describes multiple devices for minimally invasive mitral valve repair. In one embodiment, the &#39;838 publication describes a device including an internal member having a plurality of slots and an external member having a plurality of slots. When the slots on the internal member are aligned with the slots on the external member, the device is flexible so as to follow the natural curvature of the coronary sinus. When the slots on both members are oriented away from each other, the device is straight and rigid and able to apply an anteriorly-directed force to the mitral valve annulus. 
     In another embodiment, the &#39;838 publication describes an elongated body having a “w” shape. When the body is positioned in the coronary sinus, the center of the “w” is directed towards the anterior mitral annulus and inverts the natural curvature of the coronary sinus. 
     Another example of a minimally invasive technique for mitral valve repair can be found in U.S. Pat. No. 6,402,781 issued to Langberg et al. (“the &#39;781 patent”). The &#39;781 patent describes a two-dimensional prosthesis deployed into the coronary sinus via a delivery catheter. The tissue contacting surface of the prosthesis is provided with ridges, teeth or piercing structures that exert tension and enhance friction to engage to discrete portions of the wall of the coronary sinus. Moreover, the device provides an open loop through the coronary sinus and the entire coronary venous system with control lines that extend outside of the patient. 
     Another device is described in U.S. Pat. No. 6,790,231 to Liddicoat et al. (“the &#39;231 patent”). The &#39;231 patent describes a two-dimensional elongated body having a guide wire that controls a spine of the elongated body to form an arc. The elongate body has discrete barbs along its spine to apply frictional force to discrete portions of the wall of the coronary sinus. 
     U.S. Pat. No. 6,676,702 to Mathis (“the &#39;702 patent”) describes a two-dimensional mitral valve therapy device that forms an arc inside the coronary sinus to exert force on the mitral annulus. A guide wire extending from the device changes the shape of the device and the device applies pressure on discrete portions of the coronary sinus. 
     Despite recent attempts at minimally invasive repair of the mitral annulus using devices residing in the coronary sinus, there is a need for such endovascular correction devices that do not require an external member, such as a wire, to alter the shape of the device, yet still provide enough force to reshape the mitral annulus. Further, there is a need for devices, including those that use an external member, that are less traumatic to the sinus, both during and after their insertion into the coronary sinus, and are also more reliable over long periods of time. Finally, there is a need for better control over the shape in which the mitral annulus is deformed by such endovascular correction devices. 
     SUMMARY 
     The invention described herein provides a more reliable and a safer way to treat a dilated mitral annulus. Devices in accordance with principles of the present invention may comprise one or more components suitable for deployment in the coronary sinus and adjoining coronary veins. The devices may be configured to bend in-situ to apply a compressive load to the mitral valve annulus with or without a length change, or may include multiple components that are drawn or contracted towards one another to remodel the mitral valve annulus. Any of a number of types of anchors may be used to engage the surrounding vein and tissue, including anchors comprising ultraviolet (UV) curable materials, hydrogels, hydrophilic materials, or biologically anchored components. Remodeling of the mitral valve annulus may be accomplished during initial deployment of the device, or by biological actuation during subsequent in-dwelling of the device. 
     One embodiment of the invention comprises an elongate body having a proximal, central and distal stent section, wherein a backbone fixes the stent sections relative to one another and wherein the central stent section has a plurality of rings connected to the backbone. The elongate body has two states: a first state wherein the elongate body has a shape that is adaptable to the shape of the coronary sinus and a second state wherein the elongate body pushes on the coronary sinus to reduce dilatation. Further, the elongate body has a greater axial length in the first state than in the second state. 
     When the body is deployed, the proximal and distal stent sections are expanded to act as anchors in the coronary sinus. Expansion of the central stent section foreshortens the elongate body, drawing the proximal and distal stent sections toward the central stent section, and cinching the mitral valve and closing the gap between mitral valve leaflets. When the gap between the mitral valve leaflets is closed, the effects of mitral valve regurgitation are drastically reduced or eliminated. 
     In another embodiment, the device comprises proximal and distal transitional sections in addition to the proximal, central and distal stent sections. The transitional sections allow the body to have enough flexibility to conform to the curvature of the coronary sinus. 
     Yet another embodiment comprises a proximal stent module and a distal stent module, wherein each stent module has an anchor section, a central section and a backbone. When both stent modules are inserted into the coronary sinus, the central sections of the two modules may overlap, effectively providing for one continuous stent. Additionally, based on the degree of rigidity desired, the backbones of the stents may be misaligned to provide for increased flexibility. 
     Yet another embodiment comprises a tubular elongate body having such dimensions so as to be insertable into the coronary sinus. The body has two states: a first state wherein the body has a linear shape adaptable to the shape of the coronary sinus and a second state, to which the body is transferable from the first state, wherein the device has a nonlinear shape. 
     In yet another embodiment, the invention comprises a proximal stent section, a central stent section, and a distal stent section, where a diameter of the elongate body varies from the proximal stent section to the distal stent section. The body expands into a three-dimensional shape that conforms to the anatomy of the coronary sinus, thereby applying more uniform stress to the walls of the inner radius of the coronary sinus. The device achieves remodeling of the mitral annulus through foreshortening, which reduces the overall length of the coronary sinus and as a result, reduces the circumference of the mitral annulus. 
     In accordance with the invention, in one embodiment, the elongate body is a multi-filament woven structure, where an angle of weave in the woven structure determines the degree of expansion force and foreshortening of the coronary sinus. The woven structure is made of metal with memory effect, such as Nitinol, Elgiloy, or spring steel. 
     Also in accordance with this aspect of the invention, in one embodiment a rigid inner elongated body is placed inside of the elongate body. In one example, the rigid inner elongate body is placed along the central stent section of the elongate body and fitted into the central stent section of the elongate body. The inner elongate body is made from rigid metal, such as stainless steel. Moreover, the elongate body may be self expandable or balloon expandable. 
     In yet another embodiment, the invention comprises a proximal and distal anchor, and a bridge between the proximal and distal anchors. The bridge has an elongated state, having first axial length, and a shortened state, having a second axial length, wherein the second axial length is shorter than the first axial length. A resorbable thread may be woven into the bridge to hold the bridge in the elongated state and to delay the transfer of the bridge to the shortened state. In an additional embodiment, there may be one or more central anchors between the proximal and distal anchors with a bridge connecting adjacent anchors. 
     In another embodiment of the present invention, the device comprises proximal and distal anchor elements, wherein the proximal anchor element comprises a deployable flange. The proximal and distal anchor elements are delivered into the coronary sinus in a contracted state, and then are deployed preferably within the coronary sinus so that the flange of the proximal anchor element engages the coronary sinus ostium. A cinch mechanism, for example, comprising a plurality of wires and eyelets, is provided to reduce the distance between proximal and distal anchor elements, thereby reducing the circumference of the mitral valve annulus. 
     To reduce trauma to the intima of the coronary sinus during actuation of the cinch mechanism, the distal anchor element preferably is chemically or mechanically bonded to the intima of the coronary sinus prior to actuation of the cinch mechanism. The distal anchor element may comprise a UV-curable material that causes the distal anchor element to bond with the intima of the coronary sinus when a UV source is provided. Alternatively, the distal anchor element may comprise a hydrogel or hydrophilic foam that causes the distal anchor element to chemically bond with the intima of the coronary sinus, which in effect may reduce trauma to the intima of the vessel wall during actuation of the cinch mechanism. 
     In another embodiment of the present invention, a proximal balloon catheter is used in conjunction with a distal balloon catheter to treat mitral insufficiency. The balloons of the proximal and distal catheters may be deployed spaced apart a selected distance, preferably substantially within the coronary sinus, and then manipulated so that they remodel the curvature of the coronary sinus. This remodeling in turn applies a compressive force upon the mitral valve to remodel the mitral valve annulus. With the compressive force applied, a substance, such as a biological hardening agent, may be introduced into a cavity formed between the two balloons to cause a hardened mass to form in the cavity. When the balloons of the proximal and distal catheters subsequently are removed, the mass ensures that the coronary sinus is retained in the remodeled shape. 
     In yet a further embodiment of the present invention, a stent is provided having proximal and distal sections coupled to one another by a central section, so that expansion and/or curvature of the central section causes the proximal and distal sections to be drawn together. In this embodiment, the central section includes one or more biodegradable structures, such as biodegradable sutures, that retain the central section in its contracted state until the vessel endothelium has overgrown a portion of the proximal and distal sections. This provides biological anchoring of the proximal and distal sections of the stent within at least a portion of the coronary sinus. 
     After the proximal and distal sections have become endothelialized, the biodegradable structure degrades, releasing the central section and enabling it to expand and/or assume a desired curvature. The expansion and/or curvature of the central section causes the stent to reduce the radius of curvature of the coronary sinus, thereby causing remodeling of the mitral valve annulus. 
     In another embodiment, a device for the treatment of mitral annulus dilatation includes a cylindrical proximal stent module having an anchor section and a central section and a cylindrical distal stent module having an anchor section and a central section, wherein the proximal and distal stent modules have two states, a first state wherein the proximal and distal stent modules have a shape that is adaptable to the shape of the coronary sinus, and a second state wherein the elongate body pushes on the coronary sinus to reduce dilatation, wherein each stent module has a backbone, and each backbone fixes the anchor section relative to the central section on each module along one side of the module, and wherein, when the proximal and distal stent modules are in the second state, the central section of the proximal stent overlaps the central section of the distal stent. 
     In this embodiment, the device may be inserted into a coronary sinus, and the anchor sections of the proximal stent module and the distal stent module anchor each module, respectively, to the coronary sinus when the modules are in the second state. The proximal and distal stent modules may be made from stainless steel. 
     In this embodiment, the stent modules may be inserted into the coronary sinus, and the backbone of the proximal stent section may be separated from the backbone of the distal stent section. 
     For example, the backbone of the proximal stent section may be angularly separated from the backbone of the distal stent section by between about 60°-180°. 
     In this embodiment, the proximal and distal stent sections may be transferable from the first state to the second state by a balloon. The proximal and distal stent modules may have a greater axial length in the first state than in the second state. 
     In another embodiment, a device for the treatment of mitral annulus dilatation includes a tubular elongate body having such dimensions as to be insertable into a coronary sinus, wherein the elongate body has two states, a first state wherein the elongate body has a linear shape that is adaptable to the shape of the coronary sinus, and a second state, to which the elongate body is transferable from the first state, wherein the device has a nonlinear shape. 
     In another embodiment, the tubular elongate body in the second state has a substantially w-shaped configuration. The elongate body may be transferable from a first state to a second state by a balloon. The elongate body may also include at least two spines. In another embodiment, the tubular elongate body further includes a plurality of interconnecting members extending between the at least two spines. 
     In another embodiment, a device for treatment of mitral annulus dilation includes an outer elongate body having such dimensions as to be insertable into a coronary sinus, the outer elongate body comprising a proximal stent section, a central stent section, and a distal stent section, wherein a diameter of the outer elongate body varies from the proximal stent section to the distal stent section, the outer elongate body having two states, a first state wherein the outer elongate body is adaptable to be inserted into the coronary sinus, and a second state wherein the outer elongate body expands inside the coronary sinus to provide foreshortening of the coronary sinus; and a rigid inner elongate body being placed inside of the outer elongate body when the outer elongate body is in the second state. 
     In another embodiment, a method of treating mitral annulus dilation includes providing an elongate body for treatment of mitral annulus dilation, the elongate body comprising a curved configuration to conform to an anatomy of a coronary sinus, the elongate body having a proximal stent section, a central stent section, and a distal stent section, wherein a diameter of the elongate body varies from the proximal stent section to the distal stent section; inserting the elongate body into the coronary sinus; expanding the elongate body into a three-dimensional shape to make substantial contact with walls of the coronary sinus; and foreshortening the elongate body. 
     In another embodiment, the method includes inserting a rigid inner elongate body inside the expanded elongate body using a balloon; and expanding the inner elongate body to make a substantial contact with the outer elongate body. 
     In another embodiment, an apparatus for treating mitral annulus dilatation includes (a) a proximal anchor element; (b) a distal anchor element adapted to be at least partially bonded to an intima of a patient&#39;s vessel; and (c) means for drawing the distal anchor element towards the proximal anchor element. 
     In another embodiment, the proximal anchor element further comprises a flange configured to abut a coronary ostium. 
     In another embodiment, the proximal anchor element comprises a self-deploying stent. 
     In another embodiment, the distal anchor element comprises a self-deploying stent configured to engage an intima of a patient&#39;s vessel in an expanded state. 
     In another embodiment, the distal anchor element further comprises an expandable foam member having proximal and distal ends and a bore extending therebetween, wherein the foam member is configured to engage an intima of a patient&#39;s vessel in an expanded state. 
     In another embodiment, the foam member comprises a hydrophilic foam. 
     In another embodiment, the distal anchor element further comprises a light-reactive binding agent. 
     In another embodiment, a catheter having proximal and distal ends, a lumen extending therebetween, and at least one port disposed at the distal end, wherein the catheter is configured to transmit light from the proximal end to the port via the lumen. 
     In another embodiment, at least one radiopaque marker band disposed on the distal end of the catheter. 
     In another embodiment, the distal anchor element further comprises a hydrogel. 
     In another embodiment, a method for treating mitral annulus dilatation includes (a) providing apparatus comprising a proximal anchor element and a distal anchor element in contracted states, (b) deploying the distal anchor element at a first location in a patient&#39;s vessel; (c) deploying the proximal anchor element at a second location in a patient&#39;s vessel; (d) bonding at least a portion of the distal anchor element to an intima of the patient&#39;s vessel; and (e) drawing the distal anchor towards the proximal anchor element to apply a compressive force upon the mitral annulus. 
     In another embodiment, the distal anchor element is chemically bonded to an intima of a patient&#39;s coronary sinus. 
     In another embodiment, the method further includes (a) providing a light-reactive binding agent disposed on at least a portion of the distal anchor element; (b) providing a light source; and (c) exposing the light-reactive binding agent to the light source to cause at least a portion of the distal anchor element to polymerize. 
     In another embodiment, the method further includes (a) providing a hydrogel disposed on at least a portion of the distal anchor element; and (b) causing the hydrogel to harden. 
     In another embodiment, the method further includes (a) providing a hydrophilic foam member; and (b) causing the hydrophilic foam member to engage an intima of the patient&#39;s coronary sinus and or great cardiac vein. 
     In another embodiment, a method for treating mitral annulus dilatation includes (a) providing a first balloon catheter having proximal and distal ends, a lumen extending therebetween, and a balloon disposed at the distal end; (b) providing a second balloon catheter having proximal and distal ends, a lumen extending therebetween, and a balloon disposed at the distal end; (c) deploying the balloon of the first catheter at a first location in a patient&#39;s coronary sinus; (d) deploying the balloon of the second catheter at a second location in a patient&#39;s vessel, the second location being proximal to the first location; (e) drawing the balloon of the first catheter towards the balloon of the second catheter to apply a compressive force upon the mitral annulus; (f) forming a coherent mass in a cavity formed between the balloon of the first catheter and the balloon of the second catheter; (g) contracting the balloon of the first catheter and the balloon of the second catheter; and (h) removing the first catheter and the second catheter. 
     In another embodiment, forming a coherent mass comprises injecting a substance into the cavity. 
     In another embodiment, injecting the substance into the cavity comprises injecting the substance into the cavity via an annulus formed between an outer surface of the first catheter and an interior surface of the second catheter. 
     In another embodiment, drawing the balloon of the first catheter towards the balloon of the second catheter further comprises causing a plurality of ribs or bumps disposed about the balloon of the first catheter to engage a portion of a vessel wall. 
     In another embodiment, at least an exterior surface of the first catheter is coated with a non-stick adherent. 
     In another embodiment, an apparatus for treating mitral annulus dilatation includes (a) a stent having proximal and distal sections, wherein the proximal and distal sections have a radially contracted state suitable for insertion into a vessel and radially expanded state in which they are substantially flush with a vessel wall; and (b) a central section disposed between the proximal and distal sections, wherein the central section has a elongated state suitable for insertion into a vessel and a foreshortened state having a curvature configured to apply a compressive force to and a foreshortening force on the mitral valve annulus. 
     In another embodiment, one or more biodegradable structures are disposed on the central section in the contracted state. 
     In another embodiment, the proximal section is configured to become biologically anchored to a vessel before the one or more biodegradable structures degrade. 
     In another embodiment, the distal section is configured to become biologically anchored to a vessel before the one or more biodegradable structures degrade. 
     In another embodiment, the central section comprises a shape memory material. 
     In another embodiment, an apparatus for treating mitral annulus dilatation includes a stent having proximal and distal sections, wherein the proximal and distal sections have a radially contracted state suitable for insertion into a vessel and radially expanded state in which they have a diameter greater than the diameter of the vessel wall; and a central section disposed between the proximal and distal sections, wherein the central section has an elongated long state suitable for insertion into a vessel and a foreshortened state having a curvature configured to apply a compressive force upon the mitral annulus and a foreshortening force on the mitral valve annulus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis generally being placed upon illustrating the principles of the invention. 
         FIG. 1  is a three-dimensional view of the mitral valve, coronary sinus and adjacent aortic valve. 
         FIG. 2  is a side view of an embodiment of an elongate body of the present invention including a central stent section with a backbone and a severed region. 
         FIG. 3  is a perspective schematic view of the body of  FIG. 2  in an expanded state. 
         FIG. 4  is a cross-sectional view of a mitral valve and a coronary sinus into which an embodiment of a body of the present invention and a first balloon have been inserted. 
         FIG. 5  is a cross-sectional view of a mitral valve and a coronary sinus in which proximal and distal sections of an embodiment of a body of the present invention have been expanded and wherein a balloon has been inserted into a central section of the body. 
         FIG. 6  is a side view of an embodiment of an elongate body of the present invention including a proximal and a distal transitional section. 
         FIG. 7  is a side view of a distal stent module of an embodiment of the present invention. 
         FIG. 8  is a side view of a proximal stent module of an embodiment of the present invention. 
         FIG. 9  is a side view of a distal and proximal stent module as they may be oriented when inserted into a coronary sinus. 
         FIG. 10  is a flat view of a camel stent of the present invention. 
         FIG. 11  is a top view of a camel stent embodiment of the present invention. 
         FIG. 12  is a side view of a camel stent embodiment of the present invention. 
         FIG. 13  is a three-dimensional view of an exemplary embodiment of an elongate body of the present invention. 
         FIG. 14  is another three-dimensional view of the elongate body of  FIG. 13  depicted from a different angle. 
         FIGS. 15A-15S  are side views of further alternative devices of the present invention. 
         FIG. 16  is a perspective view of an alternate device of the present invention. 
         FIG. 17  schematically depicts a first state of the elongate body of  FIG. 13 . 
         FIG. 18  schematically depicts a second state of the elongate body of  FIG. 13 . 
         FIG. 19  schematically depicts a second state of an alternate embodiment of the present invention having an outer elongate body and an inner elongate body positioned inside the coronary sinus. 
         FIG. 20  is a side view of an embodiment of an elongate body of the present invention including a proximal anchor, a distal anchor and a bridge having resorbable thread connecting the proximal and distal anchors. 
         FIG. 21  is a detail of the bridge of  FIG. 20 . 
         FIG. 22  is a side view of an embodiment of an elongate body of the present invention including a proximal anchor, a distal anchor and a central anchor with a bridge having resorbable thread connecting the anchors together. 
         FIG. 23  is a side view of an embodiment of an elongate body of the present invention including a proximal anchor, a distal anchor and two central anchors with a bridge having resorbable thread connecting the anchors together. 
         FIGS. 24A-24D  describe a further embodiment of the present invention. 
         FIGS. 25A-25C  illustrate exemplary embodiments of the anchor elements of  FIGS. 24A-24D . 
         FIGS. 26A-26B  illustrate deployment and actuation of the device of  FIGS. 24A-24D . 
         FIGS. 27A-27L  illustrate alternative embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a coronary sinus  20  extends from a right atrium  22  and a coronary ostium  24  and wraps around a mitral valve  26 . The term coronary sinus is used herein as a generic term to describe a portion of the vena return system that is situated adjacent to the mitral valve  26  along the atrioventricular groove. The term coronary sinus  20  used herein generally includes the coronary sinus, the great cardiac vein and the anterior intraventricular vein. A mitral annulus  28  is a portion of tissue surrounding a mitral valve orifice to which several leaflets attach. The mitral valve  26  has two leaflets, an anterior leaflet  29  and a posterior leaflet  31  having three scallops P 1 , P 2  and P 3 . 
     The problem of mitral regurgitation often results when a posterior aspect of the mitral annulus  28  dilates and displaces one or more of the posterior leaflet scallops P 1 , P 2  or P 3  away from the anterior leaflet  29 . To reduce or eliminate mitral regurgitation, therefore, it is desirable to move the posterior aspect of the mitral annulus  28  in an anterior direction. For instance, in the specific case of ischemic mitral regurgitation, the posterior section of the mitral valve may dilate symmetrically or asymmetrically. In the case of symmetric dilatation, the dilation is usually more pronounced in the P 2  scallop of the posterior section, while in the case of asymmetric dilatation, the dilation is usually more pronounced in the P 3  scallop of the posterior section. Consequently, it is desirable to move the area of the mitral annulus  28  adjacent to the area of dilatation of the mitral valve  26  while leaving the remaining section of the mitral annulus unaltered. The catheter-based devices of the present invention can be inserted within the coronary sinus  20  to the proper location so as to perform the desired reshaping procedure on the mitral annulus  28 . 
     The following embodiment comprises an elongate body  10 , as shown, for example, in  FIG. 2 . The elongate body  10  is manufactured by programming a desired pattern into a computer and cutting the pattern into a tube of stainless steel. The tube may be, however, cut by any other appropriate means.  FIG. 2  is a “flat pattern” view showing the elongate body  10  cut along its axial length and laid flat. 
     As shown in  FIG. 2 , the elongate body  10  has a proximal stent section  12 , a distal stent section  14 , and a central stent section  16 . As used herein, “distal” means the direction of the device as it is being inserted into a patient&#39;s body or a point of reference closer to the leading end of the device as it is inserted into a patient&#39;s body. Similarly, as used herein “proximal” means the direction of the device as it is being removed from a patient&#39;s body or a point of reference closer to a trailing end of a device as it is inserted into a patient&#39;s body. 
     The distal and proximal stent sections  14 ,  12  are used to anchor the body  10  into the distal and proximal ends, respectively, of the coronary sinus  20 . The proximal end of the coronary sinus is located at or near the coronary sinus ostium  24 . The central stent section  16  is attached between a distal end of the proximal stent section  12  and a proximal end of the distal stent section  14  and serves to “foreshorten” the coronary sinus  20 . The reduction in length of a stent section when it is expanded is referred to as foreshortening. 
     The elongate body  10  has two states, a compressed state (not shown) and an expanded state, as shown in  FIG. 3 . In the compressed state, the elongate body  10  has a diameter that is less than the diameter of the coronary sinus  20  and the elongate body is generally flexible enough to conform to the shape of the coronary sinus. In this state, the elongate body  10  has a substantially uniform diameter of between about 1.5 to 4 mm. In the expanded state, the elongate body  10  has a diameter that is about equal to or greater than a diameter of a non-expanded coronary sinus  20 . Specifically, in the expanded state the diameter of the distal stent section  14  is between about 3 to 6 mm, the diameter of the proximal stent section  12  is between about 10 to 15 mm, and the diameter of the central stent section  16  is between about 6 to 10 mm. 
     Referring to  FIGS. 2 and 3 , one embodiment of the device comprises a tubular elongate body  10  made of stainless steel in a mesh configuration. The mesh configuration includes a series of connected stainless steel loops, for example,  56 ,  57 . In the depicted embodiment, the loops have a zigzag shape including alternating peaks  42 . 
     In the depicted embodiment, the proximal stent section  12  includes five loops. When a first loop  56  loop is connected to an adjacent loop  57  at least two peaks  42 , a four-sided opening  40  is formed. In an exemplary embodiment, the four-sided openings  40  of the proximal stent section have a compressed length of about 2 to 10 mm and a height of essentially 0 to 1 mm. 
     As shown in  FIG. 2 , the distal stent section  14  includes five loops. A first loop  70  and an adjacent second loop  72  are connected at each peak  42  to form a ring of four-sided openings  40 . The second loop  72  is partially connected to a third loop  74  at four peaks  42  and the third loop is partially connected to a fourth loop  76  at four peaks. The fourth loop  76  is partially connected to a fifth loop  78  at two peaks. The number of loops and the number of peaks by which each loop is connected to an adjacent loop is not critical and numerous permutations are possible. However, the distal stent  14  should be flexible enough to make the body  10  steerable through the coronary sinus  20 . In an exemplary embodiment, the four-sided openings  40  of the distal stent section  14  have a compressed length of about 2 to 10 mm and a height of essentially 0 to 1 mm. 
     As further shown in  FIG. 2 , the central stent section  16  separates the proximal stent section  12  and the distal stent section  14 . The connections between the stent sections  12 ,  14  and  16  are flexible joints to allow the stent to conform to the local curvature of the coronary sinus  20 . For example, in the depicted embodiment, the central stent section  16  is partially connected to the proximal stent section  12  at three peaks  42  and it is also connected to the distal stent section  14  at three peaks. 
     The central stent section  16  includes twenty-eight loops. In this section, a first loop  80  is joined to a second loop  81  at every peak to form a first ring  54 . Further, a third loop  82  is joined to a fourth loop  83  to form a second ring  55 . The adjacent first and second rings  54 ,  55  are partially connected to each other at three peaks  42 . The central stent section  16  of the depicted embodiment includes fourteen rings each partially connected to an adjacent ring at three peaks. The structure of the rings allows the axis of the central stent section  16  to conform to the curvature of the coronary sinus  20 . The region of the central stent section  16  that forms continuous four-sided openings  40 , i.e. where the peaks  42  of adjacent rings are connected to each other, is a backbone  50 . The region of the central stent section  16  where the rings are not connected to each other is a severed region  52 . In an exemplary embodiment, the four-sided openings  40  of the central stent section  16  have a compressed length of about 2 to 10 mm and a height of essentially 0 to 1 mm. Again, the number of loops and the number of peaks by which each loop is connected to an adjacent loop is not critical and numerous permutations are possible. 
     The device of the first embodiment is deployed as follows. As shown in  FIG. 4 , the elongate body  10 , in the compressed state, is mounted onto a first balloon  58 , which acts as a delivery catheter. The first balloon  58  has a length generally corresponding to the length of the distal stent section  14  and is inserted so that it is enveloped by the distal stent section. The elongate body  10  and the first balloon  58  are inserted into the coronary sinus  20  from the coronary sinus ostium  24 , e.g., until the central stent section  16  is generally aligned with the P 2  scallop. Once the elongate body  10  and the first balloon  58  are positioned in the coronary sinus, the first balloon is expanded by introducing, for example, a saline solution through the delivery catheter and into the balloon. Alternately, any biocompatible solution may be used to inflate the balloon. The force of the expansion of the first balloon  58  expands the distal stent section  14  so that its circumference is forced against the circumference of the coronary sinus  20  and anchors it into the wall of the coronary sinus. Once the distal stent section  14  is anchored, the first balloon  58  is deflated and removed. 
     A second balloon (not shown) having a length generally corresponding to the length of the proximal stent section  12  is then inserted into the elongate body  10  so that it is enveloped by the proximal stent section. The second balloon is then expanded as above using a saline solution to fill the balloon. The expansion force of the second balloon expands the proximal stent section  12  so that its circumference is forced against the coronary sinus  20  and anchors it to the wall of the coronary sinus. The second balloon is then deflated and removed. In one embodiment, the proximal stent section  12  is sized such that expansion of the proximal stent section makes it into a funnel shape adjacent to the right atrium  22 . The funnel shape conforms to the coronary sinus ostium  24  to help secure the proximal stent section  12  in place. 
     Although the described method of deployment and expansion of the stent sections involves expanding the distal section prior to expanding the proximal section, it will be appreciated that the proximal section may be expanded prior to the distal section. In addition, the same balloon or different balloons, or balloons shorter or longer than the proximal and distal stent sections may be used as desired. 
     Once both the proximal and distal stent sections  12 ,  14  have been expanded and anchored to the coronary sinus  20 , a third balloon  62  is inserted into the elongate body  10  so that it is enveloped by the central stent section  16  as shown in  FIG. 5 . The third balloon  62  has a length generally corresponding to the length of the central stent section  16 . The central stent section  16  is then expanded by filling the third balloon  62  with a saline solution. The severed regions  52  of the central stent section  16  allow the body  10  the flexibility to generally conform to the shape of the coronary sinus  20  as the body expands. 
     In an alternate embodiment, a shorter balloon may be used to expand the central stent section  16  in sections to achieve the desired diameters along the central stent section. By expanding the central stent section  16  in sections, the amount of foreshortening of the coronary sinus  20  can be more accurately adjusted. 
     When the central stent section  16  expands, the length of the four-sided openings  40  is reduced as the height of the four-sided openings is increased. The body  10  is designed such that when it is expanded, it has a curved shape that generally follows the anatomical curvature of the coronary sinus  20 . Additionally, as a result of the reduction in the length of the four-sided openings  40 , the length of the entire central stent section  16  is foreshortened. The foreshortening of the central stent section  16  pulls the distal stent section  14  and the proximal stent section  12  toward each other. As a result, the distance between the proximal and distal stent sections  12 ,  14  is reduced. Since the proximal and distal stent sections  12 ,  14  are anchored to the walls of the coronary sinus  20 , the length of the coronary sinus is thereby also reduced. The reduction in length of the coronary sinus  20  cinches the coronary sinus more tightly around the P 1 , P 2  and P 3  scallops of the mitral valve  26  and pushes one or more of the scallops, closer to the anterior leaflet  29  of the mitral valve. This allows a gap between the anterior leaflet  29  and the P 1 , P 2  and P 3  scallops of the posterior leaflet  31  to close. When the gap between the mitral valve leaflets is closed, the effects of mitral valve regurgitation are drastically reduced or eliminated. 
     A second embodiment of the elongate body is shown in  FIG. 6 . In this embodiment, an elongate body  110  has a mesh configuration similar to that described with respect to the previous embodiment. In addition to a distal stent section  114 , a proximal stent section  112 , and a central stent section  116 , the second embodiment also includes a distal transitional section  120  and a proximal transitional section  118 . The distal and proximal stent sections  114 ,  112  are used to anchor the body  110  into the distal and proximal ends, respectively, of the coronary sinus  20 . The distal and proximal transitional sections  120 ,  118 , located between the central stent section  116  and the distal and proximal stent sections  114 ,  112 , respectively, provide a flexible transition zone for improved load distribution. In addition, the transitional sections  112  and  120  may experience significant foreshortening during expansion providing the additional benefit of coronary sinus contraction. 
     The second embodiment is similar to the first embodiment in that it has two states, a compressed state and an expanded state. Further, the structure of the proximal and distal stent sections  112 ,  114  are identical to those of the first embodiment. The purpose of these flexible stent sections  112  and  114  is to provide a large conforming contact area between the stent and the outer wall of the coronary sinus  20  which better distributes the force exerted on the body  110  by the vessel wall. The central stent section  116  includes eighteen loops to form seventeen rings of four-sided openings  40 . Since each ring of the central stent section  116  of the second embodiment is connected to the ring adjacent to it at each peak  42 , the rings form a continuous mesh configuration. 
     The proximal transitional section  118  of the second embodiment is connected to the distal end of the proximal stent section  112  and the proximal end of the central stent section  116 . The proximal transitional section  118  includes two loops. As shown in  FIG. 6 , a first loop  170  is connected to a most distal loop  171  of the proximal stent section  112  at three peaks  42  and a second loop  172  is connected to a most proximal loop  173  of the central stent section  116  at three peaks. The first loop  170  is also connected to the second loop  172  at three peaks  42  along the same axis as it is connected to the proximal and central stent sections  112 ,  116 , thus forming a backbone  50  and a severed region  52  for flexibility similar to the central stent section  116  of the first embodiment. It will be appreciated that a fewer number or greater number of loops may be used in the proximal transitional section  118 , or no loops, wherein the proximal stent section  112  is connected to the central stent section  116 . 
     As also shown in  FIG. 6 , the distal transitional section  120  is located between a distal end of the central stent section  116  and a proximal end of the distal stent section  114 . Specifically, a most proximal loop  174  in the distal transitional section  120  is partially connected to a distal-most loop  179  in the central stent section  116  at three peaks and a distal-most loop  181  in the distal transitional section  120  is partially connected to a proximal-most loop  180  in the distal stent section at three peaks. The distal transitional region  120  includes ten loops. The first loop  174  in the distal transitional section  120  is joined to a second loop  175  at every peak to form a first ring  154 . Further, a third loop  176  is joined to a fourth loop  177  to form a second ring  155 . The adjacent rings  154  and  155  are partially connected to each other at three peaks  42 . The distal transitional section  120  of the present embodiment includes five such rings each connected to an adjacent ring at three peaks. The region that forms continuous four-sided openings  40  is a backbone  50  and the region where the rings are not connected is a severed region  52 . It will be appreciated that a fewer number or greater number of loops may be used in the distal transitional section  120 , or no loops, wherein the distal stent section  114  is connected to the central stent section  116 . 
     The proximal and distal stent sections  112  and  114  of the second embodiment are deployed as described above with respect to the first embodiment. The elongate body  110  is positioned in the coronary sinus  20  so that the central stent section  116  is generally aligned with the P 2  scallop of the posterior leaflet  31  of the mitral valve  26 . In an alternate embodiment, the distal stent section  114  may be of increased flexibility to allow for placement in the proximal region of the great cardiac vein (not shown). In addition, the same balloon or different balloons, or balloons shorter or longer than the proximal and distal stent sections may be used as desired. 
     Once both the proximal and distal stent sections  112 ,  114  are balloon expanded and anchored to the coronary sinus  20 , a third balloon (not shown) having a length generally corresponding to the combined lengths of the central stent section  116 , the proximal transitional stent section  118  and the distal transitional stent section  120  is inserted into the elongate body  110  so that it is enveloped by all three stent sections  116 ,  118  and  120 . These three sections  116 ,  118 ,  120  are then expanded using the third balloon. As the central stent section  116  is expanded, its rigidity straightens a central section of the coronary sinus. As the coronary sinus  20  straightens, the P 1 , P 2  and/or P 3  scallops, of the mitral valve  26  are moved anteriorly, thereby closing the gap between the scallops and the anterior leaflet  29  of the mitral valve  26 . Additionally, expanding the central stent section  116  and the proximal and distal transitional sections  118 ,  120  foreshortens the elongate body  110 , reducing the distance between the proximal and distal stent sections  112 ,  114  and cinching the coronary sinus  20  more tightly around the P 1 , P 2  and P 3  scallops. The severed region  52  of the transitional sections  118 ,  120  allows the elongate body  110  the flexibility to generally conform to the curvature of the coronary sinus  20  as the body expands. 
     Alternatively, a shorter balloon may be used to expand the central stent section  116 , proximal transitional section  118  and distal transitional section  120  in steps to achieve the desired diameters along the central stent section  116 . By expanding the central stent section  116  in parts, the amount of foreshortening and straightening of the coronary sinus  20  can be better adjusted. 
     Inserting a stent deep into the coronary sinus  20  toward the anterior intraventricular vein may sometimes be difficult because of the curved shape of the distal region of the coronary sinus. Therefore, the distal part of a device insertable into the coronary sinus  20  needs to be flexible. One possible way to achieve a more flexible stent is to reduce the wall thickness of a stent and provide for a more flexible design of the stent. On the other hand, using two overlapping stents allows for a flexible stent in the curvy distal region of the coronary sinus  20  and a stronger, more rigid part in the proximal region. More specifically, the area where two stents overlap will have a higher radial strength and become more rigid when it is expanded. This rigidity in turn will provide a more effective straightening effect in the desired area of the coronary sinus  20 . 
     In that regard, a third embodiment of the present invention, as shown in  FIGS. 7 and 8 , comprises a proximal stent module  200  ( FIG. 8 ) and a distal stent module  205  ( FIG. 7 ). Both the proximal and distal stent modules  200 ,  205  have a compressed and expanded state, as described above with respect to the previous embodiments. 
     In one embodiment, the distal stent module  205  has an anchor section  214 , located at the distal end of the distal stent module, and a central section  217 . The anchor section  214  includes three loops. A first loop  270  is connected to a second loop  271  at four peaks  42  and the second loop is connected to a third loop  272  at two peaks. Accordingly, the distal stent module will be more flexible in the distal direction. The central stent section  217  includes thirty-six loops. As with respect to the first embodiment described above, alternating pairs of loops are connected at each peak to form rings of four-sided openings  40 . Each ring is connected to an adjacent ring at three peaks, where the connected portion forms a backbone  250  and the unconnected portion forms a severed region similar to the central stent section  16  of the first embodiment.  FIGS. 7 and 8  both include lines  220  in places of the modules  200  and  205  where larger pieces of material will be removed by laser cutting. These single lines  220  represent a cut to be made by the laser that will allow the large pieces of material to be more easily removed while leaving the remaining material undamaged. 
     As shown in  FIG. 8 , the proximal stent module  200  has an anchor section  212 , located at the proximal end of the proximal stent module  200 , and a central section  215 . The anchor section  212  is a combination of the proximal stent section  112  and the proximal transitional section  118  as described above with respect to the second embodiment. The central section  215  includes twenty-four loops. Similarly to the central section  217  of the distal stent module  205 , alternating pairs of loops are connected at each peak to form rings of four-sided openings  40 . Each ring is connected to an adjacent ring at three peaks  42 , where the connected portion forms a backbone  254  and the unconnected portion forms a severed region. 
     The device of the third embodiment is deployed as follows. The distal stent module  205  in a compressed state is mounted onto a first balloon (not shown), which acts as a delivery catheter. The first balloon has a length generally corresponding to the length of the anchor section  214  and is inserted so that it is enveloped by the anchor section. The distal stent module  205  and the first balloon are inserted into the coronary sinus  20  from the coronary sinus ostium  24  so that the central section  215  is generally aligned with, e.g., the P 2  scallop. Once the distal stent module  205  and the first balloon are positioned in the coronary sinus  20 , the first balloon is expanded by introducing a saline solution through the delivery catheter and into the balloon. The balloon expands the distal stent module  205  so that the module&#39;s circumference is forced against to the circumference of the coronary sinus  20  and so that the module is anchored to the wall of the coronary sinus. Once the distal stent module  205  is anchored, the first balloon is deflated and removed. 
     A second balloon (not shown) is then mounted on the proximal stent module  200 , the second balloon having a length corresponding to the length of the anchor section  212 . The proximal stent module  200  and the second balloon are then inserted into the coronary sinus so that the central section  215  of the proximal stent module  200  overlaps the central section  217  of the distal stent module  205  by at least about 2 cm. Further, as shown in  FIG. 9 , upon insertion, the backbone  250  of the proximal stent module  200  is angularly separated from the backbone  254  of the distal stent module  205  depending on the anatomy of the patient and the desired rigidity of the overlapping section. Although the backbones  250  and  254  may be aligned, in alternate embodiments the backbones are separated by about 60°-180°. The closer the backbones  250 ,  254  are together, the less rigid the overlapping section will be. On the other hand, if the backbones  250  and  254  are spaced 180° apart, the overlapping section will be as rigid as possible and able to provide the most strength to straighten the coronary sinus  20 . 
     Once the proximal stent module  200  is in place, the second balloon  260  is expanded using a saline solution to fill the balloon. The balloon expands the proximal stent module  200  so that the module&#39;s circumference is forced against the circumference of the coronary sinus  20  and so that the module is anchored to the wall of the coronary sinus. Once the proximal stent module  200  is anchored, the second balloon is deflated and removed. In addition, the same balloon or different balloons, or balloons shorter or longer than the proximal and distal stent sections may be used as desired. 
     Once the proximal and distal stent modules  200 ,  205  have been anchored in the coronary sinus, a third balloon (not shown) is inserted. The third balloon has a length generally corresponding to the entire length of the combined central sections  215  and  217 , i.e., the balloon extends the entire distance between the anchor sections  212  and  214 . The third balloon is then expanded using a saline solution, and such expansion simultaneously expands the central sections  215  and  217  so that these sections have a circumferences of approximately the circumference of the coronary sinus  20 . The proximal and distal stent modules  200 ,  205  effectively become one stent as they expand due to the overlapping region of the central stent sections  215  and  217  becoming secured together as a result of the proximal stent module  200  expanding into the distal stent module  205 . The expanded central sections  215 ,  217  serve to straighten the coronary sinus  20  and push the posterior leaflet  31  of the mitral valve  26  anteriorly. Further, expanding the central sections  215  and  217  foreshortens the “combined” stent and cinches the coronary sinus around the P 1 , P 2  and/or P 3  scallops, of the posterior leaflet  31 . 
     A fourth embodiment of the invention comprises a “camel” stent  310 . The camel stent is an elongate tubular member having two diametrically opposed spines  320  and  322 .  FIG. 9  is a “flat pattern” view showing the camel stent  310  cut along its axial length and laid flat. In this case, the stent  310  has been cut along one spine  322  of the two spines  320 ,  322  running the length of the stent. In an exemplary embodiment, the length of the stent  310  is about 40 to 120 mm. The stent  310  includes two stainless steel loops  354  and  356 , each loop having a zigzag shape with alternating peaks  42 . One loop  354  is located at a proximal end  312  and one loop  356  is located at a distal end  314  of the stent  310 . Extending between the loops  354  and  356  are the two spines  320  and  322  spaced 180° apart. In a proximal half of the stent  310 , angularly extending about one quarter the length of the stent from the first spine  320  to the second spine  322  are first and second interconnecting members  324 ,  326 . At the location where the first two interconnecting members  324 ,  326  meet the second spine  322 , a third and a fourth interconnecting member  328 ,  330  extend angularly about one quarter of the length of the stent  310  from the second spine  322  to the first spine  324 . The third and fourth interconnecting members  328 ,  330  meet the first longitudinal member  320  at about the middle of the camel stent  310 . The distal half of the stent  310  is a mirror image of the proximal half, the distal half having two interconnecting members  332 ,  334  that extend from the first spine  320  to the second spine  322  and two interconnecting members  336 ,  338  extend from the second spine  322  to the first spine  320 . 
     On the proximal half of the stent extending between the first and second interconnecting members  324 ,  326  bisected by the second spine  322  are four strands  311  of zigzag shaped stainless steel having at least one peak  42 . Similarly, there are four strands  311  extending between the first and second interconnecting members  324 ,  326  bisected by the first spine  320 . Further, four strands  311  extend between the third and fourth interconnecting members  328 ,  330  and are bisected by the second spine  322  and four strands are bisected by the first spine  320 . The structure of the distal half of the stent  310  is a mirror image of the structure of the proximal half of the stent. 
     The camel stent  310  has two states, a compressed state and an expanded state. In the compressed state, the camel stent  310  has a diameter that is less that the diameter of the coronary sinus  20  and the stent is flexible enough to be suitably located in the coronary sinus. In this state, the camel stent  310  has a substantially uniform diameter of about 1.5 to 4 mm. In the expanded state, as shown in  FIGS. 11 and 12  the camel stent is generally “w” shaped and has a diameter of about 4 to 12 mm. 
     The camel stent  310  is deployed as follows. The camel stent is mounted on a balloon catheter (not shown). The balloon has a length generally corresponding to the entire length of the camel stent  310 . The camel stent  310  and the balloon are inserted into the coronary sinus  20  from the coronary sinus ostium  24  so that the center of the stent is generally aligned, e.g., with the P 2  scallop. Once the stent  310  is positioned in the coronary sinus  20 , the balloon is expanded using a saline solution, as described above. The expansion of the zigzag shaped strands  311  and the structure of the spines  320 ,  322  and interconnecting members  324 ,  326 ,  328 ,  330 ,  332 ,  334 ,  336  and  338  causes the expanded stent  310  to have a substantially w-shaped structure. 
     The “w” shape of the camel stent  310  in its expanded state anchors the camel stent inside the coronary sinus  20 . Further, since the center of the stent  310  is adjacent to the P 2  scallop, it pushes the P 2  scallop anteriorly, thereby closing the gap between the anterior leaflet  29  and posterior leaflet  31  of the coronary sinus  20 . In other embodiments, the design of the camel stent  310  may be modified to have only a single bend, two bends or more than three bends and/or may have a nonuniform diameter. Additionally, the camel stent  310  may be part of a stent system having proximal and distal stent sections. 
       FIG. 13  shows yet another embodiment of the invention comprising an elongate body  1300 . In this embodiment, the elongate body  1300  self expands into a three-dimensional shape that conforms to the anatomy of the coronary sinus, thereby applying substantially uniform stress to the walls of the coronary sinus  20 . Such expansion of the elongate body  1300  achieves remodeling of the mitral annulus through foreshortening, which reduces the overall length of the coronary sinus  20  and, in turn, reduces the circumference of the mitral annulus  28 . 
     As illustrated in  FIG. 1 , the coronary sinus  20  is a curved tubular structure that enwraps the posterior leaflet  31  of the mitral valve  26  with scallops P 1 , P 2 , and P 3 . The coronary sinus  20 , as shown, has a central portion Y located in an x-y plane defining the annulus of the mitral valve  26 . A proximal portion of the coronary sinus  20  extends slightly upwardly out of the x-y plane towards the coronary ostium  24  of the right atrium  22 . A distal portion X of the coronary sinus  20  extends downwardly behind the P 1  scallop out of the x-y plane into the great cardiac vein and anterior interventricular vein. 
     The diameter of the coronary sinus  20  decreases from the proximal end to the distal end of the coronary sinus  20 . The diameter of the central section of the coronary sinus  20  remains generally uniform throughout its length. 
       FIG. 13  illustrates a three-dimensional view of an embodiment of the elongate body  1300  in its unstressed, natural state. The elongate body  1300  is compressible to permit insertion into the coronary sinus  20  percutaneously and has the ability to self expand into a three-dimensional shape to conform to the anatomy of the coronary sinus  20 . The elongate body  1300  has a proximal stent section  1305 , a central stent section  1310 , and a distal stent section  1315 , each of which conforms generally in size and shape to the part of the coronary sinus  20  into which it will be inserted. In one exemplary embodiment, in its unstressed state, the diameter of the elongate body  1300  along its length is greater than the diameter of the coronary sinus  20  along its length for reasons to be discussed below. The proximal and distal stent sections  1305  and  1315  are used to anchor the elongate body  200  into the proximal and distal ends, respectively, of the coronary sinus  20 . The central stent section  1310  is attached between a distal end of the proximal stent section  1305  and a proximal end of the distal stent section  1315 . After the elongate body is deployed in the coronary sinus, the central stent section  1310  is located in the x-y plane shown in  FIG. 13  generally aligned, for example, with the P 2  scallop along the posterior leaflet  31  of the mitral valve  26  (FIG. The proximal stent section  1305  extends slightly upwardly out of the x-y plane towards the coronary ostium  24 . The distal stent section  1315  extends downwardly behind the P 1  scallop extending out of the x-y plane into the great cardiac vein. 
       FIG. 14  illustrates another three-dimensional view of the embodiment of the elongate body  1300  depicted from a different angle wherein the viewer is looking into the proximal end of the elongate body. As shown in  FIG. 14 , to better emulate the slight upward extension of the proximal portion of the coronary sinus  20 , the end of the proximal stent section  1305  slightly bends and faces upward. Moreover, the slightly upward facing end of the proximal stent section  1305  and the downward facing end of the distal stent section  1315  of the elongate body  1300  flare out in a funnel shape to securely anchor the elongate body to the wall of the coronary sinus  20 . 
     To match with the varying diameters of the coronary sinus  20 , the diameter of the elongate body  1300  decreases from the proximal stent section  1305  to the distal stent section  1315  and the diameter of the central stent section  1310  remains generally uniform. In one embodiment, for the elongate body  1300  having the initial total length of about 155 mm, the proximal stent section  1305  has the diameter of about 22 mm, the central stent section  1310  has the diameter of about 6 mm, the distal stent section  1315  has the diameter of about 11 mm in its unstressed state. In another embodiment of the elongate body  1300  also having the initial total length of about 155 mm, the proximal stent section  1305  has the diameter of about 21 mm, the central stent section  1310  has the diameter of about 8 mm and the distal stent section  1315  has the diameter of about 19 mm in its unstressed state. 
     Furthermore, referring again to  FIG. 13 , to conform with a radial arc of the coronary sinus along the x-y plane of the P 2  scallop, a radial arc  1320  of the central stent section  1310  of the elongate body  1300  arches along the x-y plane in the range of 90 to 150 degrees in its unstressed state. 
     Referring again to  FIG. 13 , the elongate body  1300  has a multi-filament woven structure made from shape metal with memory effect, such as, but not limited to, Nitinol, Elgiloy, or spring steel. The self-expansion force and the anchoring force of the elongate body  1300 , which affects the degree of foreshortening of the coronary sinus  20 , is controlled by various factors, such as the angle of the weave (i.e., intersection of the strands), the thickness of the material, and the spacing between the strands. For example, depending on the angle of the weave, the degree of expansion and anchoring forces may vary. And, depending on the degree of expansion and anchoring forces exerted onto the wall of the inside surface of the coronary sinus  20 , which results in reshaping of the wall, the diameter and the length of the coronary sinus  20  will gradually change over a period of time. For example, a smaller angle of weave (i.e., tight weaving) generally exerts greater expansion force as the elongate body  1300  expands. Moreover, due to its spring-like configuration, when the elongate body  1300  is compressed along the longitudinal axis of the elongate body  1300 , the angle of the weave also tightens or reduces, preferably close to 0 degrees. However, when the elongate body  1300  is released or expanded along the longitudinal axis of the elongate body  1300 , the angle of the weave expands, for example, in the range of 45 to 90 degrees radially along the longitudinal axis, to retain its original shape. As the angle of the weave expands further in the radial direction along the longitudinal axis of the elongate body  1300 , the expansion force weakens. 
     With regard to the thickness of the material, thicker material exerts greater expansion force as the elongate body  1300  transforms from its compressed state to the expanded state. With regard to the spacing between the strands, smaller spacing between the strands requires a greater number of strands in the elongate body, resulting in greater expansion force as the elongate body  1300  transforms from its compressed state to the expanded state. At the same time, it is important to select a material and control the above-mentioned factors to ensure a smooth surface of the elongate body  1300  that minimizes trauma to the coronary sinus  20 . 
     As briefly mentioned above, the elongate body  1300  has two states, a compressed state and an expanded state, as shown in  FIGS. 17 and 18 , respectively. Referring to  FIG. 17 , in the compressed state, the elongate body  1300  is enclosed within a lumen  1505  of a sheath  1500  and is inserted into the coronary sinus  20  via the sheath  1500 , which acts as a delivery catheter. The elongate body  1300 , still enclosed within the lumen  1505  is positioned in the coronary sinus  20  so that the central stent section  1310  is generally aligned, for example, with the P 2  scallop. In the compressed state, the elongate body  1300  has a diameter that has been compressed to fit into the lumen  1505  and is flexible enough to move with the sheath  1500  along the curvatures of the coronary sinus  20 . In this state, the elongate body  1300  has a uniform diameter that ranges from about 1.5 to 4 mm as it is enclosed within the lumen  1505 . 
     Referring to  FIG. 18 , the sheath is pulled from the elongate body  1300  to expose the elongate body  1300  to the walls of the coronary sinus  20  and to allow it to expand into a three-dimensional shape that conforms to the anatomy of the coronary sinus  20 . As the elongate body  1300  expands, the strands of the weave of the three-dimensional shape make contact with the circumference of the coronary sinus  20  and the entire length of the elongate body  1300  anchors tightly onto the wall of the inside surface of the coronary sinus  20 . In addition to the anchoring provided by the woven structure of the elongate body  20 , the funnel-shaped flare ends and slight bend of the proximal and distal stent sections  1305 ,  1315  provide further anchoring of the elongate body  1300 . In one embodiment, the flare end of the proximal stent section  1305  expands against the circumference of the coronary sinus ostium  24  and the flare end of the distal stent section  1315  expands against the circumference at the distal end of the coronary sinus  20 . 
     As discussed above, the elongate body  1300  is designed so that when it is expanded, it has a curved shape that follows the anatomical curvature of the coronary sinus  20  and makes substantial contact with the walls along the inside of the arcuate path of the coronary sinus  20 . The expansion force of the elongate body  1300 , which has been determined by various factors such as the angle of the weave, continues to push the walls of the coronary sinus  20  radially outward and pull the ends of the elongate body  1300  toward the central section  1310  of the elongate body  1300 . Over a period of time, e.g. several weeks, the diameter elongate body continues to expand. As the elongate body  1300  expands, radially, it gradually grows through the wall of the coronary sinus  20  and attaches to scar tissue created by the elongate body&#39;s penetration of the wall of the coronary sinus ( FIG. 16 ). Radial expansion of the elongate body  1300  through the wall of the coronary sinus  20  foreshortens the coronary sinus and also reduces the radius of curvature of the coronary sinus. Such changes in the coronary sinus  20  cinches the coronary sinus more tightly around the P 1 , P 2  and P 3  scallops of the mitral valve  26  and pushes one or more of the scallops, closer to the anterior leaflet  28  of the mitral valve. This allows a gap between the anterior leaflet  29  and the P 1 , P 2  and P 3  scallops of the posterior leaflet  31  to close and achieve remodeling of the mitral annulus  28  over the span of several weeks. When the gap between the mitral valve leaflets is closed, the effects of mitral valve regurgitation are drastically reduced or eliminated. The elongate body  1300  may be coated with antithrombogenic material to prevent thrombosis and occlusion of the coronary sinus, which may occur in the remodeling of the coronary sinus. 
       FIGS. 15A to 15S  in general show various additional embodiments of the present invention. 
     Referring now to  FIGS. 15A-15C , a further alternative embodiment of the present invention is described, in which the device comprises a tapered stent having proximal and distal sections that are joined by a central section capable of assuming a predetermined curvature. In  FIG. 15A , elongate body  1300  includes a wire mesh stent having proximal stent section  1305 , distal stent section  1315  and central stent section  1310 , and is designed to conform to the taper of the coronary sinus. In  FIG. 15A , the elongate body  1300  is shown in its elongated and radially crimped state. Elongate body  1300  is shown in its fully radially expanded and axially foreshortened state in  FIG. 15C . Further in accordance with the principles of the present invention, elongate body  1300  includes one or more biodegradable structures  858 , such as sutures, disposed on central stent section  1310  to retain that section in the contracted shape for a predetermined period after placement of the device in a patient&#39;s coronary sinus. Examples of biodegradable structures are described in more detail below. 
     Elongate body  1300  also includes at least one proximal retaining element  853  that retains proximal stent section  1305  in a contracted state, and further includes at least one distal retaining element  855  that retains distal stent section  1315  in a contracted state. Proximal and distal retaining elements  853  and  855  may comprise one or more sutures disposed about proximal and distal sections  1305  and  1315 , respectively. Proximal and distal retaining elements  853  and  855  may be coupled to distal ends of strands  863  and  865 , respectively. A physician may actuate strands  863  and  865 , e.g., by retracting proximal ends of the strands, to deploy proximal and distal sections  1305  and  1315 , respectively, as shown in  FIG. 15B . 
     Proximal and distal sections  1305  and  1315  may comprise a shape-memory alloy, such as Nitinol, that self-expands to a predetermined shape when retaining elements  853  and  855  are removed. 
     In another embodiment of the present invention as shown in  FIGS. 15D-15F , the central stent section  1310  of the elongate body  1300  delivered in a restraining catheter has a restraining thread  867  extending outside of the vasculature and the patient to be retracted by the physician at the desired time. Retraction of the restraining thread  867  will allow the central section  1310  of the elongate body  1300  to expand radially. 
     Additionally, as shown in  FIGS. 15G-15I , a single restraining thread  869  may cover the entire elongate body  1300 . The thread may be wrapped around the elongate body  1300  in such a way that, when it is retracted by the physician, it unravels from the proximal end  1305  to the distal end  1315  of the elongate body  1300 . Alternatively, as shown in  FIGS. 15J-15L , the single restraining thread  869  may be wrapped around the elongate body  1300  in such a way that, when it is retracted by the physician, it unravels from the distal end  854  to the proximal end  152  of the elongate body  1300 . Such restraint, as described by at least the last two embodiments, makes a restraining catheter unnecessary. Alternatively, retaining elements  853  and  855  may be omitted, and proximal and distal sections  1305  and  1315  may self-expand to the predetermined shape upon retraction of a constraining sheath. 
     In yet another embodiment of the present invention, as shown in  FIGS. 15M-15P , a restraining catheter  881  is placed over the elongate body  1300  before the device is inserted into a patient. Additionally, a biodegradable restraining thread  858  is placed around the central stent section  1310  of the elongate body  1300 . When the restraining catheter  881  is removed, the proximal and distal stent sections  1305 ,  1315  of the elongate body  1300  expand immediately, while the central stent section  1310  will expand over time as the restraining thread  858  is absorbed by the body. Alternatively, as shown in  FIGS. 15Q-15S , only a restraining catheter  881  is placed over the elongate body  1300 . Thus, as the restraining catheter is retracted, the elongate body  1300  expands immediately from the distal end  1315  to the proximal end  1305 . 
     In one exemplary embodiment, all three sections  1305 ,  1310 ,  1315  of the stent are integrally formed from a single shape memory alloy tube, e.g., by laser cutting. The sections  1305 ,  1310 ,  1315  are then processed, using known techniques, to form a self-expanding unit. In another embodiment, the device may be braided from Nitinol, stainless steel or other metal alloy threads and cut to the appropriate length. Such braiding permits the creation of three-dimensional shapes, allowing the device to more closely conform to the shape of the coronary sinus. 
     Unlike some of the preceding embodiments, which rely upon drawing proximal and distal elements together at the time of deploying the device, this embodiment of the present invention permits proximal and distal sections  1305  and  1315  to become biologically anchored in the venous vasculature before those sections are drawn together by expansion and/or curvature of central stent section  1310  to remodel the mitral valve annulus. 
     The elongate body  1300  may be deployed as follows. Elongate body  1300  is loaded into a delivery sheath and positioned within the patient&#39;s coronary sinus. The delivery sheath then is retracted proximally to expose distal stent section  1315 , as shown in  FIG. 15B . Distal stent section  1315  may be deployed when the proximal end of strand  865 , which is coupled to retaining element  855 , is actuated by a physician. Alternatively, retaining element  855  may be omitted and distal stent section  1315  may self-expand upon retraction of the delivery sheath. Upon deployment using either technique, distal stent section  1315  radially expands to engage the intima of the coronary sinus. 
     The delivery sheath is then further proximally retracted to expose proximal stent section  1305  as shown in  FIG. 15B . Proximal stent section  1305  may be deployed when strand  863 , which is coupled to retaining element  853 , is actuated by a physician. Alternatively, retaining element  853  may be omitted and proximal stent section  1305  may self-expand upon further retraction of the delivery sheath. Upon deployment using either technique, proximal stent section  1305  radially expands to engage the intima of the coronary sinus. 
     At the time of deployment of proximal and distal sections  1305  and  1315 , central stent section  1310  is retained in a contracted state by biodegradable structures  858 , illustratively biodegradable sutures, e.g., a poly-glycol lactide strand or VICREL suture, offered by Ethicon, Inc., New Brunswick, N.J., USA. 
     Over the course of several weeks to months, proximal and distal sections  1305  and  1315  of the stent will endothelialize, i.e., the vessel endothelium will form a layer that extends through the apertures in the proximal and distal sections of elongate body  1300  and causes those sections to become biologically anchored to the vessel wall. This phenomenon may be further enhanced by the use of a copper layer on the proximal and distal stent sections, as this element is known to cause an aggressive inflammatory reaction. Conversely, to reduce thrombosis on the central stent section  1310  of the stent  850 , the central section and associated structures may be coated with an anticoagulant material. As a further alternative, the central section of the stent may be coated with a taxol derivative or other elutable drug. 
     Over the course of several weeks to months, or after the proximal and distal sections have become anchored in the vessel, biodegradable structures  858  that retain central stent section  1310  in the contracted state will biodegrade. Eventually, the self-expanding force of the central section will cause the biodegradable structures to break, and release central stent section  1310 . Because central stent section  1310  is designed to assume a predetermined curvature as it expands radially, it causes the proximal and distal sections  1305  and  1315  of elongate body  1300  to curve accordingly, resulting in the fully deployed shape depicted in  FIG. 15C . The forces created by expansion and curvature of central stent section  1310  thereby compressively loads, and thus remodels, the mitral valve annulus. 
     In an alternative embodiment, as shown in  FIG. 16 , the elongate body  1300  is “oversized.” In other words, the elongate body  1300  is manufactured deliberately to be larger than the natural size of the coronary sinus, even in the coronary sinus&#39; most expanded state. Thus, as the elongate body  1300  expands, it slowly passes through the wall of the coronary sinus, causing the coronary sinus to form tissue and grow around the device. Since the device “outgrows” the coronary sinus, additional foreshortening may be achieved and the mitral valve annulus will be able to be more remodeled than with an ordinary sized device. 
     Biodegradable sutures may be designed to rupture simultaneously, or alternatively, at selected intervals over a prolonged period of several months or more. In this manner, progressive remodeling of the mitral valve annulus may be accomplished over a gradual period, without additional interventional procedures. In addition, because the collateral drainage paths exist for blood entering the coronary sinus, it is possible for the device to accomplish its objective even if it results in gradual total occlusion of the coronary sinus. 
     Another embodiment of the present invention, as shown in  FIG. 19 , comprises an outer elongate body  1700  and a rigid inner elongate body  1705  placed inside of the outer elongate body  1700  and eventually tightly fitted onto the wall of the inside surface of the outer elongate body  1700 . The outer elongate body  1700  is flexible such that it can evenly distribute the expansion forces along the wall of the coronary sinus  20  during the foreshortening of the coronary sinus  20 . For example, elongate body  1300  described in  FIG. 13  may be used. The rigid inner elongate body  1705 , which is placed inside of the outer elongate body  1700  and has the length in the range of 30 mm to 80 mm in its unstressed state, provides higher radial strength and rigidity to further straighten the coronary sinus  20  and to exert greater force onto the mitral annulus  28 , in addition to the foreshortening provided by the outer elongate body  1700  (shown by the arrows  1730  in  FIG. 19 ). To provide sufficient rigidity with an effective straightening effect, the inner elongate body  1705  is made of a rigid metal, such as stainless steel. In one configuration, the inner elongate body  1705  is a tubular structure made of stainless steel in a mesh configuration. The mesh configuration includes a series of connected stainless steel loops, each loop having a zigzag shape with peaks. For example, the elongate body  10  described in  FIG. 2  may be used. 
     The two elongate bodies  1700 ,  1705  are deployed with separate delivery means. First, the outer elongate body  1700 , which may be self-expandable, as described with respect to the elongate body  1300  of  FIGS. 13 and 14 , or balloon-expandable, is deployed and placed into the coronary sinus  20  as shown in  FIG. 19 . The expansion of the outer elongate body  1700  results in foreshortening of the coronary sinus  20 , which in turn results in reshaping of the mitral annulus  28 . 
     Next, the inner elongate body  1705 , which may be self-expandable or balloon-expandable, is deployed and placed inside of the inner surface of the outer elongate body  1700 . In one configuration, the inner elongate body  1705  is deployed with a balloon. In this configuration, the inner elongate body  1705  is mounted onto a balloon (not shown), which acts as a delivery catheter. Once the inner elongate body  1705  and the balloon are appropriately positioned inside of the outer elongate body  1700 , the balloon is expanded by introducing, for example, a saline solution through the delivery catheter and into the balloon. Alternately, any biocompatible solution may be used to inflate the balloon. Once the inner elongate body  1705  is expanded to make substantial contact with the outer elongate body  1700  and is tightly fitted along the walls of the inside surface of the outer elongate body  1700 , the balloon is deflated and removed. Depending on the location of the regurgitation jet in the mitral valve, the rigid inner elongate body  1705  can be placed anywhere along the wall of the coronary sinus  20  that aligns with the posterior section of the mitral annulus  28  to further increase the effect of the inward displacement of the mitral annulus  28  (as shown by the arrows of  FIG. 19 ). Typically, the inner elongate body  1705  is placed within the central stent section of the outer elongate body  1700  to straighten the central section of the coronary sinus  20 , which is generally aligned with the P 2  scallop. 
     Resorbable materials have been used in connection with valve repair devices as a means to provide a “delayed release” mechanism allowing a device to effect a change to a valve over time. Examples of embodiments that include resorbable material may be found in U.S. patent application Ser. No. 10/141,348 to Solem, et al., 10/329,720 to Solem, et al., and 10/500,188 to Solem, et al., which are incorporated herein by reference. 
     As shown in  FIG. 20 , a new embodiment of the present invention includes an elongate body  410  having resorbable thread sutured through the openings of a bridge  416 . The elongate body further includes a proximal anchor  412  and a distal anchor  414  connected by the bridge  416  with the resorbable material. 
     Resorbable materials are those that, when implanted into a human body, are resorbed by the body by means of enzymatic degradation and also by active absorption by blood cells and tissue cells of the human body. Examples of such resorbable materials are PDS (Polydioxanon), Pronova (Poly-hexafluoropropylen-VDF), Maxon (Polyglyconat), Dexon (polyglycolic acid) and Vicryl (Polyglactin). As explained in more detail below, a resorbable material may be used in combination with a shape memory material, such as nitinol, Elgiloy or spring steel to allow the superelastic material to return to a predetermined shape over a period of time. 
     In one embodiment as shown in  FIG. 20 , the proximal and distal anchors  412 ,  414  are both generally cylindrical and are both made from tubes of shape memory material, for example, nitinol. However, the anchors  412  and  414  may also be made from any other suitable material, such as stainless steel. Both anchors  412 ,  414  have a mesh configuration comprising loops  54  of zigzag shaped shape memory material having alternating peaks  42 . The loops  54  are connected at each peak  42  to form rings  56  of four-sided openings  40 . Other configurations may also be used as known in the art. Additionally, other types of anchors known in the art may also be used. 
     The proximal and distal anchors  412 ,  414  each have a compressed state and an expanded state. In the compressed state, the anchors  412 ,  414  have a diameter that is less than the diameter of the coronary sinus  20 . In this state, the anchors  412  and  414  have a substantially uniform diameter of between about 1.5 to 4 mm. In the expanded state, the anchors  412 ,  414  have a diameter that is about equal to or greater than a diameter of the section of a non-expanded coronary sinus  20  to which each anchor will be aligned. Since the coronary sinus  20  has a greater diameter at its proximal end than at its distal end, in the expanded state the diameter of the proximal anchor  412  is between about 10-15 mm and the diameter of the distal anchor is between about 3-6 mm. 
     In one embodiment, the bridge  416  is connected between the proximal anchor  412  and distal anchor  414  by links  418 ,  419 . More specifically as shown in  FIG. 20 , a proximal link  418  connects the proximal stent section  412  to a proximal end of the bridge  416  and a distal link  419  connects the distal stent section  414  to a distal end of the bridge  416 . The links  418  and  419  have a base  421  and arms  422  that extend from the base and which are connected to two peaks  42  on each anchor  412 ,  414 . Further, the links  418  and  419  contain a hole  428 , as shown in  FIG. 21 , which serves as a means through which to pass the end of the resorbable thread and secure it to the bridge  416 . 
     The bridge  416  in one embodiment is made from a shape memory material and is flexible to allow the body  410  to conform to the shape of the coronary sinus  20 . The bridge  416  comprises X-shaped elements  424  wherein each X-shaped element is connected to an adjacent X-shaped element at the extremities of the “X,” allowing a space  425  to be created between adjacent X-shaped elements, as shown in  FIG. 23 . The X-shaped elements  424  further have rounded edges that minimizes the chances that a sharp edge of the bridge  416  will puncture or cut a part of the coronary sinus  20  as the device is inserted. The bridge  416  has two states: an elongated state in which the bridge  416  has a first length, and a shortened state in which the bridge has a second length, the second length being shorter than the first length. In the present embodiment, resorbable thread  420  is woven into the spaces  425  between adjacent X-shaped elements  424  to hold the bridge  416  in its elongated state. The thread  420  acts as a temporary spacer. When the resorbable thread  420  is dissolved over time by means of resorption, the bridge assumes its shortened state. 
     The present embodiment is deployed as follows. An introduction sheath (not shown) made of synthetic material is used to gain access to the venous system. A guide wire (not shown) is then advanced through the introduction sheath and via the venous system to the coronary sinus  20 . The guide wire and/or introduction sheath is provided with radiopaque distance markers which can be identified using X-rays which allows the position of the body  410  in the coronary sinus  20  to be monitored. 
     The elongate body  410  is mounted onto a stent insertion device (not shown) so that the self-expanding anchors  412  and  414  are held in the compressed state. Thereafter, the stent insertion device with the elongate body  410  mounted thereon is pushed through the introduction sheath and the venous system to the coronary sinus  20  riding on the guide wire. After the body  410  is positioned in the coronary sinus  20  so that the center of the body is generally aligned with the center of the P 2  scallop, the stent insertion device is removed. When the stent insertion device is removed, the self-expandable anchors  412  and  414  are released so that they expand and contact the inner wall of the coronary sinus  20  and provide temporary fixation of the elongate body  410  to the coronary sinus. Alternatively, the anchor may be expanded by balloons or other means known in the art. In one embodiment, the device can be rotated so that the bridge contacts the wall of the coronary sinus that is closest to the mitral valve  26 . The guide wire and the introduction sheath are then removed. 
     After the body  410  is inserted into the coronary sinus  20 , the wall of coronary sinus will grow around the mesh configuration of the anchors  412  and  414 . Simultaneously, the resorbable thread  420  will be resorbed by the surrounding blood and tissue in the coronary sinus  20 . After a period of a few weeks, the anchors  412  and  414  will be secured into the wall of the coronary sinus  20 . During that time period, the resorbable thread  420  will be resorbed to such a degree that eventually it can no longer hold the bridge  416  in its elongated state. As the resorbable thread  420  is resorbed, the bridge  416  retracts from its elongated state to its shortened state. This shortening of the bridge  416  draws the proximal anchor  412  and the distal anchor  414  together, cinching the coronary sinus  20  and/or reducing its circumference. This cinching and/or reduction of the circumference of the coronary sinus  20  closes the gap created by dilatation of the posterior leaflet  31  of the mitral valve. 
     The body  410  may be positioned in the coronary sinus  20  by catheter technique or by any other adequate technique. The body  410  may be heparin-coated so as to avoid thrombosis in the coronary sinus  20 , thus reducing the need for aspirin, ticlopedine or anticoagulant therapy. At least part of the body  410  may contain or be covered with any therapeutic agents such as Tacrolimus, Rappamycin or Taxiferol to prohibit excessive reaction with surrounding tissue. Further, at least parts of the body  410  may contain or be covered with Vascular Endothelial Growth Factor (VEGF) to ensure smooth coverage, with endothelial cells. 
     In some cases of ischemic mitral regurgitation, the dilatation of the mitral annulus may be asymmetric with, for example, one region of the mitral annulus being more dilated than another. Thus, it may be advantageous to be able to control the degree of cinching along a particular segment of the mitral annulus. 
     As shown in  FIG. 22 , an alternate embodiment of the present invention similar to the delayed release device described above comprises an elongate body  510  including a proximal anchor  512 , a distal anchor  514  and a central anchor  516 . A first bridge  518  connects the proximal anchor  512  to the central anchor  516 , and a second bridge  520  connects the distal anchor  514  to the central anchor. 
     The structure of the elongate body  510  is substantially similar to the structure of the elongate body  410  described above. More specifically, each anchor  512 ,  514 ,  516  is generally cylindrical and has a compressed state and an expanded state. Further, each bridge  518 ,  520  has an elongated and a shortened state and comprises X-shaped elements with resorbable thread woven into spaces created between adjacent X-shaped elements. Also, each bridge  518 ,  520  is connected to its respective anchors  512 ,  514 ,  516  by a link as described above. 
     The amount of foreshortening of the bridge  518  may be variable depending on, for example, the size of the X-shaped elements, the size of the openings between adjacent X-shaped elements, the type of material used to manufacture the bridge, and the diameter of the material threaded into the bridge. 
     The present embodiment is deployed as follows. An introduction sheath (not shown) made of synthetic material is used to gain access to the venous system. A guide wire (not shown) is then advanced through the introduction sheath and via the venous system to the coronary sinus  20 . The guide wire and/or introduction sheath is provided with X-ray distance markers so that the position of the body  510  in the coronary sinus  20  may be monitored. 
     The elongate body  510  is mounted onto a stent insertion device (not shown) so that the self-expanding anchors  512 ,  514  and  516  are held in the compressed state. Thereafter, the stent insertion device with the elongate body  510  mounted thereon is pushed through the introduction sheath and the venous system to the coronary sinus  20  riding on the guide wire. After the body  510  is positioned in the coronary sinus  20  so that the central anchor  516  is generally aligned with the center of the P 2  scallop, the stent insertion device is removed. When the stent insertion device is removed, the self-expandable anchors  512 ,  514  and  516  are released so that they expand and contact the inner wall of the coronary sinus  20  and provide temporary fixation of the elongate body  510  to the coronary sinus. In one embodiment, the device may be rotated so that the bridges contact the wall of the coronary sinus that is closest to the mitral valve  26 . The guide wire and the introduction sheath are then removed. 
     After the body  510  is inserted into the coronary sinus  20 , the wall of coronary sinus will grow around the mesh configuration of the anchors  512 ,  514  and  516 . Simultaneously, the resorbable thread (not shown in detail) will be resorbed by the surrounding blood and tissue in the coronary sinus  20 . After a period of a few weeks, the anchors  512 ,  514  and  516  will be more permanently secured into the wall of the coronary sinus  20 . During that time period, the resorbable thread will be resorbed to such a degree that eventually it will not hold the bridges  518 ,  520  in their elongated state any longer. As the resorbable thread is resorbed, the bridges  518 ,  520  retract from their elongated state to their shortened state. This shortening of the bridges  518 ,  520  draws the proximal and distal anchors  512 ,  514  toward each other, cinching the coronary sinus  20  and reducing its circumference. The reduction of the circumference of the coronary sinus  20  closes the gap created by dilatation of the posterior leaflet  31  of the mitral valve. 
     Having the central anchor  520  between the proximal and distal anchors  512 ,  514  may allow for a different amount of foreshortening between each pair of adjacent anchors, depending on the length of the bridges  518 ,  520 . Thus, the elongate body  510  may be more specifically tailored to reshape the mitral annulus according to a patient&#39;s needs. For example, the bridge between the proximal anchor  512  and central anchor  516  may shorten more than the bridge between the distal anchor  514  and the central anchor or vice versa. Further, having an additional anchor serves to improve the distribution of forces that act on the proximal and distal stents as well as improving the distribution of the forces that the bridges exert on the inner wall of the coronary sinus. 
     The delayed release device described above is not limited to three anchors.  FIG. 23  shows an embodiment  610  of the present invention wherein four anchors  612 ,  614 ,  616 ,  618  and three bridges  620 ,  622 ,  624  are used, but it will be apparent to one skilled in the art that any number of anchors may be used and that the length of the bridges between each anchor may vary. 
     In addition to the embodiments described in detail above, those skilled in the art will appreciate other embodiments for connecting a proximal anchor, a distal anchor and at least one central anchor. Some of those embodiments may include a thread of shape memory material held in an elongated state by a sheath of resorbable material, scissors-shaped memory material held in an elongated state by a sheath of resorbable material or by resorbable material in tension, a coil of shape-memory material wrapped around a tube of resorbable material, ribbons of resorbable material wrapped around a tube of shape memory material. See, for example, the embodiment in Ser. No. 10/500,188. 
     Referring now to  FIGS. 24A-24D , another embodiment of the present invention is described. Apparatus  758  includes proximal anchor element  762  that is joined to distal anchor element  764  via wire  766  and cinch mechanism  767 . Proximal and distal anchor elements  762  and  764  also include substantially tubular members that self-expand to engage the intima of the vessel in which they are deployed. In accordance with principles of the present invention, distal anchor element  764  includes a means for bonding the distal anchor element to at least a portion of an intima of coronary sinus C. Preferred configurations for proximal and distal anchor elements  762  and  764 , as well as preferred means for bonding distal anchor element  764  to the intima of the coronary sinus, are described in detail with respect to  FIGS. 25A-25C . 
     As shown in  FIG. 25A , proximal anchor element  762  includes self-deploying stent  785  having proximal and distal ends, deployable flange  769  disposed at the proximal end, and cinch mechanism  767  coupled to stent  785 . Stent  785  and deployable flange  769  of proximal anchor element  762  are initially constrained within delivery sheath  760 , as shown in  FIG. 24A , and are composed of a shape memory material, e.g., Nitinol, so that stent  785  and flange  769  self-deploy to the predetermined shapes shown in  FIG. 25A  upon retraction of delivery sheath  760 . 
     Flange  769  may include a substantially circular shape-memory member, as illustrated in  FIG. 25A , a plurality of wire members, e.g., manufactured using Nitinol, that self-deploy upon removal of sheath  764  and abut ostium O, or other suitable shape. 
     As shown in  FIG. 253 , distal anchor element  764  preferably includes wire mesh stent  787  manufactured using a shape memory material, e.g., Nitinol. Wire  766  is coupled to distal anchor element  764  and is used in combination with cinch mechanism  767  of proximal anchor element  762  to remodel the coronary sinus, as described hereinbelow. Stents  785  and  787  are illustratively described as comprising wire mesh, but one of skill in the art will appreciate that other types of anchor elements including self-expanding slotted tubular stents also may be employed. 
     Distal anchor element  764 , as depicted in  FIG. 25B , in one exemplary embodiment is at least partially coated with a bonding material  791 . Bonding material  791  may have light-reactive binding agents that undergo polymerization when exposed to radiation, for example, ultraviolet (UV) radiation. When bonding material  791  has such UV-curable agents, the agents may include acrylates, and more specifically, acrylates with UV or free radical polymerization or, for example, polymethylmethacrylate. 
     Apparatus  758  may further comprise catheter  770  having proximal and distal ends, a lumen extending therebetween, and at least one port  771  disposed at the distal end of the catheter, as shown in  FIG. 24A . A light source, for example, including UV light, may be coupled to the proximal end of catheter  770  so that the light is transmitted throughout the lumen of catheter  770  and exits via port  771 . Catheter  770  further includes radiopaque marker bands  772  and  774  to aid in the positioning of port  771  under fluoroscopy, which in turn ensures the proper positioning of the UV light. 
     Alternatively, bonding material  791  may include a synthetic molding material, such as a starch-based poly ethylene glycol hydrogel, that is heat hardenable or hydrophilic. In an exemplary embodiment, a starch-based poly ethylene glycol hydrogel is used that swells when exposed to an aqueous solution. Hydrogels also may be selected to harden, for example, upon exposure to body temperature or blood pH. Hydrogels suitable for use with the present invention may be obtained, for example, from Gel Med, Inc., Bedford, Mass. 
     Referring to  FIG. 25C , alternative distal anchor element  794  may be used in lieu of distal anchor element  764  of  FIG. 25B . Distal anchor element  794  includes foam member  796  having proximal and distal ends and bore  797  extending therebetween. Foam member  796  is depicted in a deployed state in  FIG. 25C , but is capable of being contracted within delivery sheath  760  of  FIG. 24A . Foam member  796  is made from a hydrophilic foam, i.e., a foam material that has a tendency to absorb water and swell into engagement with the vessel intima. 
     Referring back to  FIG. 24A , preferred method steps for using the proximal and distal anchor elements of  FIGS. 25A-25C  are described. Apparatus  758  is navigated through the patient&#39;s vasculature with proximal and distal anchor elements  762  and  764  in a contracted state and into coronary sinus C, as shown in  FIG. 24A . The distal end of sheath  760  is disposed, under fluoroscopic guidance, at a suitable position within the coronary sinus, great cardiac vein, or adjacent vein. Push tube  768  then is held stationary while delivery sheath  760  is retracted proximally so that distal anchor element  764  deploys from within sheath  760 , thereby permitting distal anchor element  764  to self-expand into engagement with the vessel wall, as shown in  FIG. 24B . 
     In accordance with principles of the present invention, after distal anchor element  764  self-deploys, an outer surface of distal anchor element  764  will become at least partially chemically or mechanically bonded to an intima of coronary sinus C. When bonding material  791  of  FIG. 25B  comprises a light-reactive binding agent, the light-reactive binding agents will at least partially contact the vessel wall when distal anchor element  764  self-deploys. At this time, light  773 , for example, UV light, may be emitted from port  771  of catheter  770  to cause light-reactive agents  791  to polymerize, and thereby form bond B with the intima of coronary sinus C, as shown in  FIG. 25B . Catheter  770  then may be removed upon satisfactory bonding of distal anchor element  764 . 
     Alternatively, when bonding material  791  of  FIG. 25B  comprises a hydrogel, the exposure of the hydrogel to flow in the vessel will cause at least a portion of distal anchor element  764  to chemically bond with the intima of coronary sinus C. In yet another alternative embodiment, when alternative distal anchor element  794  of  FIG. 25C  is used, foam member  796  will cause distal anchor element  794  to chemically or mechanically bond with the intima of coronary sinus C when exposed to flow in the vessel due to the hydrophilic properties of foam member  796 . 
     Using any of the techniques described above, it is possible to chemically bond distal anchor element  764 , or distal anchor element  794 , to at least a portion of the intima of coronary sinus C. As will be described in detail hereinbelow, this is advantageous because shear stress to the vessel will be reduced when actuating wire  766  and cinch mechanism  767 . 
     Referring now to  FIG. 24C , in a next method step, delivery sheath  760  is retracted proximally, under fluoroscopic guidance, until proximal anchor element  762  is situated extending from the coronary sinus. Push tube  768  is held stationary while sheath  760  is further retracted, thus releasing proximal anchor element  762 . Once released from delivery sheath  760 , proximal anchor element  762  self-expands into engagement with the wall of the coronary sinus C, and flange  769  abuts against coronary ostium O, as shown in  FIG. 24C . 
     Delivery sheath  760  (and/or push tube  768 ) then may be positioned against flange  769  of proximal anchor element  762 , and wire  766  retracted in the proximal direction to draw distal anchor element  764  towards proximal anchor element  762 , as shown in  FIG. 24D . As will of course be understood, distal anchor element  764  is drawn towards proximal anchor element  762  under fluoroscopic, ultrasound or other types of guidance, so that the degree of remodeling of the mitral valve annulus may be assessed. 
     As wire  766  is drawn proximally, cinch mechanism  767  prevents distal slipping of the wire. For example, wire  766  may include a series of grooves along its length that are successively captured in a V-shaped groove, a pall and ratchet mechanism, or other well-known mechanism that permits one-way motion. Upon completion of the procedure, delivery sheath  760  and push tube  768  are removed from the patient&#39;s vessel. 
     Referring now to  FIGS. 26A-26D , a method for using apparatus  758  of  FIGS. 6 and 7  to close a central gap  782  of mitral valve  780  is described. In  FIG. 26A , proximal and distal anchor elements  762  and  764  are deployed in coronary sinus C, preferably so that flange  769  of proximal anchor element  762  abuts coronary ostium O. Distal anchor element  764  is disposed at such a distance apart from proximal anchor element  762  that the two anchor elements apply a compressive force upon mitral valve  780  when wire  766  and cinch  767  are actuated. 
     In  FIG. 26B , cinch  767  is actuated from the proximal end to reduce the distance between proximal and distal anchor elements  762  and  764 , e.g., as described hereinabove with respect to  FIG. 24D . When wire  766  and cinch mechanism  767  are actuated, distal anchor element  764  is pulled in a proximal direction, while proximal anchor element  762  may be urged in a distal direction using delivery sheath  760  and/or push tube  768 , as shown in  FIG. 24D . 
     When proximal anchor element  762  comprises flange  769 , proximal anchor element  762  is urged in the distal direction until flange  769  abuts coronary ostium O. The reduction in distance between proximal and distal anchor elements  762  and  764  reduces the circumference of mitral valve annulus  781  and thereby reduces gap  782 . Flange  769  provides a secure anchor point that prevents further distally-directed movement of proximal anchor element  762 , and reduces shear stresses applied to the proximal portion of the coronary sinus. Moreover, because distal anchor element  764  is bonded to the intima of coronary sinus C using any of the techniques described above, shear stress to the intima of coronary sinus C will be reduced when actuating wire  766  and cinch mechanism  767 . 
     Referring now to  FIGS. 27A-27L , alternative apparatus and methods suitable for treating mitral insufficiency are described. In  FIG. 27A , distal balloon catheter  804  having proximal and distal ends, lumen  815  extending therebetween, and balloon  805  disposed at the distal end is positioned within coronary sinus C with balloon  805  in a contracted state. Distal catheter  804  may be positioned using a conventional guidewire (not shown), according to techniques that are known in the art. Distal catheter  804  further comprises an inflation lumen (not shown) extending between the proximal and distal ends that is in fluid communication with an opening of balloon  805 , so that balloon  805  may be inflated via the inflation lumen, as shown in  FIG. 27B . 
     Balloon  805  preferably includes a plurality of ribs or bumps  806  disposed about its circumference that are configured to engage the intima of a vessel wall and resist movement of balloon  805 , when inflated, relative to the vessel. 
     After balloon  805  of distal catheter  804  is deployed in coronary sinus C, proximal balloon catheter  802  having proximal and distal ends, lumen  816  extending therebetween, and balloon  803  disposed at the distal end then may be advanced distally over distal catheter  804 . 
     Lumen  816  of proximal catheter  802  comprises an inner diameter that is larger than an outer diameter of distal catheter  804 , so that annulus  807  is defined as the space between an interior surface of proximal catheter  802  and an outer surface of distal catheter  804 . 
     Proximal catheter  802  is provided with balloon  803  in a contracted state, and may be under fluoroscopy at a location whereby proximal section  819  of balloon  803  remains proximal of coronary ostium O, as shown in  FIG. 27B . At this time, balloon  803  is inflated via an inflation lumen (not shown) of proximal catheter  802  to deploy balloon  803 . 
     In the deployed state, balloon  803  of proximal catheter  802  comprises flange  809  disposed about proximal section  819  of balloon  803 , as shown in  FIG. 27C . In the deployed state, flange  809  is configured to abut against the wall of coronary ostium O, while a distal section of balloon  803  is configured to be substantially flush with the intima of coronary sinus C, as shown in  FIG. 27C . An interior portion of coronary sinus C that is formed between deployed balloons  803  and  805  defines cavity  827 . 
     Referring to  FIG. 27D , balloon  805  of distal catheter  804  then may be retracted proximally and/or balloon  803  of proximal catheter  802  may be urged distally so that the distance between balloons  803  and  805  is reduced. Balloon  805  is disposed at such a distance apart from balloon  803  that the two balloons will apply a compressive force upon mitral valve  820  when the distance between balloons is reduced. 
     Ribs  806  of balloon  805  may engage the intima of coronary sinus C when balloon  805  is retracted, so that balloon  805  does not move with respect to coronary sinus C. Proximal retraction of balloon  805  causes coronary sinus C to shorten and remodel the curvature of the mitral valve annulus, as shown in  FIG. 27D . The reduction in distance between balloons  803  and  805  applies a compressive force upon mitral valve  820  that reduces the circumference of mitral valve annulus  121  and thereby closes gap  822 . 
     Referring now to  FIG. 27E , with gap  822  reduced or closed as described hereinabove with respect to  FIG. 27D , substance  811  then may be introduced into cavity  827  via annulus  807 . Substance  811  may be a biological or synthetic biocompatible material that is injected in a fluid state, and which hardens to a rigid or semi-rigid state. 
     For example, substance  811  may comprise a biological hardening agent, such as fibrin, that induces blood captured in cavity  827  to form a coherent mass, or it may comprise a tissue material, such as collagen, that expands to fill the cavity. If fibrin is employed, it may be obtained from commercially available sources, or it may be separated out of a sample of the patient&#39;s blood prior to the procedure, and then injected into cavity  827  via annulus  807  to cause thrombosis. On the other hand, collagen-based products, such as are available from Collatec, Inc., Plainsboro, N.J., may be used to trigger thrombosis of the volume of blood in cavity  827 . 
     Alternatively, substance  811  may comprise a synthetic molding material, such as a starch-based poly ethylene glycol hydrogel or a polymer, such as poly-capro-lactone, that is heat hardenable or hydrophilic. In a preferred embodiment, a starch-based poly ethylene glycol hydrogel is used that swells when exposed to an aqueous solution. Hydrogels suitable for use with the present invention are described hereinabove with respect to  FIG. 25B . Hydrogels or polymers also may be selected to harden, for example, upon exposure to body temperature or blood pH. 
     The injection of substance  811  between balloons  803  and  805  and into cavity  827  forms coherent mass  812 , as shown in  FIG. 27F . It is expected that, depending upon the type of hardening agent or molding material used, solidification of the content of cavity  827  may take about ten minutes or less. 
     After solidification of mass  812  has occurred, balloons  803  and  805  may be deflated. To facilitate removal of distal catheter  804  and balloon  805  from solidified mass  812 , the exterior surface of distal catheter  804  and balloon  805  may be coated with a suitable non-stick coating, for example, Teflon®, a registered trademark of the E.I. duPont de Nemours Company, Wilmington, Del. (polytetrafluorethylene), or other suitable biocompatible material, such as Oparylene, available from Paratech®, Inc., Aliso Viejo, Calif. Proximal catheter  802  and/or balloon  803  also may be coated with such a non-stick coating to facilitate removal from within the patient&#39;s vessel. 
     Upon removal of proximal and distal catheters  802  and  804 , solidified mass  812  maintains mitral valve  820  in the remodeled shape with gap  822  closed. The removal of distal catheter  804  from within solidified mass  812  may form bore  828  within the mass, as shown in  FIG. 27F , which allows blood flow to be maintained within coronary sinus C. Because blood oxygenating the myocardium can drain directly into the left ventricle via the Thebesian veins, it is also permissible for the coronary sinus to be completely occluded with little or no adverse effect. 
     In an alternate embodiment of the present invention as shown in  FIGS. 27G and 27H , the catheter  802  reaches all the way to the distal balloon  805 . The distal balloon  805  with the catheter  802  is inserted into the great cardiac vein beyond where the vein turns away from the mitral valve plane at about 90 degrees. When a substance  811  is introduced into the device, the substance may also enter side branches  813  creating small arms there. These arms will aid in axially fixing the device once the substance is cured as described below. After the device has foreshortened as described above by moving the balloons  803 ,  805  towards each other and temporarily fixing their positions relative to each other, the lumen  816  of catheter  802  is filled with a substance  811  that when cured, for example by an ultraviolet light or by adding a proper chemical, becomes a hardened mass. Using this technique, a three-dimensional mass  812  having a small central bore  828  is created. This mass  812  is smaller in diameter than the coronary sinus C and the great cardiac vein, permitting close to normal blood flow in the vessel. Due to its three-dimensional shape and rigid configuration, the mass  812  is restricted to almost no axial movement. Thus, the shape of the coronary sinus C, the great cardiac vein and the mitral valve held temporarily by means of the two balloons  803 ,  805  may be held permanently by the mass  812 . 
     In another embodiment as shown in  FIGS. 27I and 27J , a film sack  880  is attached to the distal end of the proximal balloon  803 . The diameter of the film sack is approximately equal to the diameter of the coronary sinus C and tapers down to approximately the diameter of the distal catheter  804  near the distal balloon  805  as shown in  FIG. 27J . The film sack  880  is removably attached to the distal balloon  805  and may be manufactured from any thin plastic biocompatible material. A curable substance  811  is then introduced via the annulus  807  and cured by ultraviolet light or by the addition of a chemical as described above. When cured, the substance  811  forms a hardened mass that retains its shape and forces the affected vessels to also retain that shape. Once the substance  811  has hardened, the catheter  804 , balloons  803 ,  805  and film sack  880  are removed. 
     in yet another embodiment, as shown in  FIGS. 27K and 27L , the film sack  880  extends to outside the patient&#39;s body rather than being attached to the proximal balloon  803 . Once the substance  811  is introduced, it can then be cured so as to form a hardened mass that extends all the way to the ostium O. This allows the cured substance to encompass a greater amount of the mitral valve annulus and ensures better closure of the gap created by mitral valve dilatation. The excess substance  811  that is not cured remains fluid and may be removed when the catheter  804 , balloons  803 ,  805  and film sack  880  are removed. 
     Dilatation of the heart ventricles may lead to heart failure, which affects both the electrical and mechanical properties of the heart. Specifically, dilatation may cause distortion of the synchronization between the heart ventricles and atria. To correct this distortion, a pacemaker to stimulate contraction of the heart may be implanted into the heart, either through the chest wall or percutaneously through the venous system. Stent-type mechanisms are known that are connected to the tip of a pacing lead to securely anchor the pacing lead into a target vessel, such as those described in U.S. Pat. Nos. 5,071,407 (Termin, et al.), 5,224,491 (Mehra), 5,496,275 (Sirhan, et al.), 5,531,779 (Dahl, et al.) and 6,161,029 (Spreigl, et al.). 
       FIGS. 28A-28C  illustrate another embodiment of the present invention. A pacing lead  901  such as described above may be attached to any of the previously described mitral valve annulus reshaping devices, for example elongate body  10  ( FIG. 28A ), elongate body  1300  ( FIG. 28B ) or elongate body  110  ( FIG. 28C ), to combine the function of the pacing lead with the function of the annulus reshaping device. Such a combination would allow for simultaneous treatment of arrhythmia and mitral regurgitation and would eliminate the need for a separate procedure to treat both conditions. Additionally, potential interference of the annulus reshaping device with the pacing lead would be avoided. As shown in  FIGS. 28A-C , two pacing activity leads are used with each depicted elongate body which allows for effect at two locations. However, the number of pacing leads used is not critical and more or fewer than two leads may be used. 
     While the foregoing describes the preferred embodiments of the invention, various alternatives, modifications and equivalents may be used. For instance, although the described embodiments have generally been is directed to placement in the coronary sinus for treatment of the mitral valve, the embodiments may also be placed in, for example, the anterior right ventricular cardiac vein to treat the tricuspid valve. Additionally, the order in which the stent sections of the various embodiments are expanded may be varied. Moreover, it will obvious that certain other modifications may be practiced within the scope of the appended claims.