Patent Publication Number: US-2005137449-A1

Title: Tissue shaping device with self-expanding anchors

Description:
BACKGROUND OF THE INVENTION  
      This invention relates generally to devices and methods for shaping tissue by deploying one or more devices in body lumens adjacent to the tissue. One particular application of the invention relates to a treatment for mitral valve regurgitation through deployment of a tissue shaping device in the patient&#39;s coronary sinus or great cardiac vein.  
      The mitral valve is a portion of the heart that is located between the chambers of the left atrium and the left ventricle. When the left ventricle contracts to pump blood throughout the body, the mitral valve closes to prevent the blood being pumped back into the left atrium. In some patients, whether due to genetic malformation, disease or injury, the mitral valve fails to close properly causing a condition known as regurgitation, whereby blood is pumped into the atrium upon each contraction of the heart muscle. Regurgitation is a serious, often rapidly deteriorating, condition that reduces circulatory efficiency and must be corrected.  
      Two of the more common techniques for restoring the function of a damaged mitral valve are to surgically replace the valve with a mechanical valve or to suture a flexible ring around the valve to support it. Each of these procedures is highly invasive because access to the heart is obtained through an opening in the patient&#39;s chest. Patients with mitral valve regurgitation are often relatively frail thereby increasing the risks associated with such an operation.  
      One less invasive approach for aiding the closure of the mitral valve involves the placement of a tissue shaping device in the cardiac sinus and vessel that passes adjacent the mitral valve. The tissue shaping device is designed to push the vessel and surrounding tissue against the valve to aid its closure. This technique has the advantage over other methods of mitral valve repair because it can be performed percutaneously without opening the chest wall. Examples of such devices are shown in U.S. patent application Ser. No. 10/142,637, “Body Lumen Device Anchor, Device and Assembly” filed May 8, 2002; U.S. patent application Ser. No. 10/331,143, “System and Method to Effect the Mitral Valve Annulus of a Heart” filed Dec. 26, 2002; and U.S. patent appl. Ser. No. 10/429,172, “Device and Method for Modifying the Shape of a Body Organ,” filed May 2, 2003. The disclosures of these patent applications are incorporated herein by reference.  
      When deploying a tissue shaping device in a vein or artery to modify adjacent tissue, care must be taken to avoid constricting nearby arteries. For example, when treating mitral valve regurgitation, a tissue shaping device may be deployed in the coronary sinus to modify the shape of the adjacent mitral valve annulus. Coronary arteries such as the circumflex artery may cross between the coronary sinus and the heart, however, raising the danger that deployment of the support may limit perfusion to a portion of the heart by constricting one of those arteries. See, e.g., the following applications, the disclosures of which are incorporated herein by reference: U.S. patent application Ser. No. 09/855,945, “Mitral Valve Therapy Device, System and Method,” filed May 14, 2001 and published Nov. 14, 2002, as U.S. 2002/0169504 A1; U.S. patent application Ser. No. 09/855,946, “Mitral Valve Therapy Assembly and Method,” filed May 14, 2001 and published Nov. 14, 2002, as U.S. 2002/0169502 A1; and U.S. patent application Ser. No. 10/003,910, “Focused Compression Mitral Valve Device and Method” filed Nov. 1, 2001. It is therefore advisable to monitor cardiac perfusion during and after such mitral valve regurgitation therapy. See, e.g., U.S. patent application Ser. No. 10/366,585, “Method of Implanting a Mitral Valve Therapy Device,” filed Feb. 12, 2003, the disclosure of which is incorporated herein by reference.  
     BRIEF SUMMARY OF THE INVENTION  
      The anatomy of the heart and its surrounding vessels varies from patient to patient. For example, the location of the circumflex artery and other key arteries with respect to the coronary sinus can vary. Specifically, the distance along the coronary sinus from the ostium to the crossing point with the circumflex artery can vary from patient to patient. In addition, the diameter and length of the coronary sinus can vary from patient to patient.  
      We have invented a tissue shaping device, a set of tissue shaping devices and a method that maximize the therapeutic effect (i.e., reduction of mitral valve regurgitation) while minimizing adverse effects, such as an unacceptable constriction of the circumflex artery or other coronary arteries. The tissue shaping device, set of devices and method of this invention enable the user to adapt the therapy to the patient&#39;s anatomy.  
      One aspect of the invention is a tissue shaping device adapted to be deployed in a vessel to reshape tissue adjacent to the vessel. In some embodiments the device includes: a distal anchor having a flexible wire with at least one bending point and first and second arms extending from the bending point, the first and second arms being adapted to deform about the bending point; a proximal anchor having a flexible wire with at least one bending point and first and second arms extending from the bending point, the first and second arms being adapted to deform about the bending point; and a connector disposed between the distal anchor and the proximal anchor. The distal anchor bending point may be disposed on a proximal side of the distal anchor, and the proximal anchor bending point may be disposed on a distal side of the proximal anchor.  
      In some embodiments the distal anchor flexible wire is arranged in a substantially figure eight configuration. The distal anchor flexible wire may then include a second bending point and third and fourth arms extending from the second bending point, the third and fourth arms being adapted to bend about the second bending point. The distal anchor flexible wire may also include first and second proximal struts, with the first and second bending points being formed in the first and second proximal struts, respectively. The bending points may each be, e.g., a section of the flexible wire having an increased radius of curvature compared to adjacent wire sections or a loop formed in the flexible wire. The distal anchor flexible wire first and second bending points may also be disposed at a tallest point of the distal anchor.  
      In some embodiments the proximal anchor flexible wire is arranged in a substantially figure eight configuration. The proximal anchor flexible wire may then include a second bending point and third and fourth arms extending from the second bending point, the third and fourth arms being adapted to bend about the second bending point. The proximal anchor flexible wire may also include first and second proximal struts, with the first and second bending points being formed in the first and second proximal struts, respectively. The bending points may each be, e.g., a section of the flexible wire having an increased radius of curvature compared to adjacent wire sections or a loop formed in the flexible wire. The proximal anchor flexible wire first and second bending points may also be disposed at a tallest point of the proximal anchor.  
      In some embodiments the distal anchor is a self-expanding anchor, and in some embodiments the proximal anchor is an actuatable anchor. The connector may have a moment of inertia that varies along its length. The distal and proximal anchors may also include crimp tubes, and the connector may be integral with the crimp tubes.  
      The invention will be described in more detail below with reference to the drawings. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       FIG. 1  is a schematic view of a tissue shaping device according to a preferred embodiment as deployed within a coronary sinus.  
       FIG. 2  is a schematic view of a tissue shaping device according to an alternative embodiment as deployed within a coronary sinus.  
       FIG. 3  is a schematic view of a tissue shaping device being delivered to a coronary sinus within a catheter.  
       FIG. 4  is a schematic view of a partially deployed tissue shaping device within a coronary sinus.  
       FIG. 5  is a schematic view of a partially deployed and cinched tissue shaping device within a coronary sinus.  
       FIG. 6  is an elevational view of yet another embodiment of a tissue shaping device according to this invention.  
       FIG. 7  is a schematic drawing showing a method of determining the crossover point between a circumflex artery and a coronary sinus.  
       FIG. 8  is a perspective drawing of a tissue shaping device according to one embodiment of this invention.  
       FIG. 9  is a partial sectional view of the tissue shaping device of  FIG. 8  in an unexpanded configuration within a catheter.  
       FIG. 10  is a perspective view of an anchor for use with a tissue shaping device according to this invention.  
       FIG. 11  is a perspective view of another anchor for use with a tissue shaping device according to this invention.  
       FIG. 12  is a perspective view of yet another anchor for use with a tissue shaping device according to this invention.  
       FIG. 13  is a perspective view of still another anchor for use with a tissue shaping device according to this invention.  
       FIG. 14  is a perspective view of another anchor for use with a tissue shaping device according to this invention.  
       FIG. 15  is a perspective view of yet another anchor for use with a tissue shaping device according to this invention.  
       FIG. 16  is a perspective view of part of an anchor for use with a tissue shaping device according to this invention.  
       FIG. 17  is a perspective view of still another anchor for use with a tissue shaping device according to this invention.  
       FIG. 18  is a perspective view of another anchor for use with a tissue shaping device according to this invention.  
       FIG. 19  is a perspective view of yet another anchor for use with a tissue shaping device according to this invention.  
       FIG. 20  is a perspective view of still another anchor for use with a tissue shaping device according to this invention.  
       FIG. 21  is a perspective view of a tandem anchor for use with a tissue shaping device according to this invention.  
       FIG. 22  is a perspective view of a connector with integral anchor crimps for us in a tissue shaping device according to this invention.  
       FIG. 23  is a perspective view of a tissue shaping device employing the connector of  FIG. 22 .  
       FIG. 24  is a perspective view of another connector for use with a tissue shaping device according to this invention.  
       FIG. 25  is a perspective view of yet another connector for use with a tissue shaping device according to this invention.  
       FIG. 26  is a side view of a connector for use with a tissue shaping device according to this invention.  
       FIG. 27  is a side view of another connector for use with a tissue shaping device according to this invention.  
       FIG. 28  is a perspective view of yet another tissue shaping device according to this invention.  
       FIG. 29  is a side view of the tissue shaping device shown in  FIG. 28 .  
       FIG. 30  is a schematic view of another embodiment demonstrating the method of this invention.  
       FIG. 31  is a schematic view of yet another embodiment demonstrating the method of this invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       FIG. 1  shows a partial view of a human heart  10  and some surrounding anatomical structures. The main coronary venous vessel is the coronary sinus  12 , defined as starting at the ostium  14  or opening to the right atrium and extending through the great cardiac vein to the anterior interventricular (“AIV”) sulcus or groove  16 . Also shown is the mitral valve  20  surrounded by the mitral valve annulus  22  and adjacent to at least a portion of the coronary sinus  12 . The circumflex artery  24  shown in  FIG. 1  passes between the coronary sinus  12  and the heart. The relative size and location of each of these structures vary from person to person.  
      Disposed within the coronary sinus  12  is a tissue shaping device  30 . As shown in  FIG. 1 , the distal end  32  of device  30  is disposed proximal to circumflex artery  24  to reshape the adjacent mitral valve annulus  22  and thereby reduce mitral valve regurgitation. As shown in  FIG. 1 , device  30  has a distal anchor  34 , a proximal anchor  36  and a connector  38 .  
      In the embodiment of  FIG. 1 , proximal anchor  36  is deployed completely within the coronary sinus. In the alternative embodiment shown in  FIG. 2 , proximal anchor is deployed at least partially outside the coronary sinus.  
       FIGS. 3-6  show a method according to this invention. As shown in  FIG. 3 , a catheter  50  is maneuvered in a manner known in the art through the ostium  14  into coronary sinus  12 . In order to be navigable through the patient&#39;s venous system, catheter  50  preferably has an outer diameter no greater than ten french, most preferably with an outer diameter no more than nine french. Disposed within catheter  50  is device  30  in an unexpanded configuration, and extending back through catheter  50  from device  30  to the exterior of the patient is a tether or control wire  52 . In some embodiments, control wire  52  may include multiple tether and control wire elements, such as those described in U.S. patent application Ser. No. 10/331,143.  
      According to one preferred embodiment, the device is deployed as far distally as possible without applying substantial compressive force on the circumflex or other major coronary artery. Thus, the distal end of catheter  50  is disposed at a distal anchor location proximal of the crossover point between the circumflex artery  24  and the coronary sinus  12  as shown in  FIG. 3 . At this point, catheter  50  is withdrawn proximally while device  30  is held stationary by control wire  52  to uncover distal anchor  34  at the distal anchor location within coronary sinus  12 . Alternatively, the catheter may be held stationary while device  30  is advanced distally to uncover the distal anchor.  
      Distal anchor  34  is either a self-expanding anchor or an actuatable anchor or a combination self-expanding and actuatable anchor. Once uncovered, distal anchor  34  self-expands, or is expanded through the application of an actuation force (such as a force transmitted through control wire  52 ), to engage the inner wall of coronary sinus  12 , as shown in  FIG. 4 . The distal anchor&#39;s anchoring force, i.e., the force with which the distal anchor resists moving in response to a proximally-directed force, must be sufficient not only to maintain the device&#39;s position within the coronary sinus but also to enable the device to be used to reshape adjacent tissue in a manner such as that described below. In a preferred embodiment, distal anchor  34  engages the coronary sinus wall to provide an anchoring force of at least one pound, most preferably an anchoring force of at least two pounds. The anchor&#39;s expansion energy to supply the anchoring force comes from strain energy stored in the anchor due to its compression for catheter delivery, from an actuation force, or a combination of both, depending on anchor design.  
      While device  30  is held in place by the anchoring force of distal anchor  34 , catheter  50  is withdrawn further proximally to a point just distal of proximal anchor  36 , as shown in  FIG. 5 . A proximally directed force is then exerted on distal anchor  34  by control wire  52  through connector  38 . In this embodiment, the distance between the distal and proximal anchors along the connector is fixed, so the proximally directed force moves proximal anchor  36  proximally with respect to the coronary sinus while distal anchor  34  remains stationary with respect to the coronary sinus. This cinching action straightens that section of coronary sinus  12 , thereby modifying its shape and the shape of the adjacent mitral valve  20 , moving the mitral valve leaflets into greater coaptation and reducing mitral valve regurgitation. In some embodiments of the invention, the proximal anchor is moved proximally about 1-6 cm., most preferably at least 2 cm., in response to the proximally directed force. In other embodiments, such as embodiments in which the distance between the distal and proximal anchors is not fixed (e.g., where the connector length is variable), the proximal anchor may stay substantially stationary with respect to the coronary sinus despite the application of a proximally directed force on the distal anchor.  
      After the appropriate amount of reduction in mitral valve regurgitation has been achieved (as determined, e.g., by viewing doppler-enhanced echocardiograms), the proximal anchor is deployed. Other patient vital signs, such as cardiac perfusion, may also be monitored during this procedure as described in U.S. patent application Ser. No. 10/366,585.  
      In preferred embodiments, the proximal anchor&#39;s anchoring force, i.e., the force with which the proximal anchor resists moving in response to a distally-directed force, must be sufficient not only to maintain the device&#39;s position within the coronary sinus but also to enable the device to maintain the adjacent tissue&#39;s cinched shape. In a preferred embodiment, the proximal anchor engages the coronary sinus wall to provide an anchoring force of at least one pound, most preferably an anchoring force of at least two pounds. As with the distal anchor, the proximal anchor&#39;s expansion energy to supply the anchoring force comes from strain energy stored in the anchor due to its compression for catheter delivery, from an actuation force, or a combination of both, depending on anchor design.  
      In a preferred embodiment, the proximal anchor is deployed by withdrawing catheter  50  proximally to uncover proximal anchor  36 , then either permitting proximal anchor  36  to self-expand, applying an actuation force to expand the anchor, or a combination of both. The control wire  52  is then detached, and catheter  50  is removed from the patient. The device location and configuration as deployed according to this method is as shown in  FIG. 1 .  
      Alternatively, proximal anchor  36  may be deployed at least partially outside of the coronary sinus after cinching to modify the shape of the mitral valve tissue, as shown in  FIG. 2 . In both embodiments, because distal anchor  34  is disposed proximal to the crossover point between coronary sinus  12  and circumflex artery  24 , all of the anchoring and tissue reshaping force applied to the coronary sinus by device  30  is solely proximal to the crossover point.  
      In alternative embodiments, the proximal anchor may be deployed prior to the application of the proximally directed force to cinch the device to reshape the mitral valve tissue. One example of a device according to this embodiment is shown in  FIG. 6 . Device  60  includes a self-expanding distal anchor  62 , a self-expanding proximal anchor  64  and a connector  66 . The design of distal anchor  62  enables it to maintain its anchoring force when a proximally directed force is applied on it to cinch, while the design of proximal anchor  64  permits it to be moved proximally after deployment while resisting distal movement after cinching. Cinching after proximal anchor deployment is described in more detail in U.S. patent application Ser. No. 10/066,426, filed Jan. 30, 2002, the disclosure of which is incorporated herein by reference. In this embodiment as well, distal anchor  62  is disposed proximal to the crossover point between coronary sinus  12  and circumflex artery  24  so that all of anchoring and tissue reshaping force applied to the coronary sinus by device  30  is solely proximal to the crossover point.  
      It may be desirable to move and/or remove the tissue shaping device after deployment or to re-cinch after initial cinching. According to certain embodiments of the invention, therefore, the device or one of its anchors may be recaptured. For example, in the embodiment of  FIG. 1 , after deployment of proximal anchor  36  but prior to disengagement of control wire  52 , catheter  50  may be moved distally to place proximal anchor  36  back inside catheter  50 , e.g., to the configuration shown in  FIG. 5 . From this position, the cinching force along connector  38  may be increased or decreased, and proximal anchor  36  may then be redeployed.  
      Alternatively, catheter  50  may be advanced distally to recapture both proximal anchor  36  and distal anchor  34 , e.g., to the configuration shown in  FIG. 3 . From this position, distal anchor  34  may be redeployed, a cinching force applied, and proximal anchor  36  deployed as discussed above. Also from this position, device  30  may be removed from the patient entirely by simply withdrawing the catheter from the patient.  
      Fluoroscopy (e.g., angiograms and venograms) may be used to determine the relative positions of the coronary sinus and the coronary arteries such as the circumflex artery, including the crossover point between the vessels and whether or not the artery is between the coronary sinus and the heart. Radiopaque dye may be injected into the coronary sinus and into the arteries in a known manner while the heart is viewed on a fluoroscope.  
      An alternative method of determining the relative positions of the vessels is shown in  FIG. 7 . In this method, guide wires  70  and  72  are inserted into the coronary sinus  12  and into the circumflex artery  24  or other coronary artery, and the relative positions of the guide wires are viewed on a fluoroscope to identify the crossover point  74 .  
       FIG. 8  illustrates one embodiment of a tissue shaping device in accordance with the present invention. The tissue shaping device  100  includes a connector or support wire  102  having a proximal end  104  and a distal end  106 . The support wire  102  is made of a biocompatible material such as stainless steel or a shape memory material such as nitinol wire.  
      In one embodiment of the invention, connector  102  comprises a double length of nitinol wire that has both ends positioned within a distal crimp tube  108 . Proximal to the proximal end of the crimp tube  108  is a distal lock bump  110  that is formed by the support wire bending away from the longitudinal axis of the support  102  and then being bent parallel to the longitudinal axis of the support before being bent again towards the longitudinal axis of the support to form one half  110   a  of distal lock bump  110 . From distal lock bump  110 , the wire continues proximally through a proximal crimp tube  112 . On exiting the proximal end of the proximal crimp tube  112 , the wire is bent to form an arrowhead-shaped proximal lock bump  114 . The wire of the support  102  then returns distally through the proximal crimp tube  112  to a position just proximal to the proximal end of the distal crimp tube  108  wherein the wire is bent to form a second half  110   b  of the distal lock  110 .  
      At the distal end of connector  102  is an actuatable distal anchor  120  that is formed of a flexible wire such as nitinol or some other shape memory material. As shown in  FIG. 8 , the wire forming the distal anchor has one end positioned within the distal crimp tube  108 . After exiting the distal end of the crimp tube  108 , the wire forms a figure eight configuration whereby it bends upward and radially outward from the longitudinal axis of the crimp tube  108 . The wire then bends back proximally and crosses the longitudinal axis of the crimp tube  108  to form one leg of the figure eight. The wire is then bent to form a double loop eyelet or loop  122  around the longitudinal axis of the support wire  102  before extending radially outwards and distally back over the longitudinal axis of the crimp tube  108  to form the other leg of the figure eight. Finally, the wire is bent proximally into the distal end of the crimp tube  108  to complete the distal anchor  120 .  
      The distal anchor is expanded by using a catheter or locking tool to exert an actuation force sliding eyelet  122  of the distal anchor from a position that is proximal to distal lock bump  110  on the connector to a position that is distal to distal lock bump  110 . The bent-out portions  110   a  and  110   b  of connector  110  are spaced wider than the width of eyelet  122  and provide camming surfaces for the locking action. Distal movement of eyelet  122  pushes these camming surfaces inward to permit eyelet  122  to pass distally of the lock bump  110 , then return to their original spacing to keep eyelet  122  in the locked position.  
      Actuatable proximal anchor  140  is formed and actuated in a similar manner by moving eyelet  142  over lock bump  114 . Both the distal and the proximal anchor provide anchoring forces of at least one pound, and most preferably two pounds.  
       FIG. 9  illustrates one method for delivering a tissue shaping device  100  in accordance with the present invention to a desired location in the body, such as the coronary sinus to treat mitral valve regurgitation. As indicated above, device  100  is preferably loaded into and routed to a desired location within a catheter  200  with the proximal and distal anchors in an unexpanded or deformed condition. That is, eyelet  122  of distal anchor  120  is positioned proximal to the distal lock bump  110  and the eyelet  142  of the proximal anchor  140  is positioned proximal to the proximal lock bump  114 . The physician ejects the distal end of the device from the catheter  200  into the coronary sinus by advancing the device or retracting the catheter or a combination thereof. A pusher (not shown) provides distal movement of the device with respect to catheter  200 , and a tether  201  provides proximal movement of the device with respect to catheter  200 .  
      Because of the inherent elasticity of the material from which it is formed, the distal anchor begins to expand as soon as it is outside the catheter. Once the device is properly positioned, catheter  200  is advanced to place an actuation force on distal anchor eyelet  122  to push it distally over the distal lock bump  110  so that the distal anchor  120  further expands and locks in place to securely engage the wall of the coronary sinus. Next, a proximally-directed force is applied to connector  102  and distal anchor  120  via a tether or control wire  201  extending through catheter outside the patient to apply sufficient pressure on the tissue adjacent the connector to modify the shape of that tissue. In the case of the mitral valve, fluoroscopy, ultrasound or other imaging technology may be used to see when the device supplies sufficient pressure on the mitral valve to aid in its complete closure with each ventricular contraction without otherwise adversely affecting the patient.  
      The proximally directed reshaping force causes the proximal anchor  140  to move proximally. In one embodiment, for example, proximal anchor  140  can be moved about 1-6 cm., most preferably at least 2 cm., proximally to reshape the mitral valve tissue. The proximal anchor  140  is then deployed from the catheter and allowed to begin its expansion. The locking tool applies an actuation force on proximal anchor eyelet  142  to advance it distally over the proximal lock bump  114  to expand and lock the proximal anchor, thereby securely engaging the coronary sinus wall to maintain the proximal anchor&#39;s position and to maintain the reshaping pressure of the connector against the coronary sinus wall. Alternatively, catheter  200  may be advanced to lock proximal anchor  140 .  
      Finally, the mechanism for securing the proximal end of the device can be released. In one embodiment, the securement is made with a braided loop  202  at the end of tether  201  and a lock wire  204 . The lock wire  204  is withdrawn thereby releasing the loop  202  so it can be pulled through the proximal lock bump  114  at the proximal end of device  100 .  
      Reduction in mitral valve regurgitation using devices of this invention can be maximized by deploying the distal anchor as far distally in the coronary sinus as possible. In some instances it may be desirable to implant a shorter tissue shaping device, such as situations where the patient&#39;s circumflex artery crosses the coronary sinus relatively closer to the ostium or situations in which the coronary sinus itself is shorter than normal. As can be seen from  FIG. 9 , anchor  120  in its unexpanded configuration extends proximally along connector  102  within catheter  200 . Making the device shorter by simply shortening the connector, however, may cause the eyelet  122  and proximal portion of the distal anchor  120  to overlap with portions of the proximal anchor when the device is loaded into a catheter, thereby requiring the catheter diameter to be larger than is needed for longer versions of the device. For mitral valve regurgitation applications, a preferred catheter diameter is ten french or less (most preferably nine french), and the tissue shaping device in its unexpanded configuration must fit within the catheter.  
       FIGS. 10-23  show embodiments of the device of this invention having flexible and expandable wire anchors which permit the delivery of tissue shaping devices 60 mm or less in length by a ten french (or less) catheter. In some embodiments, one or both of the anchors are provided with bending points about which the anchors deform when placed in their unexpanded configuration for delivery by a catheter or recapture into a catheter. These bending points enable the anchors to deform into configurations that minimize overlap with other elements of the device. In other embodiments, the distal anchor is self-expanding, thereby avoiding the need for a proximally-extending eyelet in the anchor&#39;s unexpanded configuration that might overlap with the unexpanded proximal anchor within the delivery and/or recapture catheter.  
       FIG. 10  shows an actuatable anchor design suitable for a shorter tissue shaping device similar to the device shown in  FIGS. 8 and 9 . In this embodiment, distal anchor  300  is disposed distal to a connector  302 . As in the embodiment of  FIG. 8 , anchor  300  is formed in a figure eight configuration from flexible wire such as nitinol held by a crimp tube  304 . An eyelet  306  is formed around the longitudinal axis of connector  302 . A distally directed actuation force on eyelet  306  moves it over a lock bump  308  formed in connector  302  to actuate and lock anchor  300 .  
       FIG. 10  shows anchor  300  in an expanded configuration. In an unexpanded configuration, such as a configuration suitable for loading anchor  300  and the rest of the tissue shaping device into a catheter for initial deployment to treat mitral valve regurgitation, eyelet  306  is disposed proximal to lock bump  308 , and the figure eight loops of anchor  300  are compressed against crimp  304 . In order to limit the proximal distance eyelet  306  must be moved along the connector to compress anchor  300  into an unexpanded configuration, bending points  310  are formed in the distal struts of anchor  300 . Bending points  310  are essentially kinks, i.e., points of increased curvature, formed in the wire. When anchor  300  is compressed into an unexpanded configuration, bending points  310  deform such that the upper arms  312  of the distal struts bend around bending points  310  and move toward the lower arms  314  of the distal struts, thereby limiting the distance eyelet  306  and the anchor&#39;s proximal struts must be moved proximally along the connector to compress the anchor.  
      Likewise, if distal anchor were to be recaptured into a catheter for redeployment or removal from the patient, anchor  300  would deform about bending points  310  to limit the cross-sectional profile of the anchor within the catheter, even if eyelet  306  were not moved proximally over lock bump  308  during the recapture procedure. Bending points may also be provided on the proximal anchor in a similar fashion.  
      As stated above, distal anchor  300  may be part of a tissue shaping device (such as that shown in  FIGS. 8 and 9 ) having a proximal anchor and a connector disposed between the anchors. To treat mitral valve regurgitation, distal anchor  300  may be deployed from a catheter and expanded with an actuation force to anchor against the coronary sinus wall to provide an anchoring force of at least one pound, preferably at least two pounds, and to lock anchor  300  in an expanded configuration. A proximally directed force is applied to distal anchor  300  through connector  302 , such as by moving the proximal anchor proximally about 1-6 cm., more preferably at least 2 cm., by pulling on a tether or control wire operated from outside the patient. The proximal anchor may then be deployed to maintain the reshaping force of the device.  
      One aspect of anchor  300  is its ability to conform and adapt to a variety of vessel sizes. For example, when anchor  300  is expanded inside a vessel such as the coronary sinus, the anchor&#39;s wire arms may contact the coronary sinus wall before the eyelet  306  has been advanced distally over lock bump  308  to lock the anchor in place. While continued distal advancement of eyelet  306  will create some outward force on the coronary sinus wall, much of the energy put into the anchor by the anchor actuation force will be absorbed by the deformation of the distal struts about bending points  310 , which serve as expansion energy absorption elements and thereby limit the radially outward force on the coronary sinus wall. This feature enables the anchor to be used in a wider range of vessel sizes while reducing the risk of over-expanding the vessel.  
       FIG. 11  shows another anchor design suitable for a shorter tissue shaping device similar to the device shown in  FIGS. 8 and 9 . In this embodiment, distal anchor  320  is disposed distal to a connector  322 . As in the embodiment of  FIG. 8 , anchor  320  is formed in a figure eight configuration from flexible wire such as nitinol held by a crimp tube  324 . Unlike the embodiment of  FIG. 10 , however, anchor  320  is self-expanding and is not actuatable. Eyelet  326  is held in place by a second crimp  325  to limit or eliminate movement of the anchor&#39;s proximal connection point proximally or distally, e.g., along connector  322 .  
       FIG. 11  shows anchor  320  in an expanded configuration. In an unexpanded configuration, such as a configuration suitable for loading anchor  320  and the rest of the tissue shaping device into a catheter for initial deployment to treat mitral valve regurgitation, the figure eight loops of anchor  320  are compressed. Bending points  330  are formed in the distal struts of anchor  320 . When anchor  320  is compressed into an unexpanded configuration, bending points  330  deform such that the upper arms  332  of the distal struts bend around bending points  330  and move toward the lower arms  334  of the distal struts. Depending upon the exact location of bending points  330 , very little or none of the wire portion of anchor  320  is disposed proximally along crimp  325  or connector  322  when anchor  320  is in its unexpanded configuration.  
      Likewise, if distal anchor were to be recaptured into a catheter for redeployment or removal from the patient, anchor  320  would deform about bending points  330  to limit the cross-sectional profile of the anchor within the catheter. Bending points may also be provided on the proximal anchor in a similar fashion.  
      Distal anchor  320  may be part of a tissue shaping device (such as that shown in  FIGS. 8 and 9 ) having a proximal anchor and a connector disposed between the anchors. Due to the superelastic properties of its shape memory material, distal anchor  320  may be deployed from a catheter to self-expand to anchor against the coronary sinus wall to provide an anchoring force of at least one pound, preferably at least two pounds. A proximally directed force may then be applied to distal anchor  320  through connector  322 , such as by moving the proximal anchor proximally about 1-6 cm., more preferably at least 2 cm., by pulling on a tether or control wire operated from outside the patient. The proximal anchor may then be deployed to maintain the reshaping force of the device.  
       FIG. 12  shows another embodiment of an anchor suitable for use in a shorter tissue shaping device. In this embodiment, distal anchor  340  is disposed distal to a connector  342 . As in the embodiment of  FIG. 11 , anchor  340  is formed in a figure eight configuration from flexible wire such as nitinol held by a crimp tube  344 . Also like that embodiment, anchor  340  is self-expanding and is not actuatable. The loop of anchor  340  forming the anchor&#39;s proximal struts passes through a loop  346  extending distally from a second crimp  345  to limit or eliminate movement of the anchor&#39;s proximal struts proximally or distally, e.g., along connector  342 .  
       FIG. 12  shows anchor  340  in an expanded configuration. Like the device of  FIG. 11 , in an unexpanded configuration, such as a configuration suitable for loading anchor  340  and the rest of the tissue shaping device into a catheter for initial deployment to treat mitral valve regurgitation, the figure eight loops of anchor  340  are compressed. Unlike the  FIG. 11  embodiment, however, bending points  350  are formed in the proximal struts of anchor  340 . When anchor  340  is compressed into an unexpanded configuration, bending points  350  deform such that the upper arms  352  of the distal struts bend around bending points  350  and move toward the lower arms  354  of the distal struts. The amount of the wire portion of anchor  340  extending proximally along crimp  345  and connector  342  in its unexpanded configuration depends on the location of bending points  350 . In one embodiment, the bending points are formed at the tallest and widest part of the proximal struts.  
      Distal anchor  340  may be part of a tissue shaping device (such as that shown in  FIGS. 8 and 9 ) having a proximal anchor and a connector disposed between the anchors. Due to the superelastic properties of its shape memory material, distal anchor  340  may be deployed from a catheter to self-expand to anchor against the coronary sinus wall to provide an anchoring force of at least one pound, preferably at least two pounds. A proximally directed force may then be applied to distal anchor  340  through connector  342 , such as by moving the proximal anchor proximally about 1-6 cm., more preferably at least 2 cm., by pulling on a tether or control wire operated from outside the patient. The proximal anchor may then be deployed to maintain the reshaping force of the device.  
      Bending points  350  also add to the anchoring force of distal anchor  340 , e.g., by causing the anchor height to increase as the proximal struts become more perpendicular to the connector in response to a proximally directed force, thereby increasing the anchoring force. In the same manner, bending points may be added to the distal struts of a proximal anchor to increase the proximal anchor&#39;s anchoring force in response to a distally directed force.  
       FIG. 13  shows yet another embodiment of an anchor suitable for use in a shorter tissue shaping device. In this embodiment, distal anchor  360  is disposed distal to a connector  362 . As in the embodiment of  FIG. 12 , anchor  360  is formed in a figure eight configuration from flexible wire such as nitinol held by a crimp tube  364 . Also like that embodiment, anchor  360  is self-expanding and is not actuatable. The loop of anchor  360  forming the anchor&#39;s proximal struts passes through a loop  366  extending distally from a second crimp  365  to limit or eliminate movement of the anchor&#39;s proximal struts proximally or distally, e.g., along connector  362 .  
       FIG. 13  shows anchor  360  in an expanded configuration. Like the device of  FIG. 12 , in an unexpanded configuration, such as a configuration suitable for loading anchor  360  and the rest of the tissue shaping device into a catheter for initial deployment to treat mitral valve regurgitation, the figure eight loops of anchor  360  are compressed. Unlike the  FIG. 12  embodiment, however, bending points  370  are formed in both the proximal struts and the distal struts of anchor  360 .  
      Anchor  360  may be used as part of a tissue shaping device like the embodiments discussed above.  
       FIG. 14  shows an actuatable anchor design suitable for a shorter tissue shaping device similar to the device shown in  FIGS. 8 and 9 . In this embodiment, distal anchor  380  is disposed distal to a connector  382 . As in the other embodiments, anchor  380  is formed in a figure eight configuration from flexible wire such as nitinol held by a crimp tube  384 . In contrast to the embodiment of  FIG. 10 , eyelets  386  and  387  are formed in each of the anchor&#39;s proximal struts around the longitudinal axis of connector  382 . This arrangement reduces the radially outward force of the anchor. A distally directed actuation force on eyelets  386  and  387  move them over a lock bump  388  formed in connector  382  to actuate and lock anchor  380 .  
       FIG. 14  shows anchor  380  in an expanded configuration. In an unexpanded configuration, such as a configuration suitable for loading anchor  380  and the rest of the tissue shaping device into a catheter for initial deployment to treat mitral valve regurgitation, eyelets  386  and  387  are disposed proximal to lock bump  388  and the figure eight loops of anchor  380  are compressed against crimp  384 . In order to limit the proximal distance eyelets  386  and  387  must be moved to compress anchor  380  into an unexpanded configuration, bending points  390  are formed in the distal struts of anchor  380 . When anchor  380  is compressed into an unexpanded configuration, bending points  390  deform such that the upper arms  392  of the distal struts bend around bending points  390  and move toward the lower arms  394  of the distal struts, thereby limiting the distance eyelets  386  and  387  and the anchor&#39;s proximal struts must be moved proximally along the connector to compress the anchor.  
      If distal anchor were to be recaptured into a catheter for redeployment or removal from the patient, anchor  380  would deform about bending points  390  to limit the cross-sectional profile of the anchor within the catheter, even if eyelets  386  and  387  were not moved proximally over lock bump  388  during the recapture procedure. Bending points may also be provided on the proximal anchor in a similar fashion.  
      As with the other embodiments above, distal anchor  380  may be part of a tissue shaping device (such as that shown in  FIGS. 8 and 9 ) having a proximal anchor and a connector disposed between the anchors. To treat mitral valve regurgitation, distal anchor  380  may be deployed from a catheter and expanded with an actuation force to anchor against the coronary sinus wall to provide an anchoring force of at least one pound, preferably at least two pounds, and to lock anchor  380  in an expanded configuration. A proximally directed force is applied to distal anchor  380  through connector  382 , such as by moving the proximal anchor proximally about 1-6 cm., more preferably at least 2 cm., by pulling on a tether or control wire operated from outside the patient. The proximal anchor may then be deployed to maintain the reshaping force of the device.  
      As with other embodiments, one aspect of anchor  380  is its ability to conform and adapt to a variety of vessel sizes. For example, when anchor  380  is expanded inside a vessel such as the coronary sinus, the anchor&#39;s wire arms may contact the coronary sinus wall before the eyelets  386  and  387  have been advance distally over lock bump  388  to lock the anchor in place. While continued distal advancement of eyelet  386  will create some outward force on the coronary sinus wall, much of the energy put into the anchor by the anchor actuation force will be absorbed by the deformation of the distal struts about bending points  390 .  
       FIG. 15  shows yet another embodiment of an actuatable anchor for use in a shorter tissue shaping device. Proximal anchor  400  is disposed proximal to a connector  402 . As in other embodiments, anchor  400  is formed in a figure eight configuration from flexible wire such as nitinol held by a crimp tube  404 . An eyelet  406  is formed around a lock bump  408  extending proximally from crimp  404 . A distally directed actuation force on eyelet  406  moves it over lock bump  408  to actuate and lock anchor  400 .  
       FIG. 15  shows anchor  400  in an expanded configuration. When anchor  400  is compressed into an unexpanded configuration, bending points  410  formed as loops in the anchor wire deform such that the upper arms  412  of the distal struts bend around bending points  410  and move toward the lower arms  414  of the distal struts. As with the other embodiments, proximal anchor  400  may be part of a tissue shaping device (such as that shown in  FIGS. 8 and 9 ) having a distal anchor and a connector disposed between the anchors.  
      Like other embodiments, one aspect of anchor  400  is its ability to conform and adapt to a variety of vessel sizes. For example, when anchor  400  is expanded inside a vessel such as the coronary sinus, the anchor&#39;s wire arms may contact the coronary sinus wall before the eyelet  406  has been advanced distally over lock bump  408  to lock the anchor in place. While continued distal advancement of eyelet  406  will create some outward force on the coronary sinus wall, much of the energy put into the anchor by the anchor actuation force will be absorbed by the deformation of the distal struts about bending points  410 , which serve as expansion energy absorption elements and thereby limit the radially outward force on the coronary sinus wall.  
      In other embodiments, the looped bending points of the  FIG. 15  embodiment may be formed on the anchor&#39;s proximal struts in addition to or instead of on the distal struts. The looped bending point embodiment may also be used in a distal anchor, as shown in  FIG. 16  (without the crimp or connector). Note that in the embodiment of  FIG. 16  the proximal and distal struts of anchor  420  as well as the eyelet  422  and bending points  424  are formed from a single wire.  
       FIG. 17  shows an embodiment of a distal anchor  440  similar to that of  FIG. 10  suitable for use in a shorter tissue shaping device. In this embodiment, however, extra twists  442  are added at the apex of the anchor&#39;s figure eight pattern. As in the  FIG. 10  embodiment, bending points  444  are formed in the anchor&#39;s distal struts. As shown, anchor  440  is actuatable by moving eyelet  446  distally over a lock bump  448  formed in connector  450 . Anchor  440  may also be made as a self-expanding anchor by limiting or eliminating movement of the proximal struts of anchor  440  along connector  450 , as in the embodiment shown in  FIG. 11 . As with other embodiments, the bending points help anchor  440  adapt and conform to different vessel sizes. In addition, the extra twists  442  also help the anchor adapt to different vessel diameters by keeping the anchor&#39;s apex together.  
      As in the other embodiments, anchor  440  is preferably formed from nitinol wire. Anchor  440  may be used as part of a tissue shaping device in a manner similar to the anchor of  FIG. 10  (for the actuatable anchor embodiment) or the anchor of  FIG. 11  (for the self-expanding anchor embodiment). Anchor  440  may also be used as a proximal anchor.  
       FIG. 18  shows an embodiment of a distal anchor  460  similar to that of  FIG. 17 . In this embodiment, however, the bending points  462  are formed in the anchor&#39;s proximal struts, as in the self-expanding anchor shown in  FIG. 12 . As in the  FIG. 17  embodiment, extra twists  464  are added at the apex of the anchor&#39;s figure eight pattern. As shown, anchor  460  is actuatable by moving eyelet  466  distally over a lock bump  468  formed in connector  470 . Anchor  460  may also be made as a self-expanding anchor by limiting or eliminating movement of the proximal connection point of anchor  460  along connector  470 , as in the embodiment shown in  FIG. 11 . As with the embodiment of  FIG. 17 , the bending points help anchor  460  adapt and conform to different vessel sizes. In addition, the extra twists  464  also help the anchor adapt to different vessel diameters by keeping the anchor&#39;s apex together.  
      As in the other embodiments, anchor  460  is preferably formed from nitinol wire. Anchor  460  may be used as part of a tissue shaping device in a manner similar to the anchor of  FIG. 10  (for the actuatable anchor embodiment) or the anchor of  FIG. 11  (for the self-expanding anchor embodiment). Anchor  460  may also be used as a proximal anchor.  
       FIG. 19  shows an embodiment of a self-expanding distal anchor  480  suitable for use in a shorter tissue shaping device. As in the other embodiments, anchor  480  is formed in a figure eight configuration from flexible wire such as nitinol held by a crimp tube  482 . The base of the figure eight pattern is narrower in this embodiment, however, with the anchor&#39;s proximal struts  484  passing through crimp  482 .  
      Distal anchor  480  may be part of a tissue shaping device (such as that shown in  FIGS. 8 and 9 ) having a proximal anchor and a connector disposed between the anchors. To treat mitral valve regurgitation, distal anchor  480  may be deployed from a catheter and allowed to self-expand to anchor against the coronary sinus wall to provide an anchoring force of at least one pound, preferably at least two pounds. A proximally directed force is applied to distal anchor  480  through connector  486 , such as by moving the proximal anchor proximally about 1-6 cm., more preferably at least 2 cm., by pulling on a tether or control wire operated from outside the patient. The proximal anchor may then be deployed to maintain the reshaping force of the device.  
       FIG. 20  shows an embodiment of a distal anchor suitable for use in a shorter tissue shaping device and similar to that of  FIG. 10 . In this embodiment, distal anchor  500  is disposed distal to a connector  502 . As in other embodiments, anchor  500  is formed in a figure eight configuration from flexible wire such as nitinol held by a crimp tube  504 . An eyelet  506  is formed around the longitudinal axis of connector  502 . A distally directed actuation force on eyelet  506  moves it over a lock bump  508  formed in connector  502  to actuate and lock anchor  500 .  
      The angle of proximal struts  501  and the angle of distal struts  503  are wider than corresponding angles in the  FIG. 10  embodiment, however, causing anchor  500  to distend more in width than in height when expanded, as shown. In an unexpanded configuration, such as a configuration suitable for loading anchor  500  and the rest of the tissue shaping device into a catheter for initial deployment to treat mitral valve regurgitation, eyelet  506  is disposed proximal to lock bump  508  and the figure eight loops of anchor  500  are compressed against crimp  504 . In order to limit the proximal distance eyelet  506  must be moved along the connector to compress anchor  500  into an unexpanded configuration, bending points  510  are formed in the distal struts  503 , as in the  FIG. 10  embodiment, to limit the width of the device in its unexpanded configuration within a catheter.  
      Distal anchor  500  may be part of a tissue shaping device (such as that shown in  FIGS. 8 and 9 ) having a proximal anchor and a connector disposed between the anchors. To treat mitral valve regurgitation, distal anchor  500  may be deployed from a catheter and expanded with an actuation force to anchor against the coronary sinus wall to provide an anchoring force of at least one pound, preferably at least two pounds, and to lock anchor  500  in an expanded configuration. A proximally directed force is applied to distal anchor  500  through connector  502 , such as by moving the proximal anchor proximally about 1-6 cm., more preferably at least 2 cm., by pulling on a tether or control wire operated from outside the patient. The proximal anchor may then be deployed to maintain the reshaping force of the device.  
      The anchor shown in  FIG. 20  may be used as a proximal anchor. This anchor may also be formed as a self-expanding anchor.  
       FIG. 21  shows a tandem distal anchor according to another embodiment of this invention. Self-expanding anchor  520  is formed in a figure eight configuration from flexible wire such as nitinol held by a crimp tube  522 . Eyelet  524  is held in place by the distal end of actuatable anchor  540  to limit or eliminate proximal and distal movement of the proximal struts of anchor  520 . As in the anchor shown in  FIG. 11 , bending points  530  are formed in the distal struts of anchor  520 . Depending upon the exact location of bending points  530 , very little or none of the wire portion of anchor  520  is disposed proximal to the distal end of anchor  540  when anchor  520  is in its unexpanded configuration.  
      Likewise, if distal anchor were to be recaptured into a catheter for redeployment or removal from the patient, anchor  520  would deform about bending points  530  to limit the cross-sectional profile of the anchor within the catheter. Bending points may also be provided on the proximal anchor in a similar fashion.  
      Anchor  540  is similar to anchor  120  shown in  FIG. 8 . Anchor  540  is formed in a figure eight configuration from flexible wire such as nitinol held by a crimp tube  544 . An eyelet  546  is formed around the longitudinal axis of connector  542 . A distally directed actuation force on eyelet  546  moves it over a lock bump  548  formed in connector  542  to actuate and lock anchor  540 .  
      Tandem anchors  520  and  540  may be part of a tissue shaping device (such as that shown in  FIGS. 8 and 9 ) having a proximal anchor and a connector disposed between the anchors. Anchors  520  and  540  may be made from a single wire or from separate pieces of wire. To treat mitral valve regurgitation, distal anchors  520  and  540  may be deployed from a catheter. Self-expanding anchor  520  will then self-expand, and actuatable anchor  540  may be expanded and locked with an actuation force, to anchor both anchors against the coronary sinus wall to provide an anchoring force of at least one pound, preferably at least two pounds. A proximally directed force is applied to anchors  520  and  540  through connector  542 , such as by moving the proximal anchor proximally about 1-6 cm., more preferably at least 2 cm., by pulling on a tether or control wire operated from outside the patient. The proximal anchor may then be deployed to maintain the reshaping force of the device.  
      While the anchor designs above were described as part of shorter tissue shaping devices, these anchors may be used in tissue shaping devices of any length.  
       FIGS. 22 and 23  show an alternative embodiment in which the device&#39;s connector  560  is made integral with the distal and proximal crimp tubes  562  and  564 . In this embodiment, connector  560  is formed by cutting away a section of a blank such as a nitinol (or other suitable material such as stainless steel) cylinder or tube, leaving crimp tube portions  562  and  564  intact. The radius of the semi-circular cross-section connector is therefore the same as the radii of the two anchor crimp tubes.  
      Other connector shapes are possible for an integral connector and crimp design, of course. For example, the device may be formed from a blank shaped as a flat ribbon or sheet by removing rectangular edge sections from a central section, creating an I-shaped sheet (e.g., nitinol or stainless steel) having greater widths at the ends and a narrower width in the center connector portion. The ends can then be rolled to form the crimp tubes, leaving the connector substantially flat. In addition, in alternative embodiments, the connector can be made integral with just one of the anchors.  
      As shown in  FIG. 23 , a distal anchor  566  is formed in a figure eight configuration from flexible wire such as nitinol. Distal anchor  566  is self-expanding, and its proximal struts  568  are held in place by crimp tube  562 . Optional bending points may be formed in the proximal struts  568  or distal struts  570  of anchor  566 .  
      A proximal anchor  572  is also formed in a figure eight configuration from flexible wire such as nitinol with an eyelet  574  on its proximal end. A distally directed actuation force on eyelet  574  moves it over a lock bump  576  extending proximally from crimp tube  564  to actuate and lock anchor  572 . Lock bump  576  also serves as the connection point for a tether or control wire to deploy and actuate device in the manner described above with respect to  FIGS. 8 and 9 . Optional bending points may be formed in the proximal or distal struts of anchor  572 .  
      When deployed in the coronary sinus to treat mitral valve regurgitation, the tissue shaping devices of this invention are subjected to cyclic bending and tensile loading as the patient&#39;s heart beats.  FIG. 24  shows an alternative connector for use with the tissue shaping devices of this invention that distributes over more of the device any strain caused by the beat to beat bending and tensile loading.  
      Connector  600  has a proximal anchor area  602 , a distal anchor area  604  and a central area  606 . The distal anchor area may be longer than the distal anchor attached to it, and the proximal anchor area may be longer than the proximal anchor attached to it. An optional lock bump  608  may be formed at the proximal end of connector  600  for use with an actuatable proximal anchor and for connecting to a tether or control wire, as described above. An optional bulb  610  may be formed at the distal end of connector  600  to prevent accidental distal slippage of a distal anchor.  
      In order to reduce material fatigue caused by the heartbeat to heartbeat loading and unloading of the tissue shaping device, the moment of inertia of connector  600  varies along its length, particularly in the portion of connector disposed between the two anchors. In this embodiment, for example, connector  600  is formed as a ribbon or sheet and is preferably formed from nitinol having a rectangular cross-sectional area. The thickness of connector  600  is preferably constant in the proximal anchor area  602  and the distal anchor area  604  to facilitate attachment of crimps and other components of the anchors. The central area  606  has a decreasing thickness (and therefore a decreasing moment of inertia) from the border between central area  606  and proximal anchor area  602  to a point about at the center of central area  606 , and an increasing thickness (and increasing moment of inertia) from that point to the border between central area  606  and distal anchor area  604 . The varying thickness and varying cross-sectional shape of connector  600  change its moment of inertia along its length, thereby helping distribute over a wider area any strain from the heartbeat to heartbeat loading and unloading of the device and reducing the chance of fatigue failure of the connector material.  
       FIG. 25  shows another embodiment of the connector. Like the previous embodiment, connector  620  has a proximal anchor area  622 , a distal anchor area  624  and a central area  626 . Proximal anchor area  622  has an optional two-tined prong  628  formed at its proximal end to facilitate attachment of a crimp and other anchor elements. Bent prong portions  629  may be formed at the proximal end of the prong to prevent accidental slippage of a proximal anchor. An optional bulb  630  may be formed at the distal end of connector  620  to prevent accidental distal slippage of a distal anchor.  
      Like the  FIG. 24  embodiment, connector  620  is formed as a ribbon or sheet and is preferably formed from nitinol having a rectangular cross-sectional area. The thickness of connector  620  is preferably constant in the proximal anchor area  622  and the distal anchor area  624  to facilitate attachment of crimps and other components of the anchors. The central area  626  has a decreasing thickness (decreasing moment of inertia) from the border between central area  626  and proximal anchor area  622  to a point about at the center of central area  626 , and an increasing thickness (increasing moment of inertia) from that point to the border between central area  626  and distal anchor area  624 . The varying thickness and varying cross-sectional shape of connector  620  change its moment of inertia along its length, thereby helping distribute over a wider area any strain from the heartbeat to heartbeat loading and unloading of the device and reducing the chance of fatigue failure of the connector material.  
       FIG. 26  shows a connector  640  in profile. Connector  640  may be formed like the connectors  600  and  620  or  FIGS. 24 and 25 , respectively, or may have some other configuration. Connector  640  has a proximal anchor area  642 , a distal anchor area  644  and a central area  646 . Connector  640  is preferably formed as a ribbon or sheet and is preferably formed from nitinol having a rectangular cross-sectional area.  
      In the embodiment shown in  FIG. 26 , the thicknesses of proximal anchor area  642  and distal anchor area  644  are constant. The thickness of central area  646  decreases from the border between central area  646  and proximal anchor area  642  to a point distal of that border and increases from a point proximal to the border between distal anchor area  644  and central area  646  to that border. The points in the central area where the thickness decrease ends and the thickness increase begins may be coincident or may be separated to form an area of uniform thickness within central area  646 . In this embodiment, the thickness of the central area changes as a function of the square root of the distance from the borders between the central area and the proximal and distal anchor areas.  
       FIG. 27  shows yet another embodiment of the connector. As in the embodiment of  FIG. 26 , connector  650  may be formed like the connectors  600  and  620  or  FIGS. 24 and 25 , respectively, or may have some other configuration. Connector  650  has a proximal anchor area  652 , a distal anchor area  654  and a central area  656 . Connector  650  is preferably formed as a ribbon or sheet and is preferably formed from nitinol having a rectangular cross-sectional area.  
      In the embodiment shown in  FIG. 27 , the thicknesses of proximal anchor area  652  and distal anchor area  654  are constant. The thickness of a proximal portion  658  of central area  656  decreases linearly from the border between central area  656  and proximal anchor area  652  to a constant thickness center portion  662  of central area  656 , and the thickness of a distal portion  660  of central area  656  increases linearly from center portion  662  to the border between distal anchor area  654  and central area  656 .  
      In other embodiments, the thickness of the connector may vary in other ways. In addition, the cross-sectional shape of the connector may be other than rectangular and may change over the length of the connector.  
       FIGS. 28 and 29  show yet another embodiment of the invention. Tissue shaping device  700  has a connector  706  disposed between a proximal anchor  702  and a distal anchor  704 . Connector  706  may be formed as a ribbon or sheet, such as the tapered connectors shown in  FIGS. 24-27 . Actuatable proximal anchor  702  is formed in a figure eight configuration from flexible wire such as nitinol and is fastened to connector  706  with a crimp tube  708 . Likewise, self-expanding distal anchor  704  is formed in a figure eight configuration from flexible wire such as nitinol and is fastened to connector  706  with a crimp tube  710 . A proximal lock bump  716  extends proximally from proximal anchor  702  for use in actuating and locking proximal anchor  702  and for connecting to a tether or control wire, as described above.  
      Bending points  712  are formed in the loops of proximal anchor  702 , and bending points  714  are formed in the loops of distal anchor  704 . When compressed into their unexpanded configurations for catheter-based delivery and deployment or for recapture into a catheter for redeployment or removal, the wire portions of anchors  702  and  704  bend about bending points  712  and  714 , respectively, to limit the cross-sectional profile of the anchors within the catheter. The bending points also affect the anchor strength of the anchors and the adaptability of the anchors to different vessel diameters, as discussed above.  
      In addition to different coronary sinus lengths and varying distances from the ostium to the crossover point between the coronary sinus and the circumflex artery, the diameter of the coronary sinus at the distal and proximal anchor points can vary from patient to patient. The anchors described above may be made in a variety of heights and combined with connectors of varying lengths to accommodate this patient to patient variation. For example, tissue shaping devices deployed in the coronary sinus to treat mitral valve regurgitation can have distal anchor heights ranging from about 7 mm. to about 16 mm. and proximal anchor heights ranging from about 9 mm. to about 20 mm.  
      When treating a patient for mitral valve regurgitation, estimates can be made of the appropriate length for a tissue shaping device as well as appropriate anchor heights for the distal and proximal anchors. The clinician can then select a tissue shaping device having the appropriate length and anchor sizes from a set or sets of devices with different lengths and different anchor sizes, made, e.g., according to the embodiments described above. These device sets may be aggregated into sets or kits or may simply be a collection or inventory of different tissue shaping devices.  
      One way of estimating the appropriate length and anchor sizes of a tissue shaping device for mitral valve regurgitation is to view a fluoroscopic image of a coronary sinus into which a catheter with fluoroscopically viewable markings has been inserted. The crossover point between the coronary sinus and the circumflex artery can be determined as described above, and the screen size of the coronary sinus length proximal to that point and the coronary sinus diameter at the intended anchor locations can be measured. By also measuring the screen distance of the catheter markings and comparing them to the actual distance between the catheter marking, the length and diameter measures can be scaled to actual size. A tissue shaping device with the appropriate length and anchor sizes can be selected from a set or inventory of devices for deployment in the patient to treat mitral valve regurgitation.  
       FIG. 30  shows yet another embodiment of the method of this invention. In this embodiment, a tissue shaping device  800  formed from a substantially straight rigid member  802  is disposed in the coronary sinus  804  to treat mitral valve regurgitation. When deployed as shown, the central portion of rigid member  802  exerts a remodeling force anteriorly through the coronary sinus wall toward the mitral valve  806 , while the proximal and distal ends  808  and  810 , respectively, of rigid member  802  exert posteriorly-directed forces on the coronary sinus wall. According to this invention, device  800  is disposed in relation to the circumflex artery  812  so that all of the anteriorly-directed forces from rigid member  802  are posterior to the crossover point between artery  812  and coronary sinus  804 , despite the fact that distal end  810  of device  800  and a guidewire portion  814  are distal to the crossover point.  
      The device of  FIG. 30  may also include a less rigid portion at the distal end  810  of member  802  to further eliminate any force directed toward the mitral valve distal to the crossover point. Further details of the device (apart from the method of this invention) may be found in U.S. patent application Ser. No. 10/112,354, published as U.S. Patent Appl. Publ. No. 2002/0183838, the disclosure of which is incorporated herein by reference.  
       FIG. 31  shows another embodiment of the method of this invention. Device  900  has a substantially straight rigid portion  902  disposed between a proximal angled portion  904  and a distal angled portion  906  within coronary sinus  908 . As shown, proximal angled portion  904  extends through the coronary sinus ostium  910  within a catheter (not shown). Distal angled portion  906  extends distally to a hooked portion  912  that is preferably disposed in the AIV.  
      To treat mitral valve regurgitation, the device&#39;s straight portion  902  reshapes the coronary sinus and adjacent tissue to apply an anteriorally directed force through the coronary sinus wall toward the mitral valve  914 . Due to the device&#39;s design, this reshaping force is applied solely proximal to the crossover point between coronary sinus  908  and the patient&#39;s circumflex artery  916 , despite the fact at least a part of the device&#39;s distal portion  906  and hooked portion  912  are disposed distal to the crossover point.  
      Other modifications to the inventions claimed below will be apparent to those skilled in the art and are intended to be encompassed by the claims.