Patent Publication Number: US-2022226113-A1

Title: Device for securing heart valve leaflets

Description:
CROSS-REFERENCE 
     This application is a continuation of U.S. patent application Ser. No. 15/746,788, filed Jan. 22, 2018, which is a National Phase of PCT Application No. PCT/US2016/043750, filed Jul. 22, 2016, which claims the benefit of U.S. Provisional Application No. 62/196,276, filed Jul. 23, 2015. Each of the foregoing applications is hereby incorporated by reference in its entirety herein. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to devices and methods for treating regurgitation in a heart valve. 
     Description of the Related Art 
     The tricuspid valve separates the right lower heart chamber (the right ventricle) from the right upper heart chamber (right atrium). Tricuspid regurgitation is a disorder in which this valve does not close tight enough. This problem causes blood to flow backward into the right upper heart chamber (atrium) when the right lower heart chamber (ventricle) contracts. Tricuspid regurgitation is leakage of blood backwards through the tricuspid valve each time the right ventricle contracts. Tricuspid regurgitation usually results from an enlarged lower heart chamber (called the ventricle) or from any other condition that constrains the blood flow from the right ventricle to the lungs. Sometimes long-standing disorders, such as emphysema or pulmonary stenosis can cause problems that affect the tricuspid valve which is “upstream” from the lungs. To compensate, the right ventricle enlarges so that it can pump harder, which sometimes causes the tricuspid opening to become stretched out and floppy. When valve disease is severe, it may be necessary to repair or replace the diseased valve. Valve repair is the most common surgical treatment for tricuspid valve disease. Tricuspid valve repair can be done alone or in combination with treatments for other heart problems. 
     Tricuspid valve repair using an annuloplasty ring is a common surgical approach for tricuspid regurgitation and may be performed for primary tricuspid disease or for combined cases with other valve surgery (mitral, aortic). Traditional tricuspid valve repair is an open-heart procedure performed through a 6-8 inch incision through the breastbone (sternum). 
     SUMMARY 
     For these reasons, there exists a need for minimally invasive methods of tricuspid valve repair. The present disclosure is directed to valve fixation devices that can be delivered endovascularly. 
     In one embodiment, a system is provided for delivering a distal plate to the ventricular side of the tricuspid valve and a proximal plate to the atrial side of the tricuspid valve. The system includes both tension guidewires and rigid catheters that allow positioning of the plates. The plates include slots that align to form a passage way between the plates. The system includes a locking clip having an end that is configured to pass through slots, or over the outer edges, of the plates. The locking clip is delivered along the guidewires until the end of the locking clip passes through the slots. The end of the locking clip is barbed or otherwise is configured to prevent the locking clip from separating from or backing off of the plates. 
     In one embodiment, the system includes a guidance rail that is used to deliver the fixation device to the tricuspid valve. Optionally, the guidance rail has a threaded tip that bores into the ventricular wall. In some embodiments, the guidance rail has a suction tip that reversibly holds the guidance rail to the ventricular wall. In some embodiments, the guidance rail is established by advancing a distal portion of the guidance rail into the pulmonary artery. In some embodiments, the distal portion of the guidance rail is floated into the pulmonary artery using a balloon-tipped guidewire. 
     In some aspects, the device is a heart valve prosthesis that has a distal member, a proximal member, and a connector. The distal member is configured to be advanced into a first heart chamber. The proximal member is configured to be advanced into a second heart chamber. The distal member and the proximal member each has a central portion disposed adjacent to a line of coaptation of two adjacent heart leaflets. The distal member and the proximal member each has peripheral portions that are placed into direct contact with the two adjacent heart leaflets. The proximal member is separate from the distal member and the central portions of the distal and proximal members are moveable relative to each other. The connector is configured to be disposed across a gap between the distal and proximal members to secure the central portion of the distal member to the central portion of the proximal member. 
     In some aspects, the connector is a locking clip that has an open end and a closed end. The open end is adapted to be advanced initially over the proximal member and subsequently over the distal member to secure the central portion of the distal member to the central portion of the proximal member. In certain aspects, the locking clip has an aperture sized to receive a guidewire that is connected with the distal member. In some aspects, the locking clip has a first aperture and a tracking feature. The first aperture is sized to receive a first guidewire that is coupled to the distal member. The tracking feature is sized to contact a second guidewire that is coupled to the proximal member. In some aspects, the tracking feature is a second aperture in the closed end of the locking clip. 
     In some aspects, at least one of the central portion of the distal member and the central portion of the proximal member includes a recess in which the connector can be disposed to provide a continuous periphery along at least one peripheral edge of the prosthesis. In some aspects, the proximal member has a channel disposed along a longitudinal axis of the proximal member. The channel is sized to receive a portion of a guidewire when the proximal member is in a low-profile configuration. In some embodiments, the channel extends along the peripheral portions on both sides of the central portion of the proximal member. 
     In some aspects, the connector has a first edge, a second edge, and a single guidewire aperture disposed between the first edge and the second edge. The second edge is disposed between the single guidewire aperture and a guidewire extending from the proximal member. 
     In some aspects, the connector has a first end, a second end, and an elongate body disposed between the first and second ends. The first end is configured to couple with a guidewire. The second end is configured to be disposed away from the first end. The elongate body is configured to slideably receive the distal member and the proximal member after the connector has been advanced into the patient. 
     In some embodiments, the distal member has a sheet-like configuration. The central portion of the distal member has an aperture sized to be slideable over the elongate body of the connector. In some aspects, the first end of the connector has a projection that is adapted to engage a mating feature on the distal member. The projection and the mating feature are configured so that torque applied to the connector causes rotation of the distal member about an axis that extends through the aperture of the distal member. The axis is oriented perpendicular to the aperture. 
     In some aspects, the central portion of the proximal member has an aperture configured to be advanced over the second end of the connector. The aperture is configured to lock to the connector as the proximal member is advanced from the second end of the connector toward the first end of the connector. In some aspects, the peripheral portion of one of the distal member or the proximal member has a locking aperture. The peripheral portion of the other member has a locking device that is configured to be advanced through the locking aperture to secure the distal member to the proximal member. In some aspects, the central portion of at least one of the distal and proximal members has a tubular body and the peripheral portions thereof comprise a curvature corresponding to a curvature of the tubular body at least in a delivery state. 
     In some aspects, the prosthesis further comprises a locking device configured to be advanced over the second end of the connector to releasably couple the proximal member to the connector. In some aspects, the peripheral portions of at least one of the distal and proximal members is adapted to transition from a low-profile tubular configuration to a plate-like configuration for engaging a corresponding leaflet. In some aspects, a leaflet facing side of at least one peripheral portion of at least one of the distal member and the proximal member has a barb oriented toward the central portion thereof. In some aspects, at least one surface of at least one of the distal member and the proximal member includes a pledget. 
     In some aspects, a system for treating heart valve insufficiency includes the heart valve prosthesis of any of the aspects previously described, and an anchor for securing a guidance rail to an internal surface of the heart. The anchor can have a threaded member. The anchor can have a suction tip. 
     In some aspects, a system for treating heart valve insufficiency can include the heart valve prosthesis of any of the aspects previously described, and a catheter assembly. The catheter assembly can include an outer body and an inner body. The outer body is configured to permit delivery of the distal member, the proximal member and the connector. The inner body is configured to direct a force to the proximal member in connection with moving the distal member and the proximal member toward each other. 
     In some aspects, a system for securing a leaflet of a heart valve includes a distal plate, a proximal plate, and a locking clip. The system can further include a pledget. The system can further include a guidance rail. The guidance rail can further include a suction tip. 
     In some aspects a method of performing a procedure in the heart includes providing a delivery catheter to a heart; passing a distal plate through the delivery catheter and into a right ventricle of the heart; drawing the distal plate against a leaflet of a tricuspid valve; passing a proximal plate through the delivery catheter and into a right atrium of the heart; positioning the distal and proximal plates such that the leaflet of the tricuspid valve is compressed between the distal and proximal plates; aligning the distal and proximal plates; and advancing a first end of a locking clip across the distal and proximal plates, thereby securing the distal plate to the proximal plate. Aligning the distal and proximal plates can further include moving one or both of the distal and proximal plates such that a passageway is disposed across the distal and proximal plates. In some aspects, the passageway includes a first slot or recess in the distal plate that aligns with a second slot or recess in the proximal plate. In some aspects, the locking clip is advanced into the right ventricle prior to passing the proximal plate into the right ventricle. In some aspects, the locking clip is advanced into the right atrium after passing the proximal plate into the right atrium. 
     The method can further include passing a guidance rail through the delivery catheter and into a right ventricle of the heart, wherein a distal portion of the guidance rail extends into a main pulmonary artery. The method can further include passing a guidance rail through the delivery catheter and into a right ventricle of the heart, a distal end of the guidance rail comprising a stabilization feature; and attaching the stabilization feature to a wall of the right ventricle. In some aspects, the stabilization feature is selected from the group consisting of a barbed tip, a threaded tip, and a suction tip. In some aspects, the distal plate is advanced over a first guidewire, the proximal plate is advanced over a second guidewire, with the first guidewire being spaced apart from the second guidewire. In some aspects, the proximal face of the proximal plate has a first groove that overlaps a second groove on a distal face of the proximal plate to form a passageway for a guidewire along a length of the proximal plate. In some aspects, the first guidewire is disposed in the passageway when the proximal plate is being advanced into the right atrium. 
     In some aspects, the method includes passing a locking nut through the delivery catheter and securing the locking nut to the first end of the locking clip. In some aspects, the distal plate is in a low-profile state during at least a portion of the passing, and the distal plate is in a deployed state during at least a portion of the drawing step. 
     In some aspects, the device is a heart valve prosthesis having a connector, a distal plate, and a proximal plate. The connector has a body that extends between a distal end and a proximal end of the connector. The proximal end has an opening sized to receive a guidewire into the body. The distal member is configured to be advanced into a first heart chamber and has a retention feature disposed on a central portion of the distal member. The retention feature is configured to prevent the distal end of the connector from passing beyond the distal member in a proximal direction. The proximal member is configured to be advanced into a second heart chamber. The proximal member has a second central portion configured to allow the proximal end of the connector to extend proximally beyond the proximal member. The first and second central portions are moveable relative to each other. 
     In some aspects, the heart valve has a locking feature configured to prevent the proximal end from moving through the second central portion in a distal direction after the locking feature has passed beyond the second central portion in the proximal direction. In some aspects, the locking feature comprises a push nut. In certain aspects, the distal and proximal members can move between a low-profile state and a deployed state, wherein compared to the low-profile state, in the deployed state at least a portion of the distal and proximal members is located further from the body of the connector. 
     In some aspects, at least one of the distal and proximal members comprises nitinol. In some aspects, the connector includes a protrusion configured to engage a recess on the distal member to prevent rotation of the distal member relative to the connector. In some aspects, the distal end of the connector has an opening aligned with the opening at the proximal end of the connector such that a guidewire can pass through the body of the connector. In some aspects, at least one of a distal face of the proximal member or a proximal face of the distal member includes a feature for piercing tissue disposed between the distal and proximal members. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the subject matter of this application and the various advantages thereof can be realized by reference to the following detailed description, in which reference is made to the accompanying drawings in which: 
         FIG. 1A  depicts a cross-sectional view of a heart in normal diastole. 
         FIG. 1B  depicts a cross-sectional view of a heart in normal systole. 
         FIG. 2  depicts a side view of an embodiment of a fixation device. 
         FIG. 3A  shows a side view of an embodiment of a distal plate. 
         FIG. 3B  shows a top view of an embodiment of a distal plate in a low-profile configuration. 
         FIG. 3C  is a side view of the embodiment depicted in  FIG. 3A , with an addition of a pledget intended to contact the tricuspid valve. 
         FIG. 3D  is a top view of an embodiment of a pledget. 
         FIG. 4A  is a side view of a proximal plate. 
         FIG. 4B  is a bottom view of a proximal plate. 
         FIG. 4C  is an end view of a proximal plate. 
         FIG. 4D  is a side view of the embodiment of the proximal plate depicted in  FIG. 4A , with the proximal plate being actuated to a low profile configuration. 
         FIG. 5A  is a top view of an embodiment of a locking clip. 
         FIG. 5B  is an end view of an embodiment of a locking clip. 
         FIG. 5C  is a side view of an embodiment of a locking clip. 
         FIG. 6A  is an isometric view of an embodiment of a fixation device. 
         FIG. 6B  is a top view of an embodiment of a locking clip. 
         FIG. 6C  is an end view of an embodiment of a locking clip. 
         FIG. 6D  is a side view of an embodiment of a locking clip. 
         FIG. 6E  is an isometric view of the fixation device of  FIG. 6A . 
         FIG. 6F  is a partial bottom view of the proximal plate of the fixation device of  FIG. 6A . 
         FIG. 7A  is an isometric view of an embodiment of a fixation device. 
         FIG. 7B  is a top view of an embodiment of a locking clip. 
         FIG. 7C  is an end view of an embodiment of a locking clip. 
         FIG. 7D  is a side view of an embodiment of a locking clip. 
         FIG. 8A  is an isometric view of an embodiment of a fixation device. 
         FIG. 8B  is an exploded view of the fixation device of  FIG. 8A . 
         FIG. 8C  is a bottom view of a portion of the fixation device of  FIG. 8A . 
         FIG. 8D  is a bottom view of the distal plate of  FIG. 8A . 
         FIG. 9A  is an isometric view of an embodiment of a fixation device. 
         FIG. 9B  is an isometric view of the proximal plate of  FIG. 9A  in a low-profile configuration. 
         FIG. 10A  is an isometric view of an embodiment of a fixation device. 
         FIG. 10B  is an exploded view of the fixation device of  FIG. 10A . 
         FIG. 11A  is a side view of a guidewire detachment feature in the uninflated state. 
         FIG. 11B  is a side view of the guidewire detachment feature of  11 A in the inflated state. 
         FIG. 11C  is a top view of a portion of a plate or pin that has an attachment feature. 
         FIG. 12A  is a side view of a guidewire detachment feature in the secured state. 
         FIG. 12B  is a side view of the guidewire detachment feature of  12 A in the released state. 
         FIG. 12C  is a side view of the guidewire detachment feature of  12 A in the detached state. 
         FIG. 13A  is a cross-sectional view of a heart with an embodiment of an expandable fixation device. The expandable fixation device is in its unexpanded state and the heart is in diastole. 
         FIG. 13B  depicts the embodiment of  FIG. 6A  with the heart in systole. 
         FIG. 13C  is the embodiment of  FIG. 6A  with the expandable fixation device in its expanded configuration. 
         FIG. 14  is an embodiment of a fixation device having a guidance rail embedded into the ventricular wall. 
         FIG. 15  is an embodiment of a fixation device having a suction tip. 
         FIG. 16  is an embodiment of a threaded tip for embedding into the ventricular wall. 
         FIG. 17A  is an isometric view of an embodiment of a suction tip in its partially deployed configuration. 
         FIG. 17B  is an isometric view of the embodiment of  FIG. 10A  in its fully deployed configuration. 
         FIG. 18  is an isometric view of an embodiment of a fixation device deployed over a guidance rail. 
         FIG. 19  is a top view of a tricuspid valve illustrating a non-limiting selection of locations for placement of the device across the valve leaflets. 
         FIG. 19A  is a cross-sectional view of a heart showing placing a guidewire along the venous vasculature into the heart. 
         FIG. 19B  is a cross-sectional view of a heart showing advancing a delivery system along a guidewire into the heart. 
         FIG. 19C  is a cross-sectional view of a heart showing a delivery system in the vicinity of a heart valve. 
         FIG. 19C-1  is a cross-sectional view of a delivery system showing the internal arrangement of the device components within the distal end of the delivery system. 
         FIG. 19C-2  is a cross-sectional view of a delivery system showing the internal arrangement of the device components within the distal end of the delivery system. 
         FIG. 19D  shows a pin being deployed from a delivery device. 
         FIG. 19E  shows a distal plate being deployed from a delivery device. 
         FIG. 19F  shows a proximal plate being deployed from a delivery device. 
         FIG. 19G  shows a device deployed on a heart valve. 
     
    
    
     More detailed descriptions of various embodiments of catheter based transapical delivery systems, components and methods useful to treat patients are set forth below. 
     DETAILED DESCRIPTION 
     This device represents an endovascular method of reducing tricuspid regurgitation in patients with severe tricuspid regurgitation. This device is intended to be delivered preferably through the right internal jugular vein due to anatomical considerations, but may also be delivered through the left internal jugular vein or via the inferior vena cava. 
     The working principle of this device is the reduction of tricuspid regurgitation through the fixation of tricuspid valve leaflet edges.  FIG. 1A  is a schematic representation of a heart  10  in normal diastole.  FIG. 1B  represents the heart  10  in normal systole. The heart  10  consists of four chambers and the tricuspid valve  12  is interposed between the right atrium  14  and the right ventricle  16 . 
     The present disclosure may represent a single point fixation between two leaflet edges of either two or three leaflets, or complete edge to edge fixation of the coaptation edges of two or three leaflets, or some combination of these methods. The right internal jugular vein (not shown) is preferable for delivery due to its most direct placement above the tricuspid valve  12 . However, the devices and methods herein disclosed may be delivered through the left internal jugular vein or the inferior vena cava. 
     Some aspects of the present disclosure encompass a method of delivering to the ventricular side of the tricuspid valve  12 , and steering with a steerable catheter to the desired leaflet coaptation point, an anchor that can include an attached and externalized guidewire or suture that is configured to secure the coaptation edge of two tricuspid leaflets at the ventricular surface. The externalized guidewire or suture can possess sufficient torsional rigidity to allow rotational control of the distal anchor. Tension can then be applied through the attached guidewire or suture to the distal anchor in the ventricular to atrial direction so that the coaptation edge of the two leaflets of interest may be brought closer together or, in some cases, forced closed. A means of then securing the leaflet coaptation edges can then be employed to cause the two edges to become fixed together. This procedure can then be repeated as needed to reduce the amount of tricuspid regurgitation. 
       FIG. 2  depicts a non-limiting exemplary embodiment of a device within the scope of the present disclosure. In various embodiments herein, the device  20  and variations discussed below can comprise a heart valve prosthesis. The device  20  can include two rigid or semi-rigid plates, referred to as the distal plate  22  and the proximal plate  24 . In some aspects, the distal and proximal plates  22 ,  24  can sandwich the tricuspid leaflet edges and cause the entrapped edges to become fixed together. The distal and proximal plates  22 ,  24  can have a central portion  128  and a peripheral portion  130 . In some configurations, the tricuspid leaflet edges are held between the peripheral portions  130  of the distal and proximal plates  22 ,  24 , while the central portion  128  of the plates  22 ,  24  are secured together by a connector  126  (shown in  FIG. 5B ). The connector  126  can be disposed across a gap between the distal and proximal plates  22 ,  24 . In some configurations, the distal and proximal plates  22 ,  24  can be aligned using alignment features (not shown), and locked together with a locking clip (shown in  FIGS. 5A-C ), thereby forming a durable fixation device. The distal and proximal plates  22 ,  24  may or may not feature a lengthwise curvature (not shown) as in a leaf spring to cause additional spring force to act to secure the leaflet between the plates. 
       FIGS. 3A and 3B  depict a side view and a top view of a non-limiting exemplary embodiment of a distal plate  22 . The distal plate  22  can be a rectangular plate comprised of metal (e.g., stainless steel, titanium, or titanium-containing alloy) or polymer. The distal plate  22  may incorporate slots  26  that facilitate alignment and fixation with the proximal plate  24 . A distal guidewire  30  or suture that is externalized from the patient may be attached to the distal plate  22  to allow traction to be applied to the distal plate  22 . The distal guidewire  30  can be configured to provide rotational control of the distal plate  22 . The distal plate  22  may or may not include a compliant material layer (not shown) bonded to the surface  32  of the distal plate  22  at the point of contact with the tricuspid leaflets. The distal guidewire  30  or suture can be mounted slightly off center along the long axis of the distal plate  22  on a pivoting anchor  34 , which can allow the distal plate  22  to be rotated such that its long axis is parallel to the distal guidewire  30  or suture.  FIG. 3C  shows a side view of the distal plate  22  rotated such that its long axis is parallel to the distal guidewire  30 . In some aspects, the distal plate  22  may interface with a pledget  38 . A non-limiting exemplary embodiment of a pledget  38  is shown in  FIG. 3C  and is discussed below. The distal plate  22  may provide a sturdy mechanical backing for the pledget  38 . 
       FIG. 3D  depicts a top view of a non-limiting exemplary embodiment of a pledget  38 . The pledget  38  can be made of woven or non-woven fibrous material such as Dacron or Gore-Tex or a bulk material such as silicone rubber. The pledget  38  can include a notch  39  cut into the material to allow the distal guidewire  30  to fold flat against the distal plate  22  as shown in  FIG. 3C . The pledget  38  can be configured to enhance securement of the tricuspid valve between the distal and proximal plates  22 ,  24 . In some aspects, the pledget  38  may act as a cushion. The pledget  38  may receive spikes on the proximal plate  24  that pass through the valve leaflet and penetrate the pledget  38  as the proximal plate  24  is pushed toward the distal plate  22 . In some configurations, the locking clip passes through a circular cut-out  37  of the pledget  38 . The locking clip clips completely outside the perimeter of the plates in one embodiment. Some embodiments incorporate a clip that penetrates the pledget  38 . 
       FIGS. 4A-C  depict a side view, a bottom view, and an end view of a non-limiting exemplary embodiment of a proximal plate  24 . The proximal plate  24  can be a rectangular plate comprised of metal or polymer. The proximal plate  24  may incorporate a protruding feature (not shown) that mates and self-aligns with the distal plate  22 . The proximal plate  24  may include slots  36  that align with the slots  26  of the distal plate  22 , thereby facilitating the passage of a barbed locking clip to fix the distal and proximal plates  22 ,  24  together. The proximal plate  24  can include a feature  40  (e.g., through hole) to allow passage of the distal guidewire  30  or suture from the distal plate  22 . The proximal plate  24  may have an affixed proximal guidewire  42  or suture that is externalized from the patient to allow traction and rotational control to be applied to the proximal plate  24 . The proximal guidewire  42  or suture can be mounted centrally on the proximal plate  22  on a pivoting anchor  44 . The pivoting anchor  44  may be configured to allow the proximal plate  24  to be rotated such that its long axis is parallel to the proximal guidewire  42  or suture, as shown in  FIG. 4D . A friction enhancing feature such as a series of teeth, bumps, or surface roughening may or may not be applied to the surface of the distal or proximal plate  22 ,  24  that contacts the tricuspid leaflets. The proximal plate  24  can include one or more grooves  43   a,b . The grooves  43   a,b  can extend more than halfway across the distal plate  24  and overlap with one another so that when the proximal plate  24  and its guidewire  42  are in the deployed configuration (i.e., long axis of the proximal plate  24  is perpendicular to the proximal guidewire  42 ), there exists a hole  40  through which the proximal end of the distal guidewire  30  can be threaded. When the proximal plate  24  is in the folded configuration (i.e., long axis of the proximal plate  24  is parallel to its guidewire  42 ), the grooves  43   a,b  can allow the distal guidewire  30  to clear the ends of the proximal plate  24 . When the proximal plate  24  is viewed end-on, the overlapping grooves  43   a,b  can form a through hole that allows the proximal plate  24  to be advanced lengthwise over the distal guidewire  30 , through a catheter, to the right atrium where the proximal plate  24  can be rotated 90 degrees relative to the proximal guidewire  42  to bring the proximal plate  24  into the deployed configuration. The slot configuration allows the distal guidewire  30  to clear the proximal plate  24  so that it now passes only through the hole  40 . 
       FIGS. 5A-C  depict a top view, an end view, and a side view of a non-limiting exemplary embodiment of a connector  126 . The connector  126  can be a locking clip  50 . The locking clip  50  can be a rigid part made of metal or polymer. The locking clip  50  may include an open end  120  and a closed end  122 . As described below, the open end  120  can be advanced initially over the proximal plate  24  and subsequently over the distal plate  22 . The locking clip may include spaced apart arms  51  that extend from a bridge portion  56 . The arms  51  can include raised features  52  that can be threaded through the concentric slots  26 ,  36  of the distal and proximal plates  22 ,  24 . In some configurations, the arms  51  can be pushed over the edges of the distal and proximal plates  22 ,  24 , as described below. The connector  126  can include an aperture  124  configured to receive a guidewire. The locking clip  50  can include a central hole  54  to allow passage of the distal and proximal guidewires  30 ,  42  that connect to the distal and proximal plates  22 ,  24 . The raised features  52  may incorporate a series of barbs on the ends such that passage of the locking clip  50  through the distal and proximal plates  22 ,  24  can proceed in one direction only. The bridge portion  56  prevents the locking clip  50  from passing through the concentric slots  26 ,  36  of the distal and proximal plates  22 ,  24 . The bridge portion  56  of the locking clip  50  may also integrate a compliant material where the locking clip  50  contacts the proximal plate  24 . The compliant material can act as a spring to push the proximal plate  24  against the distal plate  22 . In some aspects of the present disclosure, when the barbed ends of the raised features  52  are threaded through the concentric slots  26 ,  36 , the barbs grip the ventricular side of the distal plate  22 , thereby causing the bridge portion  56  to apply a retaining force against the atrial side of the proximal plate  22 , the effect of which is similar to a rivet holding the distal and proximal plates  22 ,  24  together. Additionally and alternatively, the locking clip  50  can be a U-shaped part featuring barbed ends that fasten externally over the distal and proximal plates  22 ,  24 . 
       FIG. 6A  depicts an embodiment of a device  20 A that is similar to the device  20  except as described differently below. The features of the device  20 A can be combined or included with the device  20  or any other embodiment discussed herein. The device  20 A can comprise a heart valve prosthesis. The device  20 A has a locking clip  50 A that fastens externally to the periphery of the distal and proximal plates  22 A,  24 A. In the illustrated embodiment, the distal and proximal plates  22 A,  24 A each have a narrows  53   a ,  53   b . The transverse width of the distal and proximal plates  22 A,  24 A is reduced at the narrows  53   a ,  53   b , as shown in  FIG. 6A . The locking clip  50 A can be advanced along the distal guidewire  30 A so that the arms  51 A of the locking clip  50 A extend through the narrows  53   a ,  53   b  and across the distal and proximal plates  22 A,  24 A. In the illustrated embodiment, the distal guidewire  30 A passes through a central hole  54 A of the locking clip  50 A, and the proximal guidewire  42 A does not pass through the locking clip  50 A. In some embodiments, the proximal guidewire  42 A is disposed laterally outward of an end surface  57 A of the narrows  53   b . In other words, the end surface  57 A of the narrows  53   b  of the proximal clip  24 A can be disposed between the proximal guidewire  42 A and a face  59 A of the locking clip  50 A. As discussed, the distal and proximal plates  22 A,  24 A can include a pledget  38 A. The illustrated embodiment shows that the pledget  38 A can be substantially uniform across the face of the plate and need not have a groove  39  (shown in  FIG. 3D ). 
     The locking clip  50 A can have a thickness dimension that is oriented normal to the face  59 A. In other words,  FIG. 6A  shows the locking clip  50 A oriented so that the thickness dimension of the locking clip  50 A is aligned parallel with the longitudinal axis of the distal and proximal plates  22 A,  24 A. By positioning the proximal guidewire  42 A outside of the locking clip  50 A, the thickness of the locking clip  50 A can be reduced. Reducing the thickness of the locking clip  50 A can reduce backflow through the anchor point (e.g., the narrows  53   a ,  53   b ) when the locking clip  50 A is secured to the valve leaflets. The locking clip  50 A can have a width dimension that is oriented along a line that extends between the arms  51 A of the locking clip  50 A. The width of the locking clip  50 A can be selected so that the side face  63 A is substantially flush with the lateral portions of the distal and proximal plates  22 A,  24 A when the locking clip  50 A is seated within the narrows  53   a ,  53   b . The locking clip  50 A can be adapted so that the outer surface of the locking clip  50 A is substantially flush with the outer surface of the distal and proximal plates  22 A,  24 A when the locking clip  50 A is seated within the narrows  53   a ,  53   b  to secure the distal and proximal plates  22 A,  24 A together, thereby giving the device  20 A a smooth outer surface. The edges of the device  20 A can be contoured to be smooth and rounded. In some configurations, the edges of the device are contoured (e.g., rounded) to avoid thrombosis. 
       FIGS. 6B-6D  show a top view, an end view, and a side view of the locking clip  50 A depicted in  FIG. 6A . The locking clip  50 A can be laser cut from flat sheet material for ease of manufacturing. As described above, the arms  51 A of the locking clip  50 A can have a raised feature  52 A that engages with the edge of the distal plate  22 A. In the illustrated embodiment, the locking clip  50 A has a raised feature  52 A with a cam surface adapted to allow the raised feature  52 A to be advanced distally over a ridge  55 A within the narrows  53   a  of the distal plate  22 A. The cam surface of the raised feature  52 A cause the arms  51 A of the locking clip  50 A to deflect laterally away from the center line of the locking clip  50 A as the locking clip  50 A is advanced distally over the ridge  55 A. Once the cam surface of the raised feature  52 A clears the ridge  55 A, the arms  51 A of the locking clip  50 A spring back toward the center line of the locking clip  50 A, thereby securing the ridge  55 A of the distal plate  22 A behind a flat proximally-facing surface of the raised feature  52 A and restricting movement of the locking clip  50 A in the proximal direction. The locking clip  50 A can be sized so that when the raised feature  52 A is seated over the ridge  55 A of the distal plate  22 A, the under surface  61 A of the bridge portion  56 A compresses the proximal plate  24 A toward the distal plate  22 A. The locking clip  50 A can be sized to compress a tissue (e.g., tricuspid valve leaflet) secured within the gap between the distal and proximal plates  22 A,  24 A. In some configurations, the locking clip  50 A can be adapted to compress a tissue by about: 1%, 5%, 10%, 20%, and values therebetween. A compression of about 10% means that the thickness of the uncompressed tissue is 10% greater than the thickness of the compressed tissue.  FIG. 6E  shows an isometric view of the other end of the device  20 A.  FIG. 6F  shows a bottom view of the proximal plate  24 A. As discussed above, the proximal plate  24 A can have a groove  43   b ′ on the leaflet-facing surface of the proximal plate  24 A. The groove  43   b ′ can accommodate the distal guidewire  30 A when the proximal plate  24 A is in the low-profile configuration. As shown in  FIG. 6F , the pledget  38 A can have a groove  39 ′ that aligns with the groove  43   b ′ of the proximal plate  24 A. 
       FIG. 7A  depicts an embodiment of a device  20 B that is similar to the device  20  and to the device  20 A except as described differently below. The features of the device  20 B can be combined or included with the device  20 ,  20 A or any other embodiment discussed herein. The device  20 B can comprise a heart valve prosthesis. The device  20 B has a locking clip  50 B that fastens externally over the distal and proximal plates  22 B,  24 B. In the illustrated embodiment, the distal and proximal guidewires  30 B,  42 B pass through holes in the body of the locking clip  50 B. As described above, the arms  51 B of the locking clip  50 B can extend over the periphery of the distal and proximal plates  22 B,  24 B. The arms  51 B of the locking clip  50 B can seat within the narrows  53   a ,  53   b  of the distal and proximal plates  22 B,  24 B. The locking clip  50 B can be adapted so that the outer surface of the locking clip  50 B is substantially flush with the outer surface of the distal and proximal plates  22 B,  24 B when the locking clip  50 B is seated within the narrows  53   a ,  53   b  to secure the distal and proximal plates  22 B,  24 B together, thereby giving the device  20 B a smooth outer surface. 
       FIGS. 7B-7D  show a top view, an end view, and a side view of the locking clip  50 B depicted in  FIG. 7A . As shown in  FIG. 7B , the locking clip  50 B can have a first hole  63 B and a second hole  65 B. The distal guidewire  30 B can pass through the first hole  63 B. The proximal guidewire  42 B can pass through the second hole  65 B. As described above, the locking clip  50 B can be adapted to compress a tissue secured within the gap between the distal and proximal plates  22 B,  24 B by about: 1%, 5%, 10%, 20%, and values therebetween. 
     In pre-delivery configuration, the distal plate  22  can be rotated about its attachment point to the distal guidewire  30  or suture, so that its long axis is parallel to the distal guidewire  30  or suture, and this assembly can be enclosed inside a delivery catheter. Likewise, the proximal plate  24  can be rotated about its attachment point to the proximal guidewire  42  or suture, so that its long axis is parallel to the proximal guidewire  42 , also referred to as a traction wire  42  or suture, and this assembly is enclosed inside the same or a separate delivery catheter. 
     A method of placement of the distal and proximal plates  22 ,  24  or the plates  22 B,  24 B within a single delivery catheter is provided below. However, this method of device placement is presented for illustrative purposes only and is not to be taken as limiting. Indeed the other heart valve prosthesis devices disclosed herein can be deployed in similar methods. The steps are not all required, nor must they be performed in the order presented.
         1. Place right internal jugular vein access sheath   2. Through this sheath, advance and steer the distal delivery catheter tip to just distal to the tricuspid valve.   3. Advance the distal plate, such as the plate  22 B or any of the other distal plates beyond a delivery catheter  208  as shown in  FIG. 19C-1  using the attached traction wire  30 A.   4. Under fluoroscopic/echocardiographic guidance, position the distal plate  22 B or any of the other distal plates parallel to the tricuspid valve plane coaptation line (perpendicular to its tension wire  30 B).   5. Withdraw and park the tip of the delivery catheter  208  into the right atrium.   6. Adjust manual tension on the distal wire  30 B, allowing the distal plate  22 B to tent the tricuspid valve closed, and evaluate tricuspid regurgitation.   7. Advance the proximal plate  24 B or any of the other proximal plates disclosed herein beyond delivery catheter  208  using the attached tension wire  42 B   8. Apply manual tension on the proximal plate wire  42 B so that proximal plate  24 B is pulled back firmly against its delivery catheter  208 , and positioned parallel to the plane of the tricuspid valve and coaptation line (perpendicular to its tension wire  42 B).   9. Holding the proximal plate  24 B against the delivery catheter  208 , advance the delivery catheter  208  with proximal plate over the distal plate wire  30 B. In the case of the embodiment of  FIGS. 2-5C , if alignment features are present one can cause the raised proximal plate alignment features to mate with the distal plate slots.   10. Simultaneously pull on the distal plate tension wire  30 B and push on the delivery catheter  208  to force the two plates  22 B,  24 B together, sandwiching and fixing the tricuspid valve leaflet edges.   11. Withdraw the delivery catheter, leaving the two tension wires in place. In one embodiment where the proximal plate has teeth that penetrate through the tricuspid valve and into a pledget backing material that is secured to the distal plate, the force of the pledget material on the proximal plate teeth can hold the leaflets together. In one embodiment, the distal plate, proximal plate, and locking clip are all enclosed in a single delivery catheter, once the proximal and distal plates are forced together, the locking clip can be advanced through the catheter to lock the proximal and distal plates together.   12. Advance the locking clip  50 B over both tension wires  30 B,  42 B, and backed with a pushing catheter or distal plate  22 B.   13. Simultaneously pull on the distal plate tension wire  30 B and push on the pusher catheter  230  with locking clip  50 B to secure the locking clip  50 B, through the proximal plate  24 B, to the distal plate  22 B such that the raised features  52 B of locking clip  50 B which can be barbs are securely engage the distal plate  22 B.   14. Withdraw locking clip pushing catheter  230 , leaving the proximal and distal tension wires  30 B,  42 B in place.   15. Thread both tension wires  30 B,  42 B through a wire cutter, and advance the wire cutter over both wires  30 B,  42 B against the proximal end of the locking clip  50 B.   16. Cut both tension wires  30 B,  42 B flush against the locking clip  50 B, and withdraw the wire cutter and tension wire remnants. Alternatively to the wire cutter, devices for detaching the wires  30 B,  42 B can be as illustrated and described in connection with  FIGS. 11A-12C     17. Re-evaluate tricuspid regurgitation; if additional repairs are required, repeat steps 2-16 to perform any additional repairs.   18. If a suitable repair has been performed, remove the right internal jugular vein sheath, performing a vascular repair with a percutaneous closure device if required.       

       FIG. 8A  depicts an embodiment of a device  20 C that is similar to the device  20  except as described differently below. The features of the device  20 C can be combined or included with the device  20  or any other embodiment discussed herein. The device  20 C can comprise a heart valve prosthesis. The device  20 C comprises a connector  126  that is a locking pin  80 C. The locking pin  80 C can pass through a central opening in each of the distal and proximal plates  22 C,  24 C. The locking pin  80 C can be coupled to a central guidewire  82 C. In some configurations, the central guidewire  82 C can be hollow, as discussed in more detail below. The central guidewire  82 C can pass through central openings  81   a ,  81   b  (shown in  FIG. 8B ) of the distal and proximal plates  22 C,  24 C. As discussed below, the locking pin  80 C can be configured to secure the distal plate  22 C and the proximal plates  24 C. For example, the locking pin  80 C can have a deformable feature with a cam surface that deflects toward the central guidewire  82 C as the locking pin  80 C is pulled through the proximal plate  24 C. Once the deformable feature passes through the central opening  81   b  of the proximal plate  24 C, the deformable feature may spring away from the central guidewire  82 C, thereby preventing the locking pin  80 C from moving distally relative to the proximal plate  22 C. In some embodiments, the locking pin  80 C can be configured like a rivet. In some configurations, the locking pin  80 C is configured so that the locking pin  80 C can collapse under compression, causing at least a portion of the locking pin  80 C to expand radially outward. The radially-expanded portion of the collapsed locking pin  80 C can be sized to prevent the locking pin  80 C from passing back through the central opening  81   b  in the distal direction. In some configurations, the locking pin  80 C engages with one or both of the pates  22 C,  24 C in a manner similar to a push nut. An interference fit can be provided between one or both of the locking pin  80 C and the plates  22 C,  24 C. 
     As discussed below, in some embodiments a reversible locking feature (e.g., threaded nut) can be used to secure the locking pin  80 C to the distal and proximal plates  22 C,  24 C. For example, the proximal end of the locking pin  80 C can have an external thread (not shown) that mates with the internal thread of a threaded nut (not shown). A pusher catheter can be used to advance the threaded nut along the central guidewire  82 C. The threaded nut can include an interlock feature (e.g., recess) that mates to a corresponding feature (e.g., protrusion) on the pusher catheter, thereby allowing the pusher catheter to advance the thread nut along the central guidewire  82 C. The interlock feature can be further adapted to allow the pusher catheter to rotate the threaded nut about the central guidewire  82 C. In this way, the pusher catheter can be used to tighten or loosen the threaded nut onto the proximal end of the locking pin  80 C. 
     The distal and proximal plates  22 C,  24 C can have a recess  83   a ,  83   b . In some embodiments, the recess  83   a ,  83   b  is configured to interlock with the locking pin  80 C. In some embodiments, the recess  83   a ,  83   b  is configured to accommodate the guidewire  82 C when the plate  22 C,  24 C is folded parallel to the guidewire  82 C to avoid the guidewire  82 C being forced to make a kink as the guidewire  82 C passes through a central opening  81   a ,  81   b  of the plate  22 C,  24 C. 
       FIG. 8B  shows an exploded view of the device  20 C, illustrating that the locking pin  80 C can have a shaft  84 C and a collar  86 C. The locking pin  80 C can be sized so that the shaft  84 C can pass through a central opening  81   a  in the distal plate  22 C and through a central opening  81   b  in the proximal plate  24 C. The collar  86 C can be adapted so that the collar  86 C cannot pass through the central opening  81   a  of the distal plate  22 C. In the illustrated embodiment, the collar  86 C and the central opening  81   a  are both substantially axisymmetric. In some configurations, the collar  86 C and the central opening  81   a  can be shaped so that the collar  86 C can pass through the central opening  81   a  in some rotational configurations but cannot pass through the central opening  81   a  in other rotational configurations. For example, the collar  86 C could have a protrusion (not shown) that can pass through the distal plate  22 C only when the protrusion is aligned with a slot (not shown) that extends from the central opening  81   a.    
     The distal and proximal plates  22 C,  24 C can be adapted to have a delivery configuration and a deployed configuration. For example, the distal and proximal plates  22 C,  24 C can be made of a compliant material (e.g., polymer) that can be elastically deformed into a low-profile configuration (e.g., rolled up) and stored within a sheath that holds the plates  22 C,  24 C in the low-profile configuration for delivery through a catheter. After the plates  22 C,  24 C reach a desired delivery location, the sheath can be retracted to expose the plates  22 C,  24 C, thereby allowing the plates  22 C,  24 C to move to the deployed configuration (e.g., unroll). In some embodiments, the distal and proximal plates  22 C,  24 C can comprise a shape memory material or super-elastic material (e.g., nitinol). In some embodiments, the distal and proximal plates  22 C,  24 C can have a contoured shape that provides stabilization of the plate in fluid flow. For example, the plate can be shaped so that the surface of the plate that is facing the valve leaflet aligns with a desired orientation (e.g., co-planar with the valve annulus) when blood is flowing past the plate. In some embodiments, the desired orientation to utilize flow to help stabilize the plates  22 C,  22 D is an inverted dome. In some configurations, the domed side (e.g., convex side) of the plate faces upstream, and the cupped side (e.g., concave side) faces downstream. 
     With continued reference to  FIG. 8B , the locking pin  80 C can include an interlock feature  88 C that mates with a corresponding feature on the distal plate  22 C. In the illustrated embodiment, the interlock feature  88 C is a notch that has a proximal-facing concave surface. The curvature of the notch matches a corresponding convex surface disposed on the distal-facing surface of the distal plate  22 C. The interlock feature  88 C can hold the distal plate  22 C rotationally fixed relative to the locking pin  80 C. The interlock feature  88 C can allow adjustment of the position of the distal plate  22 C. For example, after the interlock  88 C of the locking pin  80 C mates with a corresponding feature on the distal plate  22 C, rotation of the locking pin  80 C can cause the distal plate  22 C to rotate with the locking pin  80 C. In some embodiments, the locking pin  80 C can be rotated by rotating the central guidewire  82 C. 
       FIG. 8C  shows a bottom view of the distal plate  22 C depicted in  FIG. 8B . In the illustrated embodiment, the distal-facing surface of the distal plate  22 C has a raised feature  90 C that fits into the interlock  88 C that is on the collar  86 C of the pin  80 C. When the raised feature  90 C of the distal plate  22 C is seated in the interlock  88 C, rotation of the locking pin  80 C about the longitudinal axis of the central guidewire  82 C causes the distal plate  22 C to rotate with the locking pin  80 C about the longitudinal axis of the central guidewire  82 C. In this way, the position of the distal plate  22 C can be adjusted by manipulating the central guidewire  82 C.  FIG. 8D  shows a bottom view of the distal plate  22 C alone, i.e., without the locking pin  80 C. 
       FIG. 9A  depicts an embodiment of a device  20 D that is similar in some respects to the device  20 C. The features of the device  20 C can be combined or included with the device  20 D. The device  20 D can comprise a heart valve prosthesis. The device  20 D has a locking pin  80 D that passes through a central opening in each of the distal and proximal plates  22 D,  24 D. In the illustrated embodiment, the distal plate  22 D includes an eyelet  92 D disposed on either end of the distal plate  22 D. The eyelet  92 D is adapted to receive a barb  94 D that is disposed on the proximal plate  24 D. The barb  94 D can be configured to pierce through a valve leaflet that is secured between the distal and proximal plates  22 D,  24 D. The barb  94 D can have wing portions  96 D that spring outward as the barb  94 D is pushed through the eyelet  92 D. In some embodiments, the wing portions  96 D are configured to prevent the barb  94 D from moving proximally back through the eyelet  92 D after the wing portion  96 D has passed distally through the eyelet  92 D. In this way, the barb  94 D and eyelet  92 D can lock together the distal and proximal plates  22 D,  24 D. While not shown in  FIG. 9A , the locking pin  80 D can have a distal collar  86 D that is similar to the distal collar  86 D shown in  FIG. 8C . As discussed above, the distal collar  86 D can be configured to rotate the distal plate  22 D and can be configured to pull the distal plate  22 D toward the proximal plate  24 D when tension is applied to the central guidewire  82 D. 
     The proximal plate  24 D can be configured to have a flat configuration, as shown in  FIG. 9B . In some embodiments, the proximal plate  24 D is made of a shape memory material (e.g., nitinol sheet). In some embodiments, the proximal plate  24 D can fold flat for delivery. In some configurations, the proximal plate  24 D bends from a flat configuration (shown in  FIG. 9B ) to the bent configuration (shown in  FIG. 9A ) upon the proximal plate  22 D contacting a body fluid, or being released from a restrictive sheath, or increasing in temperature. 
       FIG. 10A  depicts an embodiment of a device  20 E that is similar to the devices  20 ,  20 C, and  20 D except as described differently below. The features of the device  20 E can be combined or included with the devices  20 ,  20 C, and  20 D or any other embodiment discussed herein. The device  20 E can comprise a heart valve prosthesis. The device  20 E has a locking pin  80 E that passes through a central opening in each of the distal and proximal plates  22 E,  24 E. The distal and proximal plates  22 E,  24 E have wings  100   a ,  100   b  that extend laterally away from a central ring  101   a ,  101   b . The central rings  101   a ,  101   b  are examples of tubular bodies that are disposed generally in a central portion of the distal and proximal plates  22 E,  24 E respectively. The wings  100   a ,  100   b  can be configured to fold into a cylinder for deliver within a sheath of a delivery catheter. When the distal and proximal plates  22 E,  24 E are released from the sheath of the delivery catheter, the wings  100   a ,  100   b  can spring open so that the lateral portions of the wings  100   a ,  100   b  are further from the central guidewire  82 E. In  FIG. 10A , the wings  100   a ,  100   b  are shown in the open or deployed configuration. As described above, the distal and proximal plates  22 E,  24 E can include an elastic or shape memory material that facilitates the distal and proximal plates  22 E,  24 E springing into the open configuration upon release of the distal and proximal plates  22 E,  24 E from a restricted state such as containment within a delivery sheath. In some embodiments, the distal and proximal plates  22 E,  24 E are fabricated from cut and formed nitinol tube. In some configurations, the distal and proximal plates  22 E,  24 E are shaped to allow for easy retrieval of the plate back into the delivery sheath if the procedure is aborted. For example, the proximal plate  24 E can be recovered into the delivery sheath from the deployed configuration by advancing the delivery sheath distally over the proximal plate  24 E to fold the wings  100   b  toward the central guidewire  82 E. The distal plate  24 E can be recovered into the delivery catheter by a lasso-like snare or by applying tension to a delivery suture that is temporary wrapped around the lateral portions of the wings  100   a , thereby drawing the wings  100   a  toward the central guidewire  82 E. In some configurations, the wings  100   a ,  100   b  have a spring-like quality that allows the wings  100   a ,  100   b  to fold toward the longitudinal axis of the central guidewire  82 E while the plates  22 E,  24 E are being withdrawn in the proximal direction. 
     The distal and proximal plates  22 E,  24 E can include a grip feature  102 E that helps secure the tissue (e.g., valve leaflet) between the distal and proximal plates  22 E,  24 E. In the illustrated embodiment, the grip feature  102 E is a directional barb that points toward the central guidewire  82 E and toward the opposing plate. The illustrated grip feature  102 E facilitates “one-way” gripping of the leaflets, allowing the leaflets to only work themselves closer together with movement while preventing the leaflets from moving farther apart. 
       FIG. 10B  is an exploded view of the device  20 E depicted in  FIG. 10A . The locking pin  80 E can have an interlock  88 E that mates with a corresponding feature on the distal plate  22 E, as described above. In the illustrated embodiment, the corresponding feature is a distal notch  89 E disposed on the central ring  101   a  of the distal plate  22 E. In  FIG. 10B , the distal notch  89 E is partially obscured by the wing  100   a  of the distal plate  22 E. However, the distal notch  89 E is similar to the proximal notch  91 E (shown in  FIG. 10A ) that is disposed on the central ring  101   b  of the proximal plate  24 E. As described for some of the embodiments previously described, tension applied to the central guidewire  82 E can draw the locking pin  80 E through the central rings  101   a ,  101   b  of the distal and proximal plates  22 E,  24 E. The interlock  88 E on the collar  86 E of the locking pin  80 E can mate with the distal notch  89 E to help rotate and position the distal plate  22 E. The collar  86 E can be sized so that the collar  86 E cannot pass through the central ring  101   a  of the distal plate  22 E in the proximal direction. Accordingly, tension applied to the central guidewire  82 E will pull the distal plate  22 E in the proximal direction. A pusher tube (not shown) can be advanced distally over the central guidewire  82 E and can be used to push the proximal plate  24 E toward the distal plate  22 E. The pusher tube can include an interlock that mates with the proximal notch  91 E to allow the pusher tube to rotate and position the proximal plate  24 E. In some configurations, the distal and proximal plates  22 E,  24 E are compressed together by pulling the distal plate  22 E toward the proximal plate  24 E while simultaneously pushing the proximal plate  24 E toward the distal plate  22 E. In some embodiments, the proximal notch  91 E can receive an interference-fit locking nut  93  (shown in  FIG. 19 ) that secures the proximal plate  24 E to the locking pin  80 E, as described in more detail below. The locking nut  93  is one example of a locking device. More generally in various embodiments a locking device can be provided that can provide a releasable coupling between the components of the device  20 F can be employed. 
       FIGS. 11A-C  show illustrative attachment features that can allow a guidewire to be detached from the distal or proximal plates  22 ,  24 . In the illustrated embodiment, the distal end of the attachment feature  104  can have an anchor feature  106  that mates with a receiving feature  105  (shown in  FIG. 11C ) disposed on a portion of the distal plate  22 - 22 F, on a portion of the proximal plate  24 - 24 F, or on a portion of the locking pin  80 C-F. In some configurations, the anchor feature  106  can be a flexible wire that fits into a slot  107  on the distal or proximal plate  22 ,  24 . The flexible wire can be biased radially outward with sufficient force such that when the flexible wire is inserted into the slotted receiving region the flexible wire cannot be pulled out of the slot without applying a sufficiently high threshold level of force. The threshold level of force needed to pull the anchor feature  106  from the receiving region can be selected so that it is greater than the expected force that will be applied during delivery of the distal or proximal plate. 
     The attachment feature  104  can have an inflatable member  108  disposed within a cavity  110  at the distal end of the attachment feature  104 . The inflatable member  108  can be in fluid communication with an inflation lumen  112  that is disposed within the guidewire.  FIG. 11A  shows the inflatable member  108  in the deflated state, in which the inflatable member is contained within the cavity  110 . The inflatable member  108  can be inflated by delivering an inflation fluid into the inflatable member  108  through the inflation lumen  112 . As shown in  FIG. 11B , when the inflatable member  108  is inflated, a portion of the inflatable member will extend beyond the cavity  110  and pry the anchor feature  106  from the distal or proximal plate  22 ,  24  (not shown), thereby disconnecting the guidewire from the distal or proximal plate  22 ,  24 . 
       FIGS. 12A-C  show another embodiment of the attachment feature  104 A. The attachment feature  104 A can include an inner elongate member  109  disposed within an outer member  111 . For example, the inner and outer elongate members  109 ,  111  can be coaxial guidewires. The proximal ends of the inner and outer elongate members  109 ,  111  can include a pin or other feature that locks the inner and outer elongate members  109 ,  111 , thereby preventing the inner and outer elongate member  109 ,  111  from moving relative to one another. The attachment feature  104 A can include a locking element  113  that secures the inner and outer elongate members  109 ,  111  to the distal or proximal plate  22 ,  24 . In the illustrated embodiment, the locking element is a ball  115  that passes through a hole of the outer elongate member  111  and sits within a recess  117  in the proximal plate  22 . As shown in  FIG. 12A , the end portion of the inner member  109  is tiered. In the locked position, the end portion of the inner elongate member  109  holds the ball a first distance D 1  from the proximal plate  22 . 
     To detach the attachment feature  104 A from the proximal plate  22 , the inner and outer elongate members  109 ,  111  are first unlocked (e.g., removing a locking pin that passes through the proximal ends of the inner and outer elongate members  109 ,  111 ) to allow the inner and outer elongate members  109 ,  111  to move relative to one another. The inner elongate member  109  is retracted proximally relative to the outer elongate member  111 , as shown in  FIG. 12B . This allows the ball  115  to drop out of the recess  117  so that the ball  115  is now a distance D 2  away from the proximal plate  22 . With the ball  115  a distance D 2  away from the proximal plate  22 , the outer elongate member  111  can now be withdrawn from the proximal plate  22 , as shown in  FIG. 12C . In this way, the attachment feature  104 A can allow the inner and outer elongate members  109 ,  111  to be detached from the proximal plate  22 . 
       FIGS. 13A-C  depict another embodiment of the present disclosure that includes the use of a collapsible and expandable feature  60  such as a balloon or wire frame that can be passed to the ventricular side of the right ventricle in the collapsed state.  FIG. 13A  depicts the expandable feature  60 , in its unexpanded state, being advanced through superior vena cava, past the tricuspid valve  12 , and into the right ventricle  16  of a heart  10  in normal diastole.  FIG. 13B  depicts the expandable feature  60  in its unexpanded state within the right ventricle of a heart in systole.  FIG. 13C  depicts the expandable feature  60  and expanded once in the right ventricle  16 . The dimensions of this expandable feature  60  can be such that the expandable feature  60  can snag or catch the leaflet edges when the tricuspid valve  12  is open but not pass between them. The tension of withdrawing the expanded expandable feature  60  from the right ventricle  12  into the right atrium  14  therefore catches the leaflets of the tricuspid valve  12 , forcing the leaflets closer together or into the closed position, thereby stabilizing them for fixation. In this way, the valve leaflets can be temporarily secured together. This device would allow the operator to pull back on the balloon in systole, and tent or force the leaflets into the closed position. The purpose of this is to evaluate any reduction in tricuspid regurgitation by fixing any coaptation line, or for temporarily holding two leaflets together while a permanent fixation device is affixed, as described below. 
     The present disclosure includes the use of a guidance rail to attain proper positioning within the tricuspid valve. In some aspects, a catheter or wire is threaded through the right atrium, through the tricuspid valve, through the right ventricle, into the right ventricular outflow tract, and into the main pulmonary artery. This catheter or wire may be guided into position utilizing flow-directed guidance, echocardiography, ultrasonography, fluoroscopy, a steerable catheter, or some combination thereof. A fixation device for the tricuspid valve can then be threaded over this guidance rail and to the level of the tricuspid valve. 
       FIG. 14  depicts another embodiment of the present disclosure that includes the use of a guidance rail. The guidance rail  60  can be advanced through the right atrium  14 , past the tricuspid valve  12 , and embedded into the right ventricle  16 . In some aspects, a catheter or wire with a penetrating threaded tip  62  can be advanced via a delivery catheter into the right ventricle. The threaded tip  62  may be configured to bore into the interventricular septum or some other portion of the right ventricle such that the catheter or wire can be made taut under tension. Positioning and guidance can be provided utilizing echocardiography, ultrasonography, fluoroscopy, or some combination. The delivery catheter can then be removed. A fixation device for the tricuspid valve  12  can then be threaded over the guidance rail  60  and to the level of the tricuspid valve  12 . At the conclusion of the procedure, the guidance rail  60  can be removed either in its entirety, or leaving the penetrating threaded tip  62  in situ and removing only the catheter or wire portion. 
       FIG. 15  depicts another embodiment of the present disclosure that includes the use of a guidance rail. A removable guidance rail  60 ′ may be advanced through the right atrium  14 , past the tricuspid valve  12 , and secured against a wall of the right ventricle  16 . The removable guidance rail  60 ′ may be secured using suction. A catheter or wire with a deployable, high compliance, and large area suction tip  64  can be advanced into the right ventricle  16  via a delivery catheter. The suction tip  64  can be positioned against a ventricular wall surface and suction can be applied, holding the suction tip  64  firmly against some portion of the right ventricle  16  such that the catheter or wire can be made taut under tension. Positioning and guidance can be provided utilizing echocardiography, ultrasonography, fluoroscopy, or some combination. The delivery catheter can then be removed. A fixation device for the tricuspid valve  12  can then be threaded over this guidance rail  60 ′ and delivered to the level of the tricuspid valve  12 . 
       FIG. 16  depicts an embodiment of the present disclosure that includes a threaded tip  62 . A delivery catheter  70  may be used to guide and deliver the threaded tip  62  into the right ventricle. The threaded tip  62  can have a penetrating tip. Torque can be transmitted through the delivery catheter  70  or through a wire  72  connected to the threaded tip  62 . 
       FIGS. 17A and 17B  depict another embodiment of the present disclosure that includes a suction tip  64 . The suction tip  64  can be a high area, high compliance skirt. The suction tip  64  can be stowed within the delivery catheter  70 .  FIG. 17A  depicts the suction tip  64  partially unfurled from its stowed configuration.  FIG. 17B  depicts the suction tip  64  in its fully deployed configuration. When unfurled, the suction tip can form a skirt that can be applied to a ventricular surface. Suction can be applied to secure the suction tip  64  to the ventricular wall. The suction tip  64  may be coupled to a guidewire  73 . The guidewire  73  may contain a lumen that allows suction to be applied to the distal face  74  of the suction tip  64 . Suction can be provided by external aspiration. 
       FIG. 18  depicts an embodiment of a device  20 F that is similar to the devices  20  and  20 C- 20 E except as described differently below. The features of the device  20 F can be combined or included with the devices  20  and  20 C- 20 E or any other embodiment discussed herein. The device  20 F can comprise a heart valve prosthesis. The device  20 F has a locking pin  80 F and configured to be deployed over a guidance rail  60 F. The central guidewire  82 F can be hollow and can concentrically surround the guidance rail  60 F that is connected to the threaded tip  62 F. The locking pin  80 F can be connected to the central guidewire  82 F using a detachable attachment feature  104  described above. The distal face of the locking pin  80 F can have an opening  87 F (shown in  FIG. 8C ) that provides access to a rail lumen (not shown) of the hollow central guidewire  82 F. The device  20 F can be preassembled by passing the proximal end of the rail  60 F through the opening  87 F and into the rail lumen of the hollow central guidewire  82 F. The rail  60 F can be sufficiently sized to pass out the proximal end of the hollow central guidewire  82 F. The hollow central guidewire  82 F may also include an inflation lumen for detaching the detachable attachment feature  104 , as described above. 
     To deploy the device  20 F, the guidance rail  60 F can first be advanced and anchored in the right ventricle. The locking pin  80 F and hollow central guidewire  82 F that were pre-assembled onto the guidance rail  60 F can then be advanced along the anchored rail  60 F. The distal plate  22 F can then be advanced over the hollow central guidewire  82 F and positioned using the collar  86 F on the locking pin  80 F. The proximal plate  24 F can then be advanced over the central guidewire  82 F. A pusher tube inserted over the central guidewire  82 F can be used to advance and position the proximal plate  24 F, as described above. The distal and proximal plates  22 F,  24 F can then be secured together by the locking pin  80 F. The central guidewire  82 F can then be detached from the distal and proximal plates  22 F,  24 F by inflating the member  106  of the detachable attachment feature  104 . 
       FIG. 19  depicts a top view of a tricuspid valve  12 , illustrating that the present disclosure envisions variable placement of the device  20  or any of the other devices  20 A- 20 F, as denoted by the dashed lines indicating potential locations L of the device  20 . Positioning of the device  20 - 20 F is variable depending on the location of tricuspid regurgitation. For the majority of cases, an attempt may be made to “bicuspidize” the tricuspid valve by deploying one or more devices  20 - 20 F along any single coaptation line, such that two leaflets are now attached and function as a single large leaflet. In some methods, echocardiography and fluoroscopy are used in conjunction with a steerable tip delivery catheter to achieve device positioning that best limits regurgitation. A device can then be deployed at that location and valve regurgitation can be re-evaluated. If needed, additional devices may be deployed to further reduce valve regurgitation. 
       FIGS. 19A-19G  illustrate a variety of delivery systems and methods that can be combined with the devices  20 - 20 F. The delivery systems can be employed in methods to place the devices  20 - 20 F as discussed above. 
       FIG. 19A  shows placing a guidewire  200  along the venous vasculature V into the heart H. The guidewire  200  can be a flow directed guidewire or can be delivered using other techniques.  FIG. 19B  shows that a delivery system  204  is advanced over the guidewire  200  until a distal portion  208  of the delivery system  204  is disposed adjacent to the heart H. The proximal portion of the delivery system  204  is not shown but would be outside the patient at a peripheral access site. As discussed further below, the delivery system  204  includes a catheter that is configured to deliver some or all of the components of any of the devices  20 - 20 F therein in an unassembled state. In other approaches, separate catheters can be used to deliver individual components of the device  20 - 20 F. 
       FIG. 19C  shows that further advancement of the delivery system  204  places the distal end  208  in the heart H, in particular at or across the tricuspid valve TV. Thereafter, the components of the device  20 - 20 F can be deployed individually. 
       FIG. 19C-1  shows details of the internal arrangement within the distal end  208  of the delivery system  204 . For example, the device  20 B is disposed in the distal end  208  in an unassembled state. The distal plate  22 B, which is one form of a distal member or a first member, is disposed in a first segment  220  of the distal portion  208 . The first segment  220  can be a distal-most segment that extends from a distal tip  221  of the distal portion  208  proximally to a location proximal of the distal plate  22 B. The proximal plate  24 B, which is one form of a proximal member or a second member, is disposed in a second segment  222  of the distal portion  208 . The second segment  222  is disposed immediately proximal of the first segment  220 . In this way, the proximal plate  24 B is disposed between the distal plate  22 B and a proximal end of the delivery system  204 . The distal plate  22 B and the proximal plate  24 B are aligned end-to-end in the distal end  208  of the delivery catheter  204 . Ends of the plates  22 B,  24 B that oppose each other are spaced apart along the length of the distal portion  208 . The locking clip  50 B is an example of a connector that connects the plates  22 B,  24 B by being advanced from a proximal side of the proximal plate  24 B over the proximal plate  24 B, then over a proximal side of the distal plate  22 B until it engages the distal plate  22 B as discussed above. The locking clip  50 B is disposed in a third segment  224  of the distal portion  208  that is disposed immediately proximal of the second segment  222 . 
     A pusher member  230 , which can be a pusher catheter, can be disposed in a lumen of the delivery catheter  204 . The pusher member  230  can act on any one or more of the distal plate  22 B,  24 B, or clip  50 B to move these components out of the delivery catheter  204  into the heart. 
       FIG. 19C-2  shows another embodiment of a delivery system  234  that can be similar to the system  204  except as described differently below. The delivery system  234  has first, second and third segments  220 ,  222 ,  224 . The locking pin  80 C, which is another form of a connector as disclosed herein, can be disposed in the first segment  220 . The locking pin  80 C is an example of a connector as disclosed herein that is advanced into the heart first and thereafter is a base onto which distal and proximal plates  22 C,  24 C are mounted. In the system  234 , the distal plate  22 C is disposed in the second segment  222  and the proximal plate  24 C is disposed in the third segment  224 . A fourth segment can include a space configured to house a locking nut or other locking device that can be used to secure the distal and proximal plates  22 C,  24 C. 
       FIGS. 19D-19G  illustrate the use of the delivery system  234  to build the device  20 C within the heart. The locking pin  80 C, which is a form of a connector, is advanced out of the distal tip  221  of the distal portion  208 .  FIG. 19D  show that the locking pin  80 C can be advanced across leaflets of the valve TV. Such movement can be by floating the pin  80 C or by pushing it using the pusher member  230 . Such movement can result from holding the pin  80 C stationary in the right ventricle and withdrawing the distal tip  221 .  FIG. 19E  shows that thereafter the distal plate  22 C can be advanced over the proximal end of the locking pin  80 C. The advancement of the distal plate  22 C can be achieved by then pusher member  230  which can thereafter be withdrawn back into the distal portion  208 . 
     After the distal plate  22 C is seated on the locking pin  80 C, the proximal plate  24 C can be advanced out of the distal portion  208 , for example using the pusher member  230 . As the proximal plate  24 C is advanced over the pin  80 C the leaflets of the tricuspid valve TV are brought together and trapped. The proximal plate  24 C can be secured to the pin  80 C by an interference fit between the proximal plate  24 C and the pin  80 C. In addition, or in the alternative, a locking nut as discussed above in connection with  FIG. 18  can be advanced over the proximal portion of the locking pin  80 C to removeably or releasably secure the proximal plate  24 C to the locking pin  80 C.  FIG. 19G  shows the leaflet of the tricuspid valve TV secured in a space between a proximal surface of the distal plate  22 C and a distal surface of the proximal plate  24 C. The leaflet thickness of the tricuspid valve TV is much greater in  FIG. 19G  illustrating that the space between the plates  22 C,  24 C can be such that the leaflets fit in the space but are securely trapped, such as by at least some compression of the leaflets. 
     Another aspect of the present disclosure may include the use of a grasper that relies on suction to securely hold each leaflet in position for repair. This grasper can include a series of orifices that are connected to an externally actuated source of vacuum, such that a leaflet positioned in proximity to the orifices will be sucked against the orifices, reducing leaflet movement. 
     Another aspect of the present disclosure may achieve fixation of the leaflet edges by securing the individual leaflet coaptation edges first, then fixing the edges of two adjacent edges together. This can be performed by any securing method such as by applying a suture or staple with or without a pledget to each leaflet coaptation edge, then securing the two sutures or staples together. This method may require the operator to secure only one leaflet edge at a time, rather than two edges simultaneously. The present methods may include affixing a winged feature to each leaflet edge individually, then securing the features together and thereby securing the leaflet edges together. The present disclosure also includes the technique of externalizing sutures that may be applied to the leaflet edges itself, or to a winged feature which is affixed to the leaflet edges, externalizing these sutures, and tying and passing the suture knot intravascularly to the tricuspid valve. 
     Another embodiment of this device achieves fixation by securing two adjacent leaflet edges by tension, clamp, or suction, and applying a fixation device such as a suture or staple, with or without a pledget, to the two adjacent leaflet edges, thereby securing them together. 
     Although the present invention has been disclosed with reference to certain specific embodiments of devices and methods, the inventors contemplate that the invention more broadly relates to methods disclosed above, such as those useful for orienting a catheter with respect to an anatomical structure, as well as performing diagnostic and/or therapeutic procedures in the heart or adjacent the heart. Accordingly, the present invention is not intended to be limited to the specific structures and steps disclosed herein, but rather by the full scope of the attached claims.