WO2025049266A1 - Prosthetic mitral valve for treating patients with small annulus dimensions - Google Patents

Abstract

A prosthetic valve assembly having a disk coupled to the inflow end of the frame and extending radially outward with respect to the frame when the frame is in the expanded condition, the disk being formed of a braided mesh or fabric configured to seal an annular space between the frame and a native valve annulus in an implanted condition of the prosthetic heart valve. In the implanted condition of the prosthetic heart valve, the frame is free of contact with the native valve annulus, the tether prevents atrial migration of the prosthetic heart valve from the native valve annulus, and the disk prevents ventricular migration of the prosthetic heart valve form the native valve annulus.

Description

Prosthetic Mitral Valve for Treating Patients with Small Annulus Dimensions

RELATED APPLICATIONS

[0001] This application claims priority to US Provisional Patent Application No.

63/578,701, filed August 25, 2023, which is hereby incorporated by reference.

BACKGROUND OF THE DISCLOSURE

[0002] The present disclosure relates to expandable prosthetic heart valves, and more particularly, to apparatus and methods for stabilizing an expandable prosthetic heart valve within a native annulus of a patient.

[0003] Prosthetic heart valves that are collapsible to a relatively small circumferential size can be delivered into a patient less invasively than valves that are not collapsible. For example, a collapsible and expandable valve may be delivered into a patient via a tube-like delivery apparatus such as a catheter, a trocar, a laparoscopic instrument, or the like. This collapsibility can avoid the need for a more invasive procedure such as full open-chest, open-heart surgery. [0004] Collapsible and expandable prosthetic heart valves typically take the form of a valve structure mounted on a stent. There are two types of stents on which the valve structures are ordinarily mounted: a self-expanding stent and a balloon-expandable stent. To place such valves into a delivery apparatus and ultimately into a patient, the valve must first be collapsed to reduce its circumferential size.

[0005] When a collapsed prosthetic valve has reached the desired implant site in the patient (e.g., at or near the native annulus of the patient's heart valve that is to be repaired by the prosthetic valve), the prosthetic valve can be deployed or released from the delivery apparatus and expanded to its full operating size. For balloon-expandable valves, this generally involves releasing the entire valve, assuring its proper location, and then expanding a balloon positioned within the valve stent. For self-expanding valves, on the other hand, the stent automatically expands as the stent is withdrawn from the delivery apparatus.

[0006] The clinical success of collapsible and expandable heart valves is dependent, in part, on the anchoring of the valve within the native valve annulus. Self-expanding valves typically rely on the radial force exerted by expanding the stent against the native valve annulus to anchor the prosthetic heart valve. However, if the radial force is too high, the heart tissue may be damaged. If, instead, the radial force is too low, the heart valve may move from its deployed position and/or migrate from the native valve annulus, for example, into the left ventricle.

[0007] Movement of the prosthetic heart valve or other ineffective sealing between the prosthetic heart valve and the native valve annulus may result in the leakage of blood between the prosthetic heart valve and the native valve annulus. This phenomenon is commonly referred to as paravalvular leakage (PVL). In mitral valves, paravalvular leakage enables blood to flow from the left ventricle back into the left atrium during ventricular systole, resulting in reduced cardiac efficiency and strain on the heart muscle.

[0008] Anchoring prosthetic heart valves within the native valve annulus of a patient, especially within the native mitral valve annulus, can be difficult. The native mitral valve annulus, for instance, has reduced calcification or plaque compared to the native aortic valve annulus which can make for a less stable surface to anchor the prosthetic heart valve. For this reason, collapsible and expandable prosthetic mitral valves often include additional anchoring features such as barbs that engage underneath the annulus and/or coils that capture native leaflets, or that wrap around chordae tendineae, thereby stabilizing the prosthetic heart valve within the native annulus.

[0009] One concern is achieving suitable anchoring within the mitral valve is Mitral Annular Calcification (MAC), in which calcium accumulates along the mitral valve annulus. This can result in an overall narrowing of the mitral valve. In such situations, as well as patients with narrow mitral valves for other reasons, the narrow mitral valve annulus can squeeze the implanted prosthetic heart valve, resulting in improper coapting of the prosthetic leaflets.

[0010] Certain existing systems attempted to solve this by providing an outer frame that serves to anchor the prosthetic heart valve relative to the native mitral valve and a separate inner frame that holds the prosthetic leaflets and is physically separated from the mitral valve annulus. This approach, however, results in a prosthetic valve of considerable diameter and can be too wide for patients with MAC and/or narrow valves.

BRIEF SUMMARY OF THE DISCLOSURE

[0011] In accordance with a one or more aspects of the present disclosure, a prosthetic heart valve, including: a collapsible and expandable frame defining an inflow end and an outflow end, the frame being cylindrical in an expanded condition of the frame; a prosthetic valve assembly disposed within the frame, the prosthetic valve assembly including a cuff and a plurality of prosthetic leaflets; a disk coupled at or near the inflow end of the frame and extending radially outward with respect to the frame when the frame is in the expanded condition, the disk being formed of a braided mesh or fabric configured to seal an annular space between the frame and a native valve annulus in an implanted condition of the prosthetic heart valve; and a tether coupled to the outflow end of the frame, wherein in the implanted condition of the prosthetic heart valve, the frame is free of contact with the native valve annulus, the tether prevents atrial migration of the prosthetic heart valve from the native valve annulus, and the disk prevents ventricular migration of the prosthetic heart valve form the native valve annulus.

[0012] In one example, the prosthetic heart valve further includes an apical pad configured to couple to the tether and secure the tether to a ventricular wall of the heart, wherein the disk resists a tension of the tether in the implanted condition.

[0013] In one example, the disk includes a top surface facing away from the outflow end of the frame, and a bottom surface facing toward the outflow end of the frame.

[0014] In one example, the disk is formed of the braided mesh and has fabric on the bottom surface.

[0015] In one example, the disk is formed of the fabric and is formed of a plurality of discrete fabric pieces.

[0016] In one example, the prosthetic heart valve is a prosthetic mitral valve.

[0017] In one example, in an expanded condition of the prosthetic heart valve, the frame has a first outer diameter and the disk has a second outer diameter greater than the first diameter, and the first outer diameter is less than an inner diameter of the native valve annulus.

[0018] In one example, the disk is coupled to the frame by sutures.

[0019] In one example, the prosthetic heart valve further includes a cuff positioned radially outward relative to the frame and coupled to the frame.

[0020] In one example, the frame is cylindrical or substantially cylinder.

[0021] In one example, the frame includes a plurality of struts that form cells connected to one another in one or more annular rows.

[0022] In one example, the annular space between the frame and the native valve annulus extends an entire longitudinal length of the frame.

[0023] In accordance with a one or more aspects of the present disclosure, a method of implanting a prosthetic heart valve within a heart of a patient, including: delivering a delivery device to a native valve annulus while the prosthetic heart valve is collapsed therein, the prosthetic heart valve including a frame, a valve assembly disposed within the frame, a disk coupled to the frame, and a tether coupled to the frame; deploying the prosthetic heart valve from the delivery device and allowing the frame and disk to expand; engaging the disk against an atrial surface of a native valve annulus; tensioning the tether; and securing the tether to an anchor engaged with a wall of the heart, wherein after securing the tether to the anchor, the frame either (i) does not contact the native valve annulus or (ii) does not exert force against the native valve annulus.

[0024] In one example, the delivering step comprises percutaneously delivering the prosthetic heart valve to the native valve annulus using a transapical approach.

[0025] In one example, the anchor comprises an apical pad.

[0026] In one example, the disk includes a top surface facing away from the outflow end of the frame, and a bottom surface facing toward the outflow end of the frame

[0027] In one example, the disk is formed of a braided mesh and has fabric on the bottom surface.

[0028] In one example, the disk is formed of a fabric and is formed of a plurality of discrete fabric pieces.

[0029] In one example, the prosthetic heart valve is a prosthetic mitral valve.

[0030] In one example, in an expanded condition of the prosthetic heart valve, the frame has a first outer diameter and the disk has a second outer diameter greater than the first diameter, and the first outer diameter is less than an inner diameter of the native valve annulus.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various embodiments of the present disclosure are described herein with reference to the drawings, wherein:

[0032] FIG. 1 is a highly schematic cutaway view of the human heart, showing two approaches for delivering a prosthetic mitral valve to an implantation location;

[0033] FIG. 2 is a highly schematic representation of a native mitral valve and associated cardiac structures;

[0034] Fig. 3 is a side perspective view of a prosthetic mitral valve according to one or more aspects of the disclosure; [0035] Fig. 4 is a highly schematic longitudinal cross-section of a prosthetic mitral valve according to an embodiment of the present disclosure; and

[0036] FIG. 5 is a side elevational view of a frame usable with the prosthetic mitral valve of Figs. 3-4.

DETAILED DESCRIPTION

[0037] Blood flows through the mitral valve from the left atrium to the left ventricle. As used herein in connection with a prosthetic heart valve, the term “inflow end” refers to the end of the heart valve through which blood enters when the valve is functioning as intended, and the term “outflow end” refers to the end of the heart valve through which blood exits when the valve is functioning as intended. Also as used herein, the terms “substantially,” “generally,” “approximately,” and “about” are intended to mean that slight deviations from absolute are included within the scope of the term so modified.

[0038] FIG. l is a schematic cutaway representation of a human heart H. The human heart includes two atria and two ventricles: right atrium RA and left atrium LA, and right ventricle RV and left ventricle LV. Heart H further includes aorta A, aortic arch AA and left ventricular outflow tract LVOT. Disposed between left atrium LA and left ventricle LV is mitral valve MV. The mitral valve, also known as the bicuspid valve or left atrioventricular valve, is a dual-flap that opens as a result of increased pressure in left atrium LA as it fills with blood. As atrial pressure increases above that in left ventricle LV, mitral valve MV opens and blood flows into the left ventricle. When left ventricle LV contracts during systole, blood is pushed from the left ventricle, through left ventricular outflow tract LVOT and into aorta A. Blood flows through heart H in the direction shown by arrows “B”.

[0039] A dashed arrow, labeled “TA”, indicates a transapical approach of implanting a prosthetic heart valve, in this case to replace the mitral valve. In the transapical approach, a small incision is made between the ribs of the patient and into the apex of left ventricle LV to deliver the prosthetic heart valve to the target site. A second dashed arrow, labeled “TS”, indicates a transseptal approach of implanting a prosthetic heart valve in which the delivery device is inserted into the femoral vein, passed through the iliac vein and the inferior vena cava into right atrium RA, and then through the atrial septum into left atrium LA for deployment of the valve. Other approaches for implanting a prosthetic heart valve are also possible and may be used to implant the collapsible prosthetic heart valve described in the present disclosure. [0040] FIG. 2 is a more detailed schematic representation of native mitral valve MV and its associated structures. As previously noted, mitral valve MV includes two flaps or leaflets, posterior leaflet PL and anterior leaflet AL, disposed between left atrium LA and left ventricle LV. Cord-like tendons, known as chordae-tendineae CT, connect the two leaflets to the medial and lateral papillary muscles P. During atrial systole, blood flows from higher pressure in left atrium LA to lower pressure in left ventricle LV. When the left ventricle LV contracts during ventricular systole, the increased blood pressure in the chamber pushes the posterior and anterior leaflets to close, preventing the backflow of blood into left atrium LA. Since the blood pressure in left atrium LA is much lower than that in left ventricle LV, the leaflets attempt to evert to low pressure regions. Chordae tendineae CT prevent the eversion by becoming tense, thus pulling on the leaflets and holding them in the closed position.

[0041] Fig. 3 is a side perspective view of a prosthetic heart valve 300 according to one or more aspects of the disclosure and Fig. 4 is a highly schematic longitudinal cross-section of the prosthetic heart valve 300 according to one or more aspects of the disclosure. In one example, the prosthetic heart valve 300 can be a prosthetic mitral valve used to repair a native mitral valve.

[0042] Prosthetic heart valve 300 can be self-expanding such that the valve 300 can automatically expand as a sheath of a delivery device (not shown), which maintains the valve 300 in a collapsed condition is withdrawn relative to the valve 300. For balloon-expandable variants, prosthetic heart valve 300 may be plastically expandable. When used to replace native mitral valve MV (shown in FIGS. 1 and 2), prosthetic heart valve 300 may have a low profile so as to minimize any interference with the heart’ s electrical conduction system pathways, atrial function or blood flow to the left ventricular outflow tract LVOT (shown in FIG. 1).

[0043] Prosthetic heart valve 300 can include a frame 310 securing a leaflet assembly 350 (depicted in Fig. 4) within the frame 310, and a tether 315 configured to be secured to both the frame 310 and an apical pad 320 or other anchor device. The frame 310 may be formed from biocompatible material(s) that are capable of self-expansion, for example, shape-memory alloys such as nitinol. Alternatively, frame 310 may be balloon expandable or expandable by another force exerted radially outward on the frame 310. If the frame 310 is balloon expandable, it may be formed of a plastically expandable material such as cobalt chromium or stainless steel. In one example, frame 310 is formed by laser cutting a predetermined pattern into a metallic tube, such as a nitinol tube. After cutting the frame 310, the frame 310 may be set to a desired shape, for example via heat treatment, so that the frame 310 tends to revert to the set shape in the absence of applied forces. The frame 310 can be cylindrical or substantially cylinder and can be circular or ovular in cross sectional shape.

[0044] The frame 310 extends along a longitudinal axis between an inflow end 312 of the frame 310 and an outflow end 314 of the frame 310 and may include a plurality of struts 310a that form cells 310b connected to one another in one or more annular rows around the frame 310. Cells 310b may all be of substantially the same size around the perimeter and along the length of frame 310. Alternatively, cells 310b near inflow end 312 may be larger than the cells near outflow end 314, or vice versa. While the cells 310b shown in Fig. 3 are generally diamond-shaped, the cells 310b can be any shape that allow for collapsing and expansion of the frame 310. It should be understood that a different number of rows of cells 310b, as well as a different number of cells 310b per row, may be suitable.

[0045] As shown in Fig. 4, the prosthetic heart valve 300 may include a leaflet assembly 350 that may be secured within frame 310 by suturing to struts 310a or by using tissue adhesives, ultrasonic welding, suture, or other suitable methods. The leaflet assembly 350 may also be secured to the cuff 360. The leaflet assembly 350 may be cylindrical or substantially cylindrical.

[0046] The leaflet assembly 350 can include a cuff 352 and a plurality of prosthetic leaflets 354 that open and close collectively to function as a one-way valve. The leaflet assembly 350, including leaflets 354 and with or without the cuff 352, may also be referred to as a valve assembly. Leaflets 354 replace the function of native mitral valve leaflets (e.g., PL and AL) described above with reference to Figs. 1-2. That is, leaflets 354 coapt with one another to function as a one-way valve. The leaflet assembly 350 of prosthetic heart valve 300 may include two or three leaflets 354, but it should be appreciated that prosthetic heart valve 300 may have more than three leaflets. Cuff 352 and/or leaflets 354 may be wholly or partly formed of any suitable biological material, such as bovine or porcine pericardium, or biocompatible polymer, such as polytetrafluorethylene (PTFE), urethanes and the like. In one particular example, prosthetic valve 300 includes three prosthetic leaflets 354 formed from pericardial tissue (e.g. bovine or porcine pericardium), and the cuff 352 is formed of PTFE, with the cuff 352 generally functioning to prevent blood from flowing through cells 310b. The leaflets 354 may include free edges that coapt with one another (as shown in Fig. 4) to prevent retrograde blood flowthrough the prosthetic heart valve 300. The leaflets 354 may also include an attached edge portion that is coupled (e.g. via sutures) to cuff 352, which in turn is coupled (e.g. via sutures) to frame 310.

[0047] In one example, the prosthetic mitral valve 300 can be implanted using a transapical approach. In this regard, an apical pad 320 can be secured to an exterior portion of a ventricular wall of the heart. A tether 315 can be secured to frame 310 (preferably at the outflow end 314 of the frame 310) and also to apical pad 320 to provide tension between the valve 300 and the apical pad 320. The tether 315 can include one or more strands 315a that couple to the frame 310, for example by coupling to one or more struts 310a of the frame 310. In other examples, the strands 315a may be formed integrally with the frame 310, as shown in Fig. 5.

[0048] Prosthetic heart valve 300 may also include a cuff 360 positioned radially outward relative to frame 310. The cuff 360 can be fabric and can be coupled directly to the frame 310. In one example, the cuff 360 is sutured to the frame 310, while in other examples any type of coupling technique can be used. The cuff 360 may be formed partially or completely of fabric, and in some cases can promote tissue ingrowth for enhanced sealing and/or long-term anchoring.

[0049] The prosthetic mitral valve 300 can include a disk 325 at or near the inflow end 312 of the frame 310 that provides both a sealing function with respect to blood flow (thereby preventing PVL) and an anchoring function with respect to the native valve annulus. The disk 325 can be annular in shape and define an inner diameter near the inflow end 312 of frame 310 and an outer diameter (d?) a spaced radial distance from the frame 310. The inner diameter can approximately the same size as an outer diameter of frame 310 (di) to allow for coupling of the disk 325 to the frame 310.

[0050] The disk 325 can include a lower surface 325a and an upper surface 325b (depicted in Fig. 4). As described in greater detail below, the disk 325 may be formed of a braided mesh of shape memory alloy. In some embodiments, the lower surface 325a may be shape set to better conform to the anatomy above the native annulus tissue. In other words, the lower surface 325a of the disk 325 may, in the absence of applied forces, tend to have a shape that is generally complementary to the contours of the atrial side of the native valve annulus which the disk 325 is intended to contact. In other examples, the disk 325 may be highly conformable so that it will tend to take a shape complementary to the surface(s) of the anatomy which it contacts. When expanded, the lower surface 325a of disk 325 engages an atrial surface of the native valve annulus and assists in anchoring prosthetic mitral valve 300 within the native valve annulus when tether 315 is tensioned and secured to apical pad 320. As mentioned above, the disk 325 also performs a sealing function by sealing the annular space between the frame 310 and the native valve annulus, thereby preventing leakage of blood between the prosthetic heart valve 300 and the native valve annulus. This may be particularly important of the frame 310 is intentionally undersized relative to the native valve annulus. In other words, self-expanding prosthetic heart valves are typically intentionally oversized so that, upon self-expansion, the frame expands into and presses against the native valve annulus to provide an anchoring force. In these systems, the nature of the frame pressing against the interior surface of the native valve annulus, particularly in combination with a sealing skirt or cuff, provides adequate sealing between the prosthetic heart valve and the native valve annulus. However, if the frame 310 is intentionally undersized (as explained in greater detail below), a separate source of sealing becomes particularly important.

[0051] The disk 325 may be composed of nitinol braid or fabric (e.g., yam, PET). In the example of a fabric disk, both the bottom surface 325a and upper surface 325b are fabric, with the fabric bottom surface 325a allowing for tissue ingrowth and preventing PVL. The fabric may be stretchable and may be a single piece of fabric or may include a plurality of discrete fabric pieces. In this example, certain fabrics, such as yams, can have a large enough stiffness to counter the tension loads of tether 315 and apical pad 320.

[0052] In the example of a braided nitinol disk, the bottom surface 325a can include fabric thereon to allow tissue ingrowth and prevent PVL. In other examples of braided nitinol disks, the disk may be provided with two (or more) layers, with a fabric or similar sealing member positioned between the layers. The disk 325 retains and secures the valve 300 in the native annulus and resists a portion of the tension from the tether 315. Advantageously, the disk provides both an anchoring/securing function as well as a sealing function, this allows for the leaflet assembly 350, including cuff 352 and/or leaflets 354, to be less impacted by calcification within the native valve annulus and the contact forces which the calcification (e.g. calcific nodules) might otherwise impart on the frame 310. During delivery of the prosthetic valve 300, the disk 325 preferably extends away from the frame 310 so that there is little or no radial overlap between the disk 325 and the frame 310, helping to minimize the profile of the prosthetic heart valve 300 when collapsed within the delivery device. However, in other embodiments, the disk 325 could overlie the frame 310 during delivery. [0053] Disk 325 may include a plurality of braided strands or wires arranged in three dimensional shapes. In one example, wires form a braided metal fabric that is resilient, collapsible and capable of heat treatment to substantially set a desired shape. One class of materials which meets these qualifications is shape-memory alloys, such as nitinol. Wires may comprise various materials other than nitinol that have elastic and/or shape memory properties, such as spring stainless steel, tradenamed alloys such as Elgiloy® and Hastelloy®, CoCrNi alloys (e.g., tradename Phynox), MP35N®, CoCrMo alloys, or a mixture of metal and polymer fibers. Depending on the individual material selected, the strand diameter, number of strands, and pitch may be altered to achieve the desired shape and properties of disk 325. Braided flange configurations are further described in US 11,364,117 to Dale et al. and US 10,743,992 to Krans et al., the entirety of each of which are incorporated herein by reference.

[0054] The disk 325 may be coupled directly or indirectly to the frame 310 at any point along the longitudinal axis. For example, the disk 325 may be coupled to frame 310 in a region of the frame 310 near the inflow end 312, while in another example the disk 325 may be coupled to the frame 310 in a region of the frame near the outflow end 314. In the particular example depicted in Fig. 4, the disk 325 is coupled to frame 310 at the inflow end 312 of frame 310. When coupled, top surface 325b is facing away from the outflow end 314 of prosthetic heart valve 300 and bottom surface 325a is facing outflow end 314.

[0055] In the examples of Fig. 3 and 4, the disk 325 is depicted is having a planar (or substantially planar) top surface 325b and a planar (or substantially planar) bottom surface 325a, with the top surface 325b and bottom surface 325a being parallel (or substantially parallel) to one another. Also depicted is that the disk 325 itself is substantially perpendicular to the central longitudinal axis of the prosthetic valve 300. In other examples, the disk 325 can have different shapes and/or configurations. For example, the disk 325 can be configured such that bottom surface 325a extends toward either inflow end 312 or outflow end 314. In other examples, the disk can be non-symmetrical with overall smooth edges, can be “petaled” like a flower, or could be round or oval in shape.

[0056] Disk 325 may be coupled to frame 310 (and optionally to leaflet assembly 350 and/or cuff 360 and/or cuff 352) by sutures, for example. Disk 325 alternatively or additionally may be connected to frame 310 via ultrasonic welds, glue, adhesives, suture, or other suitable means. [0057] As shown in Fig. 4, in the expanded condition of the prosthetic heart valve 300, disk 325 extends radially outward relative to frame 310. In this regard, the disk 325 can define a diameter d? and the frame 310 can define a diameter di. Where the frame 310 includes cuff 360, the diameter di can represent the outer diameter of the cuff 360.

[0058] Since the disk 325 performs an anchoring function relative to the native mitral valve annulus, there is no need for the frame 310 (or the cuff 360) to contact the native mitral valve annulus in the implanted state. In this regard, the diameter di of the frame 310 (or the cuff 360) is preferably less than an inner diameter of the native mitral valve annulus, with an annular space being defined between the frame 310 (and/or cuff 360) and the native mitral valve annulus. The annular space can extend a portion or an entire longitudinal length of the frame 310 (and/or cuff 360). Stated another way, the frame 310 (and/or cuff 360) is preferably mostly or entirely free from contacting, and preferably only minimally contacts or does not contact, the native mitral valve annulus in the implanted state. However, in some cases, particularly in cases with significant MAC, the cuff 360 may end up contacting the native tissue, in which case the cuff 360 may provide for enhanced sealing (beyond the sealing function provided by disk 325), for example via tissue ingrowth. Even if the cuff 360 contacts that native tissue, forces applied by the frame 310 onto the native valve annulus alone are not large enough to anchor the frame 310 within the native valve annulus without the atrial and ventricular anchoring functions performed by disk 325 and apical pad 320. In other words, even if the frame 310 applies lateral force on the native valve annulus, that force alone is not enough to prevent atrial migration or ventricular migration.

[0059] The diameter d? is greater than the diameter di. Since the disk 325 performs the anchoring and sealing function, the diameter d? is greater than a diameter of the native mitral valve annulus. In an implanted condition of the prosthetic valve 300, the bottom surface 325a confronts and engages with the atrial side of the native mitral valve annulus and the disk 325 provides resistance to the tension of tether 315. Also in the implanted condition, the disk 325 helps to prevent PVL by extending across the annular space between frame 310 (and/or cuff 360) and the native mitral valve annulus.

[0060] Use of prosthetic heart valve 300 to repair a malfunctioning native heart valve, such as a native mitral valve, or a previously implanted and malfunctioning prosthetic heart valve, will now be described with reference to Fig. 3 and 4. Although prosthetic heart valve 300 is described herein as repairing a native mitral valve using a transapical approach, it will be appreciated that the prosthetic heart valve may be used to repair the native mitral valve using a transseptal or other suitable approach, as well as to repair other cardiac valves, such as the tricuspid, aortic, or pulmonary valve, using any suitable approach.

[0061] With a first end of tether 315 secured to the frame 310, a physician may pull the free end of the tether through a loading device (not shown), such as a funnel, to crimp or collapse frame 310. After prosthetic heart valve 300 has been collapsed (or simultaneous to the collapsing), the prosthetic heart valve may be loaded within a delivery device (not shown) with the free end of tether 315 extending back towards the trailing end (not shown) of the delivery device such that it can be manipulated by a physician. For example, devices and methods for tensioning tethers and coupling tethers to anchors are described in greater detail in U.S. Patent No. 10,517,728, the disclosure of which is hereby incorporated by reference herein.

[0062] After an incision has been made between the ribs of the patient and into the apex of the heart, the delivery device (not shown) may be introduced into the patient using a transapical approach and delivered to an implant site adjacent to or within the native mitral valve annulus. Once the delivery device has reached the target site, with a leading end of delivery sheath disposed within the mitral valve annulus or within the left atrium LA, the delivery sheath may be retracted, relative to the prosthetic heart valve 300, to expose the inflow end 312 of frame 310 and to expose disk 325, thereby allowing frame 310 and disk 325 to expand and transition from the delivery condition to the expanded/deployed condition.

[0063] After the disk 325 is exposed, the physician may then retract delivery device in a proximal direction until disk 325 and, more specifically, bottom surface 325a is engaged against the atrial surface of the native mitral annulus. In some embodiments, retracting the delivery device will cause the desired proximal movement of the disk 325. In other embodiments, the tether 315 may be pulled proximally to cause proximal movement of the disk 325. During the delivery and implantation procedure, the frame 310 self-expands but does not come into contact with the native mitral valve annulus, or otherwise only minimally contacts the inner surface of the mitral valve annulus. For example, when the frame 310 fully expands to its set-shape, the frame 310 may fully avoid contact with that mitral valve annulus, or may otherwise minimally contact, but exert substantially zero radial force, onto the mitral valve annulus. A pusher or similar member may be utilized to prevent the prosthetic heart valve 300 from retracting as the delivery device is retracted. With disk 325 engaged against the atrial surface of the mitral valve annulus, the physician may further unsheathe prosthetic heart valve 300, allowing the outflow end 314 of frame 300 to expand. After the frame 310 has been expanded, a physician may determine whether prosthetic heart valve 300 has restored proper blood flow through the native mitral valve. More particularly, the physician may determine: 1) whether leaflet assembly 350 is functioning properly; and 2) whether the prosthetic heart valve 300 has been properly seated within the native valve annulus to form a seal between the prosthetic heart valve and the native mitral valve annulus.

[0064] In the event that the physician determines that the leaflet assembly 350 is malfunctioning or that prosthetic heart valve 300 is positioned incorrectly within the native mitral annulus, the physician may partially or completely recapture the prosthetic heart valve and repeat the procedure described above, or otherwise abandon the procedure by removing the prosthetic heart valve 300 entirely from the patient.

[0065] After the physician has confirmed that prosthetic heart valve 300 has been properly positioned, and leaflets 354 are properly coapting, the physician may pass the apical pad 320 over the free trailing end of the tether 315, insert apical pad 320 through the incision in the chest and into contact with the outer surface of the ventricular apex, tension the tether (e.g. by manually pulling the tether or using a tether tensioning device), and once the desired tension is achieved, lock the tether 315 and apical pad 320 together at the desired tension. Suitable apical pads 320 and tether tensioning devices are described in greater detail in U.S. Patent Nos. 11,612,480 and 11,382,753, the disclosures of which are hereby incorporated by reference herein.

[0066] Apical pad 320, which may be positioned in contact with an exterior surface of left ventricle LV at the transapical puncture site, may be reversibly locked to tether 315, preventing the tether from releasing the tension. The physician may then cut the tether located outside of the heart before removing the cut portion of the tether. With prosthetic heart valve 300 properly positioned and anchored within the native mitral valve annulus of a patient, the prosthetic heart valve may work as a one-way valve to restore proper function of the heart valve by allowing blood to flow in one direction (e.g., from the left atrium to the left ventricle) while preventing blood from flowing in the opposite direction.

[0067] FIG. 5 is a side elevational view of a frame 512 usable with the prosthetic mitral valve of Figs. 3-4, for example in place of frame 310. As shown, frame 512 extends along a longitudinal axis between an inflow end 522 and an outflow end 524. In one example, frame 512 is formed by laser cutting a predetermined pattern into a metallic tube, such as a nitinol tube, to form four portions: cusps 526, a post portion 528, a strut portion 530 and a valve stem 532 (or “tether clamp”) that secures one end of the tether 315 (shown in Figs. 3-4). Strut portion 530 may include, for example, six struts that extend radially inward from post portion 528 to tether clamp 532. When frame 512 is expanded, strut portion 530 forms a radial transition between post portion 528 and tether clamp 532 that facilitates crimping of the inner stent when tether 315 is retracted within a delivery device. Post portion 528 may also include six longitudinal posts 534 having a plurality of bores 536 for securing leaflet assembly 350 to the frame 512 by one or more sutures. Although six longitudinal posts 534 are shown, with a three- leaflet valve, only three of the posts 534 may be used to couple the prosthetic leaflets 354 (and particularly the commissures formed between adjacent prosthetic leaflets 354) to the frame 522. As shown in FIG. 5, three cusps 526 are positioned at the inflow end 522 of frame 512. Each cusp 526 is circumferentially disposed between a pair of non-adjacent longitudinal posts 534 with a single longitudinal post positioned between each of the non-adjacent longitudinal posts. The cusps 526 may be used to couple (e.g. via suturing) the bellies of the three prosthetic leaflets 354 to the frame 522.

[0068] Whether prosthetic heart valve 300 incorporates frame 310, frame 522, or another frame, it is preferable that the frame 310/522 is stiffer than the disk 325. For example, if the frame 310/522 is formed from a laser-cut tube of nitinol, and the disk 325 is formed as a braided mesh of nitinol strands, the frame 310/522 will typically be significantly stiffer than the disk 325. This may be preferable because the frame 310/522 has the main purpose of supporting the prosthetic leaflets 354 and maintaining a substantially constant geometry of the leaflet assembly 350 (excluding opening/closing of the prosthetic leaflets 354), while the disk 325 largely functions to provide sealing against the native mitral valve. A high level of flexibility (or a low level of stiffness) of the disk 325 helps the disk 325 to closely conform to the contours of the tissue it contacts, thereby providing enhanced sealing. And although the disk 325 may provide anchoring functionality, there are not significant forces that act on the prosthetic heart valve 300 to push the prosthetic heart valve 300 into the ventricle during atrial systole, because the prosthetic leaflets 354 are open during ventricular systole. In other words, a highly flexible disk 325 may simultaneously provide both the desired sealing and anchoring against ventricular migration. This is in contrast to ventricular systole, in which the prosthetic leaflets 354 are closed and significant back pressure is applied to the prosthetic heart valve 300 in the atrial direction. However, as noted above, the tether 315 and anchor 320 may assist in preventing atrial migration of the of the prosthetic heart valve 300 during ventricular systole. [0069] Further, as should be clear from the above description, prosthetic heart valve 300 is configured to provide adequate sealing and anchoring within a small-diameter mitral valve annulus, whether the size is a result of natural anatomy or heavy calcification. Because the frame 310/522, to which the prosthetic leaflets 324 are attached, does not contact (or only minimally contacts) the native valve annulus upon implantation, the frame 310/522 will tend to avoid being deformed by forces from the native mitral valve annulus. This, in turn, helps to avoid deformation of the prosthetic leaflets 324, which could result in improper coaptation and sealing of the prosthetic leaflets 324. Despite the lack of contact, proper anchoring is still provided by a combination of the disk 325 and the assembly of the tether 315 and anchor 320. [0070] Finally, as should be clear from the above description, a patient with a small native mitral valve annulus may not be a suitable candidate for treatment with a traditional doubleframed prosthetic mitral valve in which an outer frame provide anchoring force and sealing, with an inner frame supporting the prosthetic leaflets. This is because, at least in part, the prosthetic valve assembly must have a minimum size in order to provide a large enough area for sufficient blood volume to flow through. There may simply not be enough space within this patient population to have an inner frame that is large enough to support prosthetic leaflets that allow sufficient blood flow, while also having a separate outer frame that provides for anchoring and sealing. The prosthetic heart valves described herein, however, may be well- suited to treat this patient population.

[0071] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A prosthetic heart valve, comprising: a collapsible and expandable frame defining an inflow end and an outflow end, the frame being cylindrical in an expanded condition of the frame; a prosthetic valve assembly disposed within the frame, the prosthetic valve assembly including a cuff and a plurality of prosthetic leaflets; a disk coupled at or near the inflow end of the frame and extending radially outward with respect to the frame when the frame is in the expanded condition, the disk being formed of a braided mesh or fabric configured to seal an annular space between the frame and a native valve annulus in an implanted condition of the prosthetic heart valve; and a tether coupled to the outflow end of the frame, wherein in the implanted condition of the prosthetic heart valve, the frame is free of contact with the native valve annulus, the tether prevents atrial migration of the prosthetic heart valve from the native valve annulus, and the disk prevents ventricular migration of the prosthetic heart valve form the native valve annulus.

2. The prosthetic heart valve of claim 1, further comprising: an apical pad configured to couple to the tether and secure the tether to a ventricular wall of the heart, wherein the disk resists a tension of the tether in the implanted condition.

3. The prosthetic heart valve of claim 1, wherein the disk includes a top surface facing away from the outflow end of the frame, and a bottom surface facing toward the outflow end of the frame.

4. The prosthetic heart valve of claim 3, wherein the disk is formed of the braided mesh and has fabric on the bottom surface.

5. The prosthetic heart valve of claim 3, wherein the disk is formed of the fabric and is formed of a plurality of discrete fabric pieces.

6. The prosthetic heart valve of claim 1, wherein the prosthetic heart valve is a prosthetic mitral valve.

7. The prosthetic heart valve of claim 1, wherein in an expanded condition of the prosthetic heart valve, the frame has a first outer diameter and the disk has a second outer diameter greater than the first diameter, and the first outer diameter is less than an inner diameter of the native valve annulus.

8. The prosthetic heart valve of claim 1, wherein the disk is coupled to the frame by sutures.

9. The prosthetic heart valve of claim 1, further comprising a cuff positioned radially outward relative to the frame and coupled to the frame.

10. The prosthetic heart valve of claim 1, wherein the frame is cylindrical or substantially cylinder.

11. The prosthetic heart valve of claim 1, wherein the frame includes a plurality of struts that form cells connected to one another in one or more annular rows.

12. The prosthetic heart valve of claim 1, wherein the annular space between the frame and the native valve annulus extends an entire longitudinal length of the frame.

13. A method of implanting a prosthetic heart valve within a heart of a patient, comprising: delivering a delivery device to a native valve annulus while the prosthetic heart valve is collapsed therein, the prosthetic heart valve including a frame, a valve assembly disposed within the frame, a disk coupled to the frame, and a tether coupled to the frame; deploying the prosthetic heart valve from the delivery device and allowing the frame and disk to expand; engaging the disk against an atrial surface of a native valve annulus; tensioning the tether; and securing the tether to an anchor engaged with a wall of the heart, wherein after securing the tether to the anchor, the frame either (i) does not contact the native valve annulus or (ii) does not exert force against the native valve annulus.

14. The method of claim 13, wherein the delivering step comprises percutaneously delivering the prosthetic heart valve to the native valve annulus using a transapical approach.

15. The method of claim 13, wherein the anchor comprises an apical pad.

16. The method of claim 13, wherein the disk includes a top surface facing away from the outflow end of the frame, and a bottom surface facing toward the outflow end of the frame

17. The method of claim 13, wherein the disk is formed of a braided mesh and has fabric on the bottom surface.

18. The method of claim 13, wherein the disk is formed of a fabric and is formed of a plurality of discrete fabric pieces.

19. The method of claim 13, wherein the prosthetic heart valve is a prosthetic mitral valve.

20. The method of claim 13, wherein in an expanded condition of the prosthetic heart valve, the frame has a first outer diameter and the disk has a second outer diameter greater than the first diameter, and the first outer diameter is less than an inner diameter of the native valve annulus.