Interventional heart valve stent with staggered folding valve leaflets

Abstract

The invention discloses an interventional heart valve stent with staggered folding valve leaflets.The heart valve stent is in a circular ring shape, the heart valve stent comprises basic units which are repeatedly arranged in the circumferential direction, each basic unit comprises a compressible structure, and at least one compressible structure is of an inwards-concave structure; the main body structure is sequentially provided with three areas in the circumferential direction, the three valve leaflets are fixed to valve leaflet suture point positions of the three areas respectively, two side end suture point positions, located at the two ends of the circumferential direction, of each valve leaflet are fixed to the compressible structure, and the axial compression displacement of the two edge point positions is different. According to the stent structure, when the valve is pressed and held out of the conveying sheath tube, the valve leaflets are pulled to be distributed in a staggered mode in the axial direction through displacement of the valve frame and valve leaflet suture points, the number of valve leaflet folding layers is reduced, damage caused by mutual extrusion of the valve leaflets is relieved, and therefore the long-term durability rate of the valve after the valve is implanted into a human body is improved.

Description

Technical Field

[0001] This invention belongs to the technical field of artificial heart valve implantation devices, specifically relating to an interventional heart valve stent with staggered folded leaflets. Technical Background

[0002] Valvular heart disease is a common type of heart disease, mainly caused by congenital heart disease, rheumatic heart disease, or age-related degenerative changes. The most prominent pathological feature of valvular disease is the formation and accumulation of calcified nodules on the valves. Valvular calcification initially results from endothelial damage or traditional calcification risk factors (inflammation and lipid deposition). The fibrous supporting structures of the valve undergo chronic degeneration, fibrosis, and calcium salt deposition, leading to valve thickening, hardening, and deformation, which in turn causes valvular stenosis and / or regurgitation. Transcatheter valve replacement (TVR) is required, using minimally invasive techniques to deploy an interventional heart valve to the aortic or mitral valve via the femoral artery, apex, or other approaches, thereby replacing the diseased valve.

[0003] In transcatheter aortic valve resuscitation (TVR), the heart valve is anchored to a valve stent. After being squeezed to reduce its volume, it can be delivered via minimally invasive intervention. However, the squeezing process can cause the valve leaflets to curl and compress, leading to increased compressive stress, leaflet damage, and further leaflet fatigue, resulting in premature valve failure. Furthermore, the risk of leaflet damage increases significantly with the reduction in stent size after squeezing. Therefore, exploring an interventional heart valve stent that can mitigate the irreversible damage to the leaflets caused by squeezing and improve the long-term durability of the valve during its service life in the human body is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] This application addresses the technical problem that existing artificial heart valve stents cause leaflet curling and compression during the compression process, leading to increased compressive stress and damage, and further causing premature failure of the leaflets due to fatigue damage. It provides an interventional heart valve stent with staggered folded leaflets that can reduce the damage caused by mutual compression of the leaflets, thereby improving the long-term durability of the valve after implantation.

[0005] The technical solution adopted by this application to solve the above-mentioned technical problems is as follows:

[0006] An interventional cardiac valve stent with staggered folded leaflets, wherein the main structure of the cardiac valve stent is annular, the main structure includes basic units arranged repeatedly along the circumferential direction, the basic units include compressible structures, and at least one compressible structure is a concave structure; the main structure is arranged with three regions in sequence along the circumferential direction, and three leaflets are respectively fixed at the leaflet suture points in the three regions, and the two lateral suture points at both ends of each leaflet in the circumferential direction are fixed to the compressible structures, and at least two lateral suture points have different axial compression displacements.

[0007] Some basic units have variant structures, and the lateral or basal suture points of some leaflets are located on the variant structures, with the basal suture points located close to the bottom of the leaflets; the axial compression displacement at the variant structures differs from the axial compression displacement at the same position in the basic units.

[0008] The three regions have the same length along the circumference and the same length along the axis, and the number of basic units spanned by the three regions along the circumference gradually decreases along the circumferential direction.

[0009] The basic unit includes a concave hexagonal structure, a hexagonal structure, and a downward bending structure arranged sequentially along the axial direction. The lower concave point of the concave hexagonal structure and the upper vertex of the hexagonal structure are connected by a first straight line structure, and the lower vertex of the hexagonal structure and the bending point of the downward bending structure are connected by a second straight line structure.

[0010] The main structure includes a first region, a second region, and a third region arranged sequentially along a circumferential direction. The number of basic units spanned by the first region, the second region, and the third region along the circumferential direction are 4.5, 4, and 3.5, respectively. The lateral end suture points of two adjacent leaflets coincide. When the main structure is not compressed, the lateral end suture points of the three leaflets are located on the same circumferential line.

[0011] The variant structure includes a first variant structure located at the bottom suture point of the leaflet in the first region, a second variant structure located at the bottom suture point of the leaflet in the third region, and a third variant structure located at the side suture point where the leaflets of the second and third regions overlap. The side suture point where the leaflets of the first and third regions overlap is located on the side of the concave hexagonal structure. The side suture point where the leaflets of the first and second regions overlap is located at the bottom concave point of the concave hexagonal structure. The bottom suture point of the leaflet in the second region is located near the bending point of the lower bending structure.

[0012] The first variant structure is a connecting line structure extending from the connection point to the bottom side of the hexagonal structure; the second variant structure is formed by shifting the stitching points of both ends of the lower bending structure of the base unit upwards; the third variant structure has a variant bending line in the concave hexagonal structure of the base unit, while the lower concave point moves down to the convex point to form an convex point, the vertex of the hexagonal structure moves down to the concave point, the convex point connects with the bending point of the variant bending line, and the third variant structure is formed after removing the first straight line structure.

[0013] The three regions have the same length along the circumference and the same length along the axis. The number of basic units that the three regions span along the circumference is the same in the direction of circumference. The lateral suture points of the three leaflets are located at the same circumferential height, and at least one lateral suture point is located on the variant structure.

[0014] The basic unit includes a concave hexagonal structure, two connected rhombus structures, and a downward bending structure arranged sequentially along the axial direction. The lower concave point of the concave hexagonal structure is connected to the upper vertex of the upper rhombus structure, and the bottom vertex of the lower rhombus structure is connected to the downward bending structure by a straight line structure.

[0015] The lateral suture points of two adjacent leaflets coincide, and at least one set of lateral suture points in adjacent regions are located on the variant structure.

[0016] The heart valve stent is made of malleable expandable material and / or self-expanding material.

[0017] The leaflets are made of biomaterials and / or polymer materials.

[0018] The advantages of the interstitial cardiac valve stent with staggered folded leaflets described in this invention are:

[0019] (1) In the interstitial cardiac valve stent with staggered folded leaflets of the present invention, the two side suture points at both ends of each leaflet in the circumferential direction are fixed on the compressible structure, and the axial compression displacement of the two edge points is different. When axially pressed, due to the different axial displacements of the two edge points, the leaflets are pulled to curl and fold at different axial heights, expanding the leaflet folding area in the axial space, and then concentrating on the middle part to fold, avoiding damage caused by leaflet folding and squeezing, thereby improving the long-term durability of the leaflets in the human body.

[0020] (2) The interstitial cardiac valve stent with staggered folded leaflets in this invention preferably utilizes the number and structure of circumferentially uneven units. When gripped, the leaflets are pulled to curl and fold at a greater axial height through the leaflet suture point. After gripping, the three leaflets are staggered in the circumferential direction, which can further reduce the number of folding layers in the tightly folded part of the leaflets.

[0021] (3) In the interleaved folded leaflet interventional cardiac valve stent of the present invention, the structure located on the upper part of the stent in the basic unit adopts a large grid structure, which reduces the metal coverage of the inner wall of the aortic sinus, avoids the obstruction of the coronary artery entrance, and reduces the risk of insufficient coronary blood supply.

[0022] To make the technical solution of the interstitial cardiac valve stent with staggered folded leaflets of the present invention clearer, the present invention will be further described below in conjunction with specific embodiments. Attached Figure Description

[0023] Figure 1 This is a side view of the interventional cardiac valve stent with staggered folded leaflets as described in this invention.

[0024] Figure 2 This is a perspective view of the interstitial cardiac valve stent with staggered folded leaflets as described in this invention.

[0025] Figure 3 This is a schematic diagram of the basic unit of the interstitial cardiac valve stent with staggered folded leaflets as described in this invention.

[0026] Figure 4 This is a diagram showing the unfolded structure of the interstitial cardiac valve stent with staggered folded leaflets as described in this invention.

[0027] Figure 5 This is a diagram showing the unfolded structure of the interventional cardiac valve stent covering the valve leaflet, where the number of basic units in each region gradually decreases, as described in this invention.

[0028] Figure 6 This is a diagram showing the unfolded structure of an interventional cardiac valve stent with the same number of basic units in each region, as described in this invention, when covering the valve leaflets.

[0029] The attached figures are labeled as follows:

[0030] Main structure of a heart valve stent; 11- Concave hexagonal structure; 12- Hexagonal structure; 13- Bending structure; 101- First region; 102- Second region; 103- Third region; 1001- Overlapping suture point of the left end of the first leaflet and the right end of the third leaflet; 1002- Overlapping suture point of the right end of the first leaflet and the left end of the second leaflet; 1003- Bottom suture point of the first leaflet; 1004- Overlapping suture point of the right end of the second leaflet and the left end of the third leaflet; 1005- Bottom suture point of the second leaflet; 1006- Bottom suture point of the leaflet in the third region. Detailed Implementation

[0031] In this embodiment, when referring to orientation, "upper" and "lower" refer to the annular axis of the stent, corresponding to the outflow and inflow ends in the blood flow direction, respectively. In the embodiment of this application, the end of the basic unit with the concave structure is upper, and the other end is lower; "left" and "right" refer to the circumferential direction of the stent. Taking the second region as an example, the side connected to the first region is the left side, and the side connected to the third region is the right side.

[0032] Example 1

[0033] This embodiment provides an interventional cardiac valve stent with staggered folded leaflets, such as... Figure 1 and Figure 2 As shown, the main structure of the heart valve stent is annular, and the main structure of the heart valve stent consists of basic units arranged repeatedly along the circumference. The main structure includes three regions arranged sequentially along the circumference. Each region is provided with leaflet suture points, and the three leaflets are respectively fixed to the leaflet suture points in the three regions. In this embodiment, the heart valve stent is preferably made of a malleable expandable material and / or a self-expanding material. In this embodiment, it is specifically made of nickel-titanium alloy. The leaflets are made of biomaterials and / or polymer materials, specifically polyurethane and other materials.

[0034] The three regions have the same length along the circumference and the same length along the axial direction, and the number of basic units in the three regions gradually decreases along the circumferential direction. The three leaflets are fixed to the leaflet stitching points in the three regions, that is, sewn to the metal ribs of the support located at the leaflet edges. In this embodiment, the main structure includes a first region 101, a second region 102, and a third region 103 arranged sequentially along the circumferential direction, with the first leaflet, second leaflet, and third leaflet fixed to the first region 101, second region 102, and third region 103, respectively. Figure 4 and Figure 5 As shown, the three regions comprise a total of 12 basic units. The first region 101 spans 4.5 basic units circumferentially, the second region 102 spans 4 basic units circumferentially, and the third region 103 spans 3.5 basic units circumferentially. The lateral suture points of adjacent leaflets coincide, and the lateral suture points of all three leaflets are located at the same axial height. In this embodiment, the circumferential length of the heart valve stent is 81 mm, with each region having a circumferential length of 27 mm and an axial length of 22 mm. As a preferred embodiment, the circumferential length of the heart valve stent is suitable to be 72 mm-91 mm, and the axial length is suitable to be 18 mm-23 mm.

[0035] The annular basic unit of the cardiac valve stent described in this embodiment includes a compressible structure, and at least one compressible structure is concave. The two lateral suture points at both ends of each leaflet in the circumferential direction are fixed to the compressible structure, and the axial compression displacements of the two lateral suture points differ. Here, axial compression displacement refers to the displacement in the axial direction at a certain location when the stent is gripped, causing radial contraction. Figure 3 As shown, the basic unit in this embodiment includes a concave hexagonal structure, a hexagonal structure, and a bent structure arranged sequentially along the axial direction. The lower concave point of the concave hexagonal structure and the upper vertex of the hexagonal structure are connected by a first straight line structure, and the lower vertex of the hexagonal structure and the bending point of the bent structure are connected by a second straight line structure. All three structures—the concave hexagonal structure, the hexagonal structure, and the bent structure—are compressible. The concave hexagonal structure is specifically designed to be concave, and its maximum axial length is 9.5 mm.

[0036] In addition, some leaflets have lateral or basal suture points located on the modified structure, with the basal suture point located near the bottom of the leaflet. The axial compressive displacement of the modified structure where the lateral and / or basal suture points are located also differs from the axial compressive displacement at the same location on the base unit. It should be noted that the "same location" here refers to the location where the base unit and the modified structure are located in the same circumferential direction.

[0037] In this embodiment, the variant structure includes a first variant structure located at the bottom suture point of the leaflet in the first region 101, a second variant structure located at the bottom suture point of the leaflet in the third region 103, and a third variant structure located at the lateral suture point where the leaflets of the second region 102 and the third region 103 overlap. The lateral suture point where the leaflets of the first region 101 and the third region 103 overlap is located on the side of the concave hexagonal structure, such as... Figure 5 The suture point 1001, where the left end suture point of the first leaflet coincides with the right end suture point of the third leaflet, is shown. The suture point at the overlapping side ends of the leaflets in the first and second regions is located at the bottom concave point of the concave hexagonal structure, as shown in Figure 1001. Figure 5 The suture point 1002, where the right end suture point of the first leaflet coincides with the left end suture point of the second leaflet, is shown. The bottom suture point of the leaflet in the second region is located near the bending point of the lower bending structure of the base unit, as shown in Figure 1002. Figure 5 The suture point at the bottom of the second leaflet is shown in Figure 1005.

[0038] The first variant structure is a connecting line structure extending from the connection point of two adjacent lower bending structures to the bottom edge of two adjacent hexagonal structures, with the bottom suture point 1003 of the first leaflet located on the connecting line structure; the second variant structure is formed by shifting the two end suture points of the lower bending structure of the base unit upwards, with the bottom suture point 1006 of the third region leaflet located on the second variant structure, preferably close to the bending point of the second variant structure; the third variant structure has a variant bending line in the concave hexagonal structure of the base unit, and the variant bending line is connected to the original concave hexagonal structure. The top bend lines of the concave hexagonal structure are parallel, and the lower concave point of the original concave hexagonal structure moves down to the convex point to form an convex point. The vertex of the original hexagonal structure moves down to the concave point. The convex point is connected to the bend point of the variant bend line, and the third variant structure is formed after removing the first straight line structure of the original basic unit. The suture point 1004, which coincides with the suture point of the right end of the second leaflet and the suture point of the left end of the third leaflet, is located at the bend point of the variant bend line. When not pressed, the bend point of the variant bend line and the lower concave point of the concave hexagonal structure of other basic units are located on the same circumference.

[0039] The staggered folded leaflet interventional cardiac valve stent in this embodiment has a circumferentially uneven structure. Utilizing the different numbers and structures of the three stent units, during compression, the leaflets are pulled and folded at different axial heights through the leaflet suture points, guiding the leaflets to make radial and axial displacements until compression is complete. The intersection points of the three leaflets' edges with the stent, except for the free end, are suture points used to fix the leaflets on the stent. The deformation process of the key suture points of the three leaflets during compression in this embodiment is specifically as follows:

[0040] The suture point 1001, where the left end suture point of the first leaflet coincides with the right end suture point of the third leaflet, maintains its axial height when gripped. The suture point 1003 at the bottom of the first leaflet slightly deforms downwards axially when gripped. The suture point 1002, where the right end suture point of the first leaflet coincides with the left end suture point of the second leaflet, deforms upwards axially when gripped. The suture point 1005 at the bottom of the second leaflet deforms downwards axially when gripped. The suture point 1004, where the right end suture point of the second leaflet coincides with the left end suture point of the third leaflet, deforms downwards axially when gripped. The suture point 1006 at the bottom of the third leaflet deforms significantly downwards axially when gripped. This achieves a horizontal fold at a higher axial level for the first leaflet, a horizontal fold at a middle axial level for the second leaflet, and a horizontal fold at a lower axial level for the third leaflet.

[0041] In this embodiment, the downward displacement of the suture point at the bottom of the three leaflets is also different. The first leaflet has the smallest downward displacement, and the third leaflet has the largest downward displacement. After being squeezed, the three leaflets are distributed in an alternating pattern in the circumferential direction, which reduces the number of folds in the tightly folded part of the leaflet, avoids damage caused by leaflet folding and squeezing, and improves the long-term durability of the valve during its service in the human body.

[0042] Example 2

[0043] This embodiment provides an interventional cardiac valve stent with staggered folded leaflets, as shown in the unfolded diagram below. Figure 6 As shown, the heart valve stent is annular, and its main structure comprises basic units arranged repeatedly along the circumference. The main structure includes three regions arranged sequentially along the circumference. Each region has leaflet suture points, and the three leaflets are fixed to the leaflet suture points in the three regions respectively. In this embodiment, the heart valve stent is preferably made of a malleable expandable material and / or a self-expanding material, specifically a metal material, and the leaflets are made of biomaterials and / or polymer materials.

[0044] In this embodiment, the three regions have the same length along the circumferential direction and the same length along the axial direction. Furthermore, the number of basic units spanned by the three regions along the circumferential direction is the same in the circumferential direction. The lateral end suture points of adjacent leaflets coincide, and the lateral end suture points of the three leaflets are located at the same circumferential height. At least one set of overlapping lateral end suture points of adjacent regions is located on the variant structure. For example... Figure 6 As shown, there are a total of 12 basic units in the three regions. Each region spans 4 basic units along the circumference, the lateral suture points of adjacent leaflets coincide, and the lateral suture points of the three leaflets are located at the same axial height. In this embodiment, the circumferential length of the heart valve stent is 81 mm, the circumferential length of each region is 27 mm, and the axial length of the stent is 20 mm.

[0045] The basic unit in this embodiment includes a concave hexagonal structure, two connected rhombus structures, and a downward-bending structure arranged sequentially along the axial direction. The lower concave point of the concave hexagonal structure is connected to the upper vertex of the upper rhombus structure, and the bottom vertex of the lower rhombus structure is connected to the downward-bending structure via a straight line structure. In this embodiment, a set of overlapping side-end stitching points is located on the fourth variation structure. The maximum axial length of the concave hexagonal structure is 8.2 mm.

[0046] In this embodiment, the variant structure is a fourth variant structure located at the lateral suture point where the leaflets of the second and third regions overlap, such as... Figure 6As shown, this variant structure has a variant bend line in the concave hexagonal structure of the basic unit. Simultaneously, the lower concave point moves down to the convex point to form an outward convex point. The upper two sides of the upper rhombus structure are removed, and the straight line between the lower concave point of the original concave hexagonal structure and the upper vertex of the upper rhombus structure is removed to form the variant structure. The suture point 1004, where the right end suture point of the second leaflet coincides with the left end suture point of the third leaflet, is located at the bend point of the variant bend line.

[0047] In addition, the overlapping suture points 1001 of the left end suture point of the first leaflet and the right end suture point of the third leaflet, and 1002 of the overlapping suture points 1002 of the right end suture point of the first leaflet and the left end suture point of the second leaflet, are all located on the lower concave point of the concave hexagon of their respective base units. The bottom suture points 1003, 1005, and 1006 of the third region leaflet are all located at the bending points of the lower bending structure of their respective base units.

[0048] In this embodiment, the intersection points of the edges of the three leaflets (excluding the free end) with the support are all suture points, used to fix the leaflets on the support. The deformation process of the key suture points of the three leaflets during the pressing process is as follows:

[0049] The suture point 1001, where the left end suture point of the first leaflet coincides with the right end suture point of the third leaflet, deforms axially upwards when gripped; the suture point 1003, at the bottom end of the first leaflet, deforms axially downwards when gripped; the suture point 1002, where the right end suture point of the first leaflet coincides with the left end suture point of the second leaflet, deforms axially upwards when gripped; the suture point 1005, at the bottom end of the second leaflet, deforms axially downwards when gripped; the suture point 1004, where the right end suture point of the second leaflet coincides with the left end suture point of the third leaflet, deforms axially downwards when gripped; and the suture point 1006, at the bottom end of the third leaflet, shifts axially downwards when gripped. This achieves a higher axial fold in the first leaflet and a lower axial fold in the second and third leaflets.

[0050] Experimental Example

[0051] The stents in the above embodiments of this application can all achieve, during compression, the leaflets are pulled to curl and fold at different axial heights through the fixed points of the leaflets, thereby expanding the folded area of ​​the leaflets in axial space. The axial displacement (in mm) of each leaflet suture point after compression in Embodiments 1 and 2, as measured by compression experiments, is shown in the table below.

[0052] P1 P2 P3 P4 P5 P6 P7 P8 P9 Example 1 0 -0.85 1.74 1.74 -2.24 -1.88 -1.88 -4.15 0 Example 2 1.74 -5.4 1.74 1.74 -5.4 -1.79 -1.79 -5.4 1.74

[0053] In the table above, upward displacement is positive, and downward displacement is negative. P1 is the left end suture point of the first leaflet; P9 is the right end suture point of the third leaflet, P1 and P9 coincide; P2 is the bottom suture point of the first leaflet; P3 is the right end suture point of the first leaflet; P4 is the left end suture point of the second leaflet, P3 and P4 coincide; P5 is the bottom suture point of the second leaflet; P6 is the right end suture point of the second leaflet; P7 is the left end suture point of the third leaflet, P6 and P7 coincide; P8 is the bottom suture point of the third region leaflet.

[0054] In Embodiment 2 of this application, the stent can fold the suture points (P1, P3, P4, P6, P7, P9) at both ends of the leaflet in an alternating manner when it is gripped, thereby folding the free ends of the leaflet in an alternating manner; more preferably, Embodiment 1 can fold all the suture points (P1-P9) of the three leaflets in an alternating manner by deforming the stent wires when gripping, and the three leaflets after gripping have a higher degree of alternation.

[0055] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the claims.

Claims

1. An interventional cardiac valve stent with staggered folded leaflets, characterized in that, The main structure of the heart valve stent is ring-shaped, and the main structure includes basic units arranged repeatedly along the circumference. The basic units include compressible structures, and at least one compressible structure is a concave structure. The main structure has three regions arranged sequentially along the circumference. The three leaflets are fixed at the leaflet suture points in the three regions respectively. The two side suture points of each leaflet in the circumferential direction are fixed to the compressible structure, and the axial compression displacement of at least two side suture points is different.

2. The interventional cardiac valve stent with staggered folded leaflets according to claim 1, characterized in that, Some basic units have variant structures, and the lateral and / or basal suture points of some leaflets are located on the variant structures; the basal suture points are located close to the bottom of the leaflets; the axial compressive displacement at the variant structure differs from the axial compressive displacement at the same position in the basic unit.

3. The interventional cardiac valve stent with staggered folded leaflets according to claim 2, characterized in that, The three regions have the same length along the circumference and the same length along the axis, and the number of basic units spanned by the three regions along the circumference gradually decreases along the circumferential direction.

4. The interventional cardiac valve stent with staggered folded leaflets according to claim 1, 2, or 3, characterized in that, The basic unit includes a concave hexagonal structure, a hexagonal structure, and a downward bending structure arranged sequentially along the axial direction. The lower concave point of the concave hexagonal structure and the upper vertex of the hexagonal structure are connected by a first straight line structure, and the lower vertex of the hexagonal structure and the bending point of the downward bending structure are connected by a second straight line structure.

5. The interventional cardiac valve stent with staggered folded leaflets according to claim 4, characterized in that, The main structure includes a first region, a second region, and a third region arranged sequentially along a circumferential direction. The number of basic units spanned by the first region, the second region, and the third region along the circumferential direction are 4.5, 4, and 3.5, respectively. The lateral end suture points of two adjacent leaflets coincide. When the main structure is not compressed, the lateral end suture points of the three leaflets are located on the same circumferential line.

6. The interventional cardiac valve stent with staggered folded leaflets according to claim 5, characterized in that, The variant structure includes a first variant structure located at the bottom suture point of the leaflet in the first region, a second variant structure located at the bottom suture point of the leaflet in the third region, and a third variant structure located at the side suture point where the leaflets of the second and third regions overlap. The side suture point where the leaflets of the first and third regions overlap is located on the side of the concave hexagonal structure. The side suture point where the leaflets of the first and second regions overlap is located at the bottom concave point of the concave hexagonal structure. The bottom suture point of the leaflet in the second region is located near the bending point of the lower bending structure.

7. The interventional cardiac valve stent with staggered folded leaflets according to claim 6, characterized in that, The first variant structure is a connecting line structure extending from the connection point of two adjacent lower bending structures to the bottom side of the hexagonal structure; the second variant structure is formed by shifting the stitching points of the two ends of the lower bending structure of the base unit upwards; the third variant structure has a variant bending line in the concave hexagonal structure of the base unit, and at the same time, the lower concave point moves down to the convex point to form an convex point, the vertex of the hexagonal structure moves down to the concave point, the convex point connects with the bending point of the variant bending line, and the third variant structure is formed after removing the first straight line structure.

8. The interventional cardiac valve stent with staggered folded leaflets according to claim 2, characterized in that, The three regions have the same length along the circumference and the same length along the axis. The number of basic units that the three regions span along the circumference is the same in the direction of circumference. The lateral suture points of the three leaflets are located at the same circumferential height, and at least one lateral suture point is located on the variant structure.

9. The interventional cardiac valve stent with staggered folded leaflets according to claim 8, characterized in that, The basic unit includes a concave hexagonal structure, two connected rhombus structures, and a downward bending structure arranged sequentially along the axial direction. The lower concave point of the concave hexagonal structure is connected to the upper vertex of the upper rhombus structure, and the bottom vertex of the lower rhombus structure is connected to the downward bending structure by a straight line structure.

10. The interventional cardiac valve stent with staggered folded leaflets according to claim 9, characterized in that, The lateral suture points of two adjacent leaflets coincide, and at least one set of lateral suture points in adjacent regions are located on the variant structure.

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