Valve leaflet attachment in collapsible prosthetic valves

A prosthetic heart valve, comprising:

• a stent having a collapsed condition and an expanded condition, the stent extending in a longitudinal direction between a proximal end and a distal end and including a plurality of cells arranged in annular rows around a circumference of the stent, each cell being formed by a plurality of struts so that the cells have substantially a diamond shape with a first end pointing toward the distal end of the stent and a second end pointing toward the proximal end of the stent, each cell in a first annular row of cells having a strut connected to a pair of struts in an adjacent annular row of cells by a runner;
• a plurality of commissure features disposed on the stent at spaced distances from both the proximal end of the stent and the distal end of the stent;
• and
• a valve assembly secured to the stent and including a cuff and a plurality of leaflets disposed between the plurality of commissure features and the proximal end of the stent, the cuff having a proximal end and a distal end, the distal end defining a plurality of first peaks and a plurality of second peaks, the first peaks and the second peaks intersecting at intersection points, each of the first peaks extending from a pair of the intersection points to a respective one of the commissure features, each of the plurality of leaflets being sutured only to the cuff between respective pairs of the commissure features with a repeating pattern of sutures, the pattern of sutures including a descending seam at a spaced distance from one group of the plurality of struts, an ascending seam at the spaced distance from another group of the plurality of struts, and a vertex between the descending seam and the ascending seam, the pattern of sutures crossing one of the runners near the vertex.