A prosthetic mitral valve (300) includes a collapsible and expandable elliptical or "D"-shaped stent (350). The stent includes first and second commissure attachment features (316) and a collapsible and expandable valve assembly (360) disposed therein. The valve assembly includes two leaflets (362), each leaflet having a first edge (374) operably coupled to the stent and a second free edge (376). Each leaflet may include first and second tabs (370, 372) connecting first and second ends of the first and second edges, respectively. Each leaflet includes a height measured from a midpoint of the first edge to a midpoint of the second edge and a width measured from a junction of the first edge with the first tab to a junction of the first edge with the second tab. The ratio of the height to the width may be between about 0.4 and about 0.65.
