An implantable prosthetic valve, comprising: a radially collapsible and expandable annular frame, the frame having three commissure attachment posts and three rows of circumferential struts extending between the commissure attachment posts, a first row of circumferential struts defining an inflow end of the frame and second and third rows of circumferential struts (22, 24) spaced apart from the first row adjacent an outflow end of the frame, the first row connected to the second and third rows by a plurality of axial struts, each row of circumferential struts comprising angled struts arranged in a zig-zag pattern and interconnected; a leaflet structure comprising three leaflets formed of pericardial tissue, each leaflet having an upper edge, a curved lower edge and two side flaps, wherein each side flap is secured to an adjacent side flap of another leaflet to form commissures of the leaflet structure, each commissure being attached to one of the commissure attachment posts; an annular skirt member positioned between the annular frame and the leaflet structure, the curved lower edge of each leaflet sutured to an inner surface of the skirt member along a scalloped line; and a pair of reinforcing bars positioned adjacent each commissure attachment post, characterised in that each reinforcing bar comprising a plurality of holes, wherein each side flap extends around a reinforcing bar and each reinforcing bar is sutured to a commissure attachment post for reinforcing the attachments between the leaflet structure and the commissure attachment posts, and in that the angled struts are interconnected by generally U-shaped crown structure for improved collapsibility. a radially collapsible and expandable annular frame, the frame having three commissure attachment posts and three rows of circumferential struts extending between the commissure attachment posts, a first row of circumferential struts defining an inflow end of the frame and second and third rows of circumferential struts (22, 24) spaced apart from the first row adjacent an outflow end of the frame, the first row connected to the second and third rows by a plurality of axial struts, each row of circumferential struts comprising angled struts arranged in a zig-zag pattern and interconnected; a leaflet structure comprising three leaflets formed of pericardial tissue, each leaflet having an upper edge, a curved lower edge and two side flaps, wherein each side flap is secured to an adjacent side flap of another leaflet to form commissures of the leaflet structure, each commissure being attached to one of the commissure attachment posts; an annular skirt member positioned between the annular frame and the leaflet structure, the curved lower edge of each leaflet sutured to an inner surface of the skirt member along a scalloped line; and a pair of reinforcing bars positioned adjacent each commissure attachment post, characterised in that each reinforcing bar comprising a plurality of holes, wherein each side flap extends around a reinforcing bar and each reinforcing bar is sutured to a commissure attachment post for reinforcing the attachments between the leaflet structure and the commissure attachment posts, and in that the angled struts are interconnected by generally U-shaped crown structure for improved collapsibility.