An implantable prosthetic valve includes a radially collapsible and expandable annular frame having three commissure attachment posts and four rows of circumferential struts. The rows include a first row, a second row downstream of the first row, a third row downstream of the second row, and a fourth row downstream of the third row and defining an outflow end of the frame. Each row of circumferential struts includes angled struts arranged in a zig-zag pattern. A leaflet structure includes three leaflets forming three commissures, each commissure being connected to one of the commissure attachment posts only at locations along the commissure attachment posts between a first plane that is perpendicular to a longitudinal axis of the frame and intersects crowns of the third row of struts and a second plane that is perpendicular to the longitudinal axis and intersects crowns of the fourth row of struts.