A system can include a delivery catheter comprising a balloon and an implantable prosthetic heart valve. The prosthetic valve can have a plastically expandable and compressible unitary frame comprising a plurality of circumferentially extending rows of angled struts, including first, second, and third rows of angled struts forming rows of diamond-shaped cells, and a valvular structure comprising a plurality of leaflets. A cusp edge portion of each leaflet is connected to the frame by a skirt that is disposed between the frame and the cusp edge portions, the skirt being sutured to selected struts of the frame along diagonal paths extending from an inflow end portion toward an outflow end portion. Each diagonal path along which the skirt is sutured to the frame extends along the first, second, and third rows of angled struts.