An expandable stent for implantation in a right ventricular outflow tract includes a frame having a plurality of struts that define a repeating pattern of cells. The repeating pattern of cells comprises a column of exactly three generally diamond shaped cells positioned in end-to-end alignment, and a column of exactly two generally diamond shaped cells positioned in end-to-end alignment. The frame has a substantially hourglass shape with a narrow portion in between a proximal end portion and a distal end portion, wherein the proximal end portion and the distal end portion are configured to expand radially outward to contact a right ventricular outflow tract.