An expandable stent for implantation in a right ventricular outflow tract includes a frame having a waist portion that expands to a deployed size having a first diameter, first and second sealing portions extending in opposite directions from the waist portion and expanding radially outward of the waist portion. The first and second sealing portions are sized to seal against first and second portions of the inner surface of the right ventricular outflow tract at the deployed position over a range of sizes of expansion larger than the first diameter. A band is secured to the waist portion of the frame, restricting expansion of the waist portion substantially beyond the first diameter, such that the waist portion is configured to be spaced apart from the inner surface of the right ventricular outflow tract at the deployed position.