An implantable prosthetic valve for regulating fluid flow through a body vessel is provided. The prosthetic valve comprises an anchoring member, at least one leaflet, and a restraining member capable of temporarily preventing substantial movement of the leaflet between and open and closed position so as to allow fluid flow in the antegrade and retrograde directions. In various embodiments, the prosthetic valve reduces the risk of thrombosis. In various embodiments, the prosthetic valve reduces the appearance of potentially thrombogenic abnormal flow patterns at the site of implantation immediately following the implantation, allows cell deposition making the valve more biocompatible, less thrombogenic before flow changes resulting from valving action set in and allows tissue growth so that a partially or completely biological functioning valve may form on the scaffold provided by the implant.