A prosthetic valve coaptation assist device includes an anchor and a single valve assist leaflet. The anchor may be a supporting ring frame, brace or arc structure and will usually be radially self-expandable so that it can expand against surrounding natural or prosthetic tissue. The valve assist leaflet may be made of pericardium or other biological or artificial material and is shaped like the native target valve leaflet. The valve assist leaflet is typically sized larger than the target natural or prosthetic leaflet so that after implantation a significant overlap of the device body occurs.
