This invention relates to the design and function of a device which allows for retrieval of a previously implanted valve prosthesis from a beating heart without extracorporeal circulation using a transcatheter retrieval system, including a guide component to facilitate the compression of the valve and retraction into a retrieval catheter, as well as an improved prosthetic transcatheter heart valve having one or more of: a series of radially extending tines having a loop terminus to improve sealing a deployed prosthetic mitral valve against hemodynamic leaking, a pre-compressible stent-in-stent design, or an articulating cuff attached to a covered stent-valve and a commissural sealing skirt structure attached to the underside of the articulating cuff.
