Percutaneous and off-pump treatments for functional mitral regurgitation

A new era in the treatment of functional mitral regurgitation is emerging with new devices that can be placed percutaneously or minimally invasively without cardiopulmonary bypass. These devices are categorized into three groups: annuloplasty, edge-to-edge repair, and ventricular reshaping. Percutaneous annuloplasty devices, implanted via the coronary sinus, mimic surgical annuloplasty by reducing the mitral annular anterior-posterior (or septal-lateral) dimension. Several devices, such as the PTMA, CARILLON, Monarch, and PS3 systems, are in clinical trials. Percutaneous edge-to-edge repair devices mimic the surgical Alfieri edge-to-edge repair technique, creating a double-orifice mitral valve; of these, MitraClip is in clinical trials. Ventricular reshaping devices treat both mitral annular dilatation and papillary muscle displacement (and thus leaflet tethering). The surgical Coapsys device is currently in clinical trials, and its percutaneous "interventional" version, iCoapsys, is being prepared for a clinical trial. Numerous issues need to be addressed before these devices can become standard therapies for functional mitral regurgitation. Device safety and efficacy must be demonstrated in carefully designed clinical trials with the goal of achieving outcomes equal to or better than those of surgical repair.