The SAPIEN M3 system for transcatheter mitral valve replacement: A new era begins.

Mitral regurgitation (MR) remains a prevalent and undertreated valvular heart disease, particularly in patients at prohibitive surgical risk. While mitral transcatheter edge-to-edge repair (M-TEER) offers a less invasive alternative, anatomical limitations and incomplete MR reduction in some patients have fueled the development of transcatheter mitral valve replacement (TMVR) technologies. The SAPIEN M3 system (Edwards Lifesciences, Irvine, CA, USA) introduces a novel, fully percutaneous TMVR approach utilizing a two-component system: a self-expanding nitinol dock that encircles the subvalvular apparatus and a balloon-expandable SAPIEN 3 valve adapted for the mitral position. This design minimizes the risk of left ventricular outflow tract (LVOT) obstruction and enables stable, anatomy-independent anchoring without requiring annular calcification. Early feasibility studies have shown high technical success rates (>85 %), effective MR reduction, and a favorable safety profile in high-risk patients. The ongoing ENCIRCLE trial and a planned European post-market study aim to further evaluate the system's safety, durability, and long-term outcomes. Despite promising early results, challenges remain, including procedural complexity, the potential for LVOT obstruction, and limited long-term durability data.