Conclusions
The field of percutaneous transcatheter MVRe is evolving exponentially. These emerging technologies can be classified by their site of action and device mechanism. The proposed classification is based on therapies aimed at the leaflets (leaflet plication, leaflet coaptation, leaflet ablation), annuloplasty (indirect: CS approach or asymmetrical approach; and direct: true percutaneous or hybrid), percutaneous chords, and LV remodeling. Percutaneous edge-to-edge leaflet repair has been shown to be noninferior to surgery in a randomized trial. Several other technologies—including various direct and indirect annuloplasty and LV remodeling devices—have achieved first-in-man results or are in pre-clinical testing. Most likely a combination of these technologies will be required for satisfactory MVRe. However, for many patients repair will not be possible, and MVR will be required. Although there are significant challenges, several percutaneous MVR prototypes are already in development.