Percutaneous approaches to treat functional mitral regurgitation: Current state of affairs and future perspectives

Abstract

Functional mitral regurgitation (FMR) is a common complication of ischemic or dilated cardiomyopathy and portends an adverse prognosis. Undersized annuloplasty using a complete rigid ring is the most common surgical technique performed in patients with FMR but its impact on outcome remained debated. In the recent years, two percutaneous techniques as emerged as a potential alternative to surgery in patients with FMR, the percutaneous annuloplasty via the coronary sinus and the edge-to-edge-MitraClip procedure. Due to both safety (coronary artery compression) and efficacy concerns the coronary sinus approach is almost abandoned. The MitraClip has received the CE approval and thousands of patients have been implanted worldwide. Overall, the MitraClip is associated with functional improvement, MR reduction, and positive left ventricular (LV) remodeling and improvement of ejection fraction. However, robust data regarding survival benefit are still lacking. In addition, the MitraClip does not directly adress the cause of FMR-local LV remodeling and papillary muscle displacement-and in contrast to the surgical edge-to-edge procedure is not associated with an annuloplasty. Many companies are currently working on other devices trying to mimic surgical procedures or on LV reshaping devices. Strong efforts should be directed towards technological improvements but also toward clinical randomized studies clearly demonstrating that these devices improve the outcome of patients with FMR.