Functional mitral regurgitation: are we treating the real target?

Functional mitral regurgitation is a form of valve insufficiency in the presence of anatomically normal mitral valve. The cause of functional mitral regurgitation is left ventricular remodelling that tethers valve leaflet more apically decreasing their coaptation ability. Given the pathophysiologic relation between functional mitral regurgitation and ventricular dysfunction, the valve insufficiency has long been considered a surrogate of ventricular disease. Accordingly, all potential therapeutic strategies able to decrease functional mitral regurgitation have been associated with improved ventricular function. On the contrary, the surgical treatment of functional mitral regurgitation has led to contrasting results, but the main drawback is that it does not improve survival compared with medical therapy. However, surgery is characterized by many confounding factors, which might conceal the beneficial effect of the treatment of valve dysfunction in the mid-long-term follow-up. The present review underscores the potential limits of surgical treatment and hypothesized that percutaneous treatment of functional mitral regurgitation, by means of MitraClip, Abbott, Menlo Park, California, might represent a better tool to investigate treatment of functional mitral regurgitation.