Functional Mitral Regurgitation: Therapeutic Strategies for a Ventricular Disease

Functional Mitral Regurgitation: Therapeutic Strategies for a Ventricular Disease
J Cardiac Fail 2014;20:252 -267


ABSTRACT
Functional mitral regurgitation is a highly prevalent condition among patients with ischemic and dilated cardiomyopathies. Arising from remodeling of both the mitral valve annulus and the left ventricle, it is associated with high mortality and morbidity. In selected patients, cardiac resynchronization therapy helps to reduce functional mitral regurgitation, but surgical intervention remains the mainstay of therapy when medical therapy for left ventricular dysfunction has been inadequate. It is, however, associated with significant perioperative risks and does not alter long-term mortality. Percutaneous devices, and more recently the Mitraclip in particular, represent a promising alternative that can improve symptoms and ventricular remodeling with significantly lower periprocedural risk.



It remains unclear whether fMR repair is beneficial to this ventricular-valvular disease paradigm.
Current ACC/AHA and ESC guidelines do not make a distinction in recommended diagnostic modalities or in classification schema for severity, between fMR and
other etiologies of MR.
Medical therapy is limited in its ability to fully correct fMR.
CRT specifically targets myocardial dyssynchrony, which can be especially pronounced in those patients with segmental wall motion abnormalities and contributes to fMR.
MV surgery significantly reduces or eliminates fMR, reduces LV dimensions, and improves symptoms, but it is also associated with periprocedural complications,
such as mortality, bleeding, stroke, and renal dysfunction, and provides no clear long-term mortality benefit. There have been no randomized trials to compare the effectiveness of different surgical repair techniques.
Although there have been no prospective studies comparing the effects of MV surgery alone with the combination procedure of valve surgery and SVR, the combination procedure allowed for more consistent reduction in fMR but not
mortality, and they are accompanied by high perioperative risk.
Edge-to-Edge Repair (Mitraclip) corrects fMR with significantly lower periprocedural risk.