The Effects of Degenerative Mitral Regurgitation on Cardiac Structure and Function, Symptoms, and Exercise Capacity

Overview

Current American College of Cardiology/American Heart Association guidelines recommend that patients with severe degenerative mitral regurgitation be considered for mitral valve surgery. There remains a debate within the cardiology community regarding the appropriate management of patients who remain asymptomatic. In this study the investigators will perform longitudinal follow-up data with cardiac MRI to inform the prophylactic surgery vs. close follow-up debate and to better define the natural history of this condition. The investigators hypothesize, that in the majority of patients mitral regurgitation will not worsen overtime, left ventricular hemodynamics will remain stable, exercise capacity will not decline, and symptoms will not worsen during follow-up. This finding would have a significant impact on the current recommendations for treatment in patients with mitral regurgitation by supporting a conservative management approach.

Current ACC/AHA guidelines recommend that patients with severe degenerative mitral regurgitation be considered for mitral valve surgery. There remains a debate within the cardiology community regarding the appropriate management of patients who remain asymptomatic. There are those who advocate for performing early "prophylactic" mitral valve surgery while others advocate clinical follow-up until triggers emerge with echocardiography historically being the method used for longitudinal assessment of cardiac anatomy and function. Two studies showed that only \~30% of asymptomatic severe mitral regurgitation made endpoints that triggered. However, these studies were limited and did not perform rigorous follow up assessment of regurgitant volume, left ventricular hemodynamics, exercise capacity, or quality of life assessment. In addition, in these studies mitral regurgitation and left ventricular size and function was assessed by echocardiography. Echocardiography has known limitations in assessing ventricular size and, as recent studies have shown, may not be the optimal modality to assess mitral regurgitant severity. MRI is the gold standard for non-invasive quantification of the left and right ventricles volumes and function and has emerged as a reference standard for quantifying mitral regurgitation. In this study the investigators will perform longitudinal follow-up data with cardiac MRI to inform the prophylactic surgery vs. close follow-up debate and to better define the natural history of this condition. The investigators hypothesize, that in the majority of patients mitral regurgitation will not worsen overtime, left ventricular hemodynamics will remain stable, exercise capacity will not decline, and symptoms will not worsen during follow-up. This finding would have a significant impact on the current recommendations for treatment in patients with mitral regurgitation by supporting a conservative management approach.