Effectiveness of Surgical Mitral Valve Repair Versus Medical Treatment for People With Significant Mitral Regurgitation and Non-ischemic Congestive Heart Failure

Overview

Mitral regurgitation (MR), also known as mitral insufficiency, is a condition in which the heart's mitral valve, located between two of the heart's main chambers, does not firmly shut, allowing blood to leak backwards within the heart. Improper functioning of the mitral valve disrupts the proper flow of blood through the body, resulting in shortness of breath and fatigue. When mild, MR may not pose a significant danger to a person's health, but severe MR may be associated with serious complications, such as heart failure, irregular heart rhythm, and high blood pressure. Although there are treatments for MR, including medication and surgery, more information is needed on the effectiveness of these treatments in people with significant MR. This study will compare the safety and effectiveness of corrective surgery added to optimal medical treatment (OMT) versus OMT alone in treating people with significant MR caused by an enlarged heart.

It is estimated that approximately 4 out of 10 people with an enlarged heart due to heart failure develop MR, referred to as secondary MR. This type of MR is caused by enlargement of the left ventricle (LV), one of the heart's main chambers. In turn, the enlargement leads to stretching of certain heart muscles around the mitral valve and of the valve itself. Symptoms of secondary MR may include shortness of breath, fatigue, dizziness, swollen feet, cough, and heart palpitations. Mitral valve repair or replacement surgery is sometimes considered as a treatment option to restore proper heart function in people with secondary MR. Surgical repair with placement of an artificial ring around the mitral valve can help to tighten the valve and add benefit to non-surgical treatments for MR. However, although surgical placement of the ring improves mitral valve function in most people, it is not known whether this surgery helps people live longer and healthier lives. This study will compare the safety and effectiveness of surgical mitral valvuloplasty with placement of an annular ring (SMVR) added to optimal medical treatment (OMT) versus OMT alone in non-ischemic heart failure patients with significant secondary MR. Participation from baseline through follow-up in this study will last 18 months. All potential participants will initially undergo a transesophageal echocardiogram to confirm the presence of an abnormal mitral valve. Eligible participants will then undergo a number of baseline tests, which will include cardiopulmonary exercise stress testing, a chest wall echocardiogram, blood draw, 6-minute walk test, medical questionnaires, and a physical exam. Next, participants will be randomly assigned to receive immediate open heart surgery with the placement of a mitral valve ring, delayed surgery at least 18 months later, or OMT. Participants assigned to receive immediate surgery will undergo the surgery 2 weeks after baseline testing. Participants assigned to receive OMT will receive treatment with any of the following medication regimens: combination of vasodilator therapy and diuretics, nitrates and nifedipine, and beta-adrenergic blocker therapy. Follow-up visits for all participants will occur at Months 1, 3, 6, 12, and 18 and will include repeat baseline testing. Long-term survival status data may be collected beyond 18 months for some participants.