Congestive heart failure (CHF) represents an enormous healthcare and economic burden worldwide. Strategies to relieve this burden include refining current therapies to treat specific cardiac lesions. Optimal therapy (medical or surgical) for mitral regurgitation (MR) in the patient with depressed left ventricular ejection fraction (LVEF) remains unclear. Indeed, the only data available comes from single-center, non-randomized, noncomparative trials with small numbers of patients and suggests that these patients may benefit from correction of functional mitral regurgitation. Specific Aim #1 of Project 1 is to determine whether mitral valve repair (MVr) results in improved exercise capacity compared to optimal medical management (OMM) in patients with moderate to severe MR and low LVEF. Specific Aim #2 of Project 1 is to determine whether MVr results in improved quality of life (QOL) compared to OMM in patients with moderate to severe MR and low LVEF. Eligible patients will be randomized to OMM or OMM + MVr. Follow up at 1, 3, 6, and 12 months for the first year and at 6 month intervals thereafter, will evaluate endpoints. A second clinical trial will evaluate the appropriateness of current clinical practice which maintains that coronary artery bypass surgery (CABG) alone is sufficient to treat patients with coronary artery disease (CAD) and mild to moderate chronic ischemic MR. Recent clinical reports indicate a worse prognosis for low LVEF patients treated with CABG alone and is coincident with the development of worsening MR requiring aggressive medical management and even surgical intervention. Project 2 addresses the surgical management of mild to moderate chronic ischemic MR in patients with CAD and any LVEF. Importantly, patients with organic disease of the mitral valve such as mitral valve prolapse, ruptured chordae and endocarditis will be excluded from the study. Specific Aim #1 of Project 2 is to determine whether MVr + CABG results in improved survival free of cardiac events compared to CABG alone in patients with mild to moderate chronic ischemic MR, any LVEF, and coronary artery disease requiring revascularization. Specific Aim #2 of Project 2 is to determine whether MVr + CABG results in improved survival free of persistent or progressive MR compared to CABG alone in patients with mild to moderate chromic ischemic MR, any LVEF, and coronary artery disease requiring revascularization. Eligible patients will be randomized to OMM + CABG alone or OMM + CABG + MVr. Follow up at 1, 3, 6, and 12 months for the first year and at 6 month intervals thereafter, will evaluate endpoints. A Clinical Research Skills Development Core submission will accompany this proposal. (End of Abstract)