BACKGROUND Whether or not to perform adjunctive mitral repair in patients undergoing coronary artery bypass grafting (CABG) for advanced ischemic cardiomyopathy with moderately severe mitral regurgitation (MR) remains controversial. METHODS We examine the clinical and echocardiographic outcome after isolated CABG in 49 patients with ischemic cardiomyopathy and 1+ to 3+ MR undergoing surgical revascularization. The patients were identified for analysis of mitral valve-related issues from a larger series of 183 patients with ischemic cardiomyopathy (MUGA ejection fraction < or = 30%) undergoing CABG by a single surgeon from 1986 to 1996. Patient age was 66.3 years (mean, range 45 to 83 years). There were 5 women (10.2%) and 44 men (89.8%). Mean ejection fraction was 22.4% with a range of 10% to 30%. Thirty-four patients had preoperative congestive heart failure (70%) and 12 (25%) had pulmonary edema. Number of grafts was 2.8 (mean, range 1 to 5). The MR was 1+ in 18 patients (37.5%), 2+ in 26 (52%) and 3+ in 5 patients (10.5%). RESULTS Hospital mortality was 2.0% (1 of 49 patients). Ejection fraction improved from 22.0% to 31.5% (p < 0.05) after CABG. Mean degree of MR improved with CABG alone from 1.73 to 0.54 (p < 0.05) as measured at a mean interval of 36.9 months from CABG. New York Heart-Association congestive heart failure class improved from 3.3 to 1.8 (p < 0.05). Long-term survival was 88%, 65%, and 50% at 1, 3, and 5 years postoperatively. No patient required subsequent mitral valve operation or heart transplantation in long-term follow-up. CONCLUSIONS We conclude that, in patients with advanced ischemic cardiomyopathy and mild-to-moderate MR, isolated CABG (without mitral valve, repair) suffices, producing dramatic improvement in ejection fraction, in congestive heart failure, and in degree of MR, with excellent (relative) long-term survival. The improvement in MR likely results from improved left ventricular function and size consequent upon revascularization.