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.