Surgical results for mitral regurgitation from coronary artery disease

Abstract

Results of coronary artery bypass grafting with and without mitral valve replacement were analyzed retrospectively in 101 patients with preoperative ischemic mitral regurgitation to determine the effects of severity and surgical treatment of mitral regurgitation on survival. Between 1980 and 1984, a total of 1,475 patients (mean age 59, 77% male) underwent coronary bypass. These patients were divided into three groups: (1) patients without ischemic mitral regurgitation who underwent isolated coronary bypass (1,374; 93%), (2) patients with ischemic mitral regurgitation who underwent isolated coronary bypass without valve replacement (85; 6%), and (3) patients with ischemic mitral regurgitation who underwent combined mitral valve replacement and coronary bypass (16; 1%). Preoperatively, patients with ischemic mitral regurgitation compared to those without regurgitation were significantly older (+6 years, p less than 0.001), had more severe coronary artery disease (p less than 0.001), a higher incidence of congestive heart failure (24% versus 5%, p less than 0.001) and recent myocardial infarction (16% versus 8%, p less than 0.01), and a lower mean ejection fraction (45% versus 61%, p less than 0.001). Operative mortality was significantly increased in patients with ischemic mitral regurgitation who underwent coronary bypass alone (p less than 0.01) and in those who underwent coronary bypass and mitral valve replacement (p less than 0.01)--11% and 19%, respectively--than in the coronary bypass patients without ischemic mitral regurgitation (3.7%). The severity of mitral regurgitation (0 to 4+) proved to be the most significant predictor of operative mortality. The actuarial survival rate at 5 years for the coronary bypass patients without ischemic mitral regurgitation was 85% compared to 91% (p less than 0.05) for the coronary bypass patients without ischemic mitral regurgitation. These results indicate that patients with ischemic mitral regurgitation have a higher prevalence of cardiac risk factors and are at an increased risk of operative mortality. Although the severity of the ischemic mitral regurgitation was strongly predictive of early survival, it proved to have an unexpectedly modest effect on long-term survival after surgical treatment.