Impact of mitral regurgitation on long-term survival in patients with ischemic cardiomyopathy: efficacy of combined mitral valve repair and revascularization

Abstract

Ischemic cardiomyopathy complicated by severe mitral regurgitation (MR) has a poor prognosis. In such cases, whether mitral valve repair for MR improves the prognosis of survival remains unclear. In this study, 50 patients diagnosed with ischemic cardiomyopathy at our hospital between August 1991 and August 1996 were studied to examine the long-term prognosis and factors determining the prognosis. Among 17 patients with the complication of severe MR, 11 underwent mitral valve repair (repair group) and 6 did not (nonrepair group). Among the 33 patients without MR, 15 underwent revascularization (revascularization group) and 18 received medical treatment alone (medical group). Patients with MR showed significantly poorer baseline activities of daily living (ADL) [New York Heart Association (NYHA) class III or above: MR(+) vs MR(−) = 14 vs 8; P = 0.0001] and survival rate [MR(+) vs MR(−); log rank = 3.8, P = 0.05]. In contrast, patients in whom mitral valve repair was actively performed to resolve MR had favorable outcomes for both ADL (NYHA class improved from 3.9 ± 0.3 to 2.7 ± 1.0; P = 0.0004) and survival rate (MV repair vs nonrepair: long rank = 10.1, P = 0.0015). In addition, among patients without MR, the revascularization group showed more favorable results in terms of ADL (NYHA class improved from 3.5 ± 0.7 to 2.5 ± 0.8; P = 0.0059) and survival rate (revascularization vs medical: log rank = 3.7, P = 0.05), irrespective of improvement of left ventricular function. When the factors determining the prognosis for ischemic cardiomyopathy were examined by multivariate analysis, whether or not revascularization was conducted, the presence or absence of mitral regurgitation, and if present, whether or not mitral valve repair was performed were identified as independent factors determining the prognosis (revascularization: hazard ratio = 0.121, P = 0.012; absence of MR: hazard ratio = 0.104, P = 0.050; mitral valve repair: hazard ratio = 0.018, P = 0.005). These results showed that revascularization should be conducted as actively as possible in patients with ischemic cardiomyopathy; in addition, for those patients with mitral regurgitation, mitral valve repair should be conducted actively to relieve it.