Long-term survival in asymptomatic patients with severe degenerative mitral regurgitation: a propensity score-based comparison between an early surgical strategy and a conservative treatment approach.

AIMS: The management of asymptomatic severe mitral regurgitation remains controversial. The aim of the study was to assess the long-term survival, incidence of cardiac complications, factors that predict outcome, and effect of mitral surgery on the long-term prognosis of patients with asymptomatic severe mitral regurgitation amenable to valve repair. METHODS: One hundred ninety-two asymptomatic patients (mean age, 63 +/- 13 years) with severe degenerative mitral regurgitation diagnosed by 2-dimensional echocardiography between 1990 and 2001 were prospectively followed for a median of 8.5 years. RESULTS: Overall, cardiovascular, and event-free survival was evaluated in 2 groups of patients: a "conservative approach" group (n = 67) and an "early surgery" group (n = 125). Outcomes were also analyzed among patients with atrial fibrillation, pulmonary hypertension, or both, as well as in patients free of any mitral regurgitation complications. In the whole population, 10-year overall survival was significantly lower with the conservative approach than early surgery (50% +/- 7% vs 86% +/- 4%, log-rank < 0.0001). Similar results were obtained in the subgroups with atrial fibrillation and/or pulmonary hypertension. The 10-year propensity-matched score-adjusted hazards ratio for overall mortality, cardiac mortality, and cardiovascular events for the conservative treatment were 5.21, 4.83, and 4.40, respectively. CONCLUSION: Our results show that the outcome of asymptomatic patients with severe degenerative mitral regurgitation is better with an early surgical approach rather than a more conservative treatment strategy.

Long-term clinical outcome of mitral valve repair in asymptomatic severe mitral regurgitation.

OBJECTIVE: To assess the long-term survival, the incidence of cardiac complications and the factors that predict outcome in asymptomatic patients with severe degenerative mitral regurgitation (MR) undergoing mitral valve repair. METHODS: Up to 143 asymptomatic patients (mean age 63+/-12 years) with severe degenerative MR who underwent mitral valve repair between 1990 and 2001 were subsequently followed up for a median of 8 years. The study population was subdivided into three subgroups: patients with left ventricular (LV) dysfunction and/or dilatation (n=18), patients with atrial fibrillation and/or pulmonary hypertension (n=44) and patients without MR-related complications (n=81). RESULTS: For the patients, 10-year overall and cardiovascular survival was 82+/-4% and 90+/-3%. At 10 years, patients without preoperative MR-related complications had significantly better overall survival than patients with preoperative LV dysfunction and/or dilatation (89+/-4% vs 57+/-13%, log rank p=0.001). Patients without preoperative MR-related complications also tended to have a better 10-year overall and cardiovascular survival than patients with atrial fibrillation and/or pulmonary hypertension (overall survival of 79+/-8%), although this did not reach statistical significance (log rank p=0.17). Cox regression analysis identified the baseline left ventricular ejection fraction and age as the sole independent predictors of outcome. CONCLUSION: Our data indicate that in asymptomatic patients with severe degenerative MR, mitral valve repair is associated with an excellent long-term prognosis. Nonetheless, the presence of preoperative MR-related complications, in particular LV dysfunction and/or dilatation, greatly attenuates the benefits of surgery. This suggests that mitral valve repair should be performed early, before any MR-related complications ensue.