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-termprognosis 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. (J Thorac Cardiovasc Surg 2009;138:1339-48)