Association between early surgical intervention vs watchful waiting and outcomes for mitral regurgitation due to flail mitral valve leaflets.

IMPORTANCE: The optimal management of severe mitral valve regurgitation in patients without class I triggers (heart failure symptoms or left ventricular dysfunction) remains controversial in part due to the poorly defined long-term consequences of current management strategies. In the absence of clinical trial data, analysis of large multicenter registries is critical.
OBJECTIVE: To ascertain the comparative effectiveness of initial medical management (nonsurgical observation) vs early mitral valve surgery following the diagnosis of mitral regurgitation due to flail leaflets. DESIGN, SETTING, AND PARTICIPANTS: The Mitral Regurgitation International Database (MIDA) registry includes 2097 consecutive patients with flail mitral valve regurgitation (1980-2004) receiving routine cardiac care from 6 tertiary centers (France, Italy, Belgium, and the United States). Mean follow-up was 10.3 years and was 98% complete. Of 1021 patients with mitral regurgitation without the American College of Cardiology (ACC) and the American Heart Association (AHA) guideline class I triggers, 575 patients were initially medically managed and 446 underwent mitral valve surgery within 3 months following detection. MAIN OUTCOMES AND MEASURES: Association between treatment strategy and survival, heart failure, and new-onset atrial fibrillation.
RESULTS: There was no significant difference in early mortality (1.1% for early surgery vs 0.5% for medical management, P=.28) and new-onset heart failure rates (0.9% for early surgery vs 0.9% for medical management, P=.96) between treatment strategies at 3 months. In contrast, long-term survival rates were higher for patients with early surgery (86% vs 69% at 10 years, P < .001), which was confirmed in adjusted models (hazard ratio [HR], 0.55 [95% CI, 0.41-0.72], P < .001), a propensity-matched cohort (32 variables; HR, 0.52 [95% CI, 0.35-0.79], P = .002), and an inverse probability-weighted analysis (HR, 0.66 [95% CI, 0.52-0.83], P < .001), associated with a 5-year reduction in mortality of 52.6% (P < .001). Similar results were observed in relative reduction in mortality following early surgery in the subset with class II triggers (59.3 after 5 years, P = .002). Long-term heart failure risk was also lower with early surgery (7% vs 23% at 10 years, P < .001), which was confirmed in risk-adjusted models (HR, 0.29 [95% CI, 0.19-0.43], P < .001), a propensity-matched cohort (HR, 0.44 [95% CI, 0.26-0.76], P = .003), and in the inverse probability-weighted analysis (HR, 0.51 [95% CI, 0.36-0.72], P < .001). Reduction in late-onset atrial fibrillation was not observed (HR, 0.85 [95% CI, 0.64-1.13], P = .26). CONCLUSION AND RELEVANCE: Among registry patients with mitral valve regurgitation due to flail mitral leaflets, performance of early mitral surgery compared with initial medical management was associated with greater long-term survival and a lower risk of heart failure, with no difference in new-onset atrial fibrillation.