Outcomes in Mitral Regurgitation Due to Flail Leaflets. A Multicenter European Study

Objectives: The purpose of this study was to assess incidence and predictors of events associated with nonsurgical and surgical management of severe mitral regurgitation (MR) in European institutions. Background: The management of patients with MR remains disputed, warranting multicenter studies to define clinical outcome in routine clinical practice. Methods: The MIDA (Mitral Regurgitation International DAtabase) is a registry created for multicenter study of MR with echocardiographically diagnosed flail leaflet as a model of pure, organic MR. Our cases were collected from 4 European centers. We enrolled 394 patients (age 64 ± 11 years; 67% men; 64% in New York Heart Association functional class I to II; left ventricular ejection fraction 67 ± 10%). Results: During a median follow-up of 3.9 years, linearized event rates/year under nonsurgical management were 5.4% for atrial fibrillation (AF), 8.0% for heart failure (HF), and 2.6% for death. Mitral valve (MV) surgery was performed in 315 (80%) patients (repair in 250 of 315, 80%). Perioperative mortality, defined as death within 30 days from the operation, was 0.7% (n = 2). Surgery during follow-up was independently associated with reduced risk of death (adjusted hazard ratio [HR] 0.42, 95% confidence interval [CI] 0.21 to 0.84; p = 0.014). Benefit was largely driven by MV repair (adjusted HR vs. replacement 0.37, 95% CI 0.18 to 0.76; p = 0.007). In 102 patients strictly asymptomatic and with normal ventricular function, 5-year combined incidence of AF, HF, or cardiovascular death (CVD) was 42 ± 8%. In these patients, surgery also reduced rates of CVD/HF (HR 0.26, 95% CI 0.08 to 0.89; p = 0.032). Conclusions: In this multicenter study, nonsurgical management of severe MR was associated with notable rates of adverse events. Surgery especially MV repair performed during follow-up was beneficial in reducing rates of cardiac events. These findings support surgical consideration in patients with MR due to flail leaflets for whom MV repair is feasible. © 2008 American College of Cardiology Foundation.