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.