Introduction: Management of asymptomatic patients with severe mitral regurgitation (MR) and preserved EF is often challenging, and appropriate timing of mitral valve surgery remains controversial. Peak mitral inflow velocity (peak E wave velocity) has been reported as a simple and easy predictor for MR severity, however, its prognostic impact has not fully been elucidated. We hypothesized that peak E wave velocity may be a prognostic predictor for asymptomatic mitral regurgitation.
Methods and Results: Two hundred and twenty-nine consecutive patients (Age 64±14, male 63%) with grade 3+ (moderate-to-severe) or grade 4+ (severe) degenerative MR were evaluated: 129 patients were initially indicated for mitral valve surgery, and the remaining 100 patients were asymptomatic. Development of surgery for MR (symptom or left ventricle [LV] dilatation) during follow up was defined as a cardiovascular event in this study. Among the 100 asymptomatic patients (Age 61±14 years, male 65%, LV end systolic dimension 33±4mm, EF 62±6%), the mean value of peak E wave velocity was 1.13±0.28 m/s. The cutoff value for cardiovascular events were 1.24 m/s by receiver operating curve analysis. Patients with peak E wave velocity ≥ 1.24m/s (n=36) had larger left atrial volume (75[62-87] vs. 56[49-72] ml/m2, P=0.002) and higher tricuspid regurgitation pressure gradient (27[21-34] vs. 22[19-27] mmHg, P=0.009) compared to E wave <1.24m/s (n=64). No significant differences were observed in age, sex, LV dimension or EF. During a median follow up of 1521 days, 29 (29%) patients developed a cardiovascular event. Kaplan-Meier analysis revealed that patients with peak E wave velocity ≥ 1.24m/s had significantly lower event free survival compared to <1.24m/s (P=0.0016). Cox regression hazard analysis showed that peak E wave velocity was a significant predictor for cardiovascular events (unadjusted HR 1.018 [95%CI 1.005-1.031], P=0.007), even after adjusted for clinical variables including age, sex, ejection fraction, LV end systolic dimension and LA volume (adjusted HR 1.017 [95%CI 1.002-1.031], P=0.025).
Conclusions: Peak mitral inflow velocity (peak E wave velocity) was an independent predictor of cardiovascular events in asymptomatic degenerative mitral regurgitation.