Prognostic impact of peak mitral inflow velocity in asymptomatic degenerative mitral regurgitation

Appropriate timing of mitral valve surgery in asymptomatic mitral regurgitation (MR) remains controversial. Peak mitral inflow velocity (peak E wave velocity) has been reported as a simple and easy predictor of quantitative MR severity; however, its prognostic significance in asymptomatic MR remains unclear. Therefore, we sought to investigate the prognostic impact of peak E wave velocity in asymptomatic MR.

Among 529 consecutive patients with degenerative MR of grade 3+ (moderate to severe) or 4+ (severe), 188 asymptomatic patients in sinus rhythm without left ventricular (LV) dysfunction (end-systolic dimension ≥40 mm or ejection fraction <60%) or pulmonary hypertension were studied. Cardiovascular events were defined as a composite endpoint of cardiovascular death or events that indicated mitral surgery including congestive heart failure, atrial fibrillation, LV dysfunction or pulmonary hypertension.

Average peak E wave velocity was 1.05±0.26 m/s, and was significantly higher in grade 4+ than grade 3+ (1.20±0.28 vs 0.98±0.21 m/s, p<0.001). Peak E wave velocity was associated with quantitative MR severity, as well as clinical characteristics of advanced MR (higher brain natriuretic peptide, larger LV and left atrium, higher tricuspid regurgitation pressure gradient and dilated inferior vena cava). During a median follow-up of 4.3 years, 66 (35%) patients developed cardiovascular events. Multivariate Cox proportional hazards analysis showed that peak E wave velocity was an independent predictor of cardiovascular events (adjusted HR 1.245 (95% CI 1.126 to 1.378) per 0.1 m/s, p<0.001).

Peak E wave velocity was an independent predictor of cardiovascular events in asymptomatic degenerative MR with preserved LV function.