The optimal timing of surgery for asymptomatic severe mitral regurgitation (MR) with preserved left ventricular function remains uncertain. A prospective observational study, published in Circulation, evaluated 1,063 consecutive patients with severe degenerative MR enrolled from 1996 to 2016. The cohort included 673 men with a mean age of 51 years. Early surgery was performed in 545 patients, while 518 received conventional management. The median follow-up was 12 years.

In the early surgery group, there were no operative deaths, and mitral valve repair was achieved in 97% of patients. Cardiovascular deaths occurred in 8 patients (1.5%) in the early surgery group compared with 54 patients (10.4%) in the conventional group (hazard ratio [HR] 0.17; 95% confidence interval [CI] 0.07–0.40; P<0.001). Death from any cause occurred in 74 patients (13.6%) in the early surgery group and 116 patients (22.4%) in the conventional group (HR 0.72; 95% CI 0.52–0.99; P=0.046).

Propensity score matched analysis of 358 pairs showed lower 20-year cardiac mortality in the early surgery group (5.6% vs 17.4%; P=0.002) and lower overall mortality (28.2% vs 33.9%; P=0.015). The authors concluded that early surgery is associated with improved long-term survival in this patient population.