Background: The timing of surgery in asymptomatic severe mitral regurgitation remains controversial. This observational study sought to compare long-term outcomes of early surgery with a conventional treatment strategy in asymptomatic patients with severe mitral regurgitation.
Methods: From 1996 to 2016, a total of 1063 consecutive asymptomatic patients (673 men; mean±SD age, 51±14 years) with severe degenerative mitral regurgitation and preserved left ventricular function were enrolled, and followed prospectively for a median of 12 years (interquartile range, 8-17 years). Early surgery was performed on 545 patients and the conventional treatment strategy was chosen for 518 patients. We compared overall and cardiac mortality rates between these 2 treatment strategies using propensity score adjustment.
Results: In the early surgery group, no operative deaths occurred, and mitral valve repair was successfully performed in 97% of patients. During follow-up, 8 (1.5%) patients in the early surgery group and 54 (10.4%) in the conventional management group died from cardiovascular causes (hazard ratio, 0.17 [95% CI, 0.07-0.40]; P<0.001). A total of 74 (13.6%) deaths from any cause occurred in the early surgery group, whereas 116 (22.4%) occurred in the conventional management group (hazard ratio, 0.72 [95% CI, 0.52-0.99]; P=0.046). For the 358 propensity score matched pairs, the early surgery group had a significantly lower risk of cardiac mortality than the conventional treatment group (hazard ratio, 0.18 [95% CI, 0.08-0.43]; P<0.001) and significantly lower cardiac mortality rates (5.6% versus 17.4% at 20 years; P=0.002). Compared with the conventional treatment group, the early surgery group also had a significantly lower risk of overall mortality (hazard ratio, 0.66 [95% CI, 0.47-0.93]; P=0.018) and significantly lower overall mortality rates (28.2% versus 33.9% at 20 years; P=0.015).
Conclusions: Compared with conventional management, early surgery is associated with better long-term outcomes among asymptomatic patients with severe mitral regurgitation and preserved left ventricular function.
Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01703806.
Keywords: cardiac surgical procedures; mitral valve insufficiency; observation; outcome assessment; therapeutics; thoracic surgery.