Comparison of Long-term Outcomes of Early Surgery Versus Conventional Treatment for Asymptomatic Severe Mitral Regurgitation: A Propensity Analysis

Background The timing of surgery in asymptomatic severe mitral regurgitation (MR) remains controversial. This study sought to compare long-term outcomes of early surgery with a conventional treatment strategy in asymptomatic patients with severe MR.

From 1996 to 2016, a total of 1,063 consecutive asymptomatic patients (673 men, age; 51±14 years) with severe degenerative MR and preserved left ventricular function were enrolled, and followed prospectively for a median of 12 years (interquartile range: 8 to 17 years). Early surgery was performed on 545 patients, while the conventional treatment strategy was chosen for 518. We compared overall and cardiac mortality between these two treatment strategies using propensity score adjustment.

In the early surgery group, there was no operative mortality and mitral valve repair was successfully performed in 97% of patients. During follow-up, 8 patients (1.5%) in the early surgery group and 54 (10.4%) in the conventional management group died from cardiovascular causes (hazard ratio [HR], 0.17; 95% CI, 0.15 to 0.64; P = 0.001). A total of 74 deaths (13.6%) from any cause occurred in the early surgery group, whereas 116 (22.4%) occurred in the conventional management group (HR, 0.72; 95% CI, 0.52 to 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 (HR, 0.18; 95% CI, 0.08 to 0.43; P < 0.001) and significantly lower cardiac mortality rates (5.6% vs. 17.4 % at 20 years; P < 0.001). Compared with the conventional treatment group, the early surgery group also had a significantly lower risk of overall mortality (HR, 0.66; 95% CI, 0.47 to 0.93; P = 0.018) and significantly lower overall mortality rates (28.2% vs. 33.9% at 20 years; P = 0.022).

Compared with conventional management, early surgery is associated with reduced long-term cardiac and overall mortality among asymptomatic patients with severe MR and preserved left ventricular function (ClinicalTrials.gov number, NCT01703806). Competing Interest Statement The authors have declared no competing interest. Clinical Trial ClinicalTrials.gov number, NCT01703806 Funding Statement No external funding was received. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Asan Medical Center IRB I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability Because of data privacy restrictions, data from the present study are unable to be shared outside of the aurhors of the present study.