Recurrent mitral regurgitation after repair of Barlow's disease in a single-center retrospective cohort study.

Background: Barlow's disease (BD) is a common etiology of degenerative mitral valve (MV) disease, often causing significant mitral regurgitation (MR). The pathology of BD is challenging for surgeons performing MV repair (MVR). However, most MVR effectiveness studies have been based on survival and risk of reoperation. The aim of this study was to analyze the safety, efficacy, and durability of MVR in patients with BD and to identify factors that influence recurrent MR.

Methods: We retrospectively analyzed the clinical outcomes of 274 patients undergoing MVR for BD at a tertiary hospital (Guangdong People's Hospital, Guangzhou, China) between January 2010 and June 2022. To analyze the results of MVR and identify the risk factors for MR recurrence, we defined two groups: a total of 240 patients with MR grade <2+ (group A) and a total of 34 patients who had recurrent MR after MVR (group B; the patients with MR ≥2+). All patients were operated on using standard repair techniques. Recurrent MR was the primary outcome. Secondary outcomes were death and reoperation after MVR. Patients were followed up until March 2023. Patients were followed up by clinic visits, telephone calls, and postal or electronic questionnaires.

Results: The median [range] patient age was 46.00 [16-75] years and 186 (67.9%) patients were male. Concomitant procedures were performed in 123 patients: tricuspid valve repair 71 (25.9%), maze or pulmonary vein isolation (PVI) 12 (4.4%), atrial septal defect (ASD) repair 3 (1.1%), and left atrial appendage (LAA) closure 28 (10.2%). Hospital mortality was 0.4%. Long-term complications included radiofrequency ablation in 7 patients (2.6%), pacemaker implantation in 1 patient (0.4%), and stroke in 3 patients (1.1%). The median follow-up was 3.28 (range, 0-12.39) years. Considering the competing risk of mortality, the cumulative incidence of MR progression 2+ or more grades was 2.6%, 5.9%, 14.5%, and 27.7% at 1 month, 1, 5, and 10 years, respectively. Overall survival at 1, 5, and 10 years was 99.3%, 98.6%, and 98.6%, respectively. The immediate postoperative MR area [hazard ratio (HR) =1.723; 95% confidence interval (CI): 1.051-2.824; P=0.031], postoperative left ventricular end-diastolic dimension (LVEDD) (HR =1.149; 95% CI: 1.016-1.300; P=0.027), and postoperative MR grade {HR = Exp[4.500 - 0.544 × ln(t + 20)]; P=0.008} were associated with an increased risk of MR recurrence, whereas a higher left ventricular ejection fraction (LVEF) (HR =0.931; 95% CI: 0.868-0.999; P=0.049) was associated with a decreased risk.

Conclusions: MVR in patients with BD can be performed with low mortality and complications and is associated with superior long-term outcomes. However, MVR was associated with a certain risk of MR recurrence, especially in those with high postoperative LVEDD, residual MR >1+, and decreased postoperative LVEF. We recommend MVR for patients with BD, especially for those with early-stage disease. However, future randomized controlled trials are needed to confirm this.