Short- and mid-term outcomes of mitral valve repair vs. replacement in degenerative mitral regurgitation with left ventricular enlargement.

Objective: This study evaluates short- to mid-term outcomes following mitral valve repair (MVP) and mitral valve replacement (MVR) among patients with degenerative mitral regurgitation (DMR) complicated by substantial left ventricular dilatation (LVD). Methods: We performed a retrospective analysis enrolling 150 patients diagnosed with DMR and severe LVD who received either MVP or MVR. The median clinical follow-up duration was 55.5 (21.0) months. Propensity score matching (PSM) was conducted to eliminate intergroup baseline disparities. Kaplan-Meier survival curves were generated to estimate short- and mid-term all-cause survival. Results: Of the 150 enrolled patients with DMR and marked left ventricular dilatation, 56.67% underwent MVR and 43.33% received MVP. The cohort had a median age of 59 (17) years, with female patients making up 23.3% of participants. Preoperative atrial fibrillation occurred in 15.33% of patients, and 92.05% presented with severe baseline mitral valve regurgitation (MR). Analyses before and after PSM showed similar postoperative left ventricular end-diastolic dimension (LVEDD) and New York Heart Association functional class across groups. Significant intergroup differences were detected in postoperative MR ( Conclusions: In patients with DMR and dilated left ventricles (≥6.0 cm), MVR was associated with a greater incidence of postoperative hemorrhage related to long-term oral anticoagulation, whereas MVP conferred a higher risk of recurrent MR. Postoperative mortality was comparable across cohorts; however, preserved left ventricular subclinical systolic function (GLS and LVEF) in the MVP group suggests potential long-term myocardial benefits, which warrants further prospective investigation.