Outcomes of patients with mitral annular disjunction undergoing mitral valve repair†

Mitral annular disjunction (MAD) is an abnormal displacement of the posterior mitral leaflet into the left atrial wall, potentially leading to left ventricular dysfunction, malignant ventricular arrhythmias (VA) and sudden cardiac death. This study investigates the outcomes of patients with and without MAD undergoing mitral valve repair for valve prolapse (MVP).

The study retrospectively collected a single-center experience from 2021 to 2023 on 326 consecutive patients undergoing mitral valve repair for MVP. Patients were divided into two groups according to the presence of MAD. After propensity score matching 1:1, two comparable groups of 50 patients were obtained. Primary endpoints included hospital survival and early failure of the repair. Composite secondary endpoint included major adverse cardiac events (MACEs) such as reoperation, residual regurgitation ≥2, severe postoperative left ventricle (LV) dysfunction requiring prolonged (>3 days) inotropic support, cardiac arrhythmias and overall survival.

After matching, there were no significant differences between the groups in terms of preoperative characteristics. Hospital mortality was 0% in both groups, and there were no significant differences in terms of early reoperation (0%) or residual mitral regurgitation ≥2 or major atrial/VA. Nevertheless, patients with MAD presented a greater need for prolonged inotropic and mechanical circulatory support (IABP/ECMO): No-MAD 0% vs MAD 10% (P = 0.050). However, the composite outcome at midterm follow-up was similar between the groups.

Mitral valve repair in patients with MAD was associated with a significantly higher incidence of early LV dysfunction requiring mechanical support. However, no difference was found in terms of survival at follow-up.