Ventricular arrhythmic burden before and after mitral valve repair in mitral valve prolapse: the role of mitral annular disjunction

Background Mitral valve prolapse (MVP) is increasingly recognized as an arrhythmogenic condition, with a subset of patients exhibiting ventricular arrhythmias beyond the hemodynamic effects of mitral regurgitation (MR). Mitral annular disjunction (MAD) has been proposed as a structural marker associated with arrhythmic risk, but its relationship with postoperative ventricular arrhythmias after mitral valve repair remains incompletely understood. We aimed to evaluate changes in ventricular arrhythmic burden following mitral valve repair and to investigate the association between preoperative MAD and postoperative ventricular ectopy. Methods This retrospective observational study included 77 patients with MVP who underwent surgical mitral valve repair for severe MR and had both preoperative and postoperative 24-h Holter recordings. Premature ventricular complex (PVC) burden and ventricular arrhythmias were assessed before and after surgery. MAD was evaluated retrospectively using transthoracic echocardiography. Multivariable linear regression, sensitivity analyses, and sequential model comparison were performed to evaluate the independent and incremental association of MAD with postoperative PVC burden. Results Overall PVC burden decreased significantly after mitral valve repair. Patients with preoperative MAD had a substantially higher PVC burden both before surgery [7,800 (7,000–9,575) vs. 4,200 (3,200–6,200) PVCs/24 h, p < 0.001] and after surgery [5,700 (5,175–6,425) vs. 2,200 (1,800–3,500) PVCs/24 h, p < 0.001] than those without MAD. The relative reduction in PVC burden was comparable between groups (−35.4 ± 20.6% vs. −39.5 ± 29.5%, p = 0.113). In multivariable analysis, preoperative MAD remained independently associated with higher postoperative PVC burden after adjustment for clinical covariates, prolapse phenotype, residual mitral regurgitation, and baseline PVC burden. Conclusions Mitral valve repair was associated with a significant reduction in ventricular ectopic burden in patients with MVP. However, preoperative MAD identified patients with a higher postoperative ventricular ectopic burden despite a similar proportional reduction in PVCs. These findings support the potential value of postoperative rhythm surveillance in patients with preoperative MAD.