Mitral Valve Surgery with and Without Mitral Annular Disjunction: A Meta-Analysis.

BACKGROUND/OBJECTIVES: Despite growing awareness of mitral annular disjunction's (MAD) clinical significance, robust data regarding the outcomes of surgical interventions on MAD remain sparse. This meta-analysis aims to systematically evaluate the current evidence on the efficacy and safety of mitral valve (MV) surgery in patients with MAD. METHODS: A systematic review was conducted from inception until May 2025 for studies comparing patients undergoing MV surgery with and without MAD and was registered in PROSPERO: CRD42025649821. RESULTS: Patients with MAD were generally younger (59.3 ± 5.0 vs. 63.4 ± 2.2 years, standardized mean difference: -0.3073), had fewer comorbidities but more complex valve lesions (41.0% vs. 13.7%, risk difference: 0.2627) compared to those without MAD. MV replacement was performed less frequently in the MAD group than in the No-MAD group (risk ratio, RR: 0.690 [95% confidence interval, CI: 0.508; 0.937], p = 0.017), probably related to the significant difference in age between the two groups. The MAD cohort demonstrated a higher incidence of ventricular arrhythmia both after surgery (RR: 7.255 [95%CI: 1.231; 42.763], p = 0.029) and during follow-up (incidence rate ratio, IRR: 2.750 [95%CI: 1.372; 5.512], p = 0.004). Although the MAD group experienced more arrhythmic events over time, this did not translate into a significant difference in overall mortality compared to patients without MAD (IRR: 0.573 [95%CI: 0.072; 4.555], p = 0.599). CONCLUSIONS: This meta-analysis revealed significant baseline differences between the populations. Our findings suggest that patients with MAD remained at significantly higher risk for both postoperative and long-term arrhythmias. These results highlight the need for close arrhythmic surveillance in this population.