Ventricular Arrhythmias in Patients Undergoing Degenerative Mitral Repair: Prevalence and Impact on Survival.

Objective: Ventricular arrhythmias occur in a subset of patients with mitral valve prolapse. However, their impact on post-operative survival after degenerative mitral repair is unclear.

Methods: We compared long-term survival after degenerative mitral repair in patients presenting with and without arrhythmic mitral valve prolapse (defined by degenerative mitral regurgitation and ventricular arrhythmias) in a national insurance database. Our primary outcome was survival up to 5 years: our secondary outcomes were implantable cardiac defibrillator (ICD) and ventricular arrhythmia related readmissions. Multivariable adjustment accounted for baseline differences. Median follow-up was 3.8 years (IQR: 1.5-6.6).

Results: Among 20,980 patients, 1,745 (8.3%) had arrhythmic mitral valve prolapse, of whom 1,121 (64%) underwent surgical repair and 624 (36%) underwent transcatheter edge-to-edge repair (TEER). The 5-year survival after surgical repair was 86% in patients with arrhythmic mitral valve prolapse compared to 81% in patients without (HR: 0.79, 95% CI: 0.64-0.97, p = 0.02). The 5-year survival after TEER was 34% in patients with arrhythmic mitral valve prolapse compared to 43% in patients without (HR: 1.26, 95% CI: 1.07-1.49, p < 0.001). Rates of ICD were higher following surgery in patients with arrhythmia (1.3% vs. 0.4%, p<0.01) and similar following TEER (0.6% vs. 0.4%, p=0.5).

Conclusions: Arrhythmic mitral valve prolapse is not associated with worse survival after surgical mitral repair. However, arrhythmic mitral valve prolapse is associated with significantly worse survival after TEER. Prospective mechanistic studies are needed to elucidate the pathophysiology of and inform treatment choice in patients with arrhythmic mitral valve prolapse.