Abstract 17666: Impact of Myocardial Fibrosis and Female Sex on Life-Threatening Arrhythmias and Sudden Cardiac Death in MVP Patients: A Prospective CMR Study With Over 2300 Patient-Years of Follow Up

Abstract

Background: Mitral valve prolapse (MVP) is a common condition that exhibits a benign course. Conversely, a small subset of patients experiences life-threatening arrhythmias and sudden cardiac death (SCD). Multiple risk factors have been proposed for arrhythmia in MVP; however, few have been validated as independent predictors of hard arrhythmic events on longitudinal follow-up. Methods: A prospective cohort of 550 consecutive patients with MVP underwent comprehensive clinical assessment and late gadolinium enhancement (LGE) cardiac magnetic resonance. Patients were longitudinally followed for a composite outcome of SCD, aborted SCD, sustained or symptomatic ventricular tachycardia (VT) requiring implantable cardiac defibrillator (ICD) placement, or ventricular ablation. In a multivariable cox regression analysis, we adjusted for female sex, LGE, MVP leaflet involvement, mitral annular disjunction (MAD), and mitral regurgitation (MR) severity. Results: The cohort median age was 62 (IQR 51-71) years, comprising 50% women. Over a mean follow-up of 4.3 years, 44 patients (mean age 62.5 years ±10) met the composite outcome, of which n=33 (75%) were women. Myocardial fibrosis (LGE) was present in 61% of the outcome group (n=27). LGE (HR 3.52 [95%CI, 1.87-6.63], P <0.001) and female sex (HR 3.90 [95%CI, 1.92-7.95], P <0.001) were associated with worse outcomes in univariate analysis. Kaplan Meier statistics (Figure, A) indicated patients with LGE had a higher 5-year cumulative incidence of arrhythmic composite events than those without LGE (14.8% vs 4.4%, P <0.001). On multivariable analysis, female sex and myocardial fibrosis remained independent risk predictors across all models. (Figure, B). Conclusion: Female sex and myocardial fibrosis are independent predictors of life-threatening arrhythmic events and SCD in patients with MVP, suggesting that LGE should be an important component of risk stratification, especially in the female MVP population.