Prevalence, Genetics, and Imaging Characteristics of Patients with Mitral Valve Prolapse and Arrhythmogenic Right Ventricular Cardiomyopathy

Background: Concomitant arrhythmogenic right ventricular cardiomyopathy (ARVC) and mitral valve prolapse (MVP) has only been described in case reports. Little is known about genetic and phenotypic characteristics of these patients. Objective: To describe the prevalence, genetics, and imaging characteristics of MVP in ARVC patients. Methods: We identified 111 definite ARVC cases through medical record review, arrhythmia/cardiomyopathy targeted gene panels, and contrast cardiac magnetic resonance data. MVP was diagnosed on echocardiography as mitral leaflet displacement greater than 2 mm above the annular plane in systole, with borderline MVP defined as less than or equal to 2 mm. Results: We found MVP/borderline MVP in 14% of ARVC patients. Cardiac arrest occurred in 20% of those with MVP/borderline MVP compared to 16% without valve abnormalities. Among 69 ARVC patients with identified genetic variants, PKP2 mutations were highly prevalent (64%), particularly in those with MVP (83%). Most MVPs had posterior prolapse (73%) and trace/mild mitral regurgitation (87%). None had mitral annular disjunction. ARVCs with MVP had higher LV mass (93 vs. 75 g/m2, p = 0.02) and a higher prevalence of LV wall motion abnormalities (27% vs. 5%, p = 0.02) compared to ARVCs without valve abnormalities. Conclusions: MVP is prevalent in ARVC and characterized by PKP2 variants in most cases. Typical features of arrhythmic MVP like bileaflet involvement and annular disjunction are rare in ARVC with MVP; features of arrhythmogenic left-sided cardiomyopathy (increased LV mass index and wall motion abnormalities) are more common. Further studies are needed to understand the role of MVP in arrhythmic risk stratification of ARVC.