Characteristics of patients with mitral valve prolapse presenting with sudden cardiac arrest: a single-center case-control study

Background Mitral valve prolapse (MVP) has been observed in patients presenting with sudden cardiac arrest (SCA), but the clinical risk factors underlying this association remain to be elucidated. Purpose To evaluate the clinical risk factors underlying SCA in patients with MVP. Methods In this single-center case-control study we included patients with a diagnosis of arrhythmic MVP without severe mitral valve regurgitation. All patients underwent 12-leads electrocardiogram (ECG), 12-leads 24-hours Holter ECG, and cardiac magnetic resonance. The primary endpoint was the occurrence of SCA. Results 36 patients (median age 39 years; 23% female) were included. Over a median follow up of 129 months (Q1-Q3 73-139), the primary endpoint occurred in 9 subjects. All patients survived the event. The arrhythmia consisted in ventricular fibrillation in 8 (89%) and torsades de pointes in one (11%). Eight out of nine episodes occurred at rest (89%), while one had the event during the recovery of effort. Those experiencing SCA showed greater MAD (median length 10 vs 4.8 mm, p= 0.013), higher curling (median 5 vs 3 mm, p= 0.018), greater prevalence of non-sustained ventricular tachycardia (100% vs 34%, p 0.001) and higher QTc values (median 460 vs 420 ms, p <0.001). At Cox regression analysis, MAD extension (HR 1.18, 95% CI 1.04-1.41, p= 0.014) and QTc values (HR 1.51, 95% CI 1.91-2.26, p= 0.047) emerged as independent predictors of SCA. Conclusions In patients with MVP presenting with SCA, greater MAD and higher QTc values emerged as independent predictors, highlighting their relevance in identifying high-risk individuals.