Mitral valve prolapse and sudden cardiac arrest in the community

Abstract

Background Mitral valve prolapse (MVP) is relatively common in the general population with recently reported prevalence of 1% and familial clustering (Framingham Heart Study). However, the association with ventricular arrhythmias and sudden cardiac arrest (SCA) remains controversial. Objective To ascertain the frequency of MVP among SCA cases in the community and characterize the clinical profile of SCA cases with MVP Methods SCA cases were prospectively identified in the population-based, Oregon Sudden Unexpected Death Study (population approximately 1 million). Presence of MVP was identified from echocardiograms performed prior but unrelated to the SCA event. The detailed clinical profile of SCA cases with MVP was compared to those without MVP to identify potential differences. Results 729 SCA cases were evaluated over a 12 year period (69.5 ± 14.8 years; 64.6% male). MVP was seen in 17 cases pre-arrest (2.3%; 95% CI 1.2 to 3.4%). Mitral regurgitation (MR) was present in 14 (82.3%) MVP-SCA cases, and was moderate or severe in 10 (58.8%). Compared to cases without MVP, MVP-SCA cases were younger (60.9 ± 16.4 vs 69.7 ± 14.7; p=0.02), with fewer risk factors (diabetes 5.9% vs 46.4%; p=0.001; hypertension 41.2% vs 78.9%; p=0.001) or known coronary disease (29.4% vs 65.6%; p<0.001). Conclusion MVP was observed in a small proportion (2.3%) of SCA cases in the general population, suggesting a low risk overall. Since MVP-SCA cases were characterized by younger age and relatively low cardiovascular comorbidity, a focus on imaging for valve structure/insufficiency, as well as genetics could aid future risk stratification approaches.

Mitral valve prolapse: an underestimated cause of sudden cardiac death—a current review of the literature

“…MVP is the leading cause of MR in developed countries (8,9). The prevalence of MVP in the SCD victims is 2.4% reported by Freed and colleagues in the general population in the Framingham study (8).…”

“…Early repolarization has also been associated with MVP (1). QT dispersion has been documented in MVP and may have a potential role in arrhythmogenesis (8,12).…”

“…Redundant and thickened leaflets have been identified as a risk factor for SCA in MVP (8). Endocardial friction lesions in the left ventricle may serve as a focus of arrhythmias as well (8).…”

“…Endocardial friction lesions in the left ventricle may serve as a focus of arrhythmias as well (8). Some pathology studies have indicated that a cardiomyopathic process accompanying MVP or the autonomic nervous system dysfunction may play a role (8,13,14).…”

“…In a study of patients with VT and no history of heart disease, MVP was seen in 25% of cases, and these cases were characterized by increased endomyocardial fibrosis (8).…”