SCN5A Variants as Genetic Arrhythmias Triggers for Familial Bileaflet Mitral Valve Prolapse.

Mitral valve prolapse (MVP) is a common valvular heart defect with variable outcomes. Several studies reported MVP as an underestimated cause of life-threatening arrhythmias and sudden cardiac death (SCD), mostly in young adult women. Herein, we report a clinical and genetic investigation of a family with bileaflet MVP and a history of syncopes and resuscitated sudden cardiac death. Using family based whole exome sequencing, we identified two missense variants in the SCN5A gene. A rare variant SCN5A:p.Ala572Asp and the well-known functional SCN5A:p.His558Arg polymorphism. Both variants are shared between the mother and her daughter with a history of resuscitated SCD and syncopes, respectively. The second daughter with prodromal MVP as well as her healthy father and sister carried only the SCN5A:p.His558Arg polymorphism. Our study is highly suggestive of the contribution of SCN5A mutations as the potential genetic cause of the electric instability leading to ventricular arrhythmias in familial MVP cases with syncope and/or SCD history.

Excess mortality and morbidity in patients surviving infective endocarditis.

BACKGROUND: Mortality and morbidity associated with infective endocarditis may extend beyond successful treatment. The primary objective was to analyze rates, temporal changes, and predictors of excess mortality in patients surviving the acute phase of endocarditis. The secondary objective was to determine the rate of recurrence and the need for late cardiac surgery. METHODS: An observational cohort study was conducted at a university-affiliated tertiary medical center, among 328 patients who survived the active phase of endocarditis. We used age-, sex-, and calendar year-specific mortality hazard rates of the Bouches-du-Rhone French district population to calculate expected survival and excess mortality. The risk of recurrence and late valve surgery was also assessed. RESULT: Compared with expected survival, patients surviving a first episode of endocarditis had significantly worse outcomes (P = .001). The relative survival rates at 1, 3, and 5 years were 92% (95% CI, 88%-95%), 86% (95% CI, 77%-92%), and 82% (95% CI, 59%-91%), respectively. This excess mortality was observed during the entire follow-up period but was the highest during the first year after hospital discharge. Most of the recurrences and late cardiac surgeries also occurred during this period. Women exhibited a higher risk of age-adjusted excess mortality (adjusted excess hazard ratio, 2.0; 95% CI, 1.05-3.82; P = .03). Comorbidity index, recurrence of endocarditis, and history of an aortic valve endocarditis in women were independent predictors of excess mortality. CONCLUSIONS: These results justify close monitoring of patients after successful treatment of endocarditis, at least during the first year. Special attention should be paid to women with aortic valve damage.