Impact of Acute Coronary Syndrome Complicated by Ventricular Fibrillation on Long-term Incidence of Sudden Cardiac Death

Abstract

Introduction and objectives: There is little information on the effect of acute coronary syndrome complicated by ventricular fibrillation on the long-term incidence of sudden cardiac death. We analyzed this effect in a contemporary cohort of patients with acute coronary syndrome.

Methods: We studied 5302 consecutive patients with acute coronary syndrome between December 2003 and December 2012. We compared mortality during and after hospitalization according to the presence or absence of ventricular fibrillation.

Results: Ventricular fibrillation was observed in 163 (3.1%) patients, and was early onset in 72.4% of these patients. In-hospital mortality was 36.2% in the group with ventricular fibrillation and 4.7% in the group without (p<.001). After a mean follow-up of 4.7 years (standard deviation, 2.6 years), mortality was 30.7% in the ventricular fibrillation group and 24.7% in the other group (P=.23). After adjusting for confounding variables, the presence of ventricular fibrillation was not associated with an increased risk of death in the follow-up period (hazard ratio=1.29; 95% confidence interval, 0.90-1.87). The cause of death was established in 72% of patients. The incidence of sudden death was 12.9% in the ventricular fibrillation group and 11.9% in the other group (P=.71). Cardiovascular-cause mortality was also similar between the 2 groups (35.5% and 34.4%, respectively.

Conclusions: Patients with acute coronary syndrome complicated by ventricular fibrillation who survive the in-hospital phase do not appear to be at an increased risk of sudden cardiac death or other cardiovascular-cause death.

Keywords: Acute coronary syndrome; Fibrilación ventricular; Muerte súbita; Sudden death; Síndrome coronario agudo; Ventricular fibrillation.