Spectrum and Outcome of Patients Who Have Undergone Implantation of an Implantable Cardioverter Defibrillator After Aborted-Sudden Cardiac Arrest

Most of implantable cardioverter defibrillator (ICD) secondary prevention studies have been published 2 decades ago. We aimed to describe a contemporary cohort of patients who have undergone implantation of an ICD after an aborted-sudden cardiac arrest (SCA). We retrospectively evaluated consecutive patients referred to our centers between 2005 and 2013. Predictors of overall mortality or heart transplant were analyzed using Cox proportional hazards models. A total of 250 patients (76.4% male, 48.7 +/- 16.7 years) were included (mean follow-up = 49.6 +/- 35 months). The presence of a structural heart disease (SHD) was considered as the primary cause of the aborted-SCA in 160 patients (64%). In 90 patients (36%), no SHD was observed, with patients much younger (40.9 +/- 16.2 years vs 53.0 +/- 15.5 years in the SHD group, p < 0.0001). The 5-year estimated rates of death or heart transplant were 14.3% and 5.2% in the group with and without SHD, respectively (hazard ratio = 4.65, 95% confidence interval 1.40 to 15.6, p = 0.014). The 5-year estimated rates of appropriate ICD therapy in the ventricular fibrillation zone were 16.7% and 25.1% in patients without and with SHD (p = 0.24), respectively. Only left ventricular ejection fraction remained independently associated with mortality or heart transplant (hazard ratio = 0.94, 95% confidence interval 0.90 to 0.97, p = 0.0004). Overall, 69 patients (27.6%) experienced at least 1 ICD-related complication. In conclusion, compared with secondary prevention pivotal studies, the current patients who have undergone implantation of an ICD after aborted-SCA are younger, with a high proportion of structurally normal hearts. Compared with patients without SHD, who depicted a relatively favorable outcome, patients with SHD present a fourfold higher risk of death during follow-up. Reduced left ventricular ejection fraction remains the major influencing factor. (C) 2017 Elsevier Inc. All rights reserved.