Evaluating the spectrum of patients who have undergone implantation of an ICD after aborted-sudden cardiac arrest

A study published in the American Journal of Cardiology aimed at describing a contemporary cohort of patients who have undergone implantation of an implantable cardioverter defibrillator (ICD) after an aborted-sudden cardiac arrest (SCA). The researchers suggested that the current patients who have undergone implantation of an ICD after aborted-SCA are younger in comparison with secondary prevention pivotal studies. In addition, a high proportion of current patients have structurally normal hearts. Moreover, patients with structural heart disease (SHD) have a 4-times greater risk of death during follow-up compared to those without SHD who displayed a relatively favorable outcome. It was also stated that reduced left ventricular ejection fraction is the main influencing factor.

The researchers retrospectively assessed consecutive patients referred to their centers between 2005 and 2013. The results showed that the presence of a SHD was considered as the major cause of the aborted-SCA in 160 patients out of total 250 patients. No SHD was seen in 90 patients and patients were much younger (40.9 ± 16.2 vs 53.0 ± 15.5 years in the SHD group). The 5-year estimated rates of mortality or heart transplant were 14.3% and 5.2% in the group with and without SHD, respectively. The 5-year estimated rates of appropriate ICD therapy in the ventricular fibrillation zone were 25.1% and 16.7% in patients with and without SHD, respectively. An independent association was found between left ventricular ejection fraction and mortality or heart transplant.