Implantable cardioverter-defibrillator therapy in device recipients who survived a cardiac arrest associated with a reversible cause.

Background: Guideline recommendations for implantable cardioverter-defibrillators (ICD) for secondary prevention of sudden cardiac arrest (SCA) have excluded patients with reversible causes. We previously demonstrated mortality benefit with the ICD in survivors of SCA associated with reversible causes other than myocardial infarction (MI) or ischemia treated with coronary revascularization. In the current study, we examined the incidence of ICD therapy in patients with SCA related to reversible causes.

Methods: Data were collected for all patients over the age of 18 years who had survived to hospital discharge after SCA between 2002 and 2012. ICD recipients with reversible causes were divided into 2 groups based on their reversible etiology of SCA: MI + ICD (n = 132) and non-MI + ICD (n = 75). Delivered ICD therapy was examined.

Results: Over a follow-up period of 3.8 ± 3.1 years, more patients without MI/ischemia who received an ICD experienced appropriate (adjusted HR, 3.96; 95% CI, 1.32-11.84) but not inappropriate (adjusted HR, 0.65; 95% CI, 0.14-2.97) ICD therapy compared with patients without MI/ischemia. The proportion of patients receiving appropriate (P = 0.012) but not inappropriate (P = 0.80) ICD therapy was also higher in the non-MI + ICD compared with the MI + ICD group.

Conclusion: We show higher rates of appropriate ICD therapy in survivors of SCA associated with reversible causes other than MI/ischemia. This finding, in conjunction with the previously demonstrated lower all-cause mortality noted in the presence of an ICD in SCA survivors with reversible etiology other than MI/ischemia, further supports consideration of ICD implantation in this population.