First appropriate implantable defibrillator shocks in patients with Chagasic heart disease

Objetives: To assess if patients with Chagasic heart disease (CHD) received effective automatic implantable defibrillator (AID) shocks earlier than patients with ischemic heart disease (IHD).

Methods: Retrospective cohort of patients with CHD and IHD who received an implantable cardioverter defibrillator (ICD) between 2009 and 2018, in a tertiary hospital. We evaluated the time between the implant of ICD and the first effective shock in patients with CHD and compared it with the IHD control population.

Results: We included a total of 64 patients, 20 with CHD and 44 with IHD. CHD patients presented earlier an effective shock than patients with IHD during the first year (hazard ratio [HR]: 8.4; 95% confidence interval [95%CI]: 2.09-34.02; p = 0.0027), and at three years (HR: 4.61; 95%CI: 1.51-14.07; p = 0.0072). 100% of CHD patients who received the ICD as secondary prevention of sudden cardiac death presented an effective shock during the first 26 months of follow-up.

Conclusions: Patients with CHD received effective ICD shocks earlier than the IHD patients. All patients with CHD and ICD as secondary prevention had an appropriate ICD shock at short term, representing the highest risk population, and supporting the indication of the device in a setting where randomized clinical trials are lacking.