Predictors of mortality and heart transplantation in patients with Chagas' cardiomyopathy and ventricular tachycardia treated with implantable cardioverter-defibrillators.

Abstract

Data on long-term follow-up of patients with Chagas' heart disease (ChHD) receiving a secondary prevention implantable cardioverter-defibrillator (ICD) are limited and its benefit is controversial. The aim of this study was to evaluate the long-term outcomes of ChHD patients who received a secondary prevention ICD. We assessed the outcomes of consecutive ChHD patients referred to our Institution from 2006 to 2014 for a secondary prevention ICD [89 patients; 58 men; mean age 56 ± 11 years; left ventricular ejection fraction (LVEF), 42 ± 12%]. The primary outcome included a composite of death from any cause or heart transplantation. After a mean follow-up of 59 ± 27 months, the primary outcome occurred in 23 patients (5.3% per year). Multivariate analysis showed that LVEF < 35% [hazard ratio (HR) 4.64; P < 0.01] and age ≥ 65 years (HR 3.19; P < 0.01) were independent predictors of the primary outcome. Using these two risk factors, a risk score was developed, and lower- (no risk factors), intermediate- (one risk factor), and higher-risk (two risk factors) groups were recognized with an annual rate of primary outcome of 1.4%, 7.4%, and 20.4%, respectively. A high burden of appropriate ICD therapies (16% per year) and electrical storms were documented, however, ICD interventions did not impact on the primary outcome. Among ChHD patients receiving a secondary prevention ICD, older age (≥65 years) and left ventricular dysfunction (LVEF < 35%) portend a poor outcome and were associated with increased risk of death or heart transplantation. Most patients received appropriate ICD therapies, however, ICD interventions did not impact on the primary outcome.