Abstract 16574: Depressed Left Ventricular Function is the Main Prognostic Marker Despite Cardio-Defibrillator Implantation in Patients With Chagas Heart Disease
Background: Implantable cardio-defibrillators (ICD) are empirically used to treat patients with Chagas heart disease (CHD) but their effectiveness in this population has not been demonstrated. In addition, it has been postulated that even patients with preserved left ventricular ejection fraction (LVEF) should be treated with ICD to prevent sudden death due to CHD. We sought to investigate if CHD patients with low LVEF would have higher death rate despite appropriate ICD therapy.
Methods: Demographic and clinical data of ICD receivers with Chagas' disease were prospectively evaluated. Time to death was considered as outcome, LVEF< 45% as the exposure and age, gender and ICD therapy delivery were considered as potential confounders. We used time-to-event methods and Cox proportional models for analysis, censoring observations up to death or five-years follow up.
Results: 101 patients (67.3% male; 62±12 years-old) were followed for 1195±877 days after ICD implantation (62% due to sustained ventricular tachycardia, 21% due to aborted sudden cardiac death). Appropriate shock was delivered in 48% of the cases (or preceded by antitachycardia pacing in 14%). Inappropriate shock was delivered in 4 cases. Death occurred in 29 (28.7%) patients at a mean follow-up of 937±760 days, secondary in most cases (18) to cardiogenic and/or septic shock. Unadjusted incidence of death was 12.6 (95%CI 5.0;25.9) and 38.4 (95%CI 23.0;59.3)/100.000 patients/year respectively for those with LVEF higher or lower than 45%. Adjusting for potential confounders, low LVEF (Hazard Ratio 5.36 - 95%CI 2.06;13.9), age (HR 1.03 - 95%CI 1.00;1.07) and male gender (HR 0.27 -95%CI 0.11;0.64), but not ICD delivery therapy (HzR 0.80 - 95%CI 0.35;1.78), were associated with the outcome.
Conclusion: Low LVEF is associated with increased death rate among patients with CHD, despite ICD delivery therapy.
- © 2011 by American Heart Association, Inc.