Clinical characteristics, predictors of mortality, and outcome in patients with heart failure with mildly reduced ejection fraction secondary to Chagas cardiomyopathy

Clinical characteristics, predictors of mortality, and outcome of patients with Chagas cardiomyopathy (ChCM) with heart failure with mildly reduced ejection fraction (HFmrEF) are unknown. 215 patients with a positive serology for ChCM and a left ventricular EF (LVEF) < 50 % followed at our ambulatory from January 2000 to January 2010 were included in the study. 36 patients (20 %) had a LVEF between 41 % and 49 % (HFmrEF), whereas the remaining 179 (80 %) patients had a LVEF <= 40 % (HFrEF). No difference was observed between both groups regarding clinical characteristics. Beta-Blocker (BB) therapy was independently and negatively associated with all-cause mortality in patients with ChCM and HFmrEF by Cox regression analysis (hazard ratio = 0.15; 95 % Confidence Interval 0.05 to 0.42; p < 0.001). Survival analysis by Kaplan-Meir method in patients with ChCM with HFmrEF on BB therapy was 49 % in a 60-month follow up. Overall, survival was higher in patients with HFmrEF than in those with HFrEF. Thus, HFmrEF affects 20 % of patients with ChCM, who have similar clinical characteristics and a poorer outcome than patients with ChCM with HFrEF. However, outcome is dismal in patients with ChCM with HFmrEF.