The influence of aetiology on inflammatory and neurohumoral activation in patients with severe heart failure: a prospective study comparing Chagas' heart disease and idiopathic dilated cardiomyopathy.

Patients with Chagas' cardiomyopathy have the worst prognosis when compared to other aetiologies. It has been suggested that a more intense inflammatory activation could be responsible for this excessive mortality. We studied 35 patients with idiopathic dilated cardiomyopathy (IDC group) and 28 patients with Chagas' heart disease (Chagas' group) and 12 control subjects. We compared plasma tumor necrosis factor alpha (TNF-alpha), soluble TNF-alpha receptor type 1 (sTNF-R1), soluble Fas (sFas), interleukin 6 (IL-6), and brain natriuretic peptide type B (BNP) concentrations between the groups. TNF-alpha and IL-6 concentrations were higher in the IDC and Chagas groups as compared to controls (p<0.001 and p=0.001, respectively). sTNF-R1 concentration was higher in IDC after stratification for functional class (p=0.039), and there was a trend toward higher plasma TNF-alpha concentration in the Chagas' group (p=0.092). IL-6 concentration was higher in Chagas than in IDC (p=0.005). Higher IL-6 levels were associated with worse outcome (p=0.03 for Chagas; p=0.003 for IDC). sFas concentration was similar among groups. BNP concentrations were higher in IDC (350 pg/ml) and in Chagas (444.6 pg/ml) as compared to the controls (20.3 pg/ml; p<0.01). Higher BNP levels were associated with death and heart transplantation in both aetiologies. Inflammatory activation in Chagas heart disease differs from IDC and is associated with heart failure severity.