Risk stratification in a Brazilian hospital-based cohort of 1220 outpatients with heart failure: role of Chagas' heart disease.

BACKGROUND: Few studies evaluated prognostic factors of outpatients with heart failure of different etiologies including Chagas' heart disease.

METHODS: We studied 1220 outpatients with heart failure in functional classes III and IV (NYHA) to evaluate prognostic factors. Patients aged 13-72 years (mean 45.5, standard deviation 11); 952 men (78%) and 268 women (22%) were followed up for 25.6+/-26 months from 1991 to 2000. Heart failure was attributed to idiopathic dilated cardiomyopathy in 454 (37%) patients. Etiologies were Chagas' heart disease in 242 (20%) patients, ischemic cardiomyopathy in 212 (17%), hypertensive cardiomyopathy in 170 (14%) and others in 142 (12%). Statistical analyses were performed with Kaplan-Meier and Cox proportional hazards methods, following a strategy of noninvasive model as well as in an invasive model to identify the risk of death.

RESULTS: Four hundred fifteen (34%) patients died in the follow-up period, 71 (6%) patients underwent heart transplantation and 28 (2%) underwent other surgical interventions. In the noninvasive model, Chagas' heart disease (relative risk compared with other etiologies 2.26 to 2.97), left ventricular end diastolic diameter on echocardiography (relative risk 1.13) and left ventricular ejection fraction on radionuclide angiography (relative risk 0.96) were associated with higher mortality. In the invasive model, Chagas' heart disease (relative risk compared with other etiologies 2.66 to 9.13) was the most important determinant of mortality in association with the cardiac index (relative risk 0.40).

CONCLUSIONS: In this cohort of patients with heart failure of different etiologies, Chagas' heart disease was the main prognostic factor for mortality.