Prognostic value of natriuretic peptides in Chagas' disease: a 3-year follow-up investigation.

BACKGROUND: Chagas' disease (CD) affects around 18 million people in Latin America. To determine the diagnostic and prognostic value of natriuretic peptides in patients with CD, we measured atrial (ANP) and brain natriuretic peptide (BNP), and compared the findings with other dilated cardiomyopathies (DCM). METHODS: Blood samples were obtained from 111 CD patients, 62 patients with DCM due to other causes, and 43 gender- and age-matched healthy subjects. The CD and DCM patients were subdivided according to their NYHA classification. Natriuretic peptide concentrations were determined by immunoradiometric assays. RESULTS: ANP and more pronounced BNP levels were increased in CD and DCM patients in relation to the NYHA class. Circulating BNP concentrations were higher in CD patients in NYHA classes I-II than in the corresponding DCM patients (p = 0.020). Importantly, ANP and BNP were already significantly elevated in CD patients without systolic ventricular dysfunction (p < or = 0.001). In CD patients, both peptides were highly correlated with echocardiographic parameters (p < 10(-14)). Both ANP and BNP had comparable ability to predict death or the necessity for heart transplant (p < 0.0001). CONCLUSION: Natriuretic peptide levels can be used as a marker of asymptomatic CD without ventricular dysfunction and thus could be an ideal tool to identify these patients for early therapy.