Plasma B-type natriuretic peptide as a predictor of mortality in community-dwelling older adults with Chagas disease: 10-year follow-up of the Bambui Cohort Study of Aging

Abstract

In this study, the authors aimed to investigate the prognostic value of brain-type natriuretic peptide (BNP) for all-cause mortality among persons with Chagas disease, a parasitic disease caused by the protozoan Trypanosoma cruzi. The authors used data on 1,398 participants (37.5% infected with T. cruzi) aged 60 years and over from the Bambuí Cohort Study of Aging in Brazil. From 1997 to 2007, 512 participants died, leading to 12,406 person-years of observation. The hazard ratio for death was 1.27 for each unit of log-transformed BNP level (95% confidence interval (CI: 1.11, 1.45) among infected persons, independent of potentially confounding factors. Infected persons with baseline BNP levels in the top quartile had a risk of death twice that of persons in the bottom quartile (hazard ratio = 2.07, 95% CI: 1.29, 3.32). The discriminatory ability of BNP in predicting mortality (C = 0.69, 95% CI: 0.66, 0.71) was similar to that of an electrocardiogram (C = 0.68, 95% CI: 0.65, 0.71), with reasonably stable risk discrimination over time. BNP is a strong predictor of mortality in older adults with Chagas disease. Although the usefulness of BNP for risk stratification in this parasitic disease remains a topic of debate, this study found that BNP-based risk discrimination is at least comparable to that of an electrocardiogram.