RESUMO
Background Risk stratification of Chagas disease patients in the limited-resource setting would be helpful in crafting management strategies. We developed a score to predict 2-year mortality in patients with Chagas cardiomyopathy from remote endemic areas. Methods and Results This study enrolled 1551 patients with Chagas cardiomyopathy from Minas Gerais State, Brazil, from the SaMi-Trop cohort (The São Paulo-Minas Gerais Tropical Medicine Research Center). Clinical evaluation, ECG, and NT-proBNP (N-terminal pro-B-type natriuretic peptide) were performed. A Cox proportional hazards model was used to develop a prediction model based on the key predictors. The end point was all-cause mortality. The patients were classified into 3 risk categories at baseline (low, <2%; intermediate, ≥2% to 10%; high, ≥10%). External validation was performed by applying the score to an independent population with Chagas disease. After 2 years of follow-up, 110 patients died, with an overall mortality rate of 3.505 deaths per 100 person-years. Based on the nomogram, the independent predictors of mortality were assigned points: age (10 points per decade), New York Heart Association functional class higher than I (15 points), heart rate ≥80 beats/min (20 points), QRS duration ≥150 ms (15 points), and abnormal NT-proBNP adjusted by age (55 points). The observed mortality rates in the low-, intermediate-, and high-risk groups were 0%, 3.6%, and 32.7%, respectively, in the derivation cohort and 3.2%, 8.7%, and 19.1%, respectively, in the validation cohort. The discrimination of the score was good in the development cohort (C statistic: 0.82), and validation cohort (C statistic: 0.71). Conclusions In a large population of patients with Chagas cardiomyopathy, a combination of risk factors accurately predicted early mortality. This helpful simple score could be used in remote areas with limited technological resources.
