The usefulness of the exercise stress test to predict outcome in patients with chronic Chagas disease: a longitudinal cohort study

Background Risk stratification is paramount for treatment of patients with chronic Chagas disease (CCD). The exercise stress test (EST) may be useful in the risk stratification of patients with this condition, but few studies have been performed in patients with CCD. Methods This was a longitudinal, retrospective cohort study. A total of 339 patients followed at our institution from January 2000 to December 2010 were screened. A total of 76 (22%) patients underwent the EST. The Cox proportional hazards model was used to identify independent predictors of all-cause mortality. Results Sixty-five (85%) patients were alive and 11 (14%) patients died by the study's close. In the univariate analysis, decreased systolic blood pressure (BP) at the peak of exercise and the double product were associated with all-cause mortality. However, in the multivariate analysis, only systolic BP at the peak of exercise was independently associated with all-cause mortality [hazard ratio 0.97 (95% confidence interval 0.94 to 0.99), p=0.02]. Conclusion Systolic BP at the peak of EST is an independent predictor of mortality in patients with CCD.