Development and validation of a risk score for predicting death in Chagas' heart disease

N Engl J Med. 2006 Aug 24;355(8):799-808. doi: 10.1056/NEJMoa053241.


Background: Chagas' disease is an important health problem in Latin America, and cardiac involvement is associated with substantial morbidity and mortality. We developed a model to predict the risk of death in patients with Chagas' heart disease.

Methods: We retrospectively evaluated 424 outpatients from a regional Brazilian cohort. The association of potential risk factors with death was tested by Cox proportional-hazards analysis, and a risk score was created. The model was validated in 153 patients from a separate community hospital.

Results: During a mean follow-up of 7.9 years, 130 patients in the development cohort died. Six independent prognostic factors were identified, and each was assigned a number of points proportional to its regression coefficient: New York Heart Association class III or IV (5 points), evidence of cardiomegaly on radiography (5 points), left ventricular systolic dysfunction on echocardiography (3 points), nonsustained ventricular tachycardia on 24-hour Holter monitoring (3 points), low QRS voltage on electrocardiography (2 points), and male sex (2 points). We calculated risk scores for each patient and defined three risk groups: low risk (0 to 6 points), intermediate risk (7 to 11 points), and high risk (12 to 20 points). In the development cohort, the 10-year mortality rates for these three groups were 10 percent, 44 percent, and 84 percent, respectively. In the validation cohort, the corresponding mortality rates were 9 percent, 37 percent, and 85 percent. The C statistic for the point system was 0.84 in the development cohort and 0.81 in the validation cohort.

Conclusions: A simple risk score was developed to predict death in Chagas' heart disease and was validated in an independent cohort.

Publication types

  • Validation Study

MeSH terms

  • Adult
  • Analysis of Variance
  • Animals
  • Arrhythmias, Cardiac / etiology
  • Brazil / epidemiology
  • Bundle-Branch Block / etiology
  • Chagas Cardiomyopathy / mortality*
  • Chagas Disease / complications
  • Chagas Disease / mortality
  • Cohort Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Proportional Hazards Models
  • Retrospective Studies
  • Risk Assessment*
  • Risk Factors
  • Survival Analysis
  • Trypanosoma cruzi