title: Development and validation of a risk score for predicting death in Chagas' heart disease.
abstract: 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.
authors.affiliation: Division of Cardiology, Anis Rassi Hospital, Goiânia, Brazil. arassijr@arh.com.br
authors.forename: Anis
authors.initials: A
authors.lastname: Rassi
authors.forename: Anis
authors.initials: A
authors.lastname: Rassi
authors.forename: William C
authors.initials: WC
authors.lastname: Little
authors.forename: Sérgio S
authors.initials: SS
authors.lastname: Xavier
authors.forename: Sérgio G
authors.initials: SG
authors.lastname: Rassi
authors.forename: Alexandre G
authors.initials: AG
authors.lastname: Rassi
authors.forename: Gustavo G
authors.initials: GG
authors.lastname: Rassi
authors.forename: Alejandro
authors.initials: A
authors.lastname: Hasslocher-Moreno
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Sousa
authors.forename: Maurício I
authors.initials: MI
authors.lastname: Scanavacca
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology; D001938:Brazil / Q000453:epidemiology; D002037:Bundle-Branch Block / Q000209:etiology; D002598:Chagas Cardiomyopathy / Q000401:mortality*; D014355:Chagas Disease / Q000150:complications / Q000401:mortality; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D016019:Survival Analysis; D014349:Trypanosoma cruzi