title: [Pre- and post-test probability of obstructive coronary artery disease in two diagnostic strategies: relative contributions of exercise ECG and coronary CT angiography].
abstract: BACKGROUND
  The purpose of this study was to assess the change in theoretical probability of coronary artery disease (CAD) in patients with suspected CAD undergoing coronary CT angiography (CCTA) as first line test vs. patients who underwent CCTA after an exercise ECG.
  
  
  METHODS
  Pre- and post-test probabilities of CAD were assessed in 158 patients with suspected CAD undergoing dual-source CCTA as the first-line test (Group A) and in 134 in whom CCTA was performed after an exercise ECG (Group B). Pre-test probabilities were calculated based on age, gender and type of chest pain. Post-test probabilities were calculated according to Bayes' theorem.
  
  
  RESULTS
  There were no significant differences between the groups regarding pre-test probability (median 23.5% [13.3-37.8] in group A vs. 20.5% [13.4-34.5] in group B; p=0,479). In group A, the percentage of patients with intermediate likelihood of disease (10-90%) was 90% before testing and 15% after CCTA (p<0,001), while in group B, it was 95% before testing, 87% after exercise ECG (p=NS), and 17% after CCTA (p<0,001).
  
  
  CONCLUSIONS
  Unlike exercise testing, CCTA is able to reclassify the risk in the majority of patients with an intermediate probability of obstructive CAD. The use of CCTA as a first-line diagnostic test for CAD may be beneficial in this setting.
authors: Departamento Cardiovascular, Hospital dos Lusíadas, Grupo de Hospitais Privados de Portugal, Lisboa, Portugal. miguelfariaalves@gmail.com
authors: Miguel
authors: M
authors: Faria Alves
authors: António Miguel
authors: AM
authors: Ferreira
authors: Gonçalo
authors: G
authors: Cardoso
authors: Ricardo
authors: R
authors: Saraiva Lopes
authors: Maria da Graça
authors: Mda G
authors: Correia
authors: Victor
authors: V
authors: Machado Gil
mesh_terms: D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis*; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed