title: Positive predictive value of computed tomography coronary angiography in clinical practice.
abstract: BACKGROUND
  Several studies have investigated the diagnostic performance of computed tomography coronary angiography (CTCA) for the detection of significant coronary artery disease (CAD). These studies were performed in patients that were already referred for invasive coronary angiography (ICA) and prevalence of significant CAD was high. Although the negative predictive value of CTCA was consistently high, a wide range of positive predictive values (PPVs) was reported. Thus, the PPV of CTCA in patients that undergo CTCA as part of a clinical diagnostic evaluation remains unclear. This study investigated the PPV of CTCA for the detection of significant CAD in clinical practice.
  
  
  METHODS
  A total of 181 patients with low to intermediate pre-test probability CAD that were referred for non-invasive evaluation of chest pain underwent 64-slice CTCA. CTCA was scored per segment as normal, non-obstructive CAD or obstructive CAD (>50% diameter stenosis). All patients with obstructive CAD according to CTCA, underwent ICA. Significant CAD was defined as >50% diameter stenosis on ICA.
  
  
  RESULTS
  According to CTCA, 65 (35.9%) patients had obstructive CAD. In 26 (14.4%) patients, significant CAD was found by ICA. The PPV for detection of significant CAD per patient, per vessel and per segment were 40.0% (26/65, 95% CI: 30.6-50.2%), 31.3% (36/115, 95% CI: 24.7-38.8%) and 25.5% (42/165; 95% CI: 20.3-31.4%), respectively.
  
  
  CONCLUSIONS
  The PPV of CTCA for detection of significant CAD in patients with low to intermediate probability CAD that are clinically referred for non-invasive evaluation of chest pain is markedly lower than generally reported.
authors.affiliation: Interuniversity Cardiology Institute of the Netherlands, Utrecht, the Netherlands. j.groothuis@vumc.nl
authors.forename: Jan G J
authors.initials: JG
authors.lastname: Groothuis
authors.forename: Aernout M
authors.initials: AM
authors.lastname: Beek
authors.forename: Martijn R
authors.initials: MR
authors.lastname: Meijerink
authors.forename: Stijn L
authors.initials: SL
authors.lastname: Brinckman
authors.forename: Martijn W
authors.initials: MW
authors.lastname: Heymans
authors.forename: Cornelis
authors.initials: C
authors.lastname: van Kuijk
authors.forename: Albert C
authors.initials: AC
authors.lastname: van Rossum
mesh_terms: D000368:Aged; D002637:Chest Pain / Q000000981:diagnostic imaging / Q000453:epidemiology; D017023:Coronary Angiography / Q000379:methods / Q000592:standards*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000592:standards*