title: Computed tomographic coronary angiographic assessment of high-risk coronary anatomy in patients with suspected coronary artery disease and intermediate pretest probability.
abstract: BACKGROUND
  It is unclear if computed tomographic coronary angiography (CTA), an evolving technique for the evaluation of coronary artery disease (CAD), can identify patients with high-risk coronary anatomy.
  
  
  METHODS
  Among patients referred for invasive angiography at Hamilton Health Sciences (Hamilton, Ontario, Canada), those with an intermediate pretest probability (25%-60% likelihood of a significant stenosis) were prospectively identified using a multivariate risk score and were studied on a 64-detector Toshiba Aquilion scanner (Toshiba Medical Systems, Tokyo, Japan) before invasive angiography. Patients with high-risk anatomy (left main, 3-vessel CAD, or 2-vessel CAD involving the proximal left anterior descending artery) or at least 1 significant stenosis were identified on CTA and invasive angiography, and the results of these modalities were compared on a per patient basis.
  
  
  RESULTS
  Eighty patients were enrolled in the study (mean age 56 +/- 9 years, male-female ratio 43:37). Nondiagnostic scan results were obtained in 5 patients (6%). By CTA, 13 patients had high-risk anatomy and 31 patients had at least 1 significant stenosis. For the per patient detection of high-risk anatomy, CTA had 100% sensitivity (95% CI 69%-100%), 95% specificity (95% CI 86%-95%), a positive likelihood ratio of 18.0 (95% CI 6.4-50.3), and a negative likelihood ratio of 0.05 (95% CI 0-0.072). Revascularization was performed in 100% of patients with high-risk anatomy on CTA, 83% with at least 1 significant stenosis on CTA, and 0% without a significant stenosis on CTA.
  
  
  CONCLUSIONS
  In appropriately selected patients, CTA is a highly sensitive and specific technique for the detection of high-risk anatomy and maybe a valuable method for noninvasive risk stratification.
authors.affiliation: Cardiac CT, Hamilton General Hospital, Hamilton, Ontario, Canada. shetht@mcmaster.ca
authors.forename: Tej
authors.initials: T
authors.lastname: Sheth
authors.forename: Shoaib
authors.initials: S
authors.lastname: Amlani
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: Ellins
authors.forename: Shamir
authors.initials: S
authors.lastname: Mehta
authors.forename: James
authors.initials: J
authors.lastname: Velianou
authors.forename: Gail
authors.initials: G
authors.lastname: Cappelli
authors.forename: Sean
authors.initials: S
authors.lastname: Yang
authors.forename: Madhu
authors.initials: M
authors.lastname: Natarajan
mesh_terms: D000368:Aged; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed