title: Prognostic value of multidetector coronary computed tomography angiography in relation to exercise electrocardiogram in patients with suspected coronary artery disease.
abstract: OBJECTIVE
  This study was designed to determine the prognostic value of multidetector coronary computed tomography angiography (CTA) in relation to exercise electrocardiography (XECG) findings.
  
  
  BACKGROUND
  The prognostic usefulness of coronary CTA findings of coronary artery disease in relation to XECG findings has not been explored systematically.
  
  
  METHODS
  Patients with suspected coronary artery disease who had undergone both coronary CTA and XECG (<90 days between tests) from 2003 through 2009 were enrolled retrospectively. Coronary CTA results were classified according to the severity of maximal stenosis (normal, mild: <40% of luminal stenosis, moderate: 40% to 69%, severe: ≥70%), XECG results were categorized as positive and negative, and Duke XECG score was calculated. Clinical follow-up data were collected for major adverse cardiac events (MACE): cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, and revascularization after 90 days from index coronary CTA. C-statistics were calculated to compare discriminatory values of each test.
  
  
  RESULTS
  Among the 2,977 (58 ± 10 years) study patients, 12% demonstrated positive XECG results. By coronary CTA, patients were categorized as normal (56%) or having mild (26%), moderate (13%), or severe (5%) disease. During a median follow-up of 3.3 years (interquartile range: 2.3 to 4.6), 97 MACE were observed and the 5-year cumulative event rate was 3.6% (95% confidence interval: 3.0 to 4.3). Although both XECG (C-statistic: 0.790) and coronary CTA (C-statistic: 0.908) improved risk stratification beyond clinical risk factors (C-statistic: 0.746, p < 0.05 for all), XECG in addition to coronary CTA (C-statistic: 0.907) did not provide better discrimination than coronary CTA alone (p = 0.389). In subgroup analyses, coronary CTA stratified risk of MACE in groups with both positive and negative XECG results (all p < 0.001 for trend). However, positive XECG results predicted risk of MACE on coronary CTA only in the moderate stenosis group (hazard ratio: 2.58, 95% confidence interval: 1.29 to 5.19, p = 0.008) and severe stenosis group (hazard ratio: 2.28, 95% confidence interval: 1.19 to 4.38, p = 0.013).
  
  
  CONCLUSIONS
  In patients with suspected coronary artery disease, coronary CTA discriminates future risk of MACE in patients independent of XECG results. Compared with coronary CTA, XECG has an additive prognostic value only in patients with moderate to severe stenosis on coronary CTA.
authors.affiliation: Division of Cardiology Severance Cardiovascular Hospital, Yonsei University College of Medicine, Yonsei University Health System, Seoul, South Korea.
authors.forename: Iksung
authors.initials: I
authors.lastname: Cho
authors.forename: Jaemin
authors.initials: J
authors.lastname: Shim
authors.forename: Hyuk-Jae
authors.initials: HJ
authors.lastname: Chang
authors.forename: Ji Min
authors.initials: JM
authors.lastname: Sung
authors.forename: Youngtaek
authors.initials: Y
authors.lastname: Hong
authors.forename: Hackjoon
authors.initials: H
authors.lastname: Shim
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Kim
authors.forename: Byoung Wook
authors.initials: BW
authors.lastname: Choi
authors.forename: James K
authors.initials: JK
authors.lastname: Min
authors.forename: Ji-Ye
authors.initials: JY
authors.lastname: Kim
authors.forename: Chi-Young
authors.initials: CY
authors.lastname: Shim
authors.forename: Geu-Ru
authors.initials: GR
authors.lastname: Hong
authors.forename: Namsik
authors.initials: N
authors.lastname: Chung
mesh_terms: D000328:Adult; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000503:physiopathology; D003937:Diagnosis, Differential; D004562:Electrocardiography; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors