title: Incremental predictive value for obstructive coronary artery disease by combination of Duke Clinical Score and Agatston score.
abstract: OBJECTIVE
  Recent study suggests that algorithms such as the Duke Clinical score (DCS) may overestimate the pretest probability. The Agatston score representing the grade of coronary artery calcification can be simply calculated from low-radiation exposure ECG-gated plain CT. In this study, we investigated whether or not more superior diagnostic performance for obstructive coronary artery disease (CAD) can be obtained by combining DCS with the Agatston score.
  
  
  RESULTS
  Of 3939 consecutive patients suspected of having stable angina without known CAD who underwent Coronary Computed Tomography Angiography (CCTA) as well as calculation of the DCS and Agatston score at our hospital, 3688 patients were selected as subjects. Obstructive CAD was defined as >50% diameter stenosis on CCTA; we investigated the diagnostic performance based on the area under the curve (AUC) of a receiver operating characteristic (ROC) curve, Net Reclassification Improvement (NRI), and Integrated Discrimination Improvement (IDI). The AUCs of ROCs prepared using the DCS alone and combination of the DCS and Agatston score were 0.7137 and 0.8057, respectively, showing that the diagnostic performance of the combination was significantly superior to DCS alone (P < 0.001). NRI was 0.8132 and IDI was 0.1374, showing that the diagnostic performance was improved by the combination of the DCS and Agatston score compared with DCS alone (P < 0.001). NRI (0.3522) and IDI (0.0287) were improved compared with those of the Agatston score alone (P < 0.001).
  
  
  CONCLUSIONS
  The combination of the DCS and Agatston score improved the diagnostic performance for obstructive CAD compared with DCS alone and Agatston score.
authors.affiliation: Department of Cardiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan k-takamu@juntendo.ac.jp.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takamura
authors.affiliation: Department of Cardiology, Jukokai Central Hospital, Miyoshi, Aichi, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kondo
authors.affiliation: Department of Cardiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Fujimoto
authors.affiliation: Department of Cardiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hiki
authors.affiliation: Department of Cardiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Matsumori
authors.affiliation: Department of Cardiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kawaguchi
authors.affiliation: Division of Radiology, Takase Clinic, Takasaki, Gunma, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Amanuma
authors.affiliation: Department of Cardiology, Takase Clinic, Takasaki, Gunma, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Takase
authors.affiliation: Department of Cardiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Daida
mesh_terms: D000368:Aged; D000465:Algorithms; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: coronary CT angiography; coronary artery disease; obstructive coronary artery disease; pretest probability; prognosis