title: Effect of heart rate and coronary calcification on the diagnostic accuracy of the dual-source CT coronary angiography in patients with suspected coronary artery disease.
abstract: OBJECTIVE
  To evaluate the diagnostic accuracy of a dual-source computed tomography (DSCT) coronary angiography, with a particular focus on the effect of heart rate and calcifications.
  
  
  METHODS
  One hundred and nine patients with suspected coronary disease were divided into 2 groups according to a mean heart rate (< 70 bpm and >or= 70 bpm) and into 3 groups according to the mean Agatston calcium scores (<or= 100, 101-400, and > 400). Next, the effect of heart rate and calcification on the accuracy of coronary artery stenosis detection was analyzed by using an invasive coronary angiography as a reference standard. Coronary segments of less than 1.5 mm in diameter in an American Heart Association (AHA) 15-segment model were independently assessed.
  
  
  RESULTS
  The mean heart rate during the scan was 71.8 bpm, whereas the mean Agatston score was 226.5. Of the 1,588 segments examined, 1,533 (97%) were assessable. A total of 17 patients had calcium scores above 400 Agatston U, whereas 50 had heart rates >or= 70 bpm. Overall the sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) for significant stenoses were: 95%, 91%, 65%, and 99% (by segment), respectively and 97%, 90%, 81%, and 91% (by artery), respectively (n = 475). Heart rate showed no significant impact on lesion detection; however, vessel calcification did show a significant impact on accuracy of assessment for coronary segments. The specificity, PPV and accuracy were 96%, 80%, and 96% (by segment), respectively for an Agatston score less than 100% and 99%, 96% and 98% (by artery). For an Agatston score of greater to or equal to 400 the specificity, PPV and accuracy were reduced to 79%, 55%, and 83% (by segment), respectively and to 79%, 69%, and 85% (by artery), respectively.
  
  
  CONCLUSIONS
  The DSCT provides a high rate of accuracy for the detection of significant coronary artery disease, even in patients with high heart rates and evidence of coronary calcification. However, patients with severe coronary calcification (> 400 U) remain a challenge to diagnose.
authors: Shandong Province Ji'nan 4th People's Hospital, Ji'nan, China.
authors: Lingdong
authors: L
authors: Meng
authors: Lianqun
authors: L
authors: Cui
authors: Yuntao
authors: Y
authors: Cheng
authors: Xiaoyan
authors: X
authors: Wu
authors: Yuansheng
authors: Y
authors: Tang
authors: Yong
authors: Y
authors: Wang
authors: Fayun
authors: F
authors: Xu
mesh_terms: D002114:Calcinosis / Q000000981:diagnostic imaging*; D017023:Coronary Angiography / Q000379:methods / Q000592:standards*; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000473:pathology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000592:standards*