title: Limited clinical utility of CT coronary angiography in a district hospital setting.
abstract: BACKGROUND
  Studies have demonstrated considerable accuracy of multi-slice CT coronary angiography (MSCT-CA) in comparison to invasive coronary angiography (I-CA) for evaluating coronary artery disease (CAD). The extent to which published MSCT-CA accuracy parameters are transferable to routine practice beyond high-volume tertiary centres is unknown.
  
  
  OBJECTIVE
  To determine the accuracy of MSCT-CA for the detection of CAD in a Scottish district general hospital.
  
  
  METHODS
  Prospective study of diagnostic accuracy.
  
  
  METHODS
  One hundred patients with suspected CAD recruited from two Glasgow hospitals underwent both MSCT-CA (Philips Brilliance 40 × 0.625 collimation, 50-200 ms temporal resolution) and I-CA. Studies were reported by independent, blinded radiologists and cardiologists and compared using the AHA 15-segment model.
  
  
  RESULTS
  Of 100 patients [55 male, 45 female, mean (SD) age 58.0 (10.7) years], 59 and 41% had low-intermediate and high pre-test probabilities of significant CAD, respectively. Mean (SD) heart rate during MSCT-CA was 68.8 (9.0) bpm. Fifty-seven per cent of patients had coronary artery calcification and 35% were obese. Patient prevalence of CAD was 38%. Per-patient sensitivity, specificity, positive and negative (NPV) predictive values for MSCT-CA were 92.1, 47.5, 52.2 and 90.6%, respectively. NPV was reduced to 75.0% in the high pre-test probability group. Specificity was compromised in patients with sub-optimally controlled heart rates, calcified arteries and elevated BMI.
  
  
  CONCLUSIONS
  Forty-Slice MSCT-CA has a high NPV for ruling out significant CAD when performed in a district hospital setting in patients with low-intermediate pre-test probability and minimal arterial calcification. Specificity is compromised by clinically appropriate strategies for dealing with unevaluable studies. Effective heart rate control during MSCT-CA is imperative. National guidelines should be utilized to govern patient selection and direct MSCT-CA reporter training to ensure quality control.
authors.affiliation: Department of Cardiology, Stobhill Hospital, 133 Balornock Road, Glasgow G21 3UW, UK. shonajenkins@hotmail.com
authors.forename: S M M
authors.initials: SM
authors.lastname: Jenkins
authors.forename: N
authors.initials: N
authors.lastname: Johnston
authors.forename: N M
authors.initials: NM
authors.lastname: Hawkins
authors.forename: C-M
authors.initials: CM
authors.lastname: Messow
authors.forename: J
authors.initials: J
authors.lastname: Shand
authors.forename: K J
authors.initials: KJ
authors.lastname: Hogg
authors.forename: H
authors.initials: H
authors.lastname: Eteiba
authors.forename: G
authors.initials: G
authors.lastname: McKillop
authors.forename: N E R
authors.initials: NE
authors.lastname: Goodfield
authors.forename: A
authors.initials: A
authors.lastname: McConnachie
authors.forename: F G
authors.initials: FG
authors.lastname: Dunn
mesh_terms: D000368:Aged; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006767:Hospitals, District; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*