title: Coronary CT angiography outperforms calcium imaging in the triage of acute coronary syndrome.
abstract: BACKGROUND
  In this prospective study we determine the diagnostic value of coronary CT angiography (CTA) and calcium imaging in low to intermediate risk acute chest pain patients.
  
  
  METHODS
  One hundred and eleven consecutive patients (57 ± 11 years, 71 males) presenting to the emergency department with chest pain suggestive of acute coronary syndrome (ACS), but without indication for immediate catheter angiography, underwent both coronary CTA and calcium imaging without disclosure of the findings to the treating physicians.
  
  
  RESULTS
  ACS was diagnosed in 19 patients (17%). Coronary calcium was present in 71 patients (64%). Coronary CTA identified 74 (67%) patients with coronary plaque and 36 (32%) patients with obstructive (≥ 50%) plaque. The sensitivity and specificity of the calcium scan were: 89% and 41%. The sensitivity and specificity of coronary CTA were: 100% and 40% based on the presence of any plaque and 89% and 79% based on the presence of >50% stenosis. C-statistics of the GRACE risk score (0.77 [95% CI 0.66-0.89]) improved after addition of coronary CTA (0.93 [0.88-0.98], p<0.01), though not after addition of calcium scores (0.81 [0.71-0.91], p=0.52). Follow-up at 3 months revealed four late revascularizations (no deaths or myocardial infarctions), all of whom had obstructive CAD with calcium on CT at presentation.
  
  
  CONCLUSIONS
  Coronary CTA outperforms calcium imaging in the triage of patients suspected of developing ACS. Absence of plaque on coronary CTA allows safe discharge. Coronary CTA has incremental value to clinical risk scores and has the potential to reduce unnecessary hospital admissions.
authors.affiliation: Department of Cardiology, Erasmus Medical Centre, Rotterdam, The Netherlands. a.dedic@erasmusmc.nl
authors.forename: Admir
authors.initials: A
authors.lastname: Dedic
authors.forename: Gert-Jan
authors.initials: GJ
authors.lastname: Ten Kate
authors.forename: Lisan A
authors.initials: LA
authors.lastname: Neefjes
authors.forename: Alexia
authors.initials: A
authors.lastname: Rossi
authors.forename: Anoeshka
authors.initials: A
authors.lastname: Dharampal
authors.forename: Pleunie P M
authors.initials: PP
authors.lastname: Rood
authors.forename: Tjebbe W
authors.initials: TW
authors.lastname: Galema
authors.forename: Carl
authors.initials: C
authors.lastname: Schultz
authors.forename: Mohamed
authors.initials: M
authors.lastname: Ouhlous
authors.forename: Adriaan
authors.initials: A
authors.lastname: Moelker
authors.forename: Pim J
authors.initials: PJ
authors.lastname: de Feyter
authors.forename: Koen
authors.initials: K
authors.lastname: Nieman
mesh_terms: D054058:Acute Coronary Syndrome / Q000000981:diagnostic imaging* / Q000378:metabolism; D000368:Aged; D002118:Calcium / Q000378:metabolism; D015331:Cohort Studies; D017023:Coronary Angiography / Q000379:methods / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016037:Single-Blind Method; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000592:standards*; D014218:Triage / Q000379:methods / Q000592:standards*
chemical_list: D002118:Calcium