title: Very high coronary calcium score unmasks obstructive coronary artery disease in patients with normal SPECT MPI.
abstract: OBJECTIVE
  To study the clinical impact of a very high coronary artery calcium score (CAC >1000) in patients with no known coronary artery disease (CAD) and normal single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). The secondary aim was to evaluate whether triple vessel disease would support the notion of balanced ischaemia as an underlying mechanism of false negative SPECT MPI in patients with very high CAC.
  
  
  BACKGROUND
  No data exist on the clinical value of high CAC in patients with normal SPECT MPI.
  
  
  METHODS
  50 patients with suspected CAD and normal stress/rest SPECT MPI and CAC >1000 prospectively underwent invasive coronary angiography as the standard of reference. Coronary lesions with ≥50% luminal diameter narrowing on invasive coronary angiography were considered to represent significant stenosis.
  
  
  RESULTS
  The median total CAC was 1975 (range 1018-8046). In 37/50 (74%) patients, coronary angiography revealed one-vessel disease (1-VD) (n=15), 2-VD (n=10) or 3-VD (n=12). Twenty-six revascularisations (percutaneous coronary intervention/coronary artery bypass grafting) were performed in seven (6/1), seven (6/1) and 12 (7/5) patients with 1-VD, 2-VD and 3-VD, respectively.
  
  
  CONCLUSIONS
  In patients with normal SPECT MPI, a CAC >1000 confers a high diagnostic added value for detecting CAD. This is not solely based on unmasking balanced ischaemia due to epicardial 3-VD, as it occurred predominantly in patients with 1-VD and 2-VD.
authors.affiliation: Cardiac Imaging, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Jelena R
authors.initials: JR
authors.lastname: Ghadri
authors.forename: Aju P
authors.initials: AP
authors.lastname: Pazhenkottil
authors.forename: Rene N
authors.initials: RN
authors.lastname: Nkoulou
authors.forename: Robert
authors.initials: R
authors.lastname: Goetti
authors.forename: Ronny R
authors.initials: RR
authors.lastname: Buechel
authors.forename: Lars
authors.initials: L
authors.lastname: Husmann
authors.forename: Bernhard A
authors.initials: BA
authors.lastname: Herzog
authors.forename: Mathias
authors.initials: M
authors.lastname: Wolfrum
authors.forename: Christophe A
authors.initials: CA
authors.lastname: Wyss
authors.forename: Christian
authors.initials: C
authors.lastname: Templin
authors.forename: Philipp A
authors.initials: PA
authors.lastname: Kaufmann
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D002114:Calcinosis / Q000175:diagnosis*; D002118:Calcium / Q000378:metabolism*; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography / Q000379:methods; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods; D011446:Prospective Studies; D011829:Radiation Dosage
chemical_list: D015415:Biomarkers; D002118:Calcium