title: SPECT myocardial perfusion imaging as an adjunct to coronary calcium score for the detection of hemodynamically significant coronary artery stenosis.
abstract: BACKGROUND
  Coronary artery calcifications (CAC) are markers of coronary atherosclerosis, but do not correlate well with stenosis severity. This study intended to evaluate clinical situations where a combined approach of coronary calcium scoring (CS) and nuclear stress test (SPECT-MPI) is useful for the detection of relevant CAD.
  
  
  METHODS
  Patients with clinical indication for invasive coronary angiography (ICA) were included into our study during 08/2005-09/2008. At first all patients underwent CS procedure as part of the study protocol performed by either using a multidetector computed tomography (CT) scanner or a dual-source CT imager. CAC were automatically defined by dedicated software and the Agatston score was semi-automatically calculated. A stress-rest SPECT-MPI study was performed afterwards and scintigraphic images were evaluated quantitatively. Then all patients underwent ICA. Thereby significant CAD was defined as luminal stenosis ≥ 75% in quantitative coronary analysis (QCA) in ≥ 1 epicardial vessel. To compare data lacking Gaussian distribution an unpaired Wilcoxon-Test (Mann-Whitney) was used. Otherwise a Students t-test for unpaired samples was applied. Calculations were considered to be significant at a p-value of <0.05.
  
  
  RESULTS
  We consecutively included 351 symptomatic patients (mean age: 61.2 ± 12.3 years; range: 18-94 years; male: n=240) with a mean Agatston score of 258.5 ± 512.2 (range: 0-4214). ICA verified exclusion of significant CAD in 66/67 (98.5%) patients without CAC. CAC was detected in remaining 284 patients. In 132/284 patients (46.5%) with CS>0 significant CAD was confirmed by ICA, and excluded in 152/284 (53.5%) patients. Sensitivity for CAD detection by CS alone was calculated as 99.2%, specificity was 30.3%, and negative predictive value was 98.5%. An additional SPECT in patients with CS>0 increased specificity to 80.9% while reducing sensitivity to 87.9%. Diagnostic accuracy was 84.2%.
  
  
  CONCLUSIONS
  In patients without CS=0 significant CAD can be excluded with a high negative predictive value by CS alone. An additional SPECT-MPI in those patients with CS>0 leads to a high diagnostic accuracy for the detection of CAD while reducing the number of patients needing invasive diagnostic procedure.
authors.affiliation: Department of Cardiology, University of Munich, Campus Grosshadern, Munich, Germany. franz.ziegler@med.uni-muenchen.de
authors.forename: Franz
authors.initials: F
authors.lastname: von Ziegler
authors.forename: Michaela
authors.initials: M
authors.lastname: Brendel
authors.forename: Christopher
authors.initials: C
authors.lastname: Uebleis
authors.forename: Susanne
authors.initials: S
authors.lastname: Helbig
authors.forename: Martin
authors.initials: M
authors.lastname: Greif
authors.forename: Janine
authors.initials: J
authors.lastname: Ruemmler
authors.forename: Christoph
authors.initials: C
authors.lastname: Becker
authors.forename: Marcus
authors.initials: M
authors.lastname: Hacker
authors.forename: Gerhard
authors.initials: G
authors.lastname: Steinbeck
authors.forename: Alexander
authors.initials: A
authors.lastname: Becker
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D061205:Vascular Calcification / Q000175:diagnosis*