Abstract 3266: Effects of Calcification and Stenting on Diagnostic Accuracy in the Evaluation of Coronary Artery Disease by 64 Slice Computed Tomography
Background: Most studies evaluating the diagnostic accuracy of multislice CT (MSCT) for the detection of coronary stenoses have excluded patients with known coronary artery disease (CAD). In clinical practice we are frequently asked to evaluate patients with known CAD, prior coronary stenting or a high calcium score. It is unclear what the diagnostic accuracy of MSCT is in this population.
Methods: Between August 2005 and May 2006, 107 patients with and without known CAD underwent 64 slice CT (Sensation 64 Heartview, Siemens) prior to cardiac catheterization (CC). At this time we have performed quantitative analysis of the MSCT and CC on the first 49 patients. The accuracy of MSCT was compared to QCA for the detection of ≥50% diameter stenosis on a per patient analysis stratified by degree of calcification or the presence of stents. All non-stented segments >2mm were analyzed.
Results: Five patients (10%) had at least 1 segment that was nondiagnostic quality and were excluded from the per patient analysis. Of the remaining 44 patients the specificity, sensitivity, PPV & NPV are displayed in the table⇓ when stratified by Agatston calcium score (CS) or the presence of stents. The incidence of ≥50% stenosis was higher in patients with stents or CS ≥400 (74%) than in those with CS <400 (36%).
Conclusion: In patients with a CS <400 and no prior stenting, MSCT accurately detects significant CAD. Accuracy for the detection of ≥50% stenosis in non-stented segments drops considerably with calcium score ≥400 or prior stenting.