Abstract 2786: Accuracy of 64-Slice CT Angiography for the Detection of Functionally Relevant Coronary Stenoses as Assessed by Myocardial Perfusion SPECT
Objectives: We prospectively compared the accuracy of 64-slice CT angiography (CTA) with myocardial perfusion imaging (MPI) using 99mTc-tetrofosmin-SPECT as gold standard for the detection of functionally relevant coronary artery disease (CAD).
Background: CTA offers a valuable alternative for the diagnosis of CAD but its value in the detection of functionally relevant coronary stenoses remains uncertain.
Methods: MPI and 64-slice CT were performed in 100 consecutive patients. CTA lesions were analyzed quantitatively and area stenoses ≥ 50 % and ≥ 75 % were compared to the MPI findings.
Results: A total of 399 coronary arteries and 1386 segments was analyzed. Eighty-four segments (6.1 %) in 23 coronary arteries (5.8 %) of 9 patients (9.0 %) were excluded due to insufficient image quality. In the remaining 1302 segments quantitative CTA revealed stenoses ≥ 50 % in 57 of 376 coronary arteries (15.2 %) and stenoses ≥ 75 % in 32 (8.5 %) coronary arteries. Using a cut-off at ≥ 75 % area stenosis CTA yielded a sensitivity, specificity, negative (NPV) and positive predictive value (PPV), and accuracy to detect any (fixed and reversible) MPI defect: by patient 75 %, 90 %, 93 %, 68 %, and 87%, respectively; by artery 76 %, 95 %, 99 %, 50 % and 94 %, respectively.
Conclusions: 64-slice CTA is a reliable tool to rule out functionally relevant CAD in a non-selected population with intermediate pretest likelihood. However, an abnormal CTA is a poor predictor of ischemia.