Usefulness of first-pass myocardial perfusion imaging at rest in combination with 64-row detector computed tomography angiography for assessing coronary artery disease

Background: Multidetector coronary computed tomography angiography (CCTA) can detect coronary stenosis, but it has limited ability to evaluate myocardial ischemia. Recent studies have also demonstrated the usefulness of stress CT myocardial perfusion imaging (CT-MPI) to detect myocardial ischemia, but the procedure is complicated. Therefore, we evaluated the usefulness of first-pass CT-MPI at rest in combination with CCTA for diagnosing coronary artery disease (CAD). Methods: A total of 105 patients with suspected CAD were enrolled. First-pass CT-MPI at rest was performed simultaneously with CCTA, and images of CT-MPI were reconstructed as color maps. 33 patients in the 105 patients were also performed SPECT-MPI. Diagnostic accuracy was assessed by comparison with invasive coronary angiography. Results: First-pass CT-MPI at rest in combination with CCTA increased diagnostic performance compared with CCTA alone. With per-vessel analysis, the sensitivity, specificity, positive predictive value, and negative predictive value increased from 83% to 88%, from 89% to 92%, from 63% to 72%, and from 96% to 97%, respectively. The area under the receiver operating characteristic (ROC) curve for detecting CAD also increased from 0.860 to 0.900 (p = 0.03). There was no significant difference in the area under the ROC curve between CCTA in combination with first-pass CT-MPI and stress SPECT-MPI (0.86 vs. 0.80, p=0.24 on a per-vessel basis and 0.79 vs. 0.76, p=0.92 on a per-patient basis). In additon, first-pass CT-MPI at rest was particularly useful for assessing unevaluable segments by CCTA alone owing to severe calcification and motion artifacts. Comparison with with multi-modalities Conclusion: First-pass CT-MPI at rest thus complements CCTA for detecting CAD.