Objective: The purpose of our study was to prospectively evaluate the incremental diagnostic value of combined dual-source coronary CT angiography (CTA) and CT myocardial perfusion imaging (MPI) for the detection of significant coronary stenoses.
Subjects and methods: Forty-five patients with known coronary artery disease detected by dual-source coronary CTA were investigated by adenosine-induced stress dual-source CTA and conventional coronary angiography. Analysis was performed in three steps: classification of coronary stenosis severity using dual-source coronary CTA, identification of myocardial perfusion defects using rest and stress CT MPI, and reclassification of coronary stenosis severity according to combined dual-source coronary CTA and CT MPI. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of dual-source coronary CTA before and after CT MPI were calculated on a per-vessel basis compared with conventional coronary angiography as the standard of reference.
Results: Dual-source coronary CTA revealed 87 significantly stenotic vessels in 45 patients. Conventional coronary angiography revealed significant stenoses in 73 vessels in 42 patients. CT MPI showed myocardial perfusion defects in 81 vessel territories in 43 patients. After the CT MPI analysis, dual-source coronary CTA identified significant stenoses in 77 coronary vessels in 42 patients. Sensitivity, specificity, PPV, and NPV of the dual-source coronary CTA on a per-vessel basis before CT MPI were 91.8%, 67.7%, 73.6%, and 87.5%, respectively, and after CT MPI were 93.2%, 85.5%, 88.3%, and 91.4%, respectively. The area under the receiver operating characteristic curve increased significantly from 0.798 to 0.893 (p = 0.004).
Conclusion: Combined dual-source coronary CTA and CT MPI provides incremental diagnostic value compared with dual-source coronary CTA alone for the detection of significant coronary stenoses.