Combined assessment of subtended myocardial volume and myocardial blood flow for diagnosis of obstructive coronary artery disease using cardiac computed tomography: A feasibility study

Background This study aimed to evaluate the combined diagnostic performance of coronary artery stenosis-subtended myocardial volume (Vsub) and myocardial blood flow (MBFsub) on computed tomography (CT) for detecting obstructive coronary artery disease (CAD) assessed by invasive coronary angiography (ICA) and fractional flow reserve (FFR). Methods Thirty-nine patients who underwent coronary CT angiography (CTA) and stress dynamic myocardial CT perfusion (CTP) prior to ICA were enrolled. Obstructive CAD was defined as severe (≥70%) or moderate (30–69%) stenosis with FFR ≤0.8 on ICA. The Vsub was semi-automatically calculated from coronary CTA data using Voronoi diagram-based myocardial segmentation. The standard CT-MBF based on the 17-segment model was calculated using dynamic stress CTP data and deconvolution analysis. The CT-MBFsub was automatically analyzed by integrating the CT-MBF and Voronoi diagram-based myocardial segmentation analyses. The diagnostic performance of combined CT-MBFsub and Vsub assessment was determined using receiver operating characteristic analysis and compared with standard CT-MBF and CT-MBFsub. Results Of 117 vessels in 39 patients, 72 vessels were suspected of significant stenosis on CTA and 33 vessels had obstructive CAD on ICA and FFR. The sensitivity and specificity for identifying obstructive CAD were 67% and 82% for standard CT-MBF, 70% and 77% for CT-MBFsub, and 85% and 82% for combined CT-MBFsub and Vsub assessment. The area under the receiver operating characteristic curve of the combined CT-MBFsub and Vsub assessment was significantly higher than those of standard CT-MBF and CT-MBFsub (0.89 vs. 0.75, 0.77; p Conclusions The Vsub may aid in increasing the diagnostic performance of CT-MBFsub for detecting obstructive CAD.