BACKGROUND: The aim of this study was to investigate the ability of coronary computed tomographic angiography (CCTA) characteristics of high-risk plaque (HRP) in moderate stenosis to improve differentiation of myocardial ischemia detected by stress CT perfusion (CTP) imaging.

MATERIAL AND METHODS: Sixty-two patients with coronary plaques and moderate stenosis confirmed by invasive coronary angiography (ICA) had stress CTP and 26 of these patients were found to have myocardial ischemia. The other 36 patients without myocardial ischemia were defined as controls. Characteristics of major plaques on CCTA images of the ischemia and non-ischemia groups were analyzed and compared.

RESULTS: Differences between the 2 groups were observed in plaque volume, burden and rough inner surface necrotic core volume, plaque-lipid interface and plaque length. In a multivariable analysis, plaque burden and necrotic core volume were significantly associated with myocardial ischemia: plaque burden odds ratio (OR) was 1.28 (95% confidence interval [CI], 1.12–1.48); necrotic core volume OR was 1.78 (95% CI, 1.03–1.34). Compared with other quantitative measurements, optimized thresholds for plaque burden (area under the curve was 0.852) and necrotic core volume (area under the curve was 0.730) showed significantly higher diagnostic performance for ischemia with threshold values of 60.8% and 11.25 mm³, respectively.

CONCLUSIONS: CCTA characteristics of major plaques may improve the discrimination of ACS patients with myocardial ischemia on stress CTP.

Keywords: Coronary Artery Disease, Myocardial Ischemia, Tomography Scanners, X-Ray Computed, computed tomography angiography, Coronary Angiography, Coronary Stenosis, Heart, myocardial perfusion imaging, Plaque, Atherosclerotic, Predictive Value of Tests, Tomography, Emission-Computed, Single-Photon