Focal pericoronary adipose tissue attenuation is related to plaque presence, plaque type, and stenosis severity in coronary CTA

Abstract

Objectives: To investigate the association of pericoronary adipose tissue mean attenuation (PCAT_MA) with coronary artery disease (CAD) characteristics on coronary computed tomography angiography (CCTA).

Methods: We retrospectively investigated 165 symptomatic patients who underwent third-generation dual-source CCTA at 70kVp: 93 with and 72 without CAD (204 arteries with plaque, 291 without plaque). CCTA was evaluated for presence and characteristics of CAD per artery. PCAT_MA was measured proximally and across the most severe stenosis. Patient-level, proximal PCAT_MA was defined as the mean of the proximal PCAT_MA of the three main coronary arteries. Analyses were performed on patient and vessel level.

Results: Mean proximal PCAT_MA was -96.2 ± 7.1 HU and -95.6 ± 7.8HU for patients with and without CAD (p = 0.644). In arteries with plaque, proximal and lesion-specific PCAT_MA was similar (-96.1 ± 9.6 HU, -95.9 ± 11.2 HU, p = 0.608). Lesion-specific PCAT_MA of arteries with plaque (-94.7 HU) differed from proximal PCAT_MA of arteries without plaque (-97.2 HU, p = 0.015). Minimal stenosis showed higher lesion-specific PCAT_MA (-94.0 HU) than severe stenosis (-98.5 HU, p = 0.030). Lesion-specific PCAT_MA of non-calcified, mixed, and calcified plaque was -96.5 HU, -94.6 HU, and -89.9 HU (p = 0.004). Vessel-based total plaque, lipid-rich necrotic core, and calcified plaque burden showed a very weak to moderate correlation with proximal PCAT_MA.

Conclusions: Lesion-specific PCAT_MA was higher in arteries with plaque than proximal PCAT_MA in arteries without plaque. Lesion-specific PCAT_MA was higher in non-calcified and mixed plaques compared to calcified plaques, and in minimal stenosis compared to severe; proximal PCAT_MA did not show these relationships. This suggests that lesion-specific PCAT_MA is related to plaque development and vulnerability.

Key points: • In symptomatic patients undergoing CCTA at 70 kVp, PCAT_MA was higher in coronary arteries with plaque than those without plaque. • PCAT_MA was higher for non-calcified and mixed plaques compared to calcified plaques, and for minimal stenosis compared to severe stenosis. • In contrast to PCAT_MA measurement of the proximal vessels, lesion-specific PCAT_MA showed clear relationships with plaque presence and stenosis degree.

Keywords: Adipose tissue; Atherosclerosis; Computed tomography angiography; Coronary arteries.