Patient-Level Pericoronary Adipose Tissue Mean Attenuation: Associations with Plaque Characteristics

Pericoronary adipose tissue attenuation (PCAT(a)), observed from coronary computed tomography angiography (CCTA), is emerging as an inflammation marker. This study evaluated the relationship between PCAT(a) and plaque characteristics, including plaque type, burden, and coronary calcification. An observational study was conducted on 466 patients with suspected chronic coronary syndrome who underwent clinically indicated CCTA. PCAT(a) was measured along the proximal 40 mm of the coronary arteries and averaged to represent the patient's level. Plaque type was assessed, compositional plaque volumes were measured, and plaque burdens were quantified. The coronary calcification scores (CCSs) were categorized into groups. Statistical methods included t-tests, ANOVA, and multivariate regression analysis. PCAT(a) differed significantly between calcified (-81.7 Hounsfield units (HU)) and soft (-77.5 HU) plaques. PCAT(a) was positively associated with total plaque burden (beta = 3.6) and non-calcified plaque burden (beta = 7.0), but negatively correlated with calcified plaque burden (beta = -3.5), independent of clinical factors and tube voltage (p < 0.05). The effect of PCAT(a) was stronger when plaques of a different composition were absent. No significant differences in PCAT(a) were found among different CCS groups. PCAT(a) increased for calcified compared to soft plaques. The non-calcified plaque burden was associated with a higher PCAT(a), while the calcified plaque burden was associated with a lower PCAT(a).<br />