Association between coronary plaque vulnerability features and multiparametric pericoronary fat indices on coronary computed tomography angiography: a cross-sectional study.

Background: Coronary plaque vulnerability is associated with the fat attenuation index (FAI) of pericoronary adipose tissue (PCAT), but the associations between vulnerability features and multiparametric indices of PCAT remain unclear. In this study, we aimed to explore the effect of four vulnerability features of atherosclerotic coronary plaque on multiparametric indices of PCAT and evaluate the relative responsiveness of these indices in determining the degree of vascular inflammation.

Methods: A retrospective study was conducted on 443 patients clinically diagnosed with coronary artery disease (CAD) at Bozhou People's Hospital from January 2022 to August 2023. The most severely plaque-burdened diseased blood vessels were selected, and plaque vulnerability features, including positive remodeling (PR), low attenuation plaque (LAP), punctate calcification (PC), and napkin-ring sign (NRS), were further evaluated. In addition, quantitative measurements of the multiparametric indices of PCAT centered around the plaque, with a vertical diameter of 40 mm, including FAI, total pericoronary fat volume (FV), perivascular water attenuation index (PVWI), FAI of non-PCAT (non-FAI), and volumetric pericoronary characterization index (VPCI), were performed. They were divided into left anterior descending (LAD)/left circumflex artery (LCx) and right coronary artery (RCA) groups; the indices of PCAT between the two groups were compared using t-test or Mann-Whitney U test. Univariate and multivariate linear regression analyses were conducted to evaluate the associations between vulnerability features, diseased vessels, and PCAT multiparametric indices.

Results: A total of 291 eligible patients were included in this study. Multivariate linear regression analysis revealed that PR, PC, LAP, and NRS were all positively correlated with FAI and non-FAI; PR and LAP were positively correlated with PVWI and VPCI, and negatively correlated with FV (all P<0.05). RCA was negatively correlated with non-FAI and PVWI, and positively correlated with VPCI and FV (all P<0.05). The values of non-FAI and PVWI in the LAD/LCx group (n=210) were higher than those in the RCA group (n=81), whereas FV and VPCI values were lower in the LAD/LCx group (all P<0.05). Multivariate linear regression analysis showed that in the LAD/LCx group, the four vulnerability features were positively correlated with FAI, PC and LAP were positively correlated with non-FAI and VPCI, and negatively correlated with FV value, and PR was positively correlated with PVWI (all P<0.05). In the RCA group, PR, PC, and LAP were positively correlated with FAI, PR, PC, and NRS were positively correlated with non-FAI, LAP was positively correlated with VPCI and PVWI, and PR and LAP were negatively correlated with FV (all P<0.05).

Conclusions: Among the five PCAT indices, the FAI and non-FAI demonstrated stronger associations with plaque vulnerability features, whereas VPCI, PVWI, and FV showed weaker associations. Vulnerable plaque features (PR, LAP) induced more severe inflammatory responses in PCAT compared to PC and NRS. Additionally, PCAT indices were influenced by the lesion-bearing vessel. These findings may guide clinical prioritization of inflammatory biomarkers and refine assessments of plaque-related inflammation severity.