High-risk plaque features and perivascular inflammation.

Background: The association between high-risk plaque (HRP) on coronary computed tomography angiography (CTA) and the level of perivascular inflammation has not been fully investigated.

Methods: Patients who underwent both CTA and optical coherence tomography (OCT) were included. The level of perivascular inflammation was assessed by pericoronary adipose tissue (PCAT) attenuation at two levels: lesion-specific and the proximal segment of the culprit vessel. HRP features included positive remodeling (PR), low-attenuation plaque (LAP), napkin-ring sign (NRS), and spotty calcification (SC).

Results: OCT features of plaque vulnerability were evaluated in culprit vessels. A total of 1360 lesions (413 culprit lesions and 947 non-culprit lesions) from 413 patients were evaluated. Lesion-specific PCAT attenuation was higher in lesions with any HRP feature except SC (present vs. absent: PR -71.3 ​± ​10.1 vs. -74.1 ​± ​11.7, P ​< ​0.001; LAP -71.7 ​± ​9.9 vs. -73.0 ​± ​11.4, P ​= ​0.025; NRS -70.3 ​± ​9.6 vs. -72.9 ​± ​11.1, P ​= ​0.001; and SC -71.9 ​± ​9.9 vs. -73.0 ​± ​11.5, P ​= ​0.082). After adjusting for confounders, only PR was associated with higher lesion-specific PCAT attenuation. The number of lesions with PR significantly correlated with higher levels of perivascular inflammation measured by culprit vessel PCAT attenuation. The number of lesions with PR was associated with higher lipid index and macrophage grade at culprit vessels.

Conclusions: Among 4 HRP features, only PR was significantly associated with higher lesion-specific PCAT attenuation. The number of plaques with PR correlated with the level of perivascular inflammation and vulnerability.

Trial Registration: clinicaltrials.gov Identifier: NCT04523194.