Association of perivascular fat density with vulnerable plaque and recent symptomatic cerebrovascular events

Abstract

The aim of this study was to investigate the association between perivascular fat density (PFD) and carotid plaque characteristics and to evaluate the discriminative ability of PFD and lipid-rich necrotic core plaques in relation to symptomatic status of cerebrovascular events. A retrospective cross-sectional analysis was conducted in 119 patients with unilateral carotid atherosclerosis. Patients were classified into symptomatic and asymptomatic groups based on the occurrence of acute ischemic stroke or transient ischemic attack within the preceding two weeks. Differences in plaque characteristics, PFD, lipid-rich core plaques, and geometric parameters between the two groups were compared using non-parametric statistical tests. Spearman rank correlation analysis was used to evaluate the association between PFD and plaque characteristics. Multivariable logistic regression analysis was performed to identify risk factors and develop discriminative models. Internal validation was performed using bootstrap-derived optimism-corrected AUC. Statistically significant differences in plaque characteristics, PFD, lipid-rich necrotic core plaques, and geometric parameters were observed between the symptomatic and asymptomatic groups ( p  < 0.001). PFD was positively correlated with plaque characteristics ( p  < 0.001). PFD, degree of stenosis, and the presence of lipid-rich core plaques were identified as independent correlates of cerebrovascular events. Receiver operating characteristic curve analysis demonstrated that the combined model improved the area under the curve from 0.885 for the stenosis-only model to 0.972. Calibration analysis demonstrated good agreement between model-estimated probabilities and observed outcomes, and decision curve analysis indicated greater net clinical benefit for the combined model than for the stenosis-only model. PFD is positively associated with carotid plaque characteristics and may serve as an imaging marker for assessing the perivascular inflammatory state. Combining PFD with stenosis severity and LRNC plaques demonstrated high discriminative value in assessing the symptomatic status of recent cerebrovascular events.