CT angiography defined plaque surface disruption and new diffusion weighted imaging lesions after carotid artery stenting: exploratory Plaque-RADS analysis

Background Carotid artery stenting (CAS) can cause silent cerebral embolization on diffusion weighted imaging (DWI). Although CT angiography (CTA) based Plaque-RADS improves long term stroke risk stratification, its relevance to periprocedural embolic risk during CAS is unknown. We evaluated whether CTA defined plaque surface disruption identifies patients at increased risk of new post-CAS DWI lesions. Methods In this retrospective single center cohort, 196 consecutive patients underwent CAS with preprocedural carotid CTA between January 2020 and December 2025. Plaques were independently classified as RADS 3 (no ulcer), RADS 3c, RADS 4a, or RADS 4c. The primary endpoint was new post-CAS DWI lesions; the secondary endpoint was 30 day major adverse cerebrovascular events or death. We first examined ordinal Plaque-RADS categories and then performed a post hoc grouped analysis comparing plaque surface disruption phenotypes (RADS 3c/4c) with non-disrupted phenotypes (RADS 3 no ulcer/4a). Results Among 196 patients (median age 70 years (IQR 64–76); 89.3% men), new DWI lesion rates were heterogeneous and non-monotonic across categories (1.2%, 14.3%, 5.6%, and 7.9%; P=0.038). Plaque surface disruption phenotype showed a higher DWI lesion rate than non-disrupted phenotypes (11.2% vs 2.6%; absolute risk difference 8.7%, 95% CI 1.2 to 16.2; P=0.016). Firth adjusted analysis was directionally consistent (adjusted OR 5.60, 95% CI 1.50 to 20.96; P=0.011). All new DWI lesions were within the treated internal carotid artery territory. Conclusions CTA defined plaque surface disruption was associated with increased post-CAS DWI lesion risk, whereas ordinal Plaque-RADS categories did not show a monotonic risk gradient.