CTA-Based Carotid Plaque Reporting and Data System Classification Improves Risk Stratification for Ischemic Cerebrovascular Events.

BACKGROUND AND PURPOSE: Ischemic cerebrovascular events (ICE) remain a leading cause of mortality and disability. The carotid Plaque Reporting and Data System (Plaque-RADS) standardizes plaque vulnerability assessment, but its prognostic value based solely on CTA remains underexplored.

MATERIALS AND METHODS: Of 7228 patients who underwent neck CTA (2019-2024), 1232 were retrospectively included and divided into symptomatic and asymptomatic groups. Propensity score matching yielded 371 matched pairs. Two radiologists independently assessed plaques using CTA-based carotid Plaque-RADS, incorporating features such as wall thickness, ulceration, intraplaque hemorrhage, and thrombus. A total of 742 patients were followed (mean, 42 [SD, 18] months) for stroke outcomes. Logistic regression, receiver operating characteristic, and Cox models were used to assess the diagnostic and prognostic performance compared with stenosis severity.

RESULTS: Plaque-RADS ≥3 was significantly more common in symptomatic patients (P < .001) and showed a moderate correlation with ICE (Kendall τ-b = 0.23; P < .001). Among the Plaque-RADS categories, Plaque-RADS 4c (intraluminal thrombus) exhibited the strongest predictive value for ischemic events (OR, 17.87; 95% CI, 6.09-52.42, P < .001). Adding Plaque-RADS to the base model (stenosis degree and clinical covariates) significantly improved model discrimination (area under the curve, 0.609, 95% CI, 0.577-0.641 versus area under the curve, 0.680; 95% CI, 0.649-0.711; DeLong P <.001). Plaque-RADS ≥3 and severe stenosis were identified as independent risk factors for both disease-free survival (DFS) and recurrence-free survival (RFS) based on Cox multivariate regression. Higher Plaque-RADS categories were significantly associated with lower DFS and RFS, particularly in patients with mild-to-moderate stenosis.

CONCLUSIONS: CTA-based carotid Plaque-RADS offers superior risk stratification for ICE compared with stenosis severity alone, especially in mild/moderate stenosis, and may guide earlier interventions.