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

ABSTRACT BACKGROUND AND PURPOSE: Ischemic cerebrovascular events (ICE) remain a leading cause of mortality and disability. The Carotid Plaque-RADS system standardizes plaque vulnerability assessment, but its prognostic value based solely on CTA remains underexplored. MATERIALS AND METHODS: Of the 7,228 patients who underwent neck CTA (2019–2024), 1,232 were retrospectively included and divided into symptomatic and asymptomatic groups. Propensity score matching (PSM) yielded 371 matched pairs. Two radiologists independently assessed plaques using CTA-based Carotid Plaque-RADS, incorporating features such as wall thickness, ulceration, intraplaque hemorrhage (IPH), and thrombus. A total of 742 patients were followed (mean 42 ± 18 months) for stroke outcomes. Logistic regression, receiver operating characteristics, and Cox models were used to assess diagnostic and prognostic performance compared to stenosis severity. RESULTS: Plaque-RADS ≥3 was significantly more common in symptomatic patients (P < 0.001) and showed a moderate correlation with ICE (Kendall’s τ-b = 0.23; P < 0.001). 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 < 0.001). Adding Plaque-RADS to a stenosis-and risk factor–based model significantly improved discrimination (AUC 0.609, 95% CI 0.577–0.641 vs. AUC 0.680, 95% CI 0.649–0.711; DeLong P < 0.001). 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 to stenosis severity alone, especially in mild/moderate stenosis, and may guide earlier intervention. ABBREVIATIONS: AUC = area under the curve; DFS = disease-free survival; GEE = generalized estimating equations; ICE = ischemic cerebrovascular event; IPH = intraplaque hemorrhage; MWT = maximum wall thickness; Plaque-RADS = Plaque Reporting and Data System; PSM = propensity score matching; RFS = recurrence-free survival