Plaque RADS Related to Cerebrovascular Event Risk with Mild/moderate Stenosis: a CARE II study

Carotid Plaque-Reporting And Data System (Plaque-RADS) provides a standardized approach for evaluating carotid plaque morphology and composition. The aim of this study was to evaluate carotid Plaque-RADS, and its relationship with clinical risk factors and ipsilateral cerebrovascular symptoms, in a prospectively-acquired multi-center, vessel-wall MRI dataset. Symptomatic patients were recruited from the CARE-II (Chinese Atherosclerosis Risk Evaluation, NCT02017756) study. This cross-sectional study included patients with recent stroke or transient ischemia attack and atherosclerotic plaques in at least one carotid artery. Lipid-rich necrotic core, ulceration, intraplaque hemorrhage, thick or thin fibrous cap, fibrous cap rupture and intraluminal thrombi were identified from multiple contrast vessel wall imaging and used to determine carotid Plaque-RADS. In addition, ancillary features including calcification and plaque burden via maximum normalized wall index (max_NWI) were collected. Degree of stenosis was classified as mild (<30%), moderate (30-69%), and severe (70-99%). Generalized Estimating Equation-based logistic regression was performed to assess the relationship between the Plaque-RADS score and cerebrovascular events. A total of 433 patients (62 years ± 9.97, 302 males (69.7%)) with 866 carotid arteries were included in this study. Symptomatic carotid arteries had higher stenosis degree (11.8%±24.7 vs 8.6%±18.8, p=0.01), plaque-RADS score (≥3: 33.9% vs 28.4%, p=0.02) and max_NWI (0.53±0.14 vs 0.51±0.13, p=0.002) compared to the asymptomatic side. Plaque RADS was significantly associated with cerebrovascular events (OR=1.11 per 1-level increase, 95%CI=1.01-1.24; p=0.04). In patients with mild/moderate bilateral carotid artery stenosis, plaque RADS≥3 was significantly associated with symptomatic events (OR=1.30, 95%CI=1.01-1.68; p=0.04). Higher plaque-RADS on the symptomatic side was related to advanced age (OR=1.27 per 10-year increase, 95%CI=1.03-1.56; p=0.03), male sex (OR=1.90, 95%CI=1.05-3.43; p=0.03), and smoking history (OR=1.99, 95%CI=1.20-3.31; p=0.007). Male patients of advanced age and with a smoking history were associated with an increased risk of higher plaque-RADS scores. Plaque-RADS demonstrated the ability to stratify patients experiencing cerebrovascular events, even in cases with mildto-moderate stenosis. However, this association did not retain statistical significance after adjusting for stenosis or max_NWI. IPH = intraplaque hemorrhage; Max-NWI = maximum normalized wall index; MWT = maximum wall thickness; RADS = Reporting And Data System; VWI = vessel wall imaging.