Investigating the Association of Carotid Atherosclerotic Plaque MRI Features and Silent Stroke After Carotid Endarterectomy.

Background: The predictive value of carotid plaque characteristics for silent stroke (SS) after carotid endarterectomy (CEA) is unclear. Objective: To investigate the associations between carotid plaque characteristics and postoperative SS in patients undergoing CEA. Study Type: Prospective. Population: One hundred fifty‐three patients (mean age: 65.4 ± 7.9 years; 126 males) with unilateral moderate‐to‐severe carotid stenosis (evaluated by CT angiography) referred for CEA. Field Strength/Sequence: 3 T, brain‐MRI:T2‐PROPELLER, T1‐/T2‐FLAIR, diffusion weighted imaging (DWI) and T2*, carotid‐MRI:black‐blood T1‐/T2W, 3D TOF, Simultaneous Non‐contrast Angiography intraplaque hemorrhage. Assessment: Patients underwent carotid‐MRI within 1‐week before CEA, and brain‐MRI within 48‐hours pre‐/post‐CEA. The presence and size (volume, maximum‐area‐percentage) of carotid lipid‐rich necrotic core (LRNC), intraplaque hemorrhage (Type‐I/Type‐II IPH) and calcification were evaluated on carotid‐MR images. Postoperative SS was assessed from pre‐/post‐CEA brain DWI. Patients were divided into moderate‐carotid‐stenosis (50%–69%) and severe‐carotid‐stenosis (70%–99%) groups and the associations between carotid plaque characteristics and SS were analyzed. Statistical Tests: Independent t test, Mann–Whitney U‐test, chi‐square test and logistic regressions (OR: odds ratio, CI: confidence interval). P value <0.05 was considered statistically significant. Results: SS was found in 8 (16.3%) of the 49 patients with moderate‐carotid‐stenosis and 21 (20.2%) of the 104 patients with severe‐carotid‐stenosis. In patients with severe‐carotid‐stenosis, those with SS had significantly higher IPH (66.7% vs. 39.8%) and Type‐I IPH (66.7% vs. 38.6%) than those without. The presence of IPH (OR 3.030, 95% CI 1.106–8.305) and Type‐I IPH (OR 3.187, 95% CI 1.162–8.745) was significantly associated with SS. After adjustment, the associations of SS with presence of IPH (OR 3.294, 95% CI 1.122–9.669) and Type‐I IPH (OR 3.633, 95% CI 1.216–10.859) remained significant. Moreover, the volume of Type‐II IPH (OR 1.014, 95% CI 1.001–1.028), and maximum‐area‐percentage of Type‐II IPH (OR 1.070, 95% CI 1.002–1.142) and LRNC (OR 1.030, 95% CI 1.000–1.061) were significantly associated with SS after adjustment. No significant (P range: 0.203–0.980) associations were found between carotid plaque characteristics and SS in patients with moderate‐carotid‐stenosis. Data Conclusions: In patients with unilateral severe‐carotid‐stenosis, carotid vulnerable plaque MR features, particularly presence and size of IPH, might be effective predictors for SS after CEA. Evidence Level: 2 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]