Intracranial Plaque Characteristics of Recurrent Ischemic Stroke After Intensive Medical Therapy for a 6-month Follow-up

BACKGROUND Intensive medical management has been recommended to ischemic stroke of intracranial atherosclerosis (ICAS), but 9.4-15% probability of recurrent stroke remains an inevitable reality. The characteristics of high-risk intracranial plaque that contribute to stroke recurrence after intensive therapy is unclear. METHODS All the patients for acute ischemic stroke due to ICAS underwent the 3D head&neck high-resolution vessel wall magnetic resonance imaging (hr-VW-MRI) at baseline and received intensive medical management within 90 days in this two-center and prospective study. The clinical risk factors and blood biomarkers were recorded. The morphological features, such as minimal lumen area (MLA), and histogram parameters including entropy were assessed based on MR images. The primary endpoint event after 6 months is recurrence of ischemic events (hyperintense signals on diffusion-weighted images or TIA in the ipsilateral vascular territory). Cox regression analysis was used to calculate the hazard ratio (HR) and 95% confidence interval (CI) for recurrent events. RESULTS 222 patients (age, 59.5±12.1; males, 153) were included in the subsequent analysis. After an average of six months of follow-up (average days, 177.4±23.1), 38 patients have reached the primary endpoint. After adjusting the age, BMI and gender, the multivariate Cox regression demonstrated that three clinical factors including smoking (HR=4.321; 95%CI, 1.838-10.161; P =0.001), taking exercise (HR=0.409; 95%CI, 0.198-0.843; P =0.015) and blood pressure management (HR=0.180; 95%CI, 0.073-0.443; P =0.001), and two MR-related parameters (MLA [HR=0.771; 95%CI, 0.625-0.951; P =0.015] and entropy [HR=0.274; 95%CI, 0.130-0.576; P =0.001]) were significant predictors of recurrent ischemic stroke. The Kaplan– Meier curve depicted that the cumulative incidences of patients with all high-risk features were significantly higher than those without(P < 0.001). CONCLUSIONS The plaque characteristics based on 3D head&neck hr-VW-MRI may provide complementary values over traditional clinical features in predicting ischemic recurrence for ICAS and help risk stratification of patients at risk of recurrent stroke.