Abstract Body: Introduction: Intracranial atherosclerosis is a common cause of stroke and is associated with a high risk of recurrent stroke. Previous RCTs did not indicate the benefits of stenting beyond medical treatment for symptomatic intracranial arterial stenosis (sICAS) patients. We aim to determine baseline risk factors and develop a prediction model for the risk of recurrent stroke in the stenting arm of the SAMMPRIS Trial and CASSISS Trial.

Methods: Patients with sICAS and treated with stenting in the SAMMPRIS (N=176) and CASSISS (N=224) trials were included. The primary outcome was defined as stroke in the territory of the qualifying artery beyond 30 days of enrollment, or any stroke or death within 30 days. Cox regression model and ROC curve were performed to evaluate baseline features to the time until an end point.

Results: A total of 400 patients were included and 71 patients (17.8%) suffered from the primary end events. In the univariate analyses, age of 59 or above (hazard ratio [HR], 1.75; 95% CI, 1.08-2.83), male (HR,1.82; 95% CI, 1.14-2.89), Asian (HR,0.44; 95% CI, 0.26-0.74), diabetes (HR, 2.32; 95% CI, 1.45-3.73), lipid disorders (HR, 2.29; 95% CI, 1.38-3.82), smoking (HR, 0.49; 95% CI, 0.25-0.95), internal carotid artery stenosis (HR, 2.21; 95% CI, 1.3-3.73), high qualifying artery stenosis degree (HR, 1.04; 95% CI, 1-1.07), high baseline NIHSS score (HR, 1.14; 95% CI, 1.03-1.26), high baseline mRS score (HR, 1.28; 95% CI, 1.02-1.61), and high HDL cholesterol level (HR, 1.41; 95% CI, 1.04-1.90) were associated (p<.05) with higher risk. Based on stepwise regression analyses, five variables were selected for the prediction model, including sex, diabetes, lipid disorders, smoking and internal carotid artery stenosis. Factors that were significantly associated with recurrent stroke were diabetes (HR, 1.94; 95% CI, 1.17-3.20; p=.010), lipid disorders (HR, 1.72; 95% CI, 1.01-2.95; p=.048), and internal carotid artery stenosis (HR, 1.83; 95% CI, 1.04-3.22; p=.036) on multivariable analyses. The area under the curve of the nomogram predicting 3-year risk of recurrent stroke was 0.71 for the total patients, and 0.81 for the Asian population in the subgroup analysis.

Conclusions: Internal carotid artery stenosis emerged as an important risk factor in patients with sICAS and treated with stenting, as well as traditional diabetes and lipid disorders. For the prediction model of 5 factors, it showed better prediction accuracy among the Asian patients.