Abstract TP210: Stroke Subtype-specific Association Of Systemic Blood Pressure And Cerebral Collateral Flow In Acute Ischemic Stroke With Large Vessel Occlusion

Abstract

Introduction: Collateral flow in acute ischemic stroke is known as a predictor of acute treatment outcome and long-term prognosis. However, studies on the factors which determine the degree of initial collateral flow are not well known. We investigated the factors related to collateral degree in acute ischemic stroke caused by large vessel occlusion (AIS-LVO) and further analyzed the results according to stroke subtype. Methods: This was a retrospective cohort using prospective stroke registry data from October 2014 to May 2021. Patients admitted within 48 hours of symptom onset with middle cerebral artery M1 occlusion on multiphasic CT angiography were included. Collateral score was graded on a six-point scale according to pial arterial filling. Results: A total of 74 patients was enrolled (mean age=72.2±11.7 years; men=37.8%). Of whom 57 (77%) were in the cardioembolism (CE) group and 17 (23%) were in the large artery atherosclerosis (LAA) group. In ordinary logistic regression analysis, initial systolic blood pressure (SBP) was associated with the score of collateral flow (odds ratio [OR]=0.982; 95% confidence interval [CI]=0.968-0.997; p=0.017). Considering multivariate models adjusted for age, sex, and atrial fibrillation, initial SBP was an independent predictor of the score of collateral flow (OR=0.977; 95% CI=0.961-0.992; p=0.011). In subgroup analysis, the lower score of collateral flow was independently associated with increased initial SBP in CE group (OR=0.965; 95% CI=0.945-0.983; p<0.001) but not in LAA group (OR=1.009; 95% CI=0.978-1.043; p=0.578). Echocardiographic parameters and anatomical variations of circle of Willis did not show significant association. Conclusions: Poor cerebral collaterals in AIS-LVO was associated with increased initial SBP. Subgroup analysis revealed the association was significant in CE group, but not in LAA group. Mechanism underlying differential effects of SBP on stroke subtypes may need further study.