ABSTRACT
BACKGROUND: Collateral circulation is an important determinant of outcome in people with acute ischemic stroke due to large vessel occlusion (LVO). OBJECTIVE: To explore the impact of the circle of Willis (CW) anatomical characteristics ipsilateral to the occlusion site, particularly the posterior communicating artery (PComA) and the A1-portion of the anterior cerebral artery (A1-ACA), on stroke outcomes in a cohort of patients with LVO and middle cerebral artery (MCA) occlusion, undergoing endovascular thrombectomy (EVT). METHODS: This is a retrospective cohort study performed in a comprehensive tertiary stroke center. The study population consisted of consecutive patients with LVO with proximal MCA occlusion (M1) between June 2016 and April 2021, undergoing EVT. Demographic, clinical, and imaging information was extracted from patient files. Patency and diameters of ipsilateral A1-ACA and PComA were manually measured on admission CT angiography images in the core laboratory. RESULTS: One hundred and five patients with LVO comprised the study cohort, mean age 72.3 years, 43.8% were male, mean National Institutes of Health Stroke Scale score at admission 15.2. The cohort was grouped according to CW vessel characteristics. On univariate analysis, a well-developed PComA was associated with lower rates of hemorrhagic transformation (1.8% vs 14.3%, P=0.01) and a trend towards lower mortality rates (8.9% vs 20.4%, P=0.08).On multivariable regression analysis a well-developed PComA emerged as an independent predictor for survival (aOR=0.09, 95% CI 0.01 to 0.4 for survival at discharge, P=0.009, aOR=0.22, 95% CI 0.05 to 0.8 for survival at 90 days, P=0.02). CONCLUSIONS: In a cohort of patients with LVO due to M1 occlusion undergoing EVT, a well-developed PComA was associated with significantly lower hemorrhagic transformation rates, a trend towards better functional outcomes, and independently predicted survival. Larger studies are needed to understand the differential effect of CW collateral conduits on stroke outcome and evaluate the practicality of incorporating such factors in the clinical decision-making process prior to EVT.
ABSTRACT
BACKGROUND: Endovascular therapy (EVT) is currently the most effective treatment for emergent large vessel occlusion (ELVO) stroke. Earlier treatment is associated with a better clinical outcome. Our aim was to examine the association between onset-to-EVT (OTE) time and clinical outcomes using real-world nationwide data from the National Acute Stroke ISraeli (NASIS)-REVASC registry. METHODS: Stroke patients undergoing EVT within the Endovascular Capable Centres (ECCs) in Israel between January 2014 and March 2016 were prospectively included. Several clinical and radiological outcomes were evaluated. The association between OTE time and outcomes was analyzed with logistic regression models using time as a continuous variable and then by OTE groups of <2, 2-4, 4-6, and >6 hours. RESULTS: 299 patients with acute stroke were included in the analysis. OTE time was significantly associated with favorable outcomes. ORs for each hour of delay in EVT were 0.84 (95% CI 0.71 to 0.99) for significant early recovery, 0.80 (95% CI 0.68 to 0.94) for discharge to home, 0.80 (95% CI 0.66 to 0.95) for freedom from disability at discharge, and 0.78 (95% CI 0.67 to 0.91) for excellent reperfusion (Thrombolysis in Cerebral Ischemia 3). The <2 OTE group was significantly associated with better outcomes than the ≥2 OTE group including significant early recovery (OR 3.3, 95% CI 1.2 to 9.1), discharge to home (OR 3.32, 95% CI 1.3 to 8.5), and excellent reperfusion (OR 4.6, 95% CI 1.3 to 29.5). The same trend was observed for freedom from disability at discharge and 3 months (OR 2.08, 95% CI 0.7 to 5.7 and OR 2.57, 95% CI 0.8 to 8.3, respectively). Only 1% of transferred patients achieved an OTE time of <2 hours. CONCLUSIONS: Nationwide real-life registry data indicate that benefit from EVT is strongly associated with OTE time and is most prominent within the 'two golden hours' from stroke onset. This time goal may not be applicable in inter-hospital transfer patients.