Abstract Number ‐ 171: Stroke location as predictor of bleeding after EVT for ischemic stroke in the anterior circulation
Authors: Kumar Ashish , Ponde Bruno , Hawkes Christine , Kapadia Anish , Da Costa Leodante 
Published: April 2023

Introduction
Hemorrhage is a known risk of Endovascular thrombectomy (EVT) for ischemic stroke . Several predictors of bleeding have been identified. However, stroke location has not yet been evaluated as an independent predictor.

Methods
Patients ≥ 18 years who underwent EVT for anterior circulation large vessel occlusion between January 1, 2020, and December 31, 2021, at our centre were included. After the exclusion criteria, a total of 344patients were analyzed. The admission CT scans were reviewed by a neuroradiologist to determine the ASPECTS, and classify the involved regions into location groups: only central core, only cortical, and both central and cortical areas. Post EVT images were evaluated to assign the Heidelberg bleeding classification. Statistical analysis was performed in R, version 4.1. For univariate analyses, Fisher’s exact or chi‐square test was used for categorical data. Quantitative data were tested for normality, and the t‐test or Mann‐Whitney test was applied accordingly. All variables in the univariate analyses with p < 0.15 were considered for the stepwise logistic regression models.

Results
Patients had a median age of 73 years (IQR 20), NIHSS of 16 (IQR 9),ASPECTS of 7 (IQR 3), systolic blood pressure of 146 mmHg (IQR 25), and glycemia of 7 mmol/L (IQR 2). The most frequent occlusion site was M1 (65.7%), and most patients had an mTICI > 2A (89.5%). Bleeding occurred in 182 (52.9%) and intraparenchymal hematoma in 73 (21.2%) patients, with most bleeding only in the central core (65.4%), with the lentiform nucleus involved in 122 (67%) of the bleeds. Thirty‐eight patients died (11%), and 237 had a modified Rankin score > 2 at discharge (68.9%). Stroke location was significant for all types of bleeding (p < 0.001) and intraparenchymal hematoma (p = 0.137) in the univariate analyses. However, after multiple logistic regression, the stroke location was not an independent predictor of any type of bleeding. On the other hand, a lower ASPECTS was a significant predictor of all types of bleeding (p < 0.001; OR 1.347; 95% CI 1.1799 ‐ 1.539) and intraparenchymal hematoma (p = 0.009; OR 1.756; 95% CI 1.152 ‐ 2.677). In addition to ASPECTS, high NIHSS (p = 0.038; OR 1.058; 95% CI 1.003 ‐ 1.115) was a significant predictor of all types of bleeding, while high systolic blood pressure (p = 0.027; OR 1. 037;95% CI 1.004 ‐ 1.071), cardioembolic stroke (p = 0.042; OR 10.408; 95% CI 1.085 ‐ 99.889), and poor collaterals (p = 0.046; OR 5.068; 95% CI 1.029 ‐ 24.951) were significant for intraparenchymal hematoma.

Conclusions
Stroke location is not an independent predictor of bleeding. However, stroke size, as indicated by the ASPECT, is a predictor of bleeding after EVT. Moreover, some modifiable predictors were not significant because they are already controlled for in the study, but systolic pressure was a significant predictor of intraparenchymal hematoma and shows that more studies are needed to determine the appropriate control levels to reduce the chance of bleeding without compromising cerebral perfusion.