Abstract DP189: Sex Differences in Treatment and Outcomes of Acute Ischemic Strokes due to Large Vessel Occlusion in Ontario

Introduction: Thrombectomy is the standard of care treatment for acute ischemic strokes with large vessel occlusion (LVO). It is not known if there are sex differences in identification of LVO and whether treatment and outcomes differ in males versus females. We evaluated population-based sex differences in the screening of LVO and thrombectomy use in patients hospitalized with acute ischemic stroke in Ontario, Canada. Methods: We used data from the Ontario Stroke Registry, a population-based clinical registry to identify patients admitted with ischemic stroke in the fiscal years 2019/20 and 2022/23 across Ontario. Given we were specifically interested in provision of thrombectomy, we only included patients who presented to an emergency department within the first 24 hours of their last seen normal or stroke onset time. We used linked administrative data to obtain long-term outcomes until March 31, 2025. We compared baseline characteristics and stroke care measures by sex using standardized difference (SD ≥ 0.1 suggests a meaningful imbalance between the male and female groups). Results: Among 22,794 patients with ischemic stroke, 16,596 patients who were within 24 hours of their last seen normal or stroke onset time, were included in the analyses (7,819 [47.1%] females, and median age, 76 years [IQR 65-85]). Female patients were older than males (median age, 79 years vs 73 years, SD = 0.438). Female patients had a higher rate compared to males in terms of history of dementia (11.9% vs 6.8%, SD= 0.177), pre-stroke dependency with mRS of 3 to 5 (22.8% vs 12.4%, SD = 0.277), and living in a retirement home (8.7% vs 3.6%, SD = 0.211) or long-term care (6.8% vs 2.6%, SD = 0.199). Females had higher NIHSS on presentation compared to males (median score, 5 vs 4, SD = 0.111). Females were less likely to undergo intracranial neurovascular imaging for LVO detection (83.8% females vs 87.9% males, SD = 0.119). Among 2,504 patients with LVO (1,267 [50.6%] females), females were less likely to receive thrombolysis (39% females vs 44.5% males, SD = 0.113), and females were less likely to receive thrombectomy (60.1% females vs 65.7% males, SD = 0.117). Multivariable analyses adjusting for baseline differences in treatment and outcomes will be presented at the ISC. Conclusion: In our population-based cohort study, we found that female patients were less likely to be screened for LVO and among those with LVO, less likely to be treated with thrombolysis or thrombectomy.