Abstract Number: Esoc2026a469 Arterial Recanalization During Inter-Hospital Transfer for Thrombectomy in the Late Time Window

Abstract Background and aims In acute ischemic stroke due to large vessel occlusion (AIS-LVO) admitted to primary stroke centers (PSCs) in the early time-window, arterial recanalization occurring during inter-hospital transfer for endovascular therapy (EVT) is strongly linked to better outcomes. Whether this applies to late-presenting patients is unknown. Methods Multicenter retrospective study of consecutive AIS-LVO patients admitted between 2020 and 2024 to 20 French PSCs beyond 4.5 hours from the last time seen well and subsequently transferred to a comprehensive center for EVT, with arterial imaging performed both at the PSC and on comprehensive center arrival. Interhospital recanalization was assessed by comparison of the baseline and post-transfer arterial imaging and was defined as mTICI score 2b-3. Results Overall, 578 patients were included (median age 71 years, NIHSS 15, last seen well-to-PSC imaging time 10.5hrs, off-label intravenous thrombolysis prior to transfer used in 40%). Inter-hospital recanalization occurred in 61/578 (11%) patients. Variables independently associated with inter-hospital recanalization were thrombolysis (aOR, 10.6 95%CI 5.1–21.8), more distal occlusions (intracranial carotid occlusion as reference: aOR, 1.8 0.7–5.0 for M1, 5.8 2.0–16.7 for M2 and 5.6 1.4–21.6 for basilar), and longer time from PSC imaging-to-recanalization assessment (aOR 1.3 1.1–1.6). Inter-hospital recanalization was associated with reduced 3-month disability (adjusted cOR, 3.1 1.9–5.0). Conclusions Consistent with findings in the early time window, recanalization occurring during interhospital transfer was associated with reduced disability in the late time window. These results underscore the need for therapeutic strategies aimed at enhancing inter-hospital recanalization in late-presenting stroke patients. Conflict of interest Pierre Seners reports speaker fees from Boerhinger-Ingelheim. Guillaume Turc reports lecturing fees from Guerbet France, consulting fees for Neurologica and AI-Stroke. Other authors have nothing to disclose.