Abstract Number: Esoc2026lt88 Lt88 - Results of Central Imaging Adjudication From Analysis of Mechanical Thrombectomy for Large Core Ischemic Stroke (Atlas) Collaboration – An Individual-Patient-Data Meta-Analysis of Six Randomized Controlled Trials

Abstract Background and aims Multiple randomized trials demonstrated efficacy and safety of endovascular thrombectomy in large ischemic stroke. An individual-patient-data metaanalysis will refine treatment effect estimates and provide insights into specific imaging subgroups. Methods We will perform an individual-patient-data meta-analysis of randomized trials to explore the evidence for efficacy and safety of EVT in large ischemic core up to 24 hours after last-known-well in imaging subgroups after central adjudication of all available neuroimaging modalities. A research plan and statistical analysis protocol was developed a-priori and registered with PROSPERO. A systematic search was executed to identify clinical trials that randomized patients with anterior circulation large vessel occlusion (ICA/MCA) and a large ischemic core on non-contrast CT/MRI(ASPECTS ≤5) and/or CT/MR perfusion/diffusion(ischemic core≥50 ml) to receive EVT vs medical care only and were published after 3/2018. Identified clinical trials were invited to contribute patient data. The primary efficacy outcome is the distribution of modified Rankin Scale score at 90-day follow-up. Secondary outcomes include functional independence(mRS 0-2), independent ambulation(mRS 0-3), symptomatic ICH(SITS-MOST) and mortality. Additionally, primary and secondary outcomes will be examined in pre-specified subgroups based on imaging characteristics. All neuroimaging will be re-evaluated centrally, including ASPECTS, ischemic core, mismatch and occlusion location. Results Six clinical trials (RESCUE Japan LIMIT, ANGEL ASPECT, SELECT2, TENSION, LASTE and TESLA) met eligibility criteria and are included in this meta-analysis. The final results with centralized imaging core lab reads will be presented at European Stroke Organization Conference 2026 and published simultaneously. Conclusions N/A Conflict of interest