Abstract Number: Esoc2026lb121 Lb121 - Large Artery Occlusion Treated in Extended Time With Mechanical Thrombectomy (Late-Mt) : A Multicentre, Randomised Controlled Trial

Abstract Background and aims High-quality randomized controlled trials (RCTs) have extended the endovascular therapy (EVT) time window to 24 hours post-stroke onset in selected patients with acute ischemic stroke (AIS). Recent retrospective studies indicate that EVT performed beyond 24 hours may still improve clinical outcomes. However, the specific benefit-risk profile in this ultra-late window remains unclear. The LATE-MT trial is designed to address this evidence gap and determine the benefit-risk balance of EVT in the ultra-late window. Methods The trial is an investigator-initiated, multicenter, prospective, randomized, open, blinded-endpoint assessment (PROBE) clinical trial. The trial adopted an adaptive group-sequential design, recruiting 336 AIS patients with large-vessel occlusion (LVO) within 24 to 72 hours of the last known well across 35 stroke centers in China. Eligible subjects who meet both clinical and imaging selection criteria are randomized 1:1 to EVT or medical management. The primary outcome is an ordinal shift analysis of scores on the modified Rankin scale (mRS) at 90 days. Results Since its initiation in November 2022, the trial completed enrollment of all 336 patients by December 2025. The trial is scheduled to complete follow-up and lock data by late March 2026. Study findings will be presented at this conference. Conclusions The LATE-MT trial is the first RCT to investigate the efficacy and safety of EVT in AIS patients beyond the 24-hour window. The results of this study will provide evidence supporting EVT for patients with LVO who experience prehospital delays or progressive stroke. Conflict of interest