Abstract Background and aims We investigated whether intravenous thrombolysis (IVT) before endovascular treatment (EVT) reduces the occurrence of infarcts in new territory (INT) and evaluated the clinical relevance of INT. Methods Individual participant data meta-analysis of six randomized clinical trials comparing IVT + EVT versus EVT alone. Imaging from all trials was centrally adjudicated by trained evaluators. INT was defined as an infarct on follow-up imaging in a vascular territory not hypoperfused during acute treatment. Mixed-effects logistic regression models with study-stratified intercepts and random study effects were used to assess the association between treatment allocation and INT, and between INT, functional outcomes, and safety outcomes. Results Evaluable imaging was available for 2024/2313 (88%) participants (1010 EVT alone; 1014 IVT + EVT). INT occurred in 265 (13%) and was less frequent after IVT + EVT compared with EVT alone (113 11% vs 152 15%; OR 0.71, 95% CI 0.55–0.92). INT was associated with worse functional outcomes at 90 days, including lower odds of improved modified Rankin Scale scores (adjusted common OR 0.57, 95% CI 0.45–0.72) and lower rates of functional independence (42% vs 52%; adjusted OR 0.61, 95% CI 0.46–0.79). INT was also associated with higher rates of symptomatic intracranial hemorrhage. Conclusions INT occurred in 13% of participants with large-vessel occlusion stroke undergoing EVT, and was associated with worse outcomes. Participants randomized to IVT + EVT had lower rates of INT, though this did not translate to improved functional outcome in our data. Conflict of interest Roman Rohner: nothing to disclose. Fabiano Cavalcante: nothing to disclose. Jianmin Liu: nothing to disclose. Yongwei Zhang: nothing to disclose. Kentaro Suzuki: nothing to disclose. Raul Nogueira: nothing to disclose. Peter Mitchell: nothing to disclose. Dr Roos reports stock holdings in Nicolab. Dr Fischer reports grants from Stryker to other; grants from Schweizerische Herzstiftung; grants from Penumbra, Inc, to other; grants from SNSF; compensation from phenox, Inc, for end point review committee services; grants from Medtronic to other; grants from phenox, Inc, to other; grants from Rapid Medical, Ltd, to other; grants from Boehringer Ingelheim; grants from Stryker to other; and grants from Medtronic to other. Dr Gralla reports compensation from Johnson & Johnson Health Care Systems, Inc, for consultant services and compensation from Medtronic USA, Inc, for other services.
Rohner et al. (2026) studied this question.