Discharge outcomes of intravenous alteplase 4.5–24 hours after symptom onset in selected patients with acute ischemic stroke: a propensity score–matched real-world study

Abstract

Background Evidence for alteplase 4.5-24 h after acute ischemic stroke (AIS) onset remains limited in routine practice. We examined associations between late-window intravenous thrombolysis (IVT) and discharge outcomes in selected patients. Methods We analyzed China Stroke Center Alliance patients arriving 4-23.5 h after onset. Alteplase-treated patients were matched 1:1 to non-IVT patients using propensity scores. The primary outcome was modified Rankin Scale (mRS) 0-1 at discharge. Secondary and safety outcomes included mRS 0-2, registry-recorded in-hospital intracranial hemorrhage (ICH), mortality, discharge against medical advice (DAMA), and mortality or DAMA. Results Among 137,157 eligible AIS patients, 874 received IVT and were matched to 874 non-IVT patients. Median onset-to-needle time was 6.05 h (interquartile range 5.12-10.04); 48.4%, 23.7%, 6.6%, and 21.3% were treated at 4.5-<6, 6-<9, 9-<12, and 12-24 h, respectively. IVT was associated with higher rates of mRS 0-1 (30.4% vs. 17.0%, odds ratio [OR] 2.14, 95% confidence interval [CI], 1.70-2.69, p < 0.001) and mRS 0-2 (65.4% vs. 58.1%; OR, 1.36; 95% CI, 1.12-1.66, p = 0.002). In-hospital ICH was more frequent (1.7% vs. 0.6%, OR 3.04, 95% CI, 1.10-8.39, p = 0.03), whereas DAMA was less frequent (5.7% vs. 8.8%, OR 0.63, 95% CI, 0.44-0.92, p = 0.02). Length of hospital stay, mortality, and mortality or DAMA did not differ significantly. Conclusions Late-window alteplase was associated with better discharge function but more registry-recorded ICH in selected patients. Because symptomatic status, hemorrhage subtype, severity, and fatality were unavailable, hemorrhagic safety remains incompletely characterized. These observational findings require cautious interpretation. Supplementary Information The online version contains supplementary material available at [https://doi.org/10.1186/s42466-026-00529-w]().