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

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.