Thrombolysis for Ischemic Stroke Beyond the 4.5-Hour Window: A Meta-Analysis of Randomized Clinical Trials

A minority of patients with stroke qualify for intravenous thrombolysis (IVT) within 4.5-hour window. The safety and efficacy of IVT beyond this period have not been well studied.

We systematically searched MEDLINE, Embase, Cochrane, and ClinicalTrials.gov for relevant randomized clinical trials. Randomized clinical trials comparing IVT versus standard medical care in patients with ischemic stroke beyond 4.5 hours of symptom onset or last known well without mechanical thrombectomy (MT) were included. Primary outcomes were excellent (modified Rankin Scale score of 0–1) and good (modified Rankin Scale score of 0–2) functional outcomes at 90 days, symptomatic intracerebral hemorrhage (sICH), and death at 90 days. Pooled odds ratios (ORs) with 95% CIs were calculated using a random-effects model. Heterogeneity was assessed by Q test and quantified by I ² values.