Extending the time window for intravenous thrombolysis in acute ischemic stroke using magnetic resonance imaging-based patient selection:

BackgroundIntravenous thrombolysis with alteplase within a time window up to 4.5 h is the only approved pharmacological treatment for acute ischemic stroke. We studied whether acute ischemic stroke patients with penumbral tissue identified on magnetic resonance imaging 4.5–9 h after symptom onset benefit from intravenous thrombolysis compared to placebo.MethodsAcute ischemic stroke patients with salvageable brain tissue identified on a magnetic resonance imaging were randomly assigned to receive standard dose alteplase or placebo. The primary end point was disability at 90 days assessed by the modified Rankin scale, which has a range of 0–6 (with 0 indicating no symptoms at all and 6 indicating death). Safety end points included death, symptomatic intracranial hemorrhage, and other serious adverse events.ResultsThe trial was stopped early for slow recruitment after the enrollment of 119 (61 alteplase, 58 placebo) of 264 patients planned. Median time to intravenous thrombolysis was 7 h 42 min. The primary ...