For a study, researchers sought to determine if adding intra-arterial alteplase after thrombectomy improves outcomes after reperfusion. From December 2018 to May 2021, 7 stroke centers participated in phase 2b randomized, double-blind, placebo-controlled experiment. The study comprised 121 patients with major vessel blockage acute ischemic stroke who were treated with thrombectomy within 24 hours of stroke start and had a Treatment in Cerebral Ischemia angiographic score of 2b50 to 3. Participants (n=61) were randomly assigned to receive intra-arterial alteplase (0.225 mg/kg; maximum dosage, 22.5 mg) given over 15 to 30 minutes or placebo (n=52). 

Due to the sheer COVID-19 pandemic, the trial was called off early due to an inability to sustain placebo supply and enrolment rates. 748 (41%) of the 1825 patients with acute ischemic stroke treated with thrombectomy at the 7 study sites met the angiographic criteria, 121 (7%) were randomized (mean age, 70.6 [SD, 13.7] years; 57 women [47%]), and 113 (6%) were treated as randomized. At 90 days, the percentage of patients with a modified Rankin Scale score of 0 or 1 was 59.0% (36/61) with alteplase and 40.4% (21/52) for placebo (adjusted risk difference, 18.4%; 95% CI, 0.3% -36.4%; P=.047). The proportion of patients who experienced symptomatic cerebral bleeding within 24 hours was 0% with alteplase and 3.8% with placebo (risk difference, 3.8%; 95% CI, 13.2% to 2.5%). 90-day mortality was 8% with alteplase and 15% with placebo (risk difference, 7.2%; 95% CI, 19.2%to 4.8%).

When comparing adjunct intra-arterial alteplase to placebo in patients with major artery blockage acute ischemic stroke and successful reperfusion following thrombectomy, the use of adjunct intra-arterial alteplase resulted in a higher chance of satisfactory neurological outcome at 90 days. However, due to research limitations, the findings should be viewed as preliminary and will need to be replicated.