Recombinant Tissue-Type Plasminogen Activator (Alteplase) for Ischemic Stroke 3 to 5 Hours After Symptom Onset

TLDR

Recombinant tissue‑type plasminogen activator improves outcomes for acute ischemic stroke but is approved only within 3 hours, leaving most patients presenting later untreated. This study aimed to evaluate the efficacy and safety of rt‑PA when given 3 to 5 hours after symptom onset. In a phase‑3, double‑blind, placebo‑controlled RCT across 140 North American hospitals, 613 patients received 0.9 mg/kg rt‑PA IV over 1 hour, with primary outcome of excellent neurologic recovery (NIHSS ≤ 1) at day 90 and secondary functional measures. The trial showed no significant improvement in 90‑day neurologic or functional outcomes, but rt‑PA markedly increased symptomatic intracerebral hemorrhage and mortality, providing no support for its use beyond 3 hours.

Abstract

ContextRecombinant tissue-type plasminogen activator (rt-PA) improves outcomes for patients with acute ischemic stroke, but current approved use is limited to within 3 hours of symptom onset. This restricts the number of patients who can be treated, since most stroke patients present more than 3 hours after symptom onset.ObjectiveTo test the efficacy and safety of rt-PA in patients with acute ischemic stroke when administered between 3 and 5 hours after symptom onset.DesignThe Alteplase ThromboLysis for Acute Noninterventional Therapy in Ischemic Stroke (ATLANTIS) study is a phase 3, placebo-controlled, double-blind randomized study conducted between December 1993 and July 1998, with up to 90 days of follow-up.SettingOne hundred forty university and community hospitals in North America.PatientsAn intent-to-treat population of 613 acute ischemic stroke patients was enrolled, with 547 of these treated as assigned within 3 to 5 hours of symptom onset. A total of 39 others were treated within 3 hours of symptom onset, 24 were treated more than 5 hours after symptom onset, and 3 never received any study drug.InterventionAdministration of 0.9 mg/kg of rt-PA (n = 272) or placebo (n = 275) intravenously over 1 hour.Main Outcome MeasuresPrimary efficacy was an excellent neurologic recovery at day 90 (National Institutes of Health Stroke Scale [NIHSS] score of ≤1); secondary end points included excellent recovery on functional outcome measures (Barthel index, modified Rankin scale, and Glasgow Outcome Scale) at days 30 and 90. Serious adverse events were also assessed.ResultsIn the target population, 32% of the placebo and 34% of rt-PA patients had an excellent recovery at 90 days (P = .65). There were no differences on any of the secondary functional outcome measures. In the first 10 days treatment with rt-PA significantly increased the rate of symptomatic intracerebral hemorrhage (ICH) (1.1% vs 7.0% [P<.001]), a symptomatic ICH (4.7% vs 11.4% [P = .004]), and fatal ICH (0.3% vs 3.0% [P<.001]). Mortality at 90 days was 6.9% with placebo and 11.0% with rt-PA (P = .09). Results in the intent-to-treat population were similar.ConclusionsThis study found no significant rt-PA benefit on the 90-day efficacy end points in patients treated between 3 and 5 hours. The risk of symptomatic ICH increased with rt-PA treatment. These results do not support the use of intravenous rt-PA for stroke treatment beyond 3 hours.