Intravenous Ancrod for Treatment of Acute Ischemic Stroke

CONTEXT: Approved treatment options for acute ischemic stroke in the United States and Canada are limited at present to intravenous tissue-type plasminogen activator, but bleeding complications, including intracranial hemorrhage, are a recognized complication. OBJECTIVE: To evaluate the efficacy and safety of the defibrinogenating agent ancrod in patients with acute ischemic stroke. DESIGN: The Stroke Treatment with Ancrod Trial (STAT), a randomized, parallel-group, double-blind, placebo-controlled trial conducted between August 1993 and January 1998. SETTING: Forty-eight centers, primarily community hospitals, in the United States and Canada. PATIENTS: A total of 500 patients with an acute or progressing ischemic neurological deficit were enrolled and included in the intent-to-treat analysis. INTERVENTIONS: Patients were randomly assigned to receive ancrod (n=248) or placebo (n =252) as a continuous 72-hour intravenous infusion beginning within 3 hours of stroke onset, followed by infusions lasting approximately 1 hour at 96 and 120 hours. The ancrod regimen was designed to decrease plasma fibrinogen levels to 1.18 to 2.03 micromol/L. MAIN OUTCOME MEASURES: The primary efficacy end point was functional status, with favorable functional status defined as survival to day 90 with a Barthel Index of 95 or more or at least the prestroke value, compared by treatment group. Primary safety variables included symptomatic intracranial hemorrhage and mortality. RESULTS: Favorable functional status was achieved by more patients in the ancrod group (42.2%) than in the placebo group (34.4%; P=.04) by the prespecified covariate-adjusted analysis. Mortality was not different between treatment groups (at 90 days, 25.4% for the ancrod group and 23% for the placebo group; P=.62), and the proportion of severely disabled patients was less in the ancrod group than in the placebo group (11.8% vs 19.8%; P=.01). The favorable functional status observed with ancrod vs placebo was consistent in all subgroups defined for age, stroke severity, sex, prestroke disability, and time to treatment ( 3 hours after stroke onset). There was a trend toward more symptomatic intracranial hemorrhages in the ancrod group vs placebo (5.2% vs 2.0%; P=.06), as well as a significant increase in asymptomatic intracranial hemorrhages (19.0% vs 10.7%; P=.01). CONCLUSION: In this study, ancrod had a favorable benefit-risk profile for patients with acute ischemic stroke.