Intravenous ancrod for treatment of acute ischemic stroke - The STAT study: A randomized controlled trial

Context Approved treatment options for acute ischemic stroke in the United States and Canada are limited at present to intravenous tissue-type plasmin ogen activator, but bleeding corn plications, including intracranial hemorr hage, are a recognized complication. Objective To evaluate the efficacy and safety of the defibrinogenating agen t ancrod in patients with acute ischemic stroke. Design The Stroke Treatment with Ancrod Trial (STAT), a randomized, paralle l-group, double-blind, placebo-controlled trial conducted between August 19 93 and January 1998. Setting Forty-eight centers, primarily community hospitals, in the United S tates and Canada. Patients A total of 500 patients with an acute or progressing ischemic neur ological 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 with in 3 hours of stroke onset, followed by infusions lasting approximately 1 h our at 96 and 120 hours. The ancrod regimen was designed to decrease plasma fibrinogen levels to 1.18 to 2.03 mu mol/L. Main Outcome Measures The primary efficacy end point was functional status, with favorable functional status defined as survival to day 90 with a Bart hel Index of 95 or more or at least the prestroke value, compared by treatm ent group. Primary safety variables included symptomatic intracranial hemor rhage and mortality. Results Favorable functional status was achieved by more patients in the an crod group (42.2%) than in the placebo group (34.4%; P=.04) by the prespeci fied covariate-adjusted analysis. Mortality was not different between treat ment 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 i n the ancrod group than in the placebo group (11.8% vs 19.8%; P=.01). The f avorable functional status observed with ancrod vs placebo was consistent i n all subgroups defined for age, stroke severity, sex, prestroke disability , and time to treatment (less than or equal to 3 or >3 hours after stroke o nset). There was a trend toward more symptomatic intracranial hemorrhages i n the ancrod group vs placebo (5.2% vs 2.0%; P=.06), as well as a significa nt increase in asymptomatic intracranial hemorrhages (19.0% vs 10.7%; P=.01 ). Conclusion In this study, ancrod had a favorable benefit-risk profile for p atients with acute ischemic stroke.