Intravenous ancrod for acute ischaemic stroke in the European Stroke Treatment with Ancrod Trial: a randomised controlled trial

Background Intravenous tissue plasminogen activator is the only approved specific treatment for acute ischaemic stroke. Ancrod, a natural defibrinogenating agent from snake venom, has proved to have a favourable effect when given within 3 h after an acute ischaemic stroke. The European Stroke Treatment with Ancrod Trial was undertaken to assess the effects of ancrod when given within 6 h. Methods 1222 patients with an acute ischaemic stroke were included in this randomised double-blind placebo-controlled trial. Brain CT scans were done to exclude intracranial haemorrhages and large evolving ischaemic infarctions. Patients were randomly assigned ancrod (n=604) or placebo (n=618). The primary outcome was functional success at 3 months (survival, Barthel Index of 95 or 100, or return to prestroke level). The analysis was by intention-to-treat. This trial is registered with ClinicalTrials.gov, trial number NCT00343174. Findings Functional success at 3 months did not differ between patients given ancrod (42%) and those given placebo (42%) (p=0.94, OR=0.99, 95% CI, 0.76-1.29). Interpretation On the basis of our findings, ancrod should not be recommended for use in acute ischaemic stroke beyond 3 h.