Glyceryl trinitrate vs. control, and continuing vs. stopping temporarily prior antihypertensive therapy, in acute stroke: rationale and design of the Efficacy of Nitric Oxide in Stroke (ENOS) trial (ISRCTN99414122)

Int J Stroke. 2006 Nov;1(4):245-9. doi: 10.1111/j.1747-4949.2006.00059.x.


High blood pressure (BP) is common in acute stroke and is independently associated with a poor outcome. Many patients with acute stroke are taking antihypertensive medications. To test the safety and efficacy of 7 days of transdermal glyceryl trinitrate (GTN, 5 mg/day) vs. no GTN in patients with acute stroke; patients taking antihypertensive therapy immediately before their stroke are also randomised to continue vs. stop this temporarily. ENOS is a prospective international multicentre single-blind randomised-controlled trial in 5000 patients with acute (<48 h of onset) ischaemic or haemorrhagic stroke. The primary outcome is combined death and dependency (modified Rankin scale >2) at 90 days measured by blinded central telephone follow-up. Secondary outcomes include: BP over the 7 days of treatment; death, impairment (Scandinavian stroke scale), recurrence, and neuroimaging at 7 days; discharge disposition, disability (Barthel index), cognition (mini-mental status examination) and quality of life (EuroQoL). The sample size will allow an absolute difference in death/dependency of 5% to be detected with 90% power at 5% significance for GTN versus no GTN. Randomisation and data collection are performed over a secure Internet site with real-time data validation. Neuroimaging and serious adverse events are adjudicated blinded to treatment.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Antihypertensive Agents / administration & dosage*
  • Humans
  • Hypertension / complications
  • Hypertension / drug therapy
  • Nitroglycerin / therapeutic use*
  • Research Design*
  • Stroke / drug therapy*
  • Stroke / etiology
  • Vasodilator Agents / therapeutic use*


  • Antihypertensive Agents
  • Vasodilator Agents
  • Nitroglycerin

Associated data

  • ISRCTN/ISRCTN99414122