%0 Journal Article %A Lucy Beishon %A Lisa J Woodhouse %A Daniel Bereczki %A Hanne K Christensen %A Ronan Collins %A John Gommans %A Christina Kruuse %A George Ntaios %A Serefnur Ozturk %A Stephen Phillips %A Stuart Pocock %A Szabolcs Szatmari %A Joanna Wardlaw %A Nikola Sprigg %A Philip M Bath %A , %T Relationship between nitrate headache and outcome in patients with acute stroke: results from the efficacy of nitric oxide in stroke (ENOS) trial %D 2021 %R 10.1136/svn-2020-000498 %J Stroke and Vascular Neurology %P 180-186 %V 6 %N 2 %X Introduction Nitrate-induced headache is common and may signify responsive cerebral vasculature. We assessed the relationship between nitrate headache and outcome in patients with acute stroke.Materials and methods Patients were those randomised to glyceryl trinitrate (GTN) versus no GTN in the efficacy of nitric oxide in stroke trial. Development of headache by end of treatment (day 7), and functional outcome (modified Rankin Scale, primary outcome) at day 90, were assessed. Analyses are adjusted for baseline prognostic factors and give OR and mean difference (MD) with 95% CI.Results In 4011 patients, headache was more common in GTN than control (360, 18.0% vs 170, 8.5%; p<0.001). Nitrate-related headache was associated with: younger age, female sex, higher diastolic blood pressure, non-total anterior circulation syndrome, milder stroke and absence of dysphasia (p<0.05). Nitrate headache was not associated with improved functional outcome (OR 0.90, 95% CI 0.73 to 1.10, p=0.30) or death (day 90) (HR 0.64, 95% CI 0.40 to 1.02, p=0.062), but reduced death or deterioration (day 7) (OR 0.45, 95% CI 0.25 to 0.82), death in hospital (OR 0.44, 95% CI 0.22 to 0.88) and improved activities of daily living (Barthel index, MD 3.7, 95% CI 0.3 to 7.1) and cognition (telephone interview cognitive screen, MD 2.0, 95% CI 0.7 to 3.3) (day 90). Non-nitrate headache was not associated with death, disability or cognition.Discussion and conclusion Development of a nitrate headache by day 7 after stroke may be associated with improved activities of daily living and cognitive impairment at day 90, which was not seen with non-nitrate headache.Data are available on reasonable request. Individual participant data will be shared with the Virtual International Stroke Trials Archive (VISTA) collaboration. From 1 January 2022, the chief investigator and trial steering committee will consider other requests to share individual participant data via email at: enos@nottingham.ac.uk. We will require a protocol detailing hypothesis, aims, analyses and intended tables and figures. Where possible, we will perform the analyses; if not, deidentified data and a data dictionary will be supplied for the necessary variables for remote analysis. Any sharing will be subject to a signed data access agreement. Ultimately, the data will be published. %U https://svn.bmj.com/content/svnbmj/6/2/180.full.pdf