Relationship between nitrate-headache and outcome in patients with acute stroke: results from the Efficacy of Nitric Oxide in Stroke (ENOS) trial

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, mRS, primary outcome) at day 90, were assessed. Analyses are adjusted for baseline prognostic factors and give odds ratio (OR) and mean difference (MD) with 95% confidence intervals (95% CI). Results In 4011 patients, headache was more common in GTN than control (360, 18.0% vs. 170, 8.5%; 2p