Effect of hyperacute administration (within 6 hours) of transdermal glyceryl trinitrate, a nitric oxide donor, on outcome after stroke

Background and Purpose — Nitric oxide donors are candidate treatments for acute stroke, potentially through hemodynamic, reperfusion, and neuroprotectant effects, especially if given early. Although the large Efficacy of Nitric Oxide in Stroke (ENOS) trial of transdermal glyceryl trinitrate (GTN) was neutral, a prespecified subgroup suggested that GTN improved functional outcome if administered early after stroke onset. Methods — Prospective analysis of subgroup of patients randomized into the ENOS trial within 6 hours of stroke onset. Safety and efficacy of GTN versus no GTN were assessed using data on early and late outcomes. Results — Two hundred seventy-three patients were randomized within 6 hours of ictus: mean (SD) age, 69.9 (12.7) years; men, 154 (56.4%); ischemic stroke, 208 (76.2%); Scandinavian Stroke Scale, 32.1 (11.9); and total anterior circulation syndrome, 86 (31.5%). When compared with no GTN, the first dose of GTN lowered blood pressure by 9.4/3.3 mm Hg (P<0.01, P=0.064) and shifted the modified Rankin Scale to a better outcome by day 90, adjusted common odds ratio, 0.51 (95% confidence interval, 0.32–0.80). Significant beneficial effects were also seen with GTN for disability (Barthel Index), quality of life (EuroQol-Visual Analogue Scale), cognition (telephone Mini-Mental State Examination), and mood (Zung Depression Scale). GTN was safe to administer with less serious adverse events by day 90 (GTN 18.8% versus no GTN 34.1%) and death (hazard ratio, 0.44; 95% confidence interval, 0.20–0.99; P=0.047). Conclusions—In a subgroup analysis of the large ENOS trial, transdermal GTN was safe to administer and associated with improved functional outcome and fewer deaths when administered within 6 hours of stroke onset

Effect of glyceryl trinitrate on hemodynamics in acute stroke

Background and Purpose- Increased blood pressure (BP), heart rate, and their derivatives (variability, pulse pressure, rate-pressure product) are associated with poor clinical outcome in acute stroke. We assessed the effects of glyceryl trinitrate (GTN) on hemodynamic parameters and these on outcome in participants in the ENOS trial (Efficacy of Nitric Oxide in Stroke). Methods- Four thousand and eleven patients with acute stroke and raised BP were randomized within 48 hours of onset to transdermal GTN or no GTN for 7 days. Peripheral hemodynamics were measured at baseline (3 measures) and daily (2 measures) during treatment. Between-visit BP variability over days 1 to 7 (as SD) was assessed in quintiles. Functional outcome was assessed as modified Rankin Scale and cognition as telephone mini-mental state examination at day 90. Analyses were adjusted for baseline prognostic variables. Data are mean difference or odds ratios with 95% CI. Results- Increased baseline BP (diastolic, variability), heart rate, and rate-pressure product were each associated with unfavorable functional outcome at day 90. Increased between-visit systolic BP variability was associated with an unfavourable shift in modified Rankin Scale (highest quintile adjusted odds ratio, 1.65; 95% CI, 1.37-1.99), worse cognitive scores (telephone mini-mental state examination: highest quintile adjusted mean difference, -2.03; 95% CI, -2.84 to -1.22), and increased odds of death at day 90 (highest quintile adjusted odds ratio, 1.57; 95% CI, 1.12-2.19). GTN lowered BP and rate-pressure product and increased heart rate at day 1 and reduced between-visit systolic BP variability. Conclusions- Increased between-visit BP variability was associated with poor functional and cognitive outcomes and increased death 90 days after acute stroke. In addition to lowering BP and rate-pressure product, GTN reduced between-visit systolic BP variability. Agents that lower BP variability in acute stroke require further study