Supplementary Material for: Glyceryl trinitrate versus sham in the treatment of hyperacute stroke: the Efficacy of Nitric Oxide in Stroke-2 (ENOS-2) feasibility randomised controlled trial

Introduction
High blood pressure is associated with a poor outcome after stroke. Trials of transdermal glyceryl trinitrate (GTN), a nitric oxide donor, have suggested that treatment between 3 and 5 hours might improve functional outcome.

Methods
We randomly assigned hospitalised patients with an acute ischaemic or haemorrhagic stroke to two days of transdermal GTN (5 mg/day) or sham, started between 3 and 5 hours after onset. The primary feasibility outcome was recruitment rate; proof of concept was assessed at 90 days by central observers blinded to treatment assignment using the modified Rankin Scale (mRS). Data are number (%), median [interquartile range] or mean (standard deviation). Comparisons by multiple linear regression.

Results
39 of an intended 120 participants were recruited. A total of 3314 people were excluded, commonly related to presentation >5 hours of onset or outside of researcher working hours, no eligible symptoms/signs or an unclear onset time. Mean age 72 (13) years, female 41%, blood pressure 161.8 (18.4)/80.8 (14.9) mmHg, time from onset at baseline 216 [186, 251] minutes. The fall in blood pressure over 24 hours did not differ between GTN versus sham. mRS at 3 months did not differ between the groups (difference in means, DIM -0.20, 95% confidence intervals -1.30, 0.90; p=0.72). GTN was associated with improved cognition on the telephone interview of cognition scale (DIM 8.0, 95% CI 1.3, 14.8; p=0.020). Although headache was more common, GTN was associated with fewer serious adverse events (p=0.020).

Conclusion
Recruitment limitations in this small single centre trial prevented demonstration of feasibility for patients in the time window of 3-5 hours post ictus. GTN demonstrated some evidence of proof-of-concept and was safe. A multicentre trial needs to further test this hypothesis.

Registration
ISRCTN17654248 Date: 31/3/2021