Applying Glyceryl Trinitrate Patch in Ambulance Fails to Improve Outcomes in Acute Stroke

February 8, 2019

By Alex Morrisson

HONOLULU -- February 7, 2019 -- The early treatment of suspected strokes by sticking adhesive patches containing glyceryl trinitrate on patients did not appear to change outcomes, according to a study presented here at the 2019 International Stroke Conference (ISC).

“This was a neutral trial,” said Philip Bath, MD, University of Nottingham, Nottingham, United Kingdom. “What we learned from this trial is that glyceryl trinitrate should not be applied to patients with suspected stroke as they are being transported to the hospital by paramedics except in the setting of a clinical trial.”

The risk of having a poor outcome, as assessed by the modified Rankin Score at discharge, was about 25% greater if the patient had been given the active patch rather than a placebo patch. The difference was not statistically significant (P = .083), but trended toward a negative result.

In the intention-to-treat population, which included patients with stroke mimics, the risk of a poor outcome increased about 4% (P = .69).

In the cases in which a patient was having an ischaemic stroke, the use of the patches had no impact on outcome; however, if the stroke turned out to be haemorrhagic, there was a worse outcome with administration of the glyceryl trinitrate patch.

The paramedics evaluated patients by using the Face/Arm/Speech Time (FAST) score. If the score was ≥2, the patient had blood pressure of ≥120 mm Hg, and the patient was being seen within 4 hours of symptom onset, the paramedics open a box with 4 patches containing glyceryl trinitrate 5 mg or placebo. One patch was placed on the patient as the ambulance was taking the patient to the hospital; the other patches were used on subsequent days at the hospital. The paramedics had been trained in the procedures developed for the Rapid Intervention with Glyceryl Trinitrate in Hypertension Stroke Trial-2 (RIGHT-2).

The patients had to have at least 2 abnormalities suggestive of stroke and be conscious to enter the trial. More than 50% of the patients consented be included in the study themselves; the others were consented by family members, or proxy consent by the paramedic, said Dr. Bath.

The researchers planned to enrol 850 patients in the trial, expecting that 12% would have stroke mimics, but the trial actually enrolled 26% of the patients with these mimic events, which required enrolling a total of 1,149 individuals.

Of the 419 patients with confirmed stroke or transient ischaemic attack who were give the active patch, 71 experienced an intracerebral haemorrhage, as did 71 of the 408 patients who received the sham patch.

[Presentation title: Glyceryl Trinitrate for Pre-Hospital Ultra-Acute Stroke: Main Results From the Rapid Intervention With Glyceryl Trinitrate in Hypertensive Stroke Trial-2 (RIGHT-2). Abstract LB2]