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Neurology Today At the Meetings: International Stroke Conference

Access daily, concise peer-reviewed reports from the International Stroke Conference selected by the Neurology Today editors.

Tuesday, February 12, 2019

Nitroglycerin Patches Applied in Ambulance Fail to Improve Stroke Outcomes

BY ED SUSMAN

HONOLULU—Patients who appear to be having a stroke do not benefit from early treatment with nitroglycerin patches on the way to the hospital, researchers reported here at the 2019 International Stroke Conference.

The risk of having a poor outcome as assessed by the modified Rankin Score at discharge was an odds ratio (OR) of 1.25 [95% CI 0.97-1.60], (p=0.083), an almost a negative result, said Philip Bath, MBBS, DSc, the Stroke Association Professor of Stroke Medicine at the University of Nottingham, United Kingdom.

In the intention-to-treat population, which included patients with stroke mimics, the risk of a poor outcome was OR 1.04 [95% CI 0.84-1.29], (p=0.69), he reported in his oral late breaker presentation.

"This was a neutral trial," Dr. Bath told Neurology Today At the Meetings. "What we learned from this trial is that glyceryl trinitrate (nitroglycerin in the United States) 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."

He said that it appears that the nitroglycerin patches had no treatment effect on patients with ischemic strokes; it appeared to have a worsening effect on people who had a hemorrhagic stroke. The poorer outcomes observed with hemorrhagic stroke drove the overall results toward a borderline negative trial, he said.

Patients who were observed with a suspected stroke—adults with a Face/Arm/Speech Time (FAST) score of 2 or more who were seen within four hours of symptom onset and who had a systolic blood pressure of 120 mmHG or greater—were treated with a 5 mg nitroglycerin patch or a sham patch by the paramedics and were given the same patch three more times 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 two abnormalities suggestive of stroke and be conscious to enter the trial. More than 50 percent of the patients consented be included in the study themselves; the others were consented by family members, or proxy consent by the paramedic, one of several novel parts of the study, Dr. Bath said.

The researchers planned to enroll 850 patients in the trial, expecting that 12 percent would have so-called stroke mimics—seizures, migraines or "hysterical" strokes, he said. But the trial actually enrolled 26 percent of the patients with these mimic events, which required enrolling a total of 1,149 individuals. Of the 419 patients with investigator confirmed stroke or transient ischemic attack (TIA) and who were give the active patch, 71 experienced an intracerebral hemorrhage; 292 were diagnosed with an ischemic stroke, and 56 were diagnosed with a TIA.

Among the 408 patients who received the sham patch, 71 has an intracerebral hemorrhage; 288 were diagnosed with an ischemic stroke, and 49 were diagnosed with TIA.

Commenting on the study, Larry B. Goldstein, MD, FAAN, chairman of the neurology and co-director of the Kentucky Neuroscience Institute at the University of Kentucky, told Neurology Today At the Meetings: "There is no indication for using this drug in patients in the early stages of stroke, and there is some concern that it could do harm in some patients."

Dr. Goldstein said that the researchers did show that this type of study could be performed in the ambulance setting, and "that is not a trivial finding. This was a well done and well analyzed trial."

One of the other findings in the study, Dr. Bath said, was that when patients with stroke mimics were treated with nitroglycerin they improved across the board (p=0.008)—whether the cause of the mimic was a seizure, a migraine headache or a hysterical stroke, often caused by sudden and often distressing life events.

"I am not sure I believe this is a real finding," he said, "because there is no unifying mechanism of action."

Dr. Goldstein had a similar reaction to the unexpected finding in the stroke mimics. "I am confounded by this as well," he said.

Dr. Bath disclosed he has served as a consultant for and on the advisory board of Platelet Solutions Ltd, Moleac, DiaMedica Therapeutics, Inc, Phagenesis, Nestle, and ReNeuron.

LINK UP FOR RELATED INFORMATION:

ISC Abstract LB2: Bath PM, Scutt P, Woodhouse LJ, et al. Glyceryl trinitrate for pre-hospital ultra-acute stroke: Main results from the Rapid Intervention with Glyceryl Trinitrate in Hypertensive Stroke Trial-2 (RIGHT-2).