Pre-hospital treatment with transdermal glyceryl trinitrate (GTN) in patients with intracranial haemorrhage (ICH) appears to lead to worse outcomes than a sham treatment.
The findings, published in Stroke, were unexpected given previous studies have suggested some benefit from GTN.
In the sub-group analysis of the RIGHT-2 trial, 145 patients with a final hospital diagnosis of ICH were randomised to either GTN or sham treatment – the first doses administered by the paramedic in the ambulance and then subsequent doses administered daily in hospital for three days.
The primary outcome, functional outcome assessed with the 7-level modified Rankin Scale (mRS) at 90 days, was not significantly different between patient groups.
However in four planned sensitivity analyses of the primary outcome, the GTN group had statistically significant worse outcomes than the sham group.
GTN treatment was associated with a significant increase in deaths in hospital and a worse discharge outcome with more patients moved to an institution.
The study also found GTN treated patients had a larger haematoma on admission to hospital and on repeat imaging at day 2.
“In summary, we have shown that the ultra-acute use of GTN may be harmful in patients with ICH and especially within 2 hours. This could result from inhibition of the earliest vasoconstrictory and platelet plugging phases of hemostasis, mechanisms that might apply to other vasodilators,” the study said.
“In this respect, RIGHT-2 is the first large trial to test the effect of inhibiting vasoconstriction in this time-critical period after ICH.”