Myocardial infarction patients gain no advantage from receiving anti-clotting therapy in the ambulance rather than when the reach hospital, according to Swedish researchers.
The finding is at odds with both European and American guidelines that recommend pre-hospital antiplatelet therapy for heart attack patients experiencing an ST-elevation myocardial infarction.
“We hope the accumulated evidence will be convincing enough to discourage this practice”
The new study, presented at European Society of Cardiology annual congress suggests the practice has no advantage over waiting for in-hospital treatment, said the researchers behind it.
The retrospective study used data from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) to identify 44,804 patients undergoing percutaneous coronary intervention from 2005-16.
Most of the patients were pre-treated with antiplatelet therapy, but 6,964 were not.
The researchers found no significant benefits of pre-treatment in terms of 30-day mortality, arterial blockage, cardiogenic shock, neurological complications, or bleeding complications.
But the authors of the current study said their findings added to a growing body of evidence that might ultimately lead to a change of guidance and practice.
Study author Dr Elmir Omerovic, from Sahlgrenska University Hospital in Gothenburg, said: “Pre-hospital administration is common practice – despite the lack of definite evidence for its benefit.
“But our study – which is the largest cohort study conducted so far – adds to some previous evidence suggesting there is potential for harm,” said Dr Omerovic.
“In fact, inadvertent prehospital administration of these drugs to patients with contraindications to antithrombotic therapy is common,” he said. “Therefore, considering all current evidence, we think pre-hospital administration should be discouraged.”
‘No advantage’ of ambulance over hospital anti-clot therapy
The researchers highlighted the ATLANTIC trial, presented at the ESC conference a few years ago, as giving the first hint that pre-treatment might offer no advantages.
However, they noted it was a study with relatively short delays for patients receiving in-hospital treatment.
Dr Omerovic said: “Our new data addresses some of the concerns with ATLANTIC and offers stronger evidence that pre-treatment is not necessary.
“We hope the accumulated evidence will be convincing enough to discourage this practice and trigger a change in recommendations,” he added.
The latest findings were presented yesterday at the ESC conference, which is being held this year in Barcelona.