A new study finds that providing antiplatelet therapy to patients with ST-elevation myocardial infarction (STEMI) provides no significant advantages over in-hospital treatment.

Although prehospital antiplatelet therapy is recommended for STEMI patients in many clinical guidelines in both North America and Europe, the study authors hope their findings will discourage the current practice.

The study, presented at the European Society of Cardiology (ESC) conference in Barcelona, Spain, suggests that it might be more prudent to wait and administer the therapy once the patent arrives at the hospital emergency department (ED).

“Prehospital administration is common practice — despite the lack of definite evidence for its benefit,” pointed out investigator Elmir Omerovic, PhD, from Sahlgrenska University Hospital in Gothenburg, Sweden. “But our study — which is the largest cohort study conducted so far — adds to some previous evidence suggesting there is potential for harm. In fact, inadvertent prehospital administration of these drugs to patients with contraindications to antithrombotic therapy is common. Therefore, considering all current evidence, we think prehospital administration should be discouraged.”

To come to that conclusion, the research team conducted a retrospective study employing data from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) to identify 44,804 STEMI patients undergoing percutaneous coronary intervention (PCI) — a revascularization procedure — between 2005 and 2016.

Although most of the patients were pretreated with antiplatelet therapy, 6,964 were not. That enabled the researchers to compare pretreated patients to those not pretreated; and they found no significant benefits of pretreatment in terms of 30-day mortality (odds ratio 0.91) or other endpoints, including measures of arterial blockage, cardiogenic shock, neurological complications, or bleeding complications.

Prehospital antiplatelet treatment is recommended by the ESC, the American College of Cardiology, and the American Heart Association, according to the study. Results based on the ATLANTIC trial — presented at the ESC Congress within the last few years — first raised questions about whether pretreatment was advantageous, but involved relatively short delays for patients receiving in-hospital treatment, Omerovic pointed out.

“Our new data addresses some of the concerns with ATLANTIC and offers stronger evidence that pretreatment is not necessary,” he said. “We hope the accumulated evidence will be convincing enough to discourage this practice and trigger a change in recommendations.”