Prehospital antiplatelet therapy in patients with out-of-hospital cardiac arrest suspected of acute coronary syndrome

Abstract

Background: There are currently no specific guidelines for prehospital antiplatelet therapy in patients with out-of-hospital cardiac arrest (OHCA) associated with acute coronary syndrome (ACS). This study aims to evaluate the efficacy and safety of a prehospital antiplatelet loading dose in patients with OHCA suspected of ACS referred to a cardiac catheterization laboratory (cath lab).

Methods: We included consecutive patients referred for coronary angiography within 24 h after OHCA from 2012 to 2024. Prehospital antiplatelet treatment was defined as prescribing aspirin alone and/or a P2Y12 inhibitor before admission to the cath lab. Outcomes included: all-cause death at 30 days, in-hospital major adverse cardiovascular events (MACE), defined as a composite of all-cause death, myocardial infarction, stent thrombosis, or stroke, and in-hospital major bleeding (BARC ≥ 3). An inverse probability weighting approach was used to compare outcomes between the two groups.

Results: Of the 411 patients admitted to the cath lab within 24 h after OHCA, 217 (52.8%) received prehospital antiplatelet therapy, either aspirin alone (44.5%) or aspirin plus a P2Y12 inhibitor (8.3%). There was no difference in 30-day all-cause death between patients who received a prehospital treatment and those who did not (56.7%[50.0%;63.1%] vs 59.8%[52.8%;66.4%], p = 0.280). Rates of in-hospital MACE and major bleeding were not significantly different between the two strategies. Results appear to be consistent in subgroups of patients with ST-segment elevation or successfully resuscitated patients.

Conclusions: Prehospital antiplatelet therapy was safe, but showed no apparent improvement in survival or cardiovascular outcomes in patients with OHCA suspected of ACS.

Keywords: Antiplatelet therapy; Bleeding/thrombotic events; Myocardial infarction; Out-of-hospital cardiac arrest; Prehospital.