Preclinical loading in patients with acute chest pain and acute coronary syndrome - PRELOAD survey

Abstract

Guidelines on myocardial infarction (MI) recommend antithrombotic and anticoagulatory treatment at time of diagnosis. MI with ST segment elevation (STEMI) is mostly acertain diagnosis. Acute coronary syndrome without ST segment elevation (NSTE-ACS) has diagnostic uncertainty and remains aworking diagnosis in the prehospital setting. Assessment of prehospital loading with aspirin and heparin depending on ACS subtype and pretreatment with oral anticoagulants. The PRELOAD survey was anationwide German study. STEMI/NSTE-ACS scenarios were designed and varied in pretreatment: I)no pretreatment, II)new oral anticoagulants (NOAC), III)vitaminK antagonist (VKA). Loading strategy was assessed and included: a)aspirin (ASA), b)unfractionated heparin (UFH), c)ASA + UFH, d)no loading. A total of 708 emergency physicians were included. In NSTE-ACS without pretreatment, 79% chose loading (p < 0.001). ASA + UFH (71.4%) was the preferred option. In corresponding STEMI scenario, 100% chose loading and 98.6% preferred ASA + UFH (p < 0.001). In NSTE-ACS with NOAC pretreatment, 69.8% favored loading (p < 0.001); in VKA pretreatment the corresponding rate was 72.3% (p < 0.001). In each scenario, ASA was the preferred option. In STEMI with NOAC pretreatment, 97.5% chose loading (p < 0.001); analogous rate was 96.8% in STEMI with VKA pretreatment (p < 0.001). ASA was the preferred option again. Prehospital loading was the preferred treatment strategy despite the diagnostic uncertainty in NSTE-ACS and guidelines recommending loading at time of diagnosis. Pretreatment with oral anticoagulants resulted in astrategy shift to loading with only aspirin. In STEMI patients, this indicates potential undertreatment.