MULTInational non-interventional study of patients with ST-segment elevation myocardial infarction treated with PRimary Angioplasty and Concomitant use of upstream antiplatelet therapy with prasugrel or clopidogrel - the European MULTIPRAC Registry

Aims: Early initiation of dual antiplatelet therapy (DAPT) is guideline-recommended. MULTIPRAC was conducted to gain insights into the use patterns and outcomes of pre-hospital DAPT initiation with prasugrel or clopidogrel. Methods and results: MULTIPRAC is a multinational, multicentre, prospective registry enrolling 2053 ST-segment elevation myocardial infarction (STEMI) patients. Patients were grouped according to adherence to the initially prescribed thienopyridine. Pre-hospital use of prasugrel increased from 12.5% to 67.1% at study end. Prasugrel compared to clopidogrel-initiated patients more often adhered to the medication through discharge (87% vs. 38%) whereas 49% of the clopidogrel-initiated patients were switched to prasugrel. Patients who continued on clopidogrel were substantially older. In-hospital mortality was 0.5%, early stent thrombosis 0.1%. The major adverse cardiac events (MACE) rate was 1.6% in prasugrel-treated vs. 2.3% in clopidogrel-treated patients (adjusted OR 0.749, 95% CI [0.285-1.968]). Non-coronary artery bypass graft (non-CABG) bleeding occurred in 4.1% of prasugrel-treated vs. 6.1% of clopidogrel-treated patients (adjusted OR 0.686 [0.349-1.349]). Pre-percutaneous coronary intervention (PCI) TIMI flow 2-3 was seen in 38.7% treated with prasugrel vs. 35.6% with clopidogrel (adjusted OR 1.170 [0.863-1.585]). Post PCI ST-segment resolution >= 50%, was 71.6% with prasugrel vs. 65.0% with clopidogrel (adjusted OR 1.543 [1.138-2.093], p=0.0052). Conclusions: MULTIPRAC demonstrated a steady increase in prasugrel use over time without an increase in bleeding rates compared to clopidogrel. ST resolution was more pronounced with prasugrel. Switching between antiplatelet drugs occurs frequently. The low rates of MACE, in-hospital mortality and bleeding, suggests that pre-hospital loading with thienopyridines is confined to low-risk patients. These results emphasize the need for more randomized pre-hospital studies and should be seen in the context of upcoming randomized trials involving pre-hospital antiplatelet therapies.