The studys evaluates the effect of prehospital administration of crushed tablets of Prasugrel loading dose (in addition to ASA and standard care) versus uncrushed tablets of Prasugrel loading dose on efficacy and safety as well as pharmacodynamics as measured by platelet reactivity using VerifyNow.

The study is a two-centre, randomized, 1:1 trial comparing prehospital prasugrel initiation therapy between crushed vs. uncrushed prasugrel tablets on efficacy and safety as well as pharmacodynamics in STEMI patients.

Patients with STEMI planned for primary PCI will be screened and, if inclusion criteria are met, included at first medical contact (paramedics). After enrolment, patients will be randomly assigned (1:1) to receive 60mg prasugrel loading dose by ingesting integral or crushed tablets.

The follow-up duration is 12 months, i.e. clinical outcomes will be analysed in-hospital, at 30 days, and 12 months

Inclusion Criteria:

Consecutive patients with STEMI planned for primary PCI:

• Deferred written informed consent within 4 hours after prasugrel loading dose
• Adult men and women aged at least 18 years
• Symptoms of acute MI of more than 30 min but less than 6 hours
• New persistent ST-segment elevation ≥ 1 mm in two or more contiguous ECG leads

Exclusion Criteria:

• Contraindication to prasugrel (e.g., hypersensitivity, active bleeding, history of previous intracranial bleed, history of any CVA including TIA, moderate to severe hepatic impairment, GI bleed within the past 6 months, major surgery within past 4 weeks)
• Patient who has received loading dose of clopidogrel or ticagrelor for the index event or are on chronic treatment of ticagrelor, or prasugrel. However, patients on maintenance dose clopidogrel for at least 7 days are included in the study (see appendix A).
• Oral anticoagulation therapy that cannot be stopped (i.e. patients requiring chronic therapy)
• Planned fibrinolytic treatment
• Patient requiring dialysis
• Known, clinically important thrombocytopenia
• Known clinically important anaemia
• Known pregnancy or lactation
• Need for a concomitant systemic therapy with strong inhibitors or strong inducers of CYP3A
• Condition which may either put the patient at risk or influence the result of the study (e.g., cardiogenic shock with severe hemodynamic instability, active cancer, risk for non-compliance, risk for being lost to follow up)
• Patient unable to swallow oral medication (i.e. intubated patients)
• Patient who have not received prasugrel loading dose in the ambulance
• Patient who vomited after randomization / receiving the loading dose prasugrel