Double-Blind, Randomized, Prospective Comparison of Loading Doses of 600 mg Clopidogrel Versus 60 mg Prasugrel in Patients With Acute ST-Segment Elevation Myocardial Infarction Scheduled for Primary Percutaneous Intervention: The ETAMI Trial (Early Thienopyridine treatment to improve primary PCI in Patients with Acute Myocardial Infarction)

Abstract Objectives This study compared the timing of onset of antiplatelet action after treatment with clopidogrel and prasugrel at first medical contact in patients with ST-segment elevation myocardial infarction (STEMI) scheduled for primary percutaneous coronary intervention (PPCI). Background Little is known about the timing of onset of antiplatelet action after a pre-percutaneous coronary intervention (PCI) loading dose of clopidogrel or prasugrel in patients with STEMI. Methods This double-blind, prospective study randomized 62 patients with STEMI scheduled for PPCI in the ambulance or the emergency department to 60 mg prasugrel (n = 31) or 600 mg clopidogrel (n = 31). The primary endpoint was the platelet reactivity index (PRI) measured with the vasodilator-stimulated phosphoprotein assay 2 h after intake of the study medication. Secondary endpoints were PRI after 4 h, TIMI (Thrombolysis In Myocardial Infarction) patency of the infarct-related artery before and after PCI, and clinical events until day 30. Results The PRI after 2 h (50.4 ± 32.7% vs. 66.3 ± 22.2%; p = 0.035) and after 4 h (39.1 ± 27.5% vs. 54.5 ± 49.3%; p = 0.038) were significantly lower with prasugrel compared with clopidogrel. In addition, the rate of patients with a PRI  Conclusions The pre-PCI administration of prasugrel in patients with STEMI undergoing PPCI was associated with a significant faster platelet inhibition compared with clopidogrel. Therefore, prasugrel should be preferred to clopidogrel in this setting. (ETAMI-Study: Early Thienopyridine Treatment to Improve Primary PCI in Patients With Acute Myocardial Infarction; NCT01327534 )