Efficacy and safety of a high loading dose of clopidogrel administered prehospitally to improve primary percutaneous coronary intervention in acute myocardial infarction: the randomized CIPAMI trial

To compare a loading dose of 600 mg clopidogrel given in the prehospital phase versus clopidogrel administered only after the diagnostic angiogram in patients with STEMI scheduled for primary PCI. The optimal time and dose for the initiation of clopidogrel therapy in patients with STEMI scheduled for primary PCI has not been studied in prospective randomized trials. The primary efficacy endpoint was the TIMI 2/3 patency of the infarct-related artery in the diagnostic angiography immediately prior to PCI. We randomized 337 patients to prehospital (n = 166) loading dose versus standard therapy (n = 171). The time interval between initiation of clopidogrel therapy and diagnostic angiography was 47 min. TIMI 2/3 patency before PCI was not different between the groups (49.3 vs. 45.1%, P = 0.5). We observed a trend towards a reduction of the combined endpoint death, re-infarction, and urgent target vessel revascularization in the prehospital-treated patients (3.0 vs. 7.0%, P = 0.09), this difference was significant if patients were classified as treated (4/161 vs. 13/174; 2.5 vs. 7.5%, P < 0.05). There was no difference in TIMI major bleeding complications (9.1 vs. 8.2%, P = 0.8). Early inhibition of the platelet ADP-receptor with a high loading dose of 600 mg clopidogrel given in the prehospital phase in patients with STEMI scheduled for primary PCI is safe, did not increase pre-PCI patency of the infarct vessel, but was associated with a trend towards a reduction in clinical events.