Genotyping Infarct Patients to Adjust and Normalize Thienopyridine Treatment

All the STEMI patients treated by primary PCI (with stent implantation) within the 24 hours following the first chest pain can be included in the GIANT study. After the PCI, they'll receive DAT (Aspirin + Clopidogrel/Prasugrel). Patients will then be genotyped to determine if they carry one of the CYP2C19 gene variants making them resistant or hyper responder to clopidogrel. The genetic profile of the patients will be communicated to the physician who took care of them so that he can (or not) adjust the thienopyridine treatment (increase of the clopidogrel dosage, switch to prasugrel or switch to clopidogrel). A treatment will be prescribed for 12 months as according to the European guidelines. One year after the PCI, the patients will have to be available for a follow up visit. They'll be submitted to a VERIFY NOW P2Y12 protocol to determine whether they were compliant to their thienopyridine treatment. A clinical follow up will be also performed to evaluate the cardiovascular events.