Ticagrelor vs High Dose Clopidogrel in Patients With ST Elevation Myocardial Infarction Post Fibrinolysis

Inclusion Criteria: 1. Age 18-85 years old 2. Patients with STEMI, having undergone fibrinolytic therapy in the previous 3 to 48 hours 3. Presenting HPR (≥208 PRU) post 300mg clopidogrel loading dose ( assessment immediately before coronary angiography) 4. Informed consent obtained in writing Exclusion Criteria: * Pregnancy * Breastfeeding * Inability to give informed consent * Cardiogenic shock * Major periprocedural complications (death, stent thrombosis, vessel perforation, arrhythmias requiring cardioversion, temporary pacemaker insertion or intravenous antiarrhythmic agents, respiratory failure requiring intubation, vascular injury (arteriovenous shunt, retroperitoneal bleeding), major bleeding (need for bood transfusion or drop in haemoglobin post-PCI by ≥ 5 gr/ dl or intracranial bleeding) * Known hypersensitivity to ticagrelor or clopidogrel * History of gastrointestinal bleeding, genitourinary bleeding or other site abnormal bleeding within the previous 3 months. * Other bleeding diathesis, or considered by investigator to be at high risk for bleeding * Any previous history of stroke, intracranial hemorrhage or disease (neoplasm, arteriovenous malformation, aneurysm). * Thombocytopenia (\<100.000 / μL) at randomization * Anaemia (Hct \<30%) at randomization * Polycytaemia (Hct \> 52%) at randomization * Periprocedural IIb/IIIa inhibitors administration * Per os anticoagulants * Recent (\< 6 weeks) major surgery or trauma, including GABG. * Subjects receiving daily treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) or cyclooxygenase-2 (COX-2) inhibitors that cannot be discontinued for the duration of the study. * Concomitant oral or IV therapy with strong CY P3A inhibitors (ketoconazole, itraconazole, voriconazole, telithromycin, clarithromycin, nefazodone, ritonavir, saquinavir, nelfinavir, indinavir, atazana vir, grapefruit juice N1 L/d), CYP3A substrates with narrow therapeutic indices (cyclosporine, quinidine), or strong CYP3A inducers (rifampin /rifampicin, phenytoin, carbamazepine). * Increased risk of bradycardiac events. * Dialysis required. * Severe uncontrolled chronic obstructive pulmonary disease * Known severe hepatic impairement