Exenatide for Myocardial Protection During Reperfusion Study

Inclusion Criteria: * Admission for primary PCI for STEMI, with enrollment within 12 hours of onset of symptoms. STEMI will be defined as typical ECG changes (ST segment elevation ≥1mm in 2 or more limb leads, or ≥2mm in 2 or more precordial leads, or new onset LBBB) associated with acute chest pain or an elevation of cardiac enzymes. * Antegrade TIMI 0 or 1 prior to PCI in the infarct-related artery * Age ≥18 years Exclusion Criteria: * Symptomatic hypoglycemia (serum glucose \<3.3 µmol/L; 60 mg/dl) * Diabetes mellitus requiring insulin therapy * Diabetic ketoacidosis * Coronary anatomy warranting emergent coronary artery bypass graft surgery * Mechanical complication of STEMI (ventricular septal rupture, free wall rupture, acute severe mitral regurgitation) * Need for hemodialysis * Malignancy, HIV, or central nervous system disorder * Cardiopulmonary resuscitation \>15 min and compromised level of consciousness. * Cardiogenic shock * Current participation in any research study involving investigational drugs or devices * Inability to give informed consent * Inability to safely undergo cMRI (presence of cardiac pacemaker, implanted cardiac defibrillator, aneurysm clips, carotid artery vascular clamp, neurostimulator, implanted drug infusion device, bone growth/fusion stimulator, cochlear, otologic, or ear implant, severe claustrophobia) * Women of childbearing potential who are known to be pregnant or lactating or who have a positive pregnancy test on admission * History of pancreatitis * Known end stage renal failure or known eGFR \<30 mL/min * Currently taking exenatide (Byetta, Bydureon), liraglutide (Victoza), or any other GLP-1 agonist