Primary Hypothesis: Prophylactic Vitamin C Intravenous Infusion at the time of percutaneous coronary intervention (PCI) would limit the size of the infarct, assessed by measurements of cardiac biomarkers, during acute myocardial infarction.

Secondary Hypotheses: Prophylactic Vitamin C Intravenous Infusion at the time of percutaneous coronary intervention (PCI) would limit the size of the infarct, as measured by the area of delayed hyperenhancement that was seen on cardiac magnetic resonance imaging (MRI), assessed on day 5 after infarction, during acute myocardial infarction.

This is a multicenter, prospective, controlled, randomized study that will be conducted at up to 5 centers in Italy. All patients who meet the eligibility criteria will be randomized to receive during surgical procedure an intravenous infusion of Vitamin C or Placebo.

Patients will have repeat clinical follow-up to 5 days, 3 and 6 months and 1 year.

The new angiography evaluation will be done if necessary. The study population will consist of at least 100 patients who presented within 12 hours after the onset of chest pain, who had ST-segment elevation of more than 0.1 mV in two contiguous leads, and for whom the clinical decision was made to treat with percutaneous coronary intervention (PCI). Following confirmation of eligibility criteria, patients will be randomized in a 1:1 ratio to receive prophylactic infusion of Vitamin C or Placebo. The coronary angiograms will be assessed at a core laboratory with Quantitative Coronary Angiography.

The incidence of clinical events, including death, myocardial infarction, target vessel revascularization, stent thrombosis, will be evaluated at 1, 3, 6 and, 12 months.

Inclusion Criteria:

• Subjects who presented within 12 hours after the onset of chest pain, who had ST-segment elevation of more than 0.1 mV in two contiguous leads, and for whom the clinical decision was made to treat with percutaneous coronary intervention (PCI)
• Patients will be eligible for the study whether they were undergoing primary PCI.
• Signed written informed consent

Exclusion Criteria:

• Patients with cardiac arrest, ventricular fibrillation, cardiogenic shock, stent thrombosis, previous acute myocardial infarction, or angina within 48 hours before infarction were not included in the study
• Patients with evidence of coronary collaterals (2-3 Rentrop) to the region at risk on initial coronary angiography (at the time of admission) will be excluded
• The patient has impaired renal function (creatinine > 3.0 mg/dl)
• The patient has known allergies to aspirin, clopidogrel bisulfate and ticlopidine, heparin, contrast media or stainless steel that cannot be managed medically
• The patient needs therapy with warfarin
• The patient has a life expectancy less than 12 months
• Recipient of heart transplant
• The patient is currently participating in an investigational drug or another device study