Combined Antioxidant Therapy for Acute Myocardial Infarction

The goal of this clinical trial is to learn if a combined antioxidant therapy (CAT) can reduce heart damage caused by the return of blood flow after blocked arteries are reopened in adults with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI). It will also learn about the safety of this treatment. The main questions it aims to answer are: 1. Does combined antioxidant therapy lower infarct size, measured by cardiac magnetic resonance imaging (CMR), compared with placebo? 2. Does combined antioxidant therapy improve heart function, blood biomarkers of heart injury, and short-term clinical outcomes? 3. What problems do participants have when receiving the therapy? Researchers will compare CAT to placebo (a look-alike infusion with no active drug) to see if the treatment lowers infarct size after STEMI. Participants will: * Be randomly assigned to receive either CAT or placebo * Receive the study infusion before and during primary PCI, in addition to standard treatment for STEMI * Have blood tests to measure heart injury, oxidative stress, inflammation, and drug levels * Undergo cardiac magnetic resonance imaging about 3 to 7 days after STEMI. * Be followed for clinical outcomes and safety for 30 days.