Evaluation in STEMI Patients Using FDY-5301

Inclusion Criteria: 1. Age ≥ 18 years 2. Anterior STEMI, based on: Symptoms of myocardial ischemia (such as chest pain, shortness of breath, jaw pain, arm pain, diaphoresis, or any anginal equivalent) and Electrocardiogram (ECG) criteria: * men \> 40 years: ≥ 2 mm of ST elevation in V2 and V3 * men ≤ 40 years: ≥ 2.5 mm of ST elevation in V2 and V3 * women ≥ 1.5 mm of ST elevation in V2 and V3 3. Planned primary PCI to occur ≤ 6 hours of onset of persistent symptoms that caused the patient to pursue medical care for myocardial infarction 4. Institutional Review Board (IRB) / Independent Ethics Committee (IEC) approved consent obtained for study participation Exclusion Criteria: 1. Life expectancy of less than 1 year due to non-cardiac pathology 2. Known thyroid disease or thyroid disorder, including subjects on thyroid hormone replacement therapy at the time of randomization 3. Known allergy to iodine or the excipient of the investigational product (sodium chloride) 4. Renal disease requiring dialysis 5. Women who are pregnant or breastfeeding. Women of reproductive potential must have a negative pregnancy test prior to randomization 6. Body weight \> 140 kg (or 309 lbs) 7. Use of thrombolytic therapy as treatment for the index STEMI event 8. Use of investigational drugs within 30 days or 5 half-lives, whichever is longer, prior to randomization or the use of investigational devices within 30 days prior to randomization 9. Any clinically significant abnormality identified prior to randomization that in the judgment of the Investigator or Sponsor would preclude safe completion of the study, or confound the anticipated benefit of FDY-5301