GENERAL INCLUSION CRITERIA: Candidates for this study must meet ALL of the following criteria:
Pre-PCI:
1. The subject must be ≥18 and ≤80 years of age.
2. AMI must be anterior.
3. Subject is experiencing clinical symptoms consistent with anterior AMI of ≤6 hour duration.
4. Signed Informed Consent.
5. Subject agrees to all required follow-up procedures and visits.
6. Negative pregnancy test for women of childbearing potential.
ANGIOGRAPHIC INCLUSION CRITERIA: These are evaluated after the subject has provided signed Informed Consent but prior to enrollment:
7. PCI is indicated for revascularization of the culprit lesion(s) with use of a commercially available coronary stent in the LAD.
8. The primary stented infarct-related lesion(s) must be in the proximal and/or mid-LAD coronary artery.
9. Baseline (pre-PCI) TIMI flow grade 0, 1, 2, or 3 flow in the LAD.
10. Successful angioplasty and no major complications such as perforation or shock.
11. Expected ability to place the SSO2 delivery catheter in the coronary ostium of the left main coronary system to deliver SSO2 Therapy with stable, coaxial alignment.
12. Planned revascularization of a non-target lesion is allowed.
Patients will be excluded if ANY of the following conditions apply:
GENERAL EXCLUSION CRITERIA
Pre-PCI:
13. Prior CABG surgery.
14. Prior myocardial infarction, or known prior systolic dysfunction.
15. Thrombolytic therapy administered for this STEMI.
16. An elective surgical procedure is planned that would necessitate interruption of anti-platelet agents during the first 30 days post-enrollment.
17. Subjects who previously underwent coronary stent implantation and in whom coronary angiography demonstrates stent thrombosis to be the cause of the anterior AMI.
18. Subjects who have previously undergone angioplasty or stenting in the LAD.
19. Subjects with ventricular pseudoaneurysm, VSD, or severe mitral valve regurgitation.
20. Any contraindication to undergo MRI imaging.
21. Impaired renal function or on dialysis.
22. Known platelet count \<100,000 cells/mm3 or \>700,000 cells/mm3 or a known Hgb \<10 g/dL.
23. Subject has active bleeding or a history of bleeding.
24. History of intracerebral mass, aneurysm, arteriovenous malformation, or hemorrhagic stroke.
25. Stroke or transient ischemic attack within the past six (6) months, or any permanent neurological defect.
26. Gastrointestinal or genitourinary bleeding within the last two (2) months, or any major surgery (including CABG) within six weeks of enrollment.
27. Subject has received any organ transplant or is on a waiting list for any organ transplant.
28. Subject has other medical illness (e.g., cancer, dementia) or known history of substance abuse (alcohol, cocaine, heroin, etc.) that a may cause non-compliance with the protocol.
29. Subject has a known hypersensitivity or contraindication to unfractionated heparin, abciximab, aspirin, bivalirudin, clopidogrel, ticlopidine, prasugrel, or ticagrelor that cannot be adequately premeditated.
30. Current use of warfarin, dabigatran, or factor Xa inhibitors.
31. Subjects presenting with or developing in the cath lab: cardiogenic shock or ventricular fibrillation or tachycardia.
32. Severe known cardiac valvular stenosis or insufficiency, pericardial disease, or non-ischemic cardiomyopathy.
33. Any significant medical condition which in the investigator's opinion may interfere with the subject's optimal participation in the study.
34. Current participation in other investigational device or drug trials that have not finished the primary endpoint follow-up period.
35. Previous enrollment in this study.
ANGIOGRAPHIC EXCLUSION CRITERIA: These are evaluated after the subject has provided signed Informed Consent but prior to enrollment:
36. Inability to achieve a stable coaxial position in the left main coronary artery with the catheter.
37. Treatment during the index procedure of any lesion in the left main, LCX, and/or RCA.
38. Coronary anatomy such that coronary artery bypass graft surgery is indicated within 30 days.
39. Post-index procedure planned intervention within 30 days.
40. Anatomic features are present which are highly unfavorable for PCI.
41. Anterior MI is due to thrombosis within or adjacent to a previously implanted stent.
42. Left ventriculography demonstrates severe mitral regurgitation, a ventricular septal defect, or a pseudoaneurysm.
43. Any left main coronary artery stenosis \>20%.
44. Any untreated LAD or diagonal branch lesion is present with diameter stenosis \>= 50% in a vessel with reference vessel diameter \> 2.0 mm or for which PCI will be required before the MRI study.
45. Presence of a non-stented coronary dissection upon completion of the PCI procedure.
