The purpose of the trial is to evaluate the completeness of struts coverage and vessel wall response (strut malapposition, neoin-timal formation) to the bio-active-stent (BAS) versus ever-olimus-eluting stent (EES) implanted for the treatment of the culprit lesion in acute coronary syndrome.

A prospective, randomized and controlled study comparing the coverage of the BAS and EES implanted in acute coronary syndrome.

Clinical follow-up at 1, 6, 12 and 18 months. OCT analysis at the time of the 6 to 8 months follow-up.

Inclusion Criteria:

• Patient is ≥ 18 years old;
• The patient is presenting with acute coronary syndrome, and according to hospital routine practice, eligible for percutaneous coronary intervention;
• Patient or the patient's legal representative has been informed of the nature of the study and has provided written informed consent as approved by the Institutional Ethics Committee of the respective clinical site.

Exclusion Criteria:

• Lesions in coronary artery bypass grafts
• Left main disease
• Killip class III-IV
• Allergy to aspirin / thienopyridine
• Patient in anticoagulation therapy
• No suitable anatomy for OCT scan
• Ostial lesion
• Tortuosity anatomy
• Very distal lesion
• Vessel size > 3.75 mm

Patients presenting with acute coronary syndrome and who were treated either BAS or EES during the index PCI.