Vessel Wall Response of the Zotarolimus Drug-eluting Stent Implanted in AMI Assessed by Optical Coherence Tomography

Prospective, Randomized, Controlled Arm Study Comparing the Coverage of the Zotarolimus-eluting Stent vs Bare Metal Stent Implanted in ST- Elevation Myocardial Infarction (STEMI).

The objective of this study is to evaluate the completeness of struts coverage and vessel wall response (strut malapposition, neointima disomogeneities in texture) to the ENDEAVOR drug-eluting stent vs the DRIVER stent (bare metal stent of identical metallic platform) implanted for the treatment of the culprit lesion in ST-elevation acute myocardial infarction (STEMI). To investigate the completeness of the coverage as well as the number of uncovered stent struts per section (embedded, uncovered, malapposed) and the neointima texture, high resolution (~ 10-15 µm axial) intracoronary optical coherence tomography (OCT)will be used.

Major concerns have been raised with regard to the safety of drug-eluting stents (DES) in patients with ST-elevation acute myocardial infarction (STEMI). Data from registry studies have suggested that implantation of DES during primary PCI could be associated with an increased risk for stent thrombosis, probably due to delayed arterial healing. Unlike first generation DES, zotarolimus-eluting stents seems to be associated with complete and uniform neointimal coverage. The objective of this prospective study is to measure the completeness of strut coverage and vessel wall response to the ENDEAVOR zotarolimus-eluting stent vs the DRIVER stent (bare metal stent of identical metallic platform) implanted in STEMI patients. Optical Coherence Tomography (OCT) that detects smaller degrees of stent strut coverage more accurately than IVUS will be used at 6 months follow-up. Intravascular ultrasound (IVUS) will be performed as per normal practice at any index procedures and at 6 months follow-up.

Inclusion Criteria:

• Acute Myocardial MI with ST segment Elevation, within 12 hours from symptoms onset
• Native coronary artery disease with >70% diameter stenosis (no prior stent implant, no prior brachytherapy)
• Vessel size in between 2.5 and 3.75 mm
• Signed patient informed consent

Exclusion Criteria:

• Lesions in coronary artery bypass grafts
• Significant left main disease
• Killip class IV
• Reecent major bleeding (6 months)
• Renal failure with creatinine value > 2.5 mg/dl
• Allergy to aspirin and or clopidogrel/ticlopidine
• Patient in anticoagulant therapy
• IMA due to a stent thrombosis
• No suitable anatomy for OCT scan: (only ostial location, very tortuous anatomy, very distal or large vessels [≥ 3.75 mm in diameter])