The routine use of glycoprotein (Gp) IIb-IIIa inhibitor such as abciximab is not recommended by current ACC/AHA guideline (Class IIb, level of evidence of A). This may be partly due to potential increase of bleeding. Compared bolus injection followed by continuous infusion of Gp IIb-IIIa inhibitor, single bolus administration was proposed to decrease bleeding complication while maintaining decrease ischemic events. It was also reported that direct intracoronary injection of abciximab might be superior to intravenous injection regarding myocardial perfusion.

Aspiration thrombectomy is regarded as important adjunctive therapy in the treatment of acute ST-elevation myocardial infarction (IIa, level of evidence of B). We hypothesized that combination of intracoronary abciximab bolus injection and aspiration thrombectomy might enhance adequate myocardial perfusion in patient with acute ST-elevation myocardial infarction. We will determine whether combination of intracoronary abciximab injection and aspiration thrombectomy is superior to each treatment only in terms of myocardial perfusion through index of microcirculatory resistance and cardiac magnetic resonance imaging.

Inclusion Criteria:

• Subject must be between at least 18 years of age and less than 80 years of age.
• Subject is able to verbally confirm understandings of risks, benefits and treatment alternatives of receiving intracoronary abciximab and/or aspiration thrombectomy.
• He/she or his/her legally authorized representative provides written informed consent prior to any study related procedure.
• Subject must have evidence of acute ST-segment elevation myocardial infarction with TIMI 0 or 1 flow, or visible thrombi (thrombus grade ≥ 3)
• Target lesion(s) must be located in a native coronary artery in the proximal to mid segment with estimated reference diameter of ≥ 2.5 mm and ≤ 4.0 mm.
• Target lesion(s) must be amenable for percutaneous coronary intervention.

Exclusion Criteria:

• The patient has a known hypersensitivity or contraindication to any of the following medications: Heparin, Aspirin, Clopidogrel, Abciximab, Contrast media (Patients with documented sensitivity to contrast media which can be effectively premedicated with steroids and diphenhydramine [e.g. rash] may be enrolled. Those with true anaphylaxis to prior contrast media, however, should not be enrolled.)
• Female of childbearing potential, unless a recent pregnancy test is negative, who possibly plan to become pregnant any time after enrollment into this study.
• History of bleeding diathesis or known coagulopathy (including heparin-induced thrombocytopenia), or refuses blood transfusions.
• Baseline hemogram with Hb<10g/dL or PLT count <100,000/μL
• Gastrointestinal or genitourinary bleeding within the prior 3 months, or major surgery within 2 months.
• Patients with severe LV systolic dysfunction (LVEF<25%) or in cardiogenic shock
• Non-cardiac co-morbid conditions are present with life expectancy <1 year or that may result in protocol non-compliance (per site investigator's medical judgment).
• Patients who are actively participating in another drug or device investigational study, which have not completed the primary endpoint follow-up period.