The purpose of this study is to determine whether prompt removal of thrombus (blood clot) from a blocked coronary artery using the AngioJet rheolytic thrombectomy device will result in improved blood flow within the heart and a smaller final infarct size (reduced injury to the heart muscle).

Occlusive thrombosis triggered by a disrupted or eroded atherosclerotic plaque is the anatomic substrate of most acute myocardial infarctions (AMI). Macro- and microembolization of thrombus during percutaneous coronary intervention (PCI) in AMI is frequent and may result in obstruction of the microvessel network, and decreased efficacy of reperfusion and myocardial salvage. Direct stenting without predilation or postdilation is the most simplistic approach to the problem of embolization, and may decrease embolization and the incidence of the no-reflow phenomenon. Other approaches to the problem of microvessel embolization include percutaneous rheolytic thrombectomy (RT) with the AngioJet catheter before stent implantation. The objectives of the study are: to assess whether RT before direct infarct artery stenting results in improved reperfusion success in patients with acute ST-segment elevation myocardial infarction (STEMI) and angiographically evident thrombus; and to validate a technique for use of the AngioJet RT catheter in the treatment of STEMI.

Comparisons: Treatment with AngioJet RT immediately before direct infarct artery stenting versus direct stenting alone, in patients with STEMI and angiographically visible thrombus presenting within 6 hours of symptom onset for primary PCI.

Inclusion Criteria:

• Patient age > 18 years
• ST-segment elevation myocardial infarction
• Angiographically visible thrombus
• Presentation within 6 hours of symptom onset for primary percutaneous coronary intervention
• Patient, or relative or legal guardian,provides written informed consent
• Patient has no childbearing potential or is not pregnant

Exclusion Criteria:

• Prior administration of thrombolysis for current MI
• Participation in another Study
• Major surgery within past 6 weeks
• History of stroke within 30 days, or any history of hemorrhagic stroke
• Severe hypertension (systolic BP > 200 mm Hg or diastolic BP > 110 mm Hg) not controlled on antihypertensive therapy
• Known neutropenia ( <1000 neutrophils per mm3) or known severe thrombocytopenia (< 50,000 platelets per mm3)
• Known prior history of renal insufficiency
• Co-morbidities with expected survival < 1 year
• Patient unwilling to receive blood products