To compare rheolytic thrombectomy (RT) with manual thrombus aspiration (MTA) in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary PCI.

Occlusive thrombosis triggered by a disrupted or eroded atherosclerotic plaque is the anatomic substrate of ST-segment elevation myocardial infarction (STEMI). Due to this substrate, macro- and microembolization 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 thrombectomy before stent implantation, and the use of antiembolic devices (filters and occlusive devices with retrieval of thromboembolic material after stent implantation). Most concluded studies on removing of thrombus before stenting used manual aspiration catheters and meta-analyses derived from these studies support the use of manual thrombus aspiration (MTA) catheters in the setting of primary PCI. MTA is currently recommended in the setting of primary PCI as a Class II b recommendation; level of evidence B. Rheolytic thrombectomy (RT) using multiple jets of saline solution and aspiration based on the Bernoulli effect has been proven to be effective in decreasing major adverse events during PCI in saphenous vein grafts or native coronary arteries with angiographic evidence of thrombus, and 2 out of 3 concluded studies have shown a better reperfusion and clinical outcome in patients randomized to RT as compared to control.

The SMART Study is an on-label, randomized, 2-arms, prospective study in patients with STEMI undergoing primary PCI. Diagnosis of STEMI is based on ECG evidence of ischemic ST changes, clinical symptoms, and elevated CK and CK-MB cardiac enzymes. Patients who are eligible for the Study and who provide written informed consent will be included in the study.

Inclusion Criteria:

• Patient is > 18 years of age.
• Patient has ST-segment elevation of at least 0.1 mV in 2 or more contiguous leads or presumably new LBBB for all types of infarcts.
• Patient's AMI presentation is greater than 30 minutes but less than 6 hours after symptom onset.
• Patient provides written informed consent.
• Patient has no childbearing potential or is not pregnant.
• Target artery has a reference vessel diameter of at least 2.5 mm on visual assessment at baseline angiography.

Exclusion Criteria:

• Known prior history of renal insufficiency (serum creatinine 2.0 mg/dL).
• Cardiogenic shock.
• Prior administration of thrombolysis for the current infarction.
• 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).
• Patient unwilling to receive blood products.
• Previously stented IRA (stent thrombosis).
• Inability to identify the IRA.
• Severe vessel tortuosity that enables OCT assessment.

Inclusion Criteria:

Clinical inclusion criteria:

• Patient is > 18 years of age.
• Patient has ST-segment elevation of at least 0.1 mV in 2 or more contiguous leads or presumably new LBBB for all types of infarcts.
• Patient's AMI presentation is greater than 30 minutes but less than 6 hours after symptom onset.
• Patient provides written informed consent. Patient has no childbearing potential or is not pregnant

Angiographic inclusion criteria:

• All patients with or without evidence of thrombus are eligible.
• Target artery has a reference vessel diameter 2.5 mm on visual assessment at baseline angiography.

Exclusion Criteria:

Clinical exclusion criteria:

• Known prior history of renal insufficiency (serum creatinine 2.0 mg/dL).
• Cardiogenic shock.
• Prior administration of thrombolysis for the current infarction.
• 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).
• Patient unwilling to receive blood products

Angiographic exclusion criteria:

• Previously stented IRA (stent thrombosis).
• Inability to identify the IRA.
• Severe vessel tortuosity that enables OCT assessment.