What is the management for coronary artery embolism causing ST-Elevation Myocardial Infarction (STEMI)?

From the Guidelines

Management of coronary artery embolism causing STEMI requires immediate reperfusion therapy, preferably with primary percutaneous coronary intervention (PCI). The patient should receive aspirin 325 mg chewed immediately, followed by a P2Y12 inhibitor such as ticagrelor 180 mg or prasugrel 60 mg loading dose 1. Anticoagulation with unfractionated heparin (70-100 units/kg bolus) or bivalirudin should be initiated. During PCI, thrombus aspiration may be particularly beneficial in embolic STEMI to remove the embolic material.

Key Considerations

• Following successful reperfusion, patients should be maintained on dual antiplatelet therapy (aspirin 81 mg daily plus ticagrelor 90 mg twice daily or prasugrel 10 mg daily) and, if an embolic source is identified (such as atrial fibrillation), oral anticoagulation should be added 1.
• The underlying cause of embolism must be investigated and treated, which may include atrial fibrillation, prosthetic valve dysfunction, endocarditis, or paradoxical embolism through a patent foramen ovale.
• Echocardiography is essential to identify potential cardiac sources of embolism, as recommended by the 2017 AHA/ACC clinical performance and quality measures for adults with ST-elevation and non-ST-elevation myocardial infarction 1.

Treatment Approach

• Primary PCI is the recommended method of reperfusion when it can be performed in a timely fashion by experienced operators, with a system goal of 90 minutes or less from first medical contact to device activation 1.
• In the absence of contraindications, fibrinolytic therapy should be administered to patients with STEMI at non–PCI-capable hospitals when the anticipated FMC-to-device time at a PCI-capable hospital exceeds 120 minutes because of unavoidable delays 1.
• A pharmaco-invasive strategy may be considered in low- and middle-income countries where access to primary PCI facilities is limited 1.

From the FDA Drug Label

In patients with STEMI, the safety and efficacy of clopidogrel were evaluated in the randomized, placebo-controlled, double-blind study, COMMIT. COMMIT included 45,852 patients presenting within 24 hours of the onset of the symptoms of myocardial infarction with supporting ECG abnormalities (i.e., The management for coronary artery embolism causing ST-Elevation Myocardial Infarction (STEMI) includes the use of clopidogrel in conjunction with aspirin.

• The recommended dose of clopidogrel is a single 300 mg oral loading dose, followed by 75 mg once daily.
• Clopidogrel should be initiated as soon as possible after the diagnosis of STEMI is made.
• The use of clopidogrel in patients with STEMI has been shown to reduce the rate of myocardial infarction and stroke 2.
• It is essential to note that clopidogrel is a prodrug that requires conversion to its active metabolite by the cytochrome P450 system, and its effectiveness may be reduced in patients with impaired CYP2C19 function 2.

From the Research

Management of Coronary Artery Embolism Causing STEMI

The management of coronary artery embolism causing ST-Elevation Myocardial Infarction (STEMI) involves several key strategies:

• Rapid diagnosis and intervention to restore coronary flow
• Use of antithrombotic therapy, including antiplatelet and anticoagulant agents
• Primary percutaneous coronary intervention (PCI) to mechanically restore blood flow
• Consideration of thrombectomy, thrombolysis, balloon angioplasty, and stent placement as treatment options

Antithrombotic Therapy

Antithrombotic therapy is a crucial component of STEMI management, as noted in studies 3, 4. This includes:

• Dual antiplatelet therapy with aspirin and an oral P2Y12-receptor inhibitor
• Use of intravenous antiplatelet drugs, such as glycoprotein IIb/IIIa inhibitors and cangrelor
• Administration of anticoagulant agents, including unfractionated heparin, low-molecular-weight heparin, and bivalirudin

Primary Percutaneous Coronary Intervention (PCI)

Primary PCI is the preferred treatment for STEMI, as it allows for rapid restoration of blood flow to the affected area, as discussed in studies 3, 5, 6. This procedure involves:

• Mechanical reperfusion using a catheter-based approach
• Use of stents, including bare-metal stents and drug-eluting stents, to maintain patency of the affected artery

Treatment of Coronary Embolism

The treatment of coronary embolism, a rare but potentially fatal phenomenon, requires a high level of suspicion and prompt intervention, as noted in study 7. This may involve:

• Thrombectomy to remove the embolus
• Thrombolysis to dissolve the clot
• Balloon angioplasty and stent placement to restore blood flow and maintain patency of the affected artery

Importance of Early Diagnosis and Intervention

Early diagnosis and intervention are critical in the management of coronary artery embolism causing STEMI, as delays in treatment can result in significant morbidity and mortality, as highlighted in studies 7, 6. A systematic approach to diagnosis and treatment, including the use of antithrombotic therapy and primary PCI, can help to improve outcomes in these patients.