What is the treatment for ST-Elevation Myocardial Infarction (STEMI)?

From the Guidelines

The treatment of ST-elevation myocardial infarction (STEMI) requires immediate reperfusion therapy, preferably primary percutaneous coronary intervention (PCI) within 90 minutes of first medical contact, as recommended by the most recent guidelines 1. This approach is supported by the European Society of Cardiology, which emphasizes the importance of primary PCI in improving outcomes for STEMI patients 1. The standard medication regimen for STEMI patients includes:

• Aspirin (325 mg loading dose, then 81 mg daily)
• A P2Y12 inhibitor such as ticagrelor (180 mg loading dose, then 90 mg twice daily) or prasugrel (60 mg loading dose, then 10 mg daily)
• Anticoagulation with unfractionated heparin (60 units/kg bolus, maximum 4000 units, followed by 12 units/kg/hour infusion) or bivalirudin Additional medications include:
• High-intensity statins (atorvastatin 80 mg or rosuvastatin 40 mg daily)
• Beta-blockers (metoprolol 25-50 mg orally twice daily)
• ACE inhibitors (lisinopril 5-10 mg daily) for patients with left ventricular dysfunction Supplemental oxygen should be provided only if oxygen saturation is below 90% 1. These interventions aim to restore coronary blood flow, prevent further clot formation, reduce myocardial oxygen demand, and limit infarct size, thereby improving survival and reducing complications such as heart failure, arrhythmias, and mechanical complications. It is essential to note that the choice of reperfusion strategy depends on the anticipated time from STEMI diagnosis to PCI-mediated reperfusion, with primary PCI being the preferred option if it can be performed within 120 minutes 1. In cases where primary PCI is not feasible, fibrinolytic therapy should be initiated immediately, within 10 minutes of STEMI diagnosis 1. The American College of Cardiology/American Heart Association also supports primary PCI as the preferred treatment for STEMI, highlighting its superiority to fibrinolytic therapy 1. Overall, the goal of STEMI treatment is to improve outcomes by reducing morbidity, mortality, and improving quality of life, and primary PCI is the most effective strategy to achieve this goal 1.

From the FDA Drug Label

5.5 Increased Risk of Heart Failure and Recurrent Ischemia when used with Planned Percutaneous Coronary Intervention (PCI) in STEMI.

In a trial of patients with STEMI, there were trends toward worse outcomes in the individual components of the primary endpoint between TNKase plus PCI versus PCI alone (mortality 6.7% vs. 4.9%, respectively; cardiogenic shock 6.3% vs. 4. 8%, respectively; and CHF 12% vs. 9.2%, respectively). In addition, there were trends towards worse outcomes in recurrent MI (6.1% vs. 3.7%, respectively; p = 0.03) and repeat target vessel revascularization (6.6% vs. 3.4%, respectively; p = 0.0045) in patients receiving TNKase plus PCI versus PCI alone [see Clinical Studies (14. 1)]. In patients with large ST segment elevation myocardial infarction, physicians should choose either thrombolysis or PCI as the primary treatment strategy for reperfusion Rescue PCI or subsequent elective PCI may be performed after administration of thrombolytic therapies if medically appropriate; however, the optimal use of adjunctive antithrombotic and antiplatelet therapies in this setting is unknown.

The treatment of STEMI with tenecteplase (IV) involves considering the risks and benefits of using thrombolysis versus PCI as the primary treatment strategy for reperfusion.

• Thrombolysis with tenecteplase may be associated with an increased risk of heart failure and recurrent ischemia when used with planned PCI.
• PCI alone may be a better option for some patients, but the optimal use of adjunctive antithrombotic and antiplatelet therapies in this setting is unknown.
• Physicians should choose either thrombolysis or PCI as the primary treatment strategy for reperfusion in patients with large ST segment elevation myocardial infarction 2.

From the Research

Treatment Options for STEMI

• The treatment of ST-segment elevation myocardial infarction (STEMI) involves the use of antiplatelet agents, such as aspirin, P2Y12 inhibitors (e.g., clopidogrel, prasugrel, ticagrelor), and anticoagulants 3, 4.
• Aspirin is the foundation antiplatelet agent, and its initial dose has been studied, with results suggesting that 162 mg may be as effective as and safer than 325 mg for the acute treatment of STEMI 5.
• Newer P2Y12 inhibitors, such as prasugrel and ticagrelor, have shown benefits compared to clopidogrel for dual antiplatelet therapy, and may be used as first-line agents for STEMI treatment 3, 6.

Antiplatelet Therapy

• The use of prasugrel or ticagrelor relative to clopidogrel in triple-antiplatelet treatment combined with glycoprotein IIb/IIIa inhibitor for patients with STEMI undergoing percutaneous coronary intervention (PCI) has been evaluated, with results suggesting that prasugrel or ticagrelor may reduce the rate of major adverse cardiovascular events (MACEs) without increasing bleeding 6.
• However, the effects of aspirin loading on the infarct size limiting effects of statins, ticagrelor, morphine, and/or postconditioning in STEMI patients undergoing primary PCI are unclear, and further studies are needed to investigate this hypothesis 7.

Anticoagulation Therapy

• Anticoagulation uses one of four choices: bivalirudin, unfractionated heparin, enoxaparin, and fondaparinux, and some patients may require triple therapy with aspirin, clopidogrel, and an anticoagulant 4.
• New oral anticoagulants have been shown to be at least as effective as vitamin K antagonists in atrial fibrillation and led to fewer bleeding complications, and may be used in combination with aspirin and clopidogrel for secondary prevention after acute coronary syndromes 4.