From the Guidelines
The immediate treatment for ST-Elevation Myocardial Infarction (STEMI) is urgent reperfusion therapy, preferably primary percutaneous coronary intervention (PCI) within 90 minutes of first medical contact, or fibrinolytic therapy within 30 minutes if PCI is not available within 120 minutes. This recommendation is based on the most recent and highest quality study available, which emphasizes the importance of timely reperfusion therapy in improving outcomes for patients with STEMI 1.
Before reperfusion, patients should receive:
- Aspirin (162-325 mg chewed)
- A P2Y12 inhibitor such as ticagrelor (180 mg loading dose) or clopidogrel (600 mg loading dose) Additional immediate measures include:
- Oxygen therapy if saturation is below 90%
- Sublingual nitroglycerin (0.4 mg every 5 minutes for chest pain, up to 3 doses)
- Morphine (2-4 mg IV) for pain unresponsive to nitroglycerin
- Anticoagulation with unfractionated heparin (70-100 units/kg IV bolus without glycoprotein IIb/IIIa inhibitors or 50-70 units/kg with them) Beta-blockers (metoprolol 5 mg IV every 5 minutes, up to 3 doses) should be given if there are no contraindications like heart failure or cardiogenic shock, as supported by earlier guidelines 1.
The choice between primary PCI and fibrinolytic therapy depends on the availability of PCI facilities and the time elapsed since symptom onset, with primary PCI being the preferred method if it can be performed in a timely manner by an experienced team 1. The goal is to restore blood flow to the occluded coronary artery, limit infarct size, reduce pain and anxiety, and prevent further clot formation and infarct extension, ultimately improving survival and reducing complications.
Key considerations in the management of STEMI include:
- Timely reperfusion therapy
- Appropriate use of antiplatelet and anticoagulant therapy
- Management of pain and anxiety
- Monitoring for and management of complications such as heart failure and cardiogenic shock
- Consideration of transfer to a PCI-capable hospital if primary PCI is not available at the initial hospital, as recommended by recent guidelines 1.
Overall, the management of STEMI requires a coordinated and timely approach to improve outcomes and reduce morbidity and mortality.
From the Research
Immediate Treatment for ST-Elevation Myocardial Infarction (STEMI)
The immediate treatment for STEMI involves reperfusion therapy, which can be achieved through either primary percutaneous coronary intervention (PPCI) or fibrinolysis.
- The choice between PPCI and fibrinolysis depends on the time from first medical contact (FMC) to the potential start of treatment, with PPCI being the preferred option if it can be initiated within 120 minutes of FMC 2.
- Fibrinolysis is recommended when PPCI is associated with a delay of ≥120 minutes from FMC 2.
- Current evidence suggests that reperfusion therapy should be initiated as soon as possible after FMC, with the goal of minimizing the time to treatment 2.
Primary Percutaneous Coronary Intervention (PPCI)
PPCI is the preferred reperfusion strategy for STEMI, offering superior outcomes compared to fibrinolysis if initiated promptly 2, 3.
- The use of anticoagulants, such as enoxaparin, is important during PPCI to prevent thrombosis, but the optimal dosing and administration route may need to be adjusted to ensure adequate antithrombotic effect 4.
- Setting up a healthcare system that enables prehospital diagnosis of STEMI and direct transfer of patients to catheterization laboratories at large-volume PCI centers can help increase the proportion of patients benefiting from PPCI 2.
Fibrinolytic Therapy
Fibrinolytic therapy provides an alternative therapeutic strategy for STEMI, particularly when PPCI cannot be delivered in a timely manner 5, 6.
- Fibrinolytic agents can be used as a bridge to PPCI, with the goal of restoring blood flow to the affected area until more definitive treatment can be provided 6.
- Clinicians should be aware of the signs of fibrinolytic therapy failure and consider rescue PPCI if necessary 6.
Considerations During the COVID-19 Pandemic
The COVID-19 pandemic has created challenges in the management of STEMI, with reduced accessibility to cardiac catheterization services and a decline in patients seeking care for myocardial infarction 5.
- Professional societies continue to recommend PPCI as the primary means of treatment for STEMI during the pandemic, with early multicenter data suggesting that the benefits of this therapy persist 5.