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

From the Guidelines

The STEMI protocol should prioritize primary percutaneous coronary intervention (PCI) within 90 minutes of first medical contact, and if this cannot be achieved within 120 minutes, fibrinolytic therapy should be administered. This approach is based on the most recent and highest quality evidence from the 2017 AHA/ACC clinical performance and quality measures for adults with ST-elevation and non-ST-elevation myocardial infarction 1. The protocol involves immediate management with aspirin (325mg chewed), P2Y12 inhibitors (ticagrelor 180mg or clopidogrel 600mg), and anticoagulation with unfractionated heparin (60 units/kg bolus, maximum 4000 units).

Key Components of STEMI Protocol

• Primary PCI should be performed in patients with STEMI and ischemic symptoms of less than 12 hours’ duration, as well as those with contraindications to fibrinolytic therapy or cardiogenic shock 1.
• Fibrinolytic therapy, such as alteplase, should be administered if primary PCI cannot be performed within 120 minutes of first medical contact, with a goal of door-to-needle time of 30 minutes or less 1.
• Additional medications include beta-blockers, ACE inhibitors or ARBs for patients with anterior MI or left ventricular dysfunction, and high-intensity statins.
• Continuous cardiac monitoring, oxygen therapy for saturations below 90%, and pain management with morphine or fentanyl are essential components of the STEMI protocol.

Importance of Timely Intervention

The STEMI protocol emphasizes the importance of minimizing door-to-balloon or door-to-needle time, as myocardial tissue death progresses rapidly, with approximately 40% of at-risk myocardium lost within 3 hours and nearly complete infarction by 6 hours 1. Therefore, timely intervention is critical for preserving heart muscle and improving survival. By prioritizing primary PCI and fibrinolytic therapy, the STEMI protocol aims to reduce morbidity, mortality, and improve quality of life for patients with ST-elevation myocardial infarction.

From the FDA Drug Label

The use of clopidogrel in CURE was associated with a decrease in the use of thrombolytic therapy In patients with STEMI, the safety and efficacy of clopidogrel were evaluated in the randomized, placebo-controlled, double-blind study, COMMIT. Patients were randomized to receive clopidogrel (75 mg once daily) or placebo, in combination with aspirin (162 mg per day), for 28 days or until hospital discharge, whichever came first. The primary endpoints were death from any cause and the first occurrence of re-infarction, stroke or death As shown in Table 5 and Figure 4 and Figure 5 below, clopidogrel significantly reduced the relative risk of death from any cause by 7% (p=0.029), and the relative risk of the combination of re-infarction, stroke or death by 9% (p=0. 002). The STEMI protocol involves the use of clopidogrel in combination with aspirin to reduce the risk of death, re-infarction, and stroke. The COMMIT study showed that clopidogrel significantly reduced the relative risk of death from any cause by 7% and the relative risk of the combination of re-infarction, stroke or death by 9%. The recommended dose of clopidogrel is 75 mg once daily, in combination with aspirin (162 mg per day), for 28 days or until hospital discharge, whichever comes first 2.

• Key points:
  • Clopidogrel is used in combination with aspirin to reduce the risk of death, re-infarction, and stroke in patients with STEMI.
  • The recommended dose of clopidogrel is 75 mg once daily.
  • The recommended dose of aspirin is 162 mg per day.
  • Treatment should be continued for 28 days or until hospital discharge, whichever comes first.

From the Research

STEMI Protocol Overview

• The STEMI protocol is a set of guidelines for the management of patients with ST-segment elevation myocardial infarction (STEMI) 3.
• The protocol emphasizes the importance of rapid reperfusion therapy to minimize the time delay between the onset of symptoms and the beginning of treatment 3.
• The goal is to keep the time intervals between the onset of symptoms and the beginning of reperfusion therapy as short as possible, ideally within a dedicated STEMI network 3.

Reperfusion Therapy

• Primary percutaneous coronary intervention (PCI) is the preferred treatment for STEMI patients, if it can be performed within 120 minutes after first medical contact (FMC) 3, 4.
• If primary PCI is not possible within 120 minutes, thrombolysis should be initiated within 30 minutes after FMC, either in the emergency medical service (EMS) ambulance or in a nearby non-PCI hospital 3.
• Thrombolytic therapy is not the final therapy, and cardiac catheterization with PCI should be performed within 24 hours after thrombolysis, if applicable 3.

Medication

• Dual antiplatelet therapy (DAPT) with aspirin and a thienopyridine (such as prasugrel or clopidogrel) is mandatory for STEMI patients 3, 5.
• Prasugrel is preferred over clopidogrel due to its faster onset of action and superior effectiveness in reducing nonfatal myocardial infarction and stent thrombosis 3.
• Anticoagulation with unfractionated heparin (UFH) or bivalirudin is recommended, with bivalirudin being an upcoming alternative 3, 5.

Clinical Outcomes

• The choice of reperfusion strategy (primary PCI or thrombolytic-facilitated PCI) does not significantly affect mortality, left ventricular ejection fraction (LVEF), or incidence of atrial fibrillation (AF) 6.
• However, thrombolytic-facilitated PCI may lead to more initial infarct-related artery (IRA) patency and less thrombectomy compared to primary PCI 6.