What is the treatment for unstable angina (acute coronary syndrome)?

From the Guidelines

The treatment of unstable angina requires immediate medical attention and typically involves a combination of medications and possibly invasive procedures, with an initial conservative (selective invasive) strategy considered as a treatment option in initially stabilized patients, as recommended by the 2012 ACCF/AHA focused update incorporated into the ACCF/AHA 2007 guidelines for the management of patients with unstable angina/non-ST-elevation myocardial infarction 1. Initial management includes:

• Aspirin (325 mg loading dose, then 81-325 mg daily)
• Anticoagulation with heparin (unfractionated or low molecular weight such as enoxaparin 1 mg/kg twice daily)
• Anti-ischemic therapy with beta-blockers (such as metoprolol 25-50 mg orally every 6 hours) and nitroglycerin (0.4 mg sublingual as needed or IV infusion at 5-10 mcg/min)
• P2Y12 inhibitors like clopidogrel (300-600 mg loading dose, then 75 mg daily), ticagrelor, or prasugrel are added for dual antiplatelet therapy
• High-intensity statins (atorvastatin 40-80 mg or rosuvastatin 20-40 mg daily) should be started immediately
• Oxygen therapy is provided if saturation is below 90% For patients with ongoing symptoms or high-risk features, early cardiac catheterization with possible percutaneous coronary intervention or coronary artery bypass grafting may be necessary, as suggested by the European Heart Journal study 1. The comprehensive approach aims to stabilize the ruptured plaque, prevent thrombus formation, reduce myocardial oxygen demand, and restore adequate coronary blood flow to prevent progression to myocardial infarction, as outlined in the Circulation study 1. Key considerations in the management of unstable angina include:
• Early risk stratification using clinical criteria and biomarkers
• The use of low-molecular-weight heparin (LMWH) such as enoxaparin as an alternative to unfractionated heparin (UFH)
• The role of platelet glycoprotein (GP) IIb/IIIa antagonists in high-risk patients undergoing percutaneous coronary intervention (PCI)
• The importance of an intensive program of secondary prevention, including lifestyle modifications and pharmacological therapy, to reduce morbidity and mortality in patients with unstable angina.

From the FDA Drug Label

Prasugrel tablets are indicated to reduce the rate of thrombotic CV events (including stent thrombosis) in patients with acute coronary syndrome (ACS) who are to be managed with percutaneous coronary intervention (PCI) as follows: Patients with unstable angina (UA) or non-ST-elevation myocardial infarction (NSTEMI) Patients with ST-elevation myocardial infarction (STEMI) when managed with primary or delayed PCI.

The treatment of unstable angina includes the use of prasugrel tablets to reduce the rate of thrombotic CV events, in combination with aspirin (75 mg to 325 mg) daily, and management with percutaneous coronary intervention (PCI). The recommended dosage is a single 60 mg oral loading dose, followed by 10 mg orally once daily 2.

• Key points:
  • Prasugrel tablets are indicated for patients with unstable angina (UA) or non-ST-elevation myocardial infarction (NSTEMI)
  • Management with percutaneous coronary intervention (PCI) is recommended
  • Aspirin (75 mg to 325 mg) daily should be taken in combination with prasugrel tablets
  • Dosage: 60 mg oral loading dose, followed by 10 mg orally once daily 2

From the Research

Treatment Overview

The treatment of unstable angina involves the use of antiplatelet agents to reduce the risk of major adverse cardiac events.

• Aspirin, clopidogrel, and glycoprotein IIb/IIIa antagonists are commonly used antiplatelet agents in the treatment of unstable angina 3.
• The choice of antiplatelet agent depends on the individual patient's risk factors and the presence of other medical conditions.

Antiplatelet Therapy

• Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is a common treatment strategy for unstable angina 4.
• Triple antiplatelet therapy (TAPT) with aspirin, a P2Y12 inhibitor, and a glycoprotein IIb/IIIa inhibitor may be considered in high-risk patients, but it is associated with an increased risk of bleeding 4.
• The use of clopidogrel, ticagrelor, and prasugrel as P2Y12 inhibitors has been studied, with clopidogrel being associated with a lower risk of bleeding compared to ticagrelor and prasugrel 5.

Combination Therapy

• Combination anticoagulant or P2Y12 inhibitor with low-dose aspirin may be considered in patients with stable coronary artery disease and/or peripheral artery disease 6.
• Rivaroxaban 2.5 mg twice daily plus low-dose aspirin has been shown to reduce the risk of major adverse cardiovascular events compared to clopidogrel plus low-dose aspirin 6.

Guideline Adherence

• Adherence to clinical practice guidelines is important in the treatment of unstable angina, and quality improvement initiatives such as the CRUSADE National Quality Improvement Initiative can help improve guideline adherence 7.
• The underuse of antiplatelet drugs, including glycoprotein IIb-IIIa inhibitors and clopidogrel, is a common problem in the treatment of unstable angina, and continued education and data dissemination are necessary to promote the prescription of guideline-recommended drugs 7.