What is the management of unstable angina?

From the Guidelines

The management of unstable angina requires immediate hospitalization and a comprehensive treatment approach, with a focus on dual antiplatelet therapy, anticoagulation, anti-ischemic therapy, and early risk stratification. Patients should receive dual antiplatelet therapy with aspirin (325 mg loading dose followed by 81 mg daily) and a P2Y12 inhibitor such as clopidogrel (300-600 mg loading dose, then 75 mg daily), as indicated by the study 1. Anticoagulation with low molecular weight heparin (enoxaparin 1 mg/kg subcutaneously twice daily) is recommended, as it has been shown to be beneficial in the management of unstable angina, as demonstrated in the study 1. Anti-ischemic therapy includes nitrates (sublingual nitroglycerin 0.4 mg every 5 minutes for up to 3 doses, followed by IV nitroglycerin if needed), beta-blockers (metoprolol 25-50 mg orally every 6 hours or 5 mg IV every 5 minutes for 3 doses), and high-intensity statins (atorvastatin 80 mg or rosuvastatin 40 mg daily), as outlined in the study 1. Some key points to consider in the management of unstable angina include:

• Early risk stratification to identify high-risk patients who require cardiac catheterization within 24-48 hours
• The use of platelet glycoprotein IIb/IIIa antagonists in high-risk patients likely to undergo percutaneous coronary intervention (PCI)
• The substitution of low-molecular-weight heparin (LMWH) for unfractionated heparin (UFH) in the management of unstable angina
• The importance of an intensive program of secondary prevention, which should be begun before hospital discharge, as emphasized in the study 1. Pain control with morphine may be necessary if symptoms persist despite nitrates. The goal of this aggressive approach is to stabilize the ruptured plaque, prevent thrombus formation, reduce myocardial oxygen demand, and restore coronary blood flow, thereby preventing progression to myocardial infarction and reducing mortality, as supported by the study 1. In terms of specific treatment strategies, the study 1 recommends that patients with suitable lesions for PCI receive clopidogrel, while patients planned for CABG should have clopidogrel stopped, except if the operation is deferred. Overall, the management of unstable angina requires a comprehensive and individualized approach, taking into account the patient's specific risk factors and clinical presentation, as outlined in the studies 1.

From the FDA Drug Label

Clopidogrel tablets are indicated to reduce the rate of myocardial infarction (MI) and stroke in patients with non–ST-segment elevation ACS (unstable angina [UA]/non–ST-elevation myocardial infarction [NSTEMI]), including patients who are to be managed medically and those who are to be managed with coronary revascularization

In patients who need an antiplatelet effect within hours, initiate clopidogrel tablets with a single 300 mg oral loading dose and then continue at 75 mg once daily.

The management of unstable angina includes the use of clopidogrel in conjunction with aspirin to reduce the rate of myocardial infarction and stroke.

• The recommended dosage is a single 300 mg oral loading dose followed by 75 mg once daily.
• Clopidogrel should be initiated as soon as possible in patients who need an antiplatelet effect within hours 2.

From the Research

Management of Unstable Angina

The management of unstable angina involves a combination of pharmacological and non-pharmacological interventions. The primary goals of treatment are to reduce the risk of myocardial infarction, prevent recurrent angina, and improve quality of life.

Pharmacological Interventions

• Aspirin: reduces the risk of death from cardiac causes and fatal and non-fatal myocardial infarction by about 50-70% in patients presenting with unstable angina 3
• Clopidogrel: acts similarly to ticlopidine but has fewer side effects and has not been reported to cause neutropenia 3
• Ticlopidine: may be substituted for aspirin in patients with hypersensitivity to aspirin or gastrointestinal intolerance 3
• Glycoprotein (GP) IIb/IIIa inhibition: may have substantial benefit in high-risk patients with refractory unstable angina and elevated troponin levels 3
• Unfractionated heparin: current practice guidelines support the use of the combination of unfractionated heparin and aspirin for the treatment of unstable angina 3
• Enoxaparin: has been shown to be more effective than unfractionated heparin in reducing the incidence of the composite end point of death, myocardial infarction, or recurrent angina 3
• Beta-blockers, nitrates, and calcium-channel blockers: are useful for antiischemic therapy in patients with acute coronary syndromes 3

Combination Antithrombotic Therapy

• The combination of aspirin and anticoagulation has been shown to reduce recurrent ischemic events in patients with unstable angina 4
• The CURE trial demonstrated that the combination of clopidogrel and aspirin is superior to aspirin alone in patients with acute coronary syndrome 5
• The benefits of combination antithrombotic therapy must be weighed against the increased risk of bleeding 6

Aspirin Dose

• The optimal daily dose of aspirin may be between 75 and 100 mg, with or without clopidogrel 7
• Higher doses of aspirin increase the risk of major bleeding, without any increase in efficacy 7