Management of Unstable Angina

Initial Assessment and Triage

• Patients with chest discomfort/pain at rest lasting >20 minutes, hemodynamic instability, or recent syncope should be immediately referred to an emergency department or specialized chest pain unit 1
• Patients with suspected unstable angina should receive continuous ECG monitoring for ischemia and arrhythmia detection, as recommended by the American College of Cardiology 2, 3
• Supplemental oxygen should be administered if arterial saturation <90% or respiratory distress, as suggested by the American College of Cardiology 2
• Initial risk stratification should be based on history, physical examination, ECG, and cardiac biomarkers, according to the American Heart Association 4

Immediate Pharmacological Management

• The American College of Cardiology recommends aspirin (162-325 mg) should be administered immediately and continued indefinitely 6
• Clopidogrel loading dose should be given if no contraindications exist, as recommended by the American College of Cardiology 6, 7
• Unfractionated heparin (UFH), enoxaparin, fondaparinux, or bivalirudin should be initiated based on institutional protocols and patient characteristics, according to the American College of Cardiology 6, 7
• Sublingual or intravenous nitroglycerin should be administered for ongoing symptoms, as suggested by the American Heart Association 4

Risk Stratification and Management Strategy

• High-risk features requiring urgent intervention include persistent or recurrent ischemic pain despite intensive medical therapy, hemodynamic instability, or angina with hypotension, as defined by the American College of Cardiology 8
• The American College of Cardiology recommends an early invasive strategy for high-risk patients, with coronary angiography within 4-24 hours of admission 5
• The American College of Cardiology suggests an initial conservative (selective invasive) strategy may be appropriate for lower-risk patients, with invasive evaluation only for patients who fail medical therapy or show objective evidence of ischemia 5

Post-Angiography Management

• If PCI is selected, the American College of Cardiology recommends continuing aspirin and administering clopidogrel loading dose if not given previously 6, 7
• If medical therapy is selected, the American College of Cardiology suggests continuing aspirin and administering clopidogrel loading dose if not given previously 6, 7
• If CABG is selected, the American College of Cardiology recommends continuing aspirin and discontinuing clopidogrel 5-7 days before elective CABG 6, 7

Common Pitfalls and Caveats

• The American College of Cardiology advises against administering fibrinolytic therapy to patients with unstable angina/NSTEMI without ST-segment elevation 7
• The American Heart Association recommends not delaying treatment while waiting for cardiac biomarker results; initial management should be based on clinical presentation 9
• The American College of Cardiology suggests not discharging patients prematurely; those with possible ACS should be observed for at least 6-12 hours with serial ECGs and cardiac biomarkers 4
• The American Heart Association advises against performing coronary angiography in patients with extensive comorbidities where risks outweigh benefits 8