What is the management approach for unstable angina?

Management of Unstable Angina

The management of unstable angina requires immediate hospitalization with continuous ECG monitoring, antiplatelet therapy (aspirin), anticoagulation, anti-ischemic medications (nitrates and beta-blockers), and risk stratification to determine the need for an invasive strategy with coronary angiography and possible revascularization. 1

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 1
  • Supplemental oxygen if arterial saturation <90% or respiratory distress 1
  • Initial risk stratification based on history, physical examination, ECG, and cardiac biomarkers 1

Immediate Pharmacological Management

• Antiplatelet therapy:

  • Aspirin (162-325 mg) should be administered immediately and continued indefinitely 1, 2
  • Clopidogrel loading dose should be given if no contraindications exist 1

• Anticoagulant therapy:

  • Unfractionated heparin (UFH), enoxaparin, fondaparinux, or bivalirudin should be initiated based on institutional protocols and patient characteristics 1

• Anti-ischemic therapy:

  • Sublingual or intravenous nitroglycerin for ongoing symptoms 1
  • Beta-blockers should be administered in the absence of contraindications (heart failure, cardiogenic shock, bradycardia, heart block) 3, 2
  • Calcium channel blockers may be considered in selected patients, particularly those with contraindications to beta-blockers 4

Risk Stratification and Management Strategy

High-Risk Features (requiring urgent intervention):

• Persistent or recurrent ischemic pain despite intensive medical therapy 1
• Hemodynamic instability or angina with hypotension 1
• Recurrent angina with heart failure symptoms, S3 gallop, pulmonary edema, worsening rales, or new/worsening mitral regurgitation 1
• Sustained ventricular tachycardia 1
• Depressed left ventricular function (EF <0.40) 1

Management Approaches:

1. Early Invasive Strategy:

   • Recommended for high-risk patients 1
   • Coronary angiography within 4-24 hours of admission 1
   • For patients with ongoing symptoms or hemodynamic/rhythm instability, urgent catheterization within minutes to hours 1
   • Continue antiplatelet and anticoagulant therapy during this period 1

2. Initial Conservative (Selective Invasive) Strategy:

   • May be appropriate for lower-risk patients 1
   • Proceed with invasive evaluation only for patients who:
     • Fail medical therapy (refractory angina despite optimal medications) 1
     • Show objective evidence of ischemia (dynamic ECG changes, high-risk stress test) 1
     • Have left ventricular ejection fraction ≤0.40 1

Post-Angiography Management

• If PCI is selected:

  • Continue aspirin 1
  • Administer clopidogrel loading dose if not given previously 1
  • Consider GP IIb/IIIa inhibitor for troponin-positive and other high-risk patients 1
  • Discontinue anticoagulant therapy after PCI for uncomplicated cases 1

• If medical therapy is selected:

  • Continue aspirin 1
  • Administer clopidogrel loading dose if not given previously 1
  • Discontinue GP IIb/IIIa inhibitor if started previously 1
  • Continue anticoagulant therapy for the duration of hospitalization 1

• If CABG is selected:

  • Continue aspirin 1
  • Discontinue clopidogrel 5-7 days before elective CABG 1
  • Discontinue GP IIb/IIIa inhibitors 4 hours before CABG 1
  • Manage anticoagulant therapy according to institutional protocols 1

Common Pitfalls and Caveats

• Do not abruptly discontinue beta-blockers in patients with coronary artery disease as this can cause severe exacerbation of angina, myocardial infarction, and ventricular arrhythmias 3
• Do not administer fibrinolytic therapy to patients with unstable angina/NSTEMI without ST-segment elevation 1
• Do not delay treatment while waiting for cardiac biomarker results; initial management should be based on clinical presentation 1, 2
• Do not discharge patients prematurely; those with possible ACS should be observed for at least 6-12 hours with serial ECGs and cardiac biomarkers 1
• Do not perform coronary angiography in patients with extensive comorbidities where risks outweigh benefits 1