What is the recommended management for unstable angina?

Management of Unstable Angina

Patients with unstable angina require immediate hospitalization with aspirin 162-325 mg, anticoagulation, dual antiplatelet therapy, and risk stratification to determine whether early invasive intervention (within 24-48 hours) or conservative management is appropriate. 1

Immediate Initial Management

Antiplatelet and Antithrombotic Therapy

• Administer aspirin 162-325 mg immediately upon presentation, as this significantly reduces cardiovascular events and should be continued indefinitely at 75-162 mg daily 1, 2
• Give clopidogrel loading dose of 300 mg followed by 75 mg daily to provide dual antiplatelet therapy 1
• Initiate anticoagulation with unfractionated heparin, enoxaparin, fondaparinux, or bivalirudin based on patient characteristics and planned management strategy 1

Anti-Ischemic Therapy

• Start sublingual or intravenous nitroglycerin for ongoing symptoms to reduce myocardial oxygen demand 1
• Initiate beta-blocker therapy in the absence of contraindications (heart failure, bradycardia, hypotension, or bronchospasm) to reduce myocardial oxygen consumption 1, 3

Risk Stratification

Use the TIMI Risk Score to assess patient risk, which incorporates age ≥65 years, ≥3 coronary risk factors, prior coronary stenosis ≥50%, ST-segment deviation, elevated cardiac markers, ≥2 anginal episodes in 24 hours, and aspirin use in prior 7 days 1

High-Risk Features Requiring Urgent Intervention

• Persistent or recurrent ischemic pain despite medical therapy 1
• Dynamic ST-segment changes (≥0.5 mm depression or transient elevation) 1
• Elevated cardiac troponin levels 1
• Hemodynamic instability or signs of heart failure 1
• Diabetes mellitus with documented coronary disease 1
• Reduced left ventricular ejection fraction (<0.40) 1

Management Strategy Based on Risk

Early Invasive Strategy (High-Risk Patients)

Proceed with coronary angiography within 24-48 hours for patients with any high-risk features listed above, as this approach reduces death and recurrent MI 1

Following angiography, management depends on anatomy:

• For suitable lesions: Proceed with PCI using intracoronary stents, continuing aspirin indefinitely and clopidogrel for appropriate duration 1
• For multivessel disease with diabetes: CABG is preferred over PCI, using internal mammary arteries when possible 1
• For left main or severe three-vessel disease: CABG is generally preferred 1

Conservative Strategy (Lower-Risk Patients)

For patients without high-risk features, continue medical therapy with antiplatelet agents, anticoagulation, beta-blockers, and nitrates 1

• Measure left ventricular ejection fraction to guide further management 1, 2
• If LVEF ≤0.40: Consider diagnostic angiography even in lower-risk patients 2
• If LVEF >0.40: Perform stress testing for further risk stratification 2

Lipid Management

Initiate high-dose statin therapy (atorvastatin 80 mg daily) within 24-96 hours of presentation, as early statin initiation reduces recurrent ischemia and improves long-term outcomes 4

• The MIRACL trial demonstrated that atorvastatin 80 mg reduced the composite endpoint of death, MI, cardiac arrest, or recurrent ischemia from 17.4% to 14.8% at 16 weeks 4
• Target LDL cholesterol <100 mg/dL, with consideration for even lower targets in very high-risk patients 4
• Add fibrate or niacin if HDL cholesterol <40 mg/dL 4

Duration of Therapy and Monitoring

During Hospitalization

• Continue anticoagulation for 72 hours, until hospital discharge, or until CABG, whichever occurs first 5
• If PCI is performed, extend anticoagulation for 24 hours post-procedure, allowing for up to 96 hours total duration 5
• Maintain aPTT 50-70 seconds with unfractionated heparin 5

Post-Discharge Management

• Continue aspirin 75-162 mg daily indefinitely 2
• Continue clopidogrel 75 mg daily for documented coronary artery disease 2
• Continue beta-blocker therapy, particularly if prior MI or heart failure 2
• Add ACE inhibitor for patients with hypertension, heart failure, LV dysfunction, prior MI with LV dysfunction, or diabetes 2

Critical Pitfalls to Avoid

Never administer fibrinolytic therapy to patients with unstable angina without ST-segment elevation, as it is contraindicated and potentially harmful 1

Do not delay treatment while waiting for cardiac biomarker results, as management should begin immediately based on clinical presentation 1

Avoid NSAIDs (except aspirin) due to increased cardiovascular event risk 2

Do not discontinue antiplatelet therapy prematurely, especially in patients who have undergone PCI 2

If CABG is planned, discontinue clopidogrel 5-7 days before elective surgery to reduce bleeding risk, but continue aspirin 1, 2

Secondary Prevention

Implement aggressive risk factor modification:

• Smoking cessation with counseling and pharmacotherapy 2
• Blood pressure control with target <130/80 mmHg 2
• Diabetes management with target HbA1c <7% 2
• Regular physical activity (30 minutes most days) 2
• Weight management with target BMI 18.5-24.9 kg/m² 2

The 30-day mortality and reinfarction rate for unstable angina/NSTEMI is approximately 15%, underscoring the serious nature of this condition and the importance of aggressive management 4