What is the treatment for Non-ST-Elevation Myocardial Infarction (NSTEMI)?

Treatment of Non-ST-Elevation Myocardial Infarction (NSTEMI)

The treatment of NSTEMI should include dual antiplatelet therapy with aspirin and a P2Y12 inhibitor, anticoagulation, beta-blockers, high-intensity statins, and consideration for early invasive management with coronary angiography within 24-48 hours for high-risk patients. 1

Initial Management

Antiplatelet Therapy

• Aspirin:

  • Loading dose: 150-300 mg (non-enteric coated, to be crushed or chewed for rapid absorption)
  • Maintenance dose: 75-100 mg daily (preferably 81 mg to minimize bleeding risk) 2, 1

• P2Y12 Inhibitor:

  • Clopidogrel: 300-600 mg loading dose, then 75 mg daily 1, 3
  • Ticagrelor: 180 mg loading dose, then 90 mg twice daily 1
  • Note: For patients on ticagrelor, limit aspirin dose to 81 mg daily 1

Anticoagulation

• Options include:
  • Unfractionated heparin: 60-70 U/kg IV bolus, followed by 12-15 U/kg/hr infusion
  • Enoxaparin: 1 mg/kg subcutaneously every 12 hours
  • Fondaparinux: 2.5 mg subcutaneously daily 1
• Continue for at least 48 hours or until revascularization

Anti-ischemic Therapy

• Beta-blockers: First-line therapy in the absence of contraindications (heart failure, cardiogenic shock, bradycardia, heart block) 1
• Nitrates: For ongoing chest pain or hypertension
• Calcium channel blockers: Alternative for patients with contraindications to beta-blockers

Risk Stratification

Risk stratification is essential to determine the timing of invasive management:

High-Risk Features (Early Invasive Strategy Recommended):

• Age ≥65 years
• ≥3 coronary risk factors
• ST-segment depression on ECG
• ≥2 anginal episodes in the last 24 hours
• Elevated cardiac markers (troponin)
• Prior aspirin use 1

Risk Assessment Tools:

• TIMI Risk Score
• GRACE Risk Score
• PURSUIT Risk Score 1

Invasive Management

• Early invasive strategy: Coronary angiography within 24-48 hours for high-risk patients 1
• Glycoprotein IIb/IIIa inhibitors: Consider in patients with positive troponin before PCI 1
• Revascularization options:
  • Percutaneous coronary intervention (PCI)
  • Coronary artery bypass grafting (CABG) - preferred for multivessel disease 1

Secondary Prevention

Medications for Long-term Management:

• Dual antiplatelet therapy: Continue for 12 months 1
• Beta-blockers: Long-term therapy 1
• ACE inhibitors or ARBs: Especially for patients with reduced left ventricular function, hypertension, or diabetes 1
• High-intensity statins: Regardless of baseline cholesterol levels 1

Lifestyle Modifications:

• Smoking cessation
• Daily exercise
• Healthy diet
• Weight control 1

Cardiac Rehabilitation:

• Refer all patients to cardiac rehabilitation programs 1

Special Considerations

Diabetic Patients:

• Strict glucose control to improve prognosis 1

Bleeding Risk:

• Monitor for bleeding complications with dual antiplatelet therapy and anticoagulation
• Consider proton pump inhibitors for patients at high risk of gastrointestinal bleeding 1
• Avoid prasugrel in patients with history of stroke or TIA 1

CYP2C19 Poor Metabolizers:

• Clopidogrel efficacy depends on conversion to an active metabolite by CYP2C19
• Consider alternative P2Y12 inhibitors in patients identified as CYP2C19 poor metabolizers 3
• Avoid concomitant use of clopidogrel with omeprazole or esomeprazole 3

Follow-up Care

• Schedule follow-up appointments 1-2 weeks after discharge for high-risk patients
• Schedule follow-up 2-6 weeks after discharge for low-risk patients or those who have undergone revascularization 1
• Continue secondary prevention measures indefinitely

By following this comprehensive approach to NSTEMI management, clinicians can significantly reduce morbidity and mortality in these patients, with particular attention to timely risk stratification and appropriate selection of invasive versus conservative strategies.