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

Medical Management for NSTEMI

The medical management of Non-ST-Elevation Myocardial Infarction (NSTEMI) should include immediate administration of aspirin (250-500mg loading dose, then 75-100mg daily), a P2Y12 inhibitor, anticoagulation with either low molecular weight heparin or unfractionated heparin, and early risk stratification to determine timing of invasive strategy. 1

Initial Evaluation and Treatment

• Perform a 12-lead ECG within 10 minutes of first medical contact to confirm NSTEMI diagnosis
• Obtain cardiac troponin measurements at 0 and 1-3 hours to assess cardiac damage
• Begin continuous multi-lead ECG monitoring for arrhythmias
• Administer initial antiplatelet therapy:
  • Aspirin 250-500mg loading dose, then 75-100mg daily 1
  • P2Y12 inhibitor (clopidogrel 300-600mg loading dose, then 75mg daily) 2

Anticoagulation Therapy

• Use one of the following:
  • Low molecular weight heparin (enoxaparin 1mg/kg SC every 12 hours)
  • Unfractionated heparin (60-70 U/kg IV bolus, then 12-15 U/kg/hr) 1
  • Fondaparinux or bivalirudin may be considered as alternatives 3

Risk Stratification and Invasive Strategy Timing

Risk stratify patients to determine timing of invasive strategy:

1. Immediate invasive strategy (<2 hours) for:

   • Hemodynamic instability
   • Recurrent/ongoing chest pain refractory to medical treatment
   • Life-threatening arrhythmias
   • Mechanical complications
   • Heart failure
   • Dynamic ST-T wave changes 1

2. Early invasive strategy (<24 hours) for:

   • Elevated troponin
   • Dynamic ST/T changes
   • GRACE score >140 1

3. Invasive strategy (<72 hours) for:

   • Diabetes mellitus
   • Renal insufficiency (eGFR <60 mL/min/1.73 m²)
   • LVEF <40% or heart failure
   • Early post-infarction angina
   • Recent PCI or prior CABG
   • GRACE score 109-140 1

Additional Pharmacological Therapy

• Beta-blockers: Start early in hemodynamically stable patients
• ACE inhibitors/ARBs: Particularly for patients with LV dysfunction, heart failure, hypertension, or diabetes
• Statins: High-intensity statin therapy should be initiated promptly regardless of cholesterol levels
• Nitroglycerin: For symptomatic relief of ongoing chest pain
• Calcium channel blockers: Consider if beta-blockers are contraindicated 1

Special Considerations

• Diabetes management: Monitor blood glucose levels frequently and avoid hypoglycemia; maintain blood glucose <180 mg/dL 3
• Renal impairment: Assess kidney function by eGFR, use low- or iso-osmolar contrast media at lowest possible volume, and adjust medication dosages as needed 1
• Elderly patients: Higher risk of bleeding with antithrombotic therapy; consider dose adjustments 1

Secondary Prevention and Follow-up

• Continue dual antiplatelet therapy for 12 months:

  • For medically managed patients without stenting: aspirin (75-162mg daily) indefinitely and clopidogrel (75mg daily) for at least 1 month and ideally up to 1 year 3
  • For patients with bare-metal stents: aspirin (162-325mg daily) for at least 1 month, then 75-162mg daily indefinitely; clopidogrel (75mg daily) for minimum 1 month and ideally up to 1 year 3

• Long-term medications:

  • Beta-blockers
  • ACE inhibitors/ARBs
  • High-intensity statins

• Schedule follow-up appointments:

  • 1-2 weeks for high-risk patients
  • 2-6 weeks for low-risk patients or those who have undergone revascularization 1

Important Considerations

• If CABG is planned, discontinue clopidogrel 5-7 days before surgery 3
• If PCI is planned, continue antiplatelet therapy and adjust anticoagulants accordingly 3
• Consider GP IIb/IIIa inhibitors for high-risk patients undergoing PCI 1
• Monitor for bleeding complications with dual antiplatelet therapy and anticoagulation; consider proton pump inhibitors for patients at high risk of gastrointestinal bleeding 1