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

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

The treatment of NSTEMI requires dual antiplatelet therapy with aspirin and a P2Y12 inhibitor, anticoagulation, risk stratification for an early invasive strategy, and initiation of cardioprotective medications. 1

Initial Management

Antiplatelet Therapy

• Aspirin:
  • Loading dose: 150-300mg (chewed or crushed for rapid absorption)
  • Maintenance: 75-100mg daily indefinitely 2, 1
• P2Y12 inhibitor: Add to aspirin for 12 months 1
  • Preferred options:
    • Ticagrelor 180mg loading dose, then 90mg twice daily
    • Prasugrel 60mg loading dose, then 10mg daily (after coronary anatomy is known)
    • Clopidogrel 300-600mg loading dose, then 75mg daily (when ticagrelor/prasugrel contraindicated) 3

Anticoagulation

• Choose one of the following:
  • Unfractionated heparin (UFH)
  • Enoxaparin
  • Fondaparinux (preferred for patients managed conservatively)
  • Bivalirudin (primarily during PCI) 1

Risk Stratification and Invasive Management

Very High-Risk Criteria (Immediate Invasive Strategy <2 hours)

• Hemodynamic instability or cardiogenic shock
• Recurrent or ongoing chest pain refractory to medical treatment
• Life-threatening arrhythmias
• Mechanical complications of MI
• Acute heart failure with refractory angina or ST deviation 1

High-Risk Criteria (Early Invasive Strategy <24 hours)

• Rise/fall in cardiac troponin compatible with MI
• Dynamic ST or T-wave changes
• GRACE score >140 1

Intermediate-Risk Criteria (Invasive Strategy <72 hours)

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

Pharmacological Therapy

Beta-Blockers

• Initiate in all patients without contraindications
• Particularly beneficial in patients with LV dysfunction or heart failure 4

ACE Inhibitors/ARBs

• Start within 24 hours in patients with:
  • Heart failure
  • LV systolic dysfunction
  • Diabetes
  • Anterior MI 1

Statins

• High-intensity statin therapy (e.g., atorvastatin 40-80mg or rosuvastatin 20-40mg) as early as possible regardless of initial cholesterol levels 1

Aldosterone Antagonists

• Consider eplerenone in patients with:
  • LVEF ≤40%
  • Heart failure or diabetes
  • No significant renal dysfunction or hyperkalemia 4

Special Considerations

Patients Requiring Oral Anticoagulation

• For patients with LV thrombus or atrial fibrillation:
  • Triple therapy (OAC + DAPT) for 1-3 months in high-risk scenarios
  • Then transition to dual therapy (OAC + single antiplatelet) for remainder of 12-month period 1
  • Warfarin with target INR 2.0-3.0 for LV thrombus should be continued for at least 3-6 months 1

Bleeding Risk Management

• Use clopidogrel as P2Y12 inhibitor when triple therapy is needed due to lower bleeding risk 1
• Avoid prasugrel in patients ≥75 years or <60kg 1
• Ticagrelor is contraindicated in patients with previous intracranial hemorrhage or ongoing bleeding 1

Post-Discharge Care

Secondary Prevention

• Continue DAPT for 12 months
• Lifelong aspirin (75-100mg daily)
• Risk factor modification:
  • Smoking cessation
  • Blood pressure control
  • Diabetes management
  • Regular physical activity
  • Dietary modification 1

Follow-up

• Schedule follow-up appointments:
  • 1-2 weeks for high-risk patients
  • 2-6 weeks for lower-risk patients or those who have undergone revascularization 1

Important Caveats

• Fibrinolytic therapy is contraindicated in NSTEMI and has been shown to increase the risk of MI 2
• Patients with CYP2C19 loss-of-function alleles may have reduced effectiveness with clopidogrel 3
• Regular monitoring for bleeding complications is essential, particularly with triple antithrombotic therapy 1
• Patients with renal impairment require dose adjustments of anticoagulants 1