What is the management plan for a patient presenting with Non-ST-Elevation Myocardial Infarction (NSTEMI)?

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

The management of NSTEMI requires immediate dual antiplatelet therapy with aspirin (150-300mg loading dose, followed by 75-100mg daily) plus a potent P2Y12 inhibitor (preferably ticagrelor or prasugrel), parenteral anticoagulation, and an early invasive strategy for high-risk patients to reduce mortality and prevent recurrent ischemic events. 1

Initial Assessment and Diagnosis

• Obtain a 12-lead ECG within 10 minutes of first medical contact and have it immediately interpreted by an experienced physician 1
• Implement the ESC 0h/1h algorithm using high-sensitivity cardiac troponin (hs-cTn) testing at 0h and 1h 1
  • If initial troponin measurements are inconclusive but clinical suspicion remains high, obtain additional testing at 3h 1
  • Alternative: Use the ESC 0h/2h algorithm if the 0h/1h protocol is unavailable 1
• Perform echocardiography to evaluate regional and global left ventricular function and rule out differential diagnoses 1
• Place patient on continuous cardiac rhythm monitoring until NSTEMI is confirmed or ruled out 1

Risk Stratification

• Use validated risk scores (GRACE or TIMI) to guide management decisions 2
• Identify very-high-risk criteria requiring immediate invasive management (<2 hours):
  • Hemodynamic instability
  • Cardiogenic shock
  • Life-threatening arrhythmias
  • Mechanical complications
  • Acute heart failure with ongoing ischemia 2
• Identify high-risk criteria requiring early invasive management (<24 hours):
  • Rise/fall in cardiac troponin compatible with MI
  • Dynamic ST/T-wave changes
  • GRACE score >140 2

Pharmacological Management

Antiplatelet Therapy

• Aspirin: 150-300mg loading dose followed by 75-100mg daily maintenance indefinitely 1
• P2Y12 inhibitor: Add to aspirin and maintain for 12 months unless contraindicated 1
  • Preferred options:
    • Ticagrelor: 180mg loading dose, then 90mg twice daily (regardless of planned treatment strategy) 1
    • Prasugrel: 60mg loading dose, then 10mg daily (5mg if ≥75 years or <60kg) - only for patients proceeding to PCI 1, 3
  • Alternative: Clopidogrel (300-600mg loading dose, then 75mg daily) only when prasugrel or ticagrelor are unavailable or contraindicated 1

Anticoagulation

• Initiate parenteral anticoagulation immediately in addition to antiplatelet therapy 1
• Options include:
  • Unfractionated heparin (UFH)
  • Enoxaparin
  • Fondaparinux (preferred for patients managed conservatively)
  • Bivalirudin (primarily during PCI) 1

Other Medications

• Initiate high-intensity statin therapy as early as possible 2
• Administer beta-blockers for patients with ongoing ischemia, hypertension, or tachycardia
• Consider ACE inhibitors/ARBs for patients with reduced left ventricular function, heart failure, diabetes, or hypertension 2

Invasive vs. Conservative Management

Early Invasive Strategy (<24 hours)

Indicated for patients with:

• Elevated cardiac biomarkers
• Dynamic ECG changes
• GRACE score >140
• Recurrent symptoms
• Heart failure or hemodynamic instability 1, 2

Routine Invasive Strategy (24-72 hours)

Indicated for patients with:

• Intermediate GRACE risk score (109-140)
• Diabetes
• Renal insufficiency
• Reduced left ventricular function (LVEF <40%)
• Prior PCI or CABG 2

Conservative Strategy

Consider for patients with:

• Low GRACE risk score (<109)
• No recurrent symptoms
• No heart failure
• No major ECG changes
• No elevation in troponin 1, 2

Revascularization Considerations

• For patients with multivessel disease (present in >40% of NSTEMI cases), treatment strategy should be determined based on clinical status, comorbidities, and coronary anatomy 4
• PCI is performed in approximately 42% of NSTEMI patients with multivessel disease, while 24-66% may be referred for CABG depending on the extent of disease 4
• In patients undergoing PCI, the culprit lesion should be treated first; complete revascularization may be considered in a staged approach 1, 4

Post-Discharge Management

• Continue dual antiplatelet therapy for 12 months unless high bleeding risk 1
• Implement secondary prevention measures:
  • High-intensity statin therapy
  • Blood pressure control
  • Diabetes management
  • Smoking cessation
  • Regular physical activity 2
• Schedule follow-up within 1-2 weeks for high-risk patients 2

Special Considerations

• Elderly patients: Higher risk of bleeding with antithrombotic therapy; consider dose adjustments 2
• Renal impairment: Adjust medication dosages, particularly anticoagulants 2
• Diabetes: Requires close monitoring of blood glucose levels; these patients have higher mortality risk 2
• Type 2 MI: When NSTEMI is caused by oxygen supply-demand mismatch rather than plaque rupture, focus on treating the underlying cause (e.g., anemia, tachyarrhythmia, respiratory failure) 5

Common Pitfalls to Avoid

• Delaying ECG acquisition and interpretation
• Administering routine pre-treatment with P2Y12 inhibitors before coronary anatomy is known 1
• Using GP IIb/IIIa inhibitors before coronary anatomy is known 1
• Measuring additional biomarkers beyond hs-cTn for initial diagnosis 1
• Failing to recognize Type 2 MI, which requires different management than Type 1 MI 5