What is the recommended management for myocardial ischemia?

Management of Myocardial Ischemia

The recommended management for myocardial ischemia includes immediate administration of aspirin (162-325 mg), antiplatelet therapy, reperfusion therapy with primary PCI for STEMI within 12 hours of symptom onset, and secondary prevention with antiplatelet agents, beta-blockers, ACE inhibitors, and statins. 1, 2

Initial Management

Immediate Interventions

• Aspirin: 162-325 mg chewed (non-enteric coated) immediately 1
• Nitroglycerin: 0.4 mg sublingual every 5 minutes (up to 3 doses) for chest pain if systolic BP >90 mmHg 1, 2
• Morphine: 2-4 mg IV with additional 2-8 mg IV every 5-15 minutes as needed for pain 1
• 12-lead ECG: Obtain within 10 minutes of first medical contact 1
• Continuous ECG monitoring: Establish with defibrillator capacity immediately 1

Reperfusion Strategy

• Primary PCI: Preferred reperfusion strategy for STEMI patients presenting within 12 hours of symptom onset 2, 1

  • Class I recommendation with Level A evidence for patients with ischemic symptoms <12 hours 2
  • Class I recommendation for patients with cardiogenic shock regardless of time delay from MI onset 2
  • Class IIa recommendation for patients with clinical/ECG evidence of ongoing ischemia between 12-24 hours after symptom onset 2

• Fibrinolytic therapy: If primary PCI cannot be performed within 120 minutes of first medical contact 2, 1

  • Initiate as soon as possible after STEMI diagnosis, preferably pre-hospital 2
  • Use fibrin-specific agents (tenecteplase, alteplase, or reteplase) 2

Pharmacological Management

Antiplatelet Therapy

• Dual antiplatelet therapy (DAPT): 2, 1
  • Aspirin 75-100 mg daily indefinitely
  • P2Y12 inhibitor for 12 months:
    • Preferred: Ticagrelor 180 mg loading dose, then 90 mg twice daily 2
    • Preferred: Prasugrel 60 mg loading dose, then 10 mg daily 2
    • Alternative: Clopidogrel 600 mg loading dose, then 75 mg daily 2, 3

Anticoagulation

• For primary PCI: 2

  • Bivalirudin monotherapy is reasonable for patients at high risk of bleeding 2
  • Avoid fondaparinux for primary PCI due to risk of catheter thrombosis 2, 1

• For fibrinolytic therapy: 2

  • Enoxaparin IV followed by SC (preferred over UFH)
  • UFH as weight-adjusted IV bolus followed by infusion

Additional Medications

• Beta-blockers: 2, 1

  • Start within 24 hours for hemodynamically stable patients
  • Oral treatment indicated for patients with heart failure and/or LVEF <40%
  • Avoid IV beta-blockers in patients with hypotension, acute heart failure, AV block, or severe bradycardia

• ACE inhibitors: 2, 1, 4

  • Start within 24 hours for patients with evidence of heart failure, LV systolic dysfunction, diabetes, or anterior infarct
  • Lisinopril has been shown to reduce mortality in acute MI patients 4

• ARBs: Alternative to ACE inhibitors in intolerant patients, preferably valsartan 2

• Statins: 2, 1

  • Start high-intensity statin therapy as early as possible
  • Target LDL-C <1.8 mmol/L (70 mg/dL) or ≥50% reduction

• Mineralocorticoid receptor antagonists (MRAs): For patients with LVEF <40% and heart failure 2

Management of Complications

Cardiogenic Shock

• Consider intra-aortic balloon pump and emergency coronary angiography 1
• Immediate transfer for cardiac catheterization and revascularization regardless of time delay from MI onset 2

Right Ventricular Infarction

• Vigorous intravascular volume expansion with normal saline 1
• Inotropic agents if hypotension persists 1

Recurrent Chest Pain

• If due to pericarditis: High-dose aspirin (650 mg every 4-6 hours) 1
• If due to ischemia: IV nitroglycerin, analgesics, and antithrombotic medications 1

Post-MI Monitoring and Follow-up

Cardiac Assessment

• Echocardiography: Assess LV and RV function, detect mechanical complications, exclude LV thrombus 2, 1
• Exercise testing: Standard exercise test to assess functional capacity and risk stratification 1

Secondary Prevention

• Cardiac rehabilitation: Recommended for all patients 2, 1
• Smoking cessation: Provide repeated advice and support 2, 1
• Proton pump inhibitors: Recommended with DAPT for patients at high risk of gastrointestinal bleeding 2

Important Considerations and Cautions

• Avoid calcium channel blockers as they have not shown mortality benefit and may be harmful in some patients 1
• Avoid oral nitrates in acute MI; use IV nitroglycerin instead for better dose titration 1
• NSAIDs (except aspirin) should not be administered during hospitalization due to increased risks 1
• Consider CYP2C19 genotype when using clopidogrel, as poor metabolizers have reduced antiplatelet effects 3
• The optimal aspirin dose for long-term therapy is between 75-160 mg/day, with lower doses potentially reducing bleeding risk while maintaining efficacy 5