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

Initial Management of NSTEMI

Immediately administer aspirin 162-325 mg orally (non-enteric coated), initiate parenteral anticoagulation with enoxaparin or unfractionated heparin, add a P2Y12 inhibitor (ticagrelor or clopidogrel upstream, prasugrel only after angiography), admit to a monitored unit, and perform risk stratification to determine timing of invasive strategy within 12-24 hours for high-risk patients. 1, 2, 3

Immediate Actions Upon Presentation

Monitoring and Initial Assessment

• Admit the patient to a monitored unit with continuous cardiac rhythm monitoring for at least 24 hours to detect life-threatening arrhythmias 1, 4
• Obtain a 12-lead ECG within 10 minutes of first medical contact 4
• Draw blood work immediately including high-sensitivity cardiac troponin (results available within 60 minutes), repeat troponin at 1-3 hours, serum creatinine, hemoglobin, hematocrit, platelet count, blood glucose, and INR if on warfarin 4, 2
• Assess vital signs regularly including blood pressure, heart rate, and perform cardiopulmonary auscultation with Killip classification 4

Antiplatelet Therapy - Start Immediately

• Give aspirin 162-325 mg orally immediately using non-enteric coated formulation for faster absorption, then continue 75-100 mg daily indefinitely 1, 2, 3
• Add a P2Y12 inhibitor before diagnostic angiography (upstream administration): 1, 2
  • Ticagrelor 180 mg loading dose, then 90 mg twice daily (preferred over clopidogrel) 4, 1, 2
  • Clopidogrel 300-600 mg loading dose, then 75 mg daily (acceptable alternative) 1, 2
  • Do NOT give prasugrel until after coronary anatomy is defined at angiography - prasugrel is contraindicated before knowing anatomy due to bleeding risk if urgent CABG is needed 5, 3

Anticoagulation Therapy - Start Immediately

• Initiate parenteral anticoagulation immediately in all patients: 1, 2, 3
  • Enoxaparin 1 mg/kg subcutaneously every 12 hours (preferred for early invasive strategy) 3, 1
  • Unfractionated heparin IV (alternative, especially if CABG planned within 24 hours) 1, 2
  • Fondaparinux 2.5 mg subcutaneously once daily (preferred for conservative strategy due to lower bleeding risk, but requires additional anticoagulant with anti-IIa activity during PCI) 3, 1

Symptom Management

• Administer sublingual or IV nitroglycerin for ongoing ischemic chest pain unless contraindicated by: 1
  • Systolic blood pressure <90 mmHg
  • Severe bradycardia or tachycardia
  • Right ventricular infarction
  • Recent phosphodiesterase inhibitor use (within 24-48 hours)
• Give supplemental oxygen only if arterial oxygen saturation is <90% - avoid routine oxygen in normoxic patients 1
• Consider morphine sulfate IV for uncontrolled chest pain despite nitroglycerin, but use cautiously as it delays P2Y12 inhibitor absorption 1, 5

Beta-Blocker Therapy

• Initiate beta-blocker therapy within 24 hours unless contraindicated to reduce myocardial oxygen demand by decreasing heart rate, blood pressure, and contractility 1, 2
• Continue indefinitely for secondary prevention 1, 2

Risk Stratification and Invasive Strategy Timing

Perform Immediate Risk Assessment

• Calculate GRACE or TIMI risk score immediately to determine timing of invasive strategy 1, 2
• Perform echocardiography to evaluate regional and global left ventricular function 2

Early Invasive Strategy (Within 12-24 Hours) - Mandatory For:

• Refractory angina despite medical therapy 1, 2
• Hemodynamic instability 1, 2
• Electrical instability (life-threatening arrhythmias) 1, 2
• Elevated cardiac troponin with high-risk features 1, 2
• High GRACE or TIMI risk score 1
• Do NOT delay angiography in high-risk patients for "medical stabilization" - early invasive approach within 24 hours reduces ischemic events 1

Conservative Strategy (Selective Invasive)

• May be considered for low-to-intermediate risk patients who are initially stabilized 1, 2

GP IIb/IIIa Inhibitor Considerations

• Do NOT routinely give GP IIb/IIIa inhibitors upstream (before angiography) in patients with planned next-day catheterization who are already receiving dual antiplatelet therapy and anticoagulation 3, 1
• May add eptifibatide or tirofiban upstream only in very high-risk patients if delay to catheterization is anticipated and patient is not at high bleeding risk 1, 3
• Never give abciximab upstream - only use if PCI is imminent 1, 3

Additional Pharmacotherapy

ACE Inhibitors/ARBs

• Start ACE inhibitor within 24 hours for patients with heart failure, left ventricular dysfunction, hypertension, or diabetes 1, 2
• Use ARB for ACE inhibitor-intolerant patients 1

Statin Therapy

• Initiate high-intensity statin therapy (atorvastatin 80 mg or rosuvastatin 40 mg) regardless of baseline LDL cholesterol 1
• Assess lipid profile in the early phase of admission 4

Critical Pitfalls to Avoid

• Never use enteric-coated aspirin initially - it has delayed and reduced absorption 3
• Never give prasugrel before coronary anatomy is defined - wait until after angiography to avoid bleeding complications if urgent CABG is needed 5, 3
• Avoid NSAIDs (except aspirin) during hospitalization - they increase mortality, reinfarction, hypertension, heart failure, and myocardial rupture risk 1
• Do not use immediate-release dihydropyridine calcium channel blockers (nifedipine) without adequate beta-blockade 1
• Avoid omeprazole and esomeprazole with clopidogrel - they reduce antiplatelet effect; use other PPIs if gastroprotection is needed 1
• If fondaparinux was used for anticoagulation, do not forget to add additional anticoagulation with anti-IIa activity during PCI (such as unfractionated heparin or bivalirudin) - fondaparinux alone has insufficient anti-IIa activity for PCI 3
• If patient requires CABG, discontinue clopidogrel 5-7 days before surgery and prasugrel at least 7 days before surgery 2, 5
• For patients <60 kg on prasugrel, consider lowering maintenance dose to 5 mg daily due to increased bleeding risk 5