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

Admission Orders for NSTEMI Patient

Immediately administer aspirin 162-325 mg orally (non-enteric coated), initiate dual antiplatelet therapy with a P2Y12 inhibitor (preferably ticagrelor 180 mg loading dose), start parenteral anticoagulation (enoxaparin 1 mg/kg subcutaneously every 12 hours or unfractionated heparin), admit to a monitored cardiac unit with continuous telemetry, and perform urgent risk stratification to determine timing of coronary angiography within 24 hours for high-risk patients. 1, 2

Immediate Stabilization and Monitoring

• Admit to monitored cardiac unit with continuous cardiac rhythm monitoring for at least 24 hours to detect arrhythmias and electrical instability 2, 3

• Supplemental oxygen should be administered only if arterial oxygen saturation is <90%; avoid routine oxygen in normoxic patients 2

• Nitroglycerin (sublingual 0.4 mg every 5 minutes up to 3 doses, or intravenous infusion starting at 10 mcg/min) for ongoing ischemic chest pain, unless contraindicated by:

  • Systolic blood pressure <90 mmHg
  • Severe bradycardia (<50 bpm) or tachycardia (>100 bpm)
  • Right ventricular infarction
  • Phosphodiesterase inhibitor use within 24 hours (sildenafil/vardenafil) or 48 hours (tadalafil) 2

• Morphine sulfate 2-4 mg intravenously every 5-15 minutes for uncontrolled ischemic chest discomfort despite nitroglycerin, though use cautiously as it may delay P2Y12 inhibitor absorption 2, 3

Antiplatelet Therapy

• Aspirin 162-325 mg orally immediately (non-enteric coated for faster absorption), then 75-100 mg daily indefinitely 1, 2

  • This is Class I, Level of Evidence A recommendation 1

• P2Y12 inhibitor loading dose before diagnostic angiography (upstream administration):

  • Ticagrelor 180 mg loading dose, then 90 mg twice daily (preferred option, with aspirin maintenance dose 81 mg daily) 1, 2
  • Clopidogrel 600 mg loading dose, then 75 mg daily (alternative if ticagrelor contraindicated) 1
  • Prasugrel should NOT be given upstream; only administer 60 mg loading dose at time of PCI once coronary anatomy is defined, then 10 mg daily (5 mg daily if weight <60 kg) 1, 4

• Continue P2Y12 inhibitor for at least 12 months regardless of whether stent is placed 1, 3

Anticoagulation Therapy

Select ONE of the following parenteral anticoagulants (Class I recommendation for all NSTEMI patients) 1:

• Enoxaparin 1 mg/kg subcutaneously every 12 hours (reduce to 1 mg/kg once daily if creatinine clearance <30 mL/min), continued for duration of hospitalization or until PCI is performed 1, 2

  • May give initial 30 mg intravenous bolus in selected patients 1

• Unfractionated heparin intravenous: 60 IU/kg loading dose (maximum 4000 IU) with initial infusion of 12 IU/kg per hour (maximum 1000 IU/h), adjusted per aPTT to maintain therapeutic anticoagulation, continued for 48 hours or until PCI is performed 1, 2

• Fondaparinux 2.5 mg subcutaneously daily, continued for duration of hospitalization or until PCI is performed (preferred for conservative strategy due to lower bleeding risk) 1, 2

  • Critical: If PCI is performed while on fondaparinux, must administer additional anticoagulant with anti-IIa activity (UFH or bivalirudin) due to risk of catheter thrombosis 1

• Bivalirudin 0.10 mg/kg loading dose followed by 0.25 mg/kg per hour (only for early invasive strategy), continued until diagnostic angiography or PCI, with only provisional use of GP IIb/IIIa inhibitor 1

Risk Stratification and Management Strategy

• Perform immediate risk stratification using GRACE or TIMI score to determine timing of invasive strategy 2, 3

• Urgent/immediate invasive strategy (angiography within 2 hours) is mandatory for patients with: 1, 2

  • Refractory angina despite medical therapy
  • Hemodynamic instability or cardiogenic shock
  • Electrical instability (ventricular tachycardia/fibrillation)
  • Mechanical complications

• Early invasive strategy (angiography within 12-24 hours) for initially stabilized high-risk patients with: 1, 2, 5

  • Elevated cardiac troponin
  • Dynamic ST-segment or T-wave changes
  • High GRACE score (>140) or TIMI score (≥3)
  • Diabetes mellitus
  • Renal insufficiency (GFR <60 mL/min)
  • Left ventricular ejection fraction <40%
  • Recent PCI or prior CABG

• Delayed invasive strategy (within 24-72 hours) is reasonable for intermediate-risk patients 1

• Conservative (ischemia-guided) strategy may be considered for low-risk patients without high-risk features, with angiography only if recurrent ischemia develops 1

GP IIb/IIIa Inhibitor Considerations

• Eptifibatide or tirofiban may be added upstream (before angiography) in very high-risk patients with positive troponin, particularly if delay to catheterization is anticipated 1, 2

  • This is Class IIb, Level of Evidence B recommendation 1

• Abciximab should NOT be given upstream; only indicated if no appreciable delay to angiography and PCI is likely to be performed 1

Additional Pharmacotherapy

• Beta-blocker (e.g., metoprolol 25-50 mg orally every 6-12 hours or 5 mg intravenously every 5 minutes for 3 doses) should be initiated within 24 hours unless contraindicated by: 2, 3

  • Heart failure or low-output state
  • Increased risk for cardiogenic shock
  • PR interval >0.24 seconds
  • Second- or third-degree heart block
  • Active asthma or reactive airway disease

• ACE inhibitor (e.g., lisinopril 2.5-5 mg orally daily, titrate upward) should be started within 24 hours for patients with: 2, 3, 5

  • Heart failure
  • Left ventricular dysfunction (LVEF <40%)
  • Hypertension
  • Diabetes mellitus

• ARB (e.g., valsartan 40 mg twice daily) for ACE inhibitor-intolerant patients 2, 3

• High-intensity statin (atorvastatin 80 mg or rosuvastatin 40 mg orally daily) should be initiated immediately regardless of baseline LDL cholesterol 2, 3

Critical Pitfalls to Avoid

• Do NOT administer fibrinolytic therapy in NSTEMI patients (Class III: Harm, Level of Evidence A) 1

• Do NOT give prasugrel upstream before coronary anatomy is defined; wait until time of PCI 4

• Do NOT delay angiography in high-risk patients for "medical stabilization"; early invasive approach (within 24 hours) reduces ischemic events 2, 3

• Avoid NSAIDs (except aspirin) during hospitalization due to increased mortality, reinfarction, hypertension, heart failure, and myocardial rupture risk 2, 3

• Avoid immediate-release dihydropyridine calcium channel blockers (nifedipine) without adequate beta-blockade 2, 3

• Avoid omeprazole and esomeprazole with clopidogrel due to reduced antiplatelet effect; use other PPIs (pantoprazole, lansoprazole) if gastroprotection is needed 2

• Do NOT discontinue antiplatelet therapy prematurely, particularly in the first few weeks after ACS, as this increases risk of subsequent cardiovascular events 1

• If fondaparinux is used, remember to add UFH or bivalirudin at time of PCI to prevent catheter thrombosis 1