What is the management for Non-ST-Elevation Myocardial Infarction (NSTEMI) in a hospital?

Management of NSTEMI in Hospital

All NSTEMI patients should receive immediate aspirin 162-325 mg (non-enteric, chewed or oral), admission to a monitored unit with continuous rhythm monitoring for at least 24 hours, anticoagulation with unfractionated heparin or enoxaparin, and risk stratification to determine timing of coronary angiography within 24-48 hours for high-risk patients or an ischemia-guided approach for lower-risk patients. 1

Immediate Management Upon Presentation

Initial Medications (First Hour)

• Aspirin 162-325 mg should be administered immediately upon presentation, non-enteric formulation, chewed or taken orally 2, 1
• Nitroglycerin (sublingual or IV) should be given for ongoing chest pain unless contraindicated (systolic BP <90 mmHg, severe bradycardia, right ventricular infarction, or recent phosphodiesterase inhibitor use within 24 hours for sildenafil or 48 hours for tadalafil) 2, 1
• Morphine sulfate IV may be considered for uncontrolled ischemic chest pain despite nitroglycerin, though use cautiously as it may delay antiplatelet absorption 1
• Supplemental oxygen should be administered only if arterial oxygen saturation is <90% 1

Monitoring and Admission

• Admit to a monitored unit with continuous rhythm monitoring for at least 24 hours (or until PCI, whichever comes first) 1, 3
• Extended monitoring beyond 24 hours is recommended for patients at increased risk for cardiac arrhythmias 3

Anticoagulation Therapy (Within First Few Hours)

Choose ONE of the following anticoagulants based on institutional protocols and bleeding risk 2, 1:

• Unfractionated heparin (UFH): Preferred for patients with high bleeding risk due to short half-life and reversibility; continue for at least 48 hours or until discharge 2, 1

  • Dosing: 60 U/kg IV bolus (maximum 4000 U), then 12 U/kg/hr infusion (maximum 1000 U/hr), adjusted to aPTT 1.5-2.5 times control 2

• Enoxaparin: 1 mg/kg subcutaneously every 12 hours; continue for duration of hospitalization up to 8 days 2, 1

• Fondaparinux: 2.5 mg subcutaneously daily; continue for duration of hospitalization up to 8 days 2, 1

• Bivalirudin: Alternative option, particularly if early invasive strategy planned 2

Anti-Ischemic Therapy

Beta-Blockers

• Initiate oral beta-blockers within 24 hours unless contraindicated (heart failure signs, low-output state, increased risk for cardiogenic shock, PR interval >0.24 seconds, second or third-degree heart block, active asthma) 2, 1
• Do NOT give IV beta-blockers to patients with signs of heart failure, low-output state, or risk factors for cardiogenic shock (age >70 years, systolic BP <120 mmHg, sinus tachycardia >110 bpm or heart rate <60 bpm, increased time since symptom onset) 2

ACE Inhibitors

• Start within 24 hours for patients with anterior MI, heart failure, or LVEF ≤0.40, unless contraindicated (hypotension with systolic BP <100 mmHg or >30 mmHg below baseline) 2
• Avoid IV ACE inhibitors within first 24 hours due to increased hypotension risk 2, 1
• ARBs are reasonable alternatives for ACE inhibitor-intolerant patients with heart failure or LVEF ≤0.40 2, 1

Risk Stratification and Timing of Angiography

High-Risk Features Requiring Early Invasive Strategy (Angiography Within 24 Hours)

• Refractory angina despite medical therapy 1
• Hemodynamic instability or cardiogenic shock 2, 1
• Life-threatening ventricular arrhythmias 2
• Recurrent angina or ischemia at rest or with low-level activity 2
• New or worsening mitral regurgitation or S3 gallop 2
• Elevated cardiac biomarkers (high-sensitivity troponin) 1
• Dynamic ST-segment changes (≥0.05 mV depression) 2
• GRACE or TIMI risk score indicating high risk 1

Conservative/Ischemia-Guided Strategy

• Appropriate for lower-risk patients without ongoing ischemia or patients with significant comorbidities where invasive risks outweigh benefits 1
• Perform stress testing before discharge if managed conservatively 1

Antiplatelet Therapy Strategy

Before Coronary Angiography

• Aspirin 162-325 mg loading dose, then 81 mg daily maintenance 2, 1
• Delay P2Y12 inhibitor loading dose until coronary anatomy is known (after angiography) to avoid excessive bleeding if urgent CABG is needed 4
  • In the pivotal TRITON-TIMI 38 trial for prasugrel, loading dose was not administered until coronary anatomy was established in UA/NSTEMI patients 4
  • A trial of 4033 NSTEMI patients showed no clear benefit when prasugrel loading dose was given prior to angiography compared to at time of PCI, but bleeding risk increased with early administration 4

After Angiography - If PCI Selected

• Continue aspirin 2, 1
• Add P2Y12 inhibitor with loading dose if not given before angiography 2, 1:
  • Ticagrelor: 180 mg loading dose, then 90 mg twice daily (reasonable to prefer over clopidogrel) 2
  • Prasugrel: 60 mg loading dose, then 10 mg daily (reasonable to prefer over clopidogrel if no prior stroke/TIA and age <75 years; contraindicated if prior stroke/TIA) 2, 4
    • Consider 5 mg daily maintenance dose if weight <60 kg 4
  • Clopidogrel: 300-600 mg loading dose, then 75 mg daily (if ticagrelor or prasugrel contraindicated or unavailable) 1, 5
• Continue dual antiplatelet therapy for 12 months unless excessive bleeding risk 2, 3

After Angiography - If CABG Selected

• Continue aspirin 2, 1
• Discontinue P2Y12 inhibitor 5-7 days before elective CABG (clopidogrel/ticagrelor 5 days, prasugrel 7 days) to limit bleeding 2, 1
• May perform urgent CABG <5 days after clopidogrel/ticagrelor or <7 days after prasugrel if clinically necessary 2

After Angiography - If Medical Management Selected

• Continue aspirin 2, 1
• Add clopidogrel 300-600 mg loading dose if not given before angiography, then 75 mg daily 1, 5

Additional Therapies

Statins

• Initiate high-intensity statin therapy (atorvastatin 40-80 mg or rosuvastatin 20-40 mg) regardless of baseline LDL levels 1

Glycoprotein IIb/IIIa Inhibitors

• Consider for high-risk patients undergoing PCI, particularly if large thrombus burden 2
• Dosing adjustments needed based on whether UFH is used and target ACT levels 2

Critical Pitfalls to Avoid

Medications to AVOID

• NSAIDs (except aspirin) should NOT be administered during hospitalization due to increased risks of mortality, reinfarction, hypertension, heart failure, and myocardial rupture 2, 1
• Immediate-release dihydropyridine calcium channel blockers should NOT be given without adequate beta-blockade 1
• IV ACE inhibitors within first 24 hours due to hypotension risk 2, 1
• IV beta-blockers in patients with heart failure signs or cardiogenic shock risk factors 2

Drug Interactions

• Avoid omeprazole or esomeprazole with clopidogrel as they significantly reduce clopidogrel's antiplatelet activity; use alternative PPI if needed 5
• Prasugrel is contraindicated in patients with prior stroke or TIA 4

Timing Considerations

• Do not delay angiography in high-risk patients based solely on symptom resolution; continuous monitoring and risk stratification remain essential 3
• Do not discontinue dual antiplatelet therapy prematurely even if symptoms resolve, as this increases recurrent event risk 3

Hospital Discharge Planning

Medications at Discharge

• Continue all anti-ischemic medications required in hospital (beta-blockers, ACE inhibitors/ARBs, nitrates as needed) with dose titration as necessary 2
• Aspirin 81 mg daily indefinitely 2
• P2Y12 inhibitor for 12 months (ticagrelor, prasugrel, or clopidogrel based on what was initiated) 2, 3
• High-intensity statin 1
• Sublingual or spray nitroglycerin with instructions for use 2

Patient Education

• Provide verbal and written instructions about medication type, purpose, dose, frequency, side effects, and duration 2
• Educate about symptoms of worsening ischemia and when to seek emergency care 2
• If angina lasts >1 minute: take 1 dose nitroglycerin; if pain does not subside within 3-5 minutes, call 9-1-1 immediately 2
• Instruct on cardiovascular risk factor modification 2