What is the management of Non-ST-Elevation Myocardial Infarction (NSTEMI)?

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

The management of NSTEMI requires a combination of antiplatelet therapy, anticoagulation, and risk stratification to determine the need for invasive versus conservative strategies, with aspirin as the cornerstone of treatment for all patients. 1, 2

Initial Management

• Administer aspirin 162-325 mg (non-enteric formulation, orally or chewed) as soon as possible after hospital presentation 1
• Admit to a monitored unit with continuous rhythm monitoring for at least 24 hours (or until PCI, whichever comes first) 1, 2
• Administer supplemental oxygen if arterial oxygen saturation is <90% 1, 3
• Consider nitroglycerin for ongoing ischemic symptoms unless contraindicated (systolic BP <90 mmHg, severe bradycardia, tachycardia without heart failure, right ventricular infarction, or recent use of phosphodiesterase inhibitors) 1, 3
• Initiate beta-blockers to reduce myocardial oxygen demand by decreasing heart rate, blood pressure, and myocardial contractility 1, 3

Risk Stratification

• Measure high-sensitivity cardiac troponin (hs-cTn) serially for both diagnosis and prognostic assessment 1, 2
• Perform echocardiography to evaluate regional and global left ventricular function 1, 2
• Assess hemodynamic stability, presence of ongoing ischemia, and risk factors for adverse outcomes 3
• Consider using risk scores such as TIMI Risk Score (age ≥65 years, >3 coronary risk factors, prior angiographic coronary obstruction, ST-segment deviation, >2 angina events within 24h, use of aspirin within 7 days, and elevated cardiac markers) 4

Antiplatelet Therapy

• Continue aspirin 75-162 mg daily long-term for all patients 4
• Administer a loading dose of a P2Y12 inhibitor (clopidogrel, ticagrelor, or prasugrel) if not given before diagnostic angiography 4, 5
• For patients managed with PCI:
  • Continue dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor 4, 6
  • Consider an intravenous GP IIb/IIIa inhibitor (abciximab, eptifibatide, or tirofiban) for troponin-positive and other high-risk patients 4

Anticoagulation

• Initiate parenteral anticoagulation for all patients in addition to antiplatelet therapy 4, 2
• Options include unfractionated heparin (UFH), enoxaparin, fondaparinux, or bivalirudin 4
• For patients managed conservatively:
  • Continue intravenous UFH for at least 48 hours or until discharge 4
  • Continue enoxaparin for duration of hospitalization, up to 8 days 4
  • Continue fondaparinux for duration of hospitalization, up to 8 days 4
  • Either discontinue bivalirudin or continue at a dose of 0.25 mg per kg per hour for up to 72 hours at physician's discretion 4

Management Strategy Selection

• For patients with ongoing ischemia refractory to medical therapy or hemodynamic instability, an early invasive strategy with cardiac catheterization is recommended 1, 3
• For patients managed with PCI:
  • Continue aspirin 4
  • Administer a loading dose of a P2Y12 inhibitor if not started before diagnostic angiography 4
  • Consider an IV GP IIb/IIIa inhibitor for high-risk patients 4
  • Discontinue anticoagulant therapy after PCI for uncomplicated cases 4
• For patients managed conservatively:
  • Continue aspirin 4
  • Administer a loading dose of a P2Y12 inhibitor if not given before diagnostic angiography 4
  • Discontinue IV GP IIb/IIIa inhibitor if started previously 4
  • Continue anticoagulant therapy as outlined above 4

Long-term Management

• Continue aspirin indefinitely 1, 2
• Continue P2Y12 inhibitor therapy for 12 months unless contraindicated or there is excessive bleeding risk 2, 6
• Initiate beta-blockers for all patients unless contraindicated 1, 2
• Consider ACE inhibitors for patients with heart failure, LV dysfunction (LVEF <0.40), hypertension, or diabetes 1, 2
• Consider ARBs for ACE inhibitor-intolerant patients 1, 2
• Measure LVEF in patients managed conservatively 4
• If LVEF is ≤0.40, consider diagnostic angiography 4
• If LVEF is >0.40, consider a stress test 4

Common Pitfalls and Caveats

• Avoid NSAIDs (except for aspirin) during hospitalization due to increased risks of mortality, reinfarction, hypertension, heart failure, and myocardial rupture 1, 3
• Do not administer immediate-release dihydropyridine calcium channel blockers without adequate beta-blockade 1, 3
• Avoid intravenous ACE inhibitors within the first 24 hours due to increased risk of hypotension 1, 3
• Do not use PDE5 inhibitors (sildenafil within 24 hours, tadalafil within 48 hours) in patients who have received nitrates due to potentially dangerous hypotensive effects 1, 3
• For patients undergoing CABG, manage antiplatelet and anticoagulant therapy as follows:
  • Continue aspirin 4
  • Discontinue clopidogrel/prasugrel 5-7 days before CABG 4
  • Discontinue IV GP IIb/IIIa inhibitor 4 hours before CABG 4
  • Continue UFH, but discontinue enoxaparin 12-24 hours before CABG, fondaparinux 24 hours before CABG, and bivalirudin 3 hours before CABG 4