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 upon presentation, initiate anticoagulation with unfractionated heparin or enoxaparin, add a P2Y12 inhibitor (preferably ticagrelor 180 mg loading dose or clopidogrel 300-600 mg), and perform risk stratification to determine whether an early invasive or conservative strategy is appropriate. 1, 2, 3

Immediate Interventions (First Minutes to Hours)

Antiplatelet Therapy

• Aspirin: Give 162-325 mg loading dose immediately, then continue 75-100 mg daily indefinitely 1, 2, 3
• P2Y12 Inhibitor: Add one of the following before diagnostic angiography (upstream loading) 4, 1:
  • Ticagrelor 180 mg loading dose (preferred), then 90 mg twice daily - can be given regardless of planned strategy 3
  • Clopidogrel 300-600 mg loading dose, then 75 mg daily - if ticagrelor unavailable or contraindicated 4, 3
  • Prasugrel 60 mg - only AFTER coronary anatomy is defined and PCI is planned, NOT before angiography unless bleeding risk is low and CABG unlikely 4

Critical caveat: Prasugrel is potentially harmful in patients with prior stroke/TIA 4. Avoid prasugrel in patients <60 kg (use 5 mg maintenance dose if necessary) or ≥75 years 4.

Anticoagulation Therapy

Initiate parenteral anticoagulation immediately in addition to antiplatelet therapy 1, 2, 3:

• Enoxaparin or fondaparinux preferred over unfractionated heparin for conservative strategy unless CABG planned within 24 hours 4
• Unfractionated heparin: Continue for at least 48 hours or until discharge 4, 1
• Enoxaparin or fondaparinux: Continue for duration of hospitalization, up to 8 days 4, 1
• Bivalirudin: Reasonable alternative, especially if upstream GP IIb/IIIa inhibitor is omitted 4

Supportive Care

• Admit to monitored unit with continuous ECG monitoring for at least 24 hours 1
• Supplemental oxygen only if arterial saturation <90% 1
• Nitroglycerin for ongoing ischemic symptoms unless contraindicated (hypotension, right ventricular infarction, recent phosphodiesterase inhibitor use) 1
• Beta-blockers (e.g., metoprolol) to reduce myocardial oxygen demand by decreasing heart rate, blood pressure, and contractility 1, 5
• Morphine sulfate IV for uncontrolled chest pain despite nitroglycerin 1

Risk Stratification and Management Strategy Selection

Early Invasive Strategy (Angiography within 24-48 hours)

Indicated for high-risk patients with 1, 2, 3:

• Refractory angina despite medical therapy
• Hemodynamic instability or cardiogenic shock
• Electrical instability (ventricular arrhythmias)
• Elevated cardiac biomarkers (troponin)
• High GRACE or TIMI risk score
• Heart failure symptoms
• Significant ST-segment depression

Conservative Strategy

Appropriate for 1, 3:

• Low-risk patients (TIMI score <2) without ongoing ischemia
• Patients with significant comorbidities where invasive risks outweigh benefits
• Patients who stabilize with medical therapy

If conservative strategy selected and patient develops recurrent symptoms, heart failure, or serious arrhythmias, proceed to diagnostic angiography 4.

GP IIb/IIIa Inhibitor Considerations

When to Add GP IIb/IIIa Inhibitors

• High-risk patients with elevated troponin, diabetes, or significant ST-depression undergoing invasive strategy 4
• Conservative strategy patients with recurrent ischemia despite aspirin, P2Y12 inhibitor, and anticoagulation 4
• Preferred agents: Eptifibatide or tirofiban (NOT abciximab unless PCI is imminent) 4

When NOT to Use GP IIb/IIIa Inhibitors

• Low-risk patients (TIMI <2) or high bleeding risk already on aspirin and P2Y12 inhibitor 4
• Abciximab should never be given if PCI is not planned 4
• Can be omitted if bivalirudin selected and ≥300 mg clopidogrel given ≥6 hours before catheterization 4

Post-Angiography Management

If PCI Selected

• Continue aspirin indefinitely 1, 2, 3
• Continue P2Y12 inhibitor for at least 12 months: Clopidogrel 75 mg daily, prasugrel 10 mg daily, or ticagrelor 90 mg twice daily 4, 1
• Earlier discontinuation only if bleeding risk outweighs benefit 4

If CABG Selected

• Continue aspirin 4, 1
• Stop clopidogrel 5-7 days before elective CABG 4, 1
• Stop prasugrel ≥7 days before surgery 3
• Stop ticagrelor ≥5 days before surgery 3

If Medical Management Selected

• Continue aspirin indefinitely 4
• Continue clopidogrel for at least 1 month, ideally up to 1 year 4

Long-Term Management

Cardiac Function Assessment

• Measure left ventricular ejection fraction (LVEF) 1, 3
• If LVEF ≤0.40: Consider diagnostic angiography 1, 3
• If LVEF >0.40: Consider stress testing 1, 3

Secondary Prevention

• ACE inhibitors for heart failure, LV dysfunction (LVEF <0.40), hypertension, or diabetes 1, 2, 3
• ARBs for ACE inhibitor-intolerant patients 1, 3
• Beta-blockers for all patients unless contraindicated 2, 3
• High-intensity statin therapy regardless of baseline LDL 1

Common Pitfalls to Avoid

• Never give prasugrel before coronary anatomy is known unless bleeding risk is low and CABG unlikely 4
• Never use prasugrel in patients with prior stroke/TIA 4
• Avoid NSAIDs (except aspirin) during hospitalization - increased mortality and reinfarction risk 1
• Do not use immediate-release dihydropyridine calcium channel blockers without adequate beta-blockade 1
• Do not give IV ACE inhibitors within first 24 hours due to hypotension risk 1
• Consider proton pump inhibitors when aspirin and clopidogrel used together to minimize GI bleeding 4