What is the treatment for a patient with Non-ST-Elevation Myocardial Infarction (NSTEMI) presenting with chest pain, diaphoresis, ST depression on electrocardiogram (ECG), and elevated troponin levels?

Treatment for NSTEMI with ST Depression and Elevated Troponin

The correct treatment is aspirin, clopidogrel, beta-blocker, and anticoagulation (heparin or LMWH), NOT primary angioplasty or fibrinolytics. 1

Why Not the Other Options?

Primary Angioplasty is WRONG

• Primary angioplasty (emergent PCI within minutes to hours) is indicated for STEMI with persistent ST-elevation, not NSTEMI 1
• NSTEMI patients require an early invasive strategy (angiography within 24-72 hours), not immediate emergent reperfusion 1
• The distinction is critical: STEMI represents complete coronary occlusion requiring immediate reperfusion, while NSTEMI involves partial or intermittent occlusion 1

Fibrinolytics are CONTRAINDICATED

• Fibrinolytic therapy is absolutely contraindicated in NSTEMI and may cause harm 1
• Fibrinolytics are only indicated for STEMI when PCI is not available within appropriate time windows 1
• The GUSTO IV-ACS trial and other studies confirmed no benefit and potential harm from aggressive reperfusion strategies in NSTEMI 1

Correct Initial Medical Management

Immediate Antiplatelet Therapy (Class I Recommendations)

Aspirin:

• Loading dose: 162-325 mg non-enteric coated (chewed or crushed for rapid absorption) 1
• Maintenance: 81 mg daily indefinitely 1
• Reduces 5-week vascular mortality by 23% relative risk reduction 1

P2Y12 Inhibitor (Clopidogrel):

• Loading dose: 300 mg orally 2, 3
• Maintenance: 75 mg daily for 9-12 months minimum 1, 2
• The CURE trial showed 20% relative risk reduction in CV death, MI, or stroke when added to aspirin in NSTEMI 2, 3
• Should be given immediately unless coronary anatomy unknown and CABG planned within 24 hours 1, 3

Anticoagulation (Class I Recommendation)

Preferred: Low Molecular Weight Heparin (LMWH)

• LMWH is superior to unfractionated heparin for NSTEMI 3, 4
• Continue until PCI or for duration of hospitalization if managed medically 1, 4

Alternative: Unfractionated Heparin (UFH)

• If LMWH unavailable or contraindicated 1, 3

Anti-Ischemic Therapy

Beta-Blockers (Class I):

• Initiate oral beta-blocker within first 24 hours 1, 5
• Contraindications: heart failure, low-output state, risk of cardiogenic shock 1

Nitrates:

• Sublingual nitroglycerin 0.3-0.4 mg every 5 minutes × 3 doses for ongoing chest pain 1
• IV nitroglycerin for persistent ischemia, heart failure, or hypertension 1

Timing of Invasive Strategy

Early Invasive Approach (within 24-72 hours)

High-risk features requiring early angiography: 1

• Elevated troponin (as in this case)
• ST-segment depression on ECG (as in this case)
• Recurrent ischemia despite medical therapy
• Hemodynamic instability
• Diabetes mellitus
• GRACE risk score indicating high risk

NOT Urgent/Emergent (within minutes)

• Unlike STEMI, NSTEMI does not require immediate catheterization 1
• The ESC guidelines recommend angiography "as soon as possible, but without undue urgency" in most high-risk NSTEMI patients 1
• Early invasive use increased from 9% (1995) to 60% (2015), with corresponding mortality reduction from 17.2% to 6.3% 1

GP IIb/IIIa Inhibitors: Conditional Use

Consider adding (Class IIa): 1

• Eptifibatide or tirofiban in moderate-to-high risk patients
• Particularly if elevated troponin, diabetes, or planned PCI 1
• Timing controversy: The EARLY ACS trial showed no benefit of upstream (early) vs. deferred (at time of PCI) administration, with increased bleeding risk when given early 1
• Current recommendation: Defer until time of PCI rather than routine upstream use 1

Critical Pitfalls to Avoid

1. Do NOT give fibrinolytics - This is harmful in NSTEMI 1
2. Do NOT rush to emergent catheterization - Early invasive (24-72h) is appropriate, not immediate 1
3. Do NOT withhold clopidogrel waiting for anatomy unless CABG planned within 24 hours 1, 3
4. Do NOT use abciximab without planned PCI - GUSTO IV-ACS showed potential harm 1
5. Do NOT forget anticoagulation - Essential component of initial therapy 3, 4

Summary Algorithm

Immediate (within 10 minutes): 1

• Aspirin 162-325 mg (chewed)
• Clopidogrel 300 mg loading dose
• LMWH or UFH
• Beta-blocker (if no contraindications)
• Sublingual nitroglycerin for ongoing pain

Within 24-72 hours: 1

• Coronary angiography with revascularization as appropriate
• Continue dual antiplatelet therapy for minimum 12 months 1, 2

Avoid: 1

• Fibrinolytics (contraindicated)
• Emergent primary PCI (not indicated for NSTEMI)