Treatment for NSTEMI
Patients with NSTEMI should receive immediate dual antiplatelet therapy (aspirin plus ticagrelor), parenteral anticoagulation (preferably enoxaparin), high-intensity statin therapy, and undergo early invasive coronary angiography within 24 hours if they have elevated troponin or other high-risk features. 1, 2
Immediate Medical Management
Antiplatelet Therapy
Initiate dual antiplatelet therapy immediately upon diagnosis:
- Aspirin: Give 150-325 mg loading dose (non-enteric coated), then 81-100 mg daily indefinitely 1, 2
- P2Y12 Inhibitor - Choose one of the following:
- Ticagrelor (preferred): 180 mg loading dose, then 90 mg twice daily - this is the preferred agent for moderate-to-high risk NSTEMI patients with elevated troponin 1, 2
- Prasugrel: 60 mg loading dose, then 10 mg daily - only if proceeding to PCI and coronary anatomy is known; contraindicated in patients with prior stroke/TIA 1
- Clopidogrel: 300-600 mg loading dose, then 75 mg daily - use only if ticagrelor or prasugrel cannot be given 1, 3
Continue P2Y12 inhibitor for 12 months after PCI, then transition to aspirin monotherapy indefinitely. 1, 2
Anticoagulation
Initiate parenteral anticoagulation immediately in addition to antiplatelet therapy:
- Enoxaparin (preferred): 1 mg/kg subcutaneously every 12 hours 2, 4
- Fondaparinux: 2.5 mg subcutaneously once daily (requires addition of UFH or bivalirudin during PCI) 2
- Unfractionated heparin: Alternative option, particularly in patients with severe renal dysfunction (GFR <30 mL/min) 1, 5
Continue anticoagulation until PCI is performed or for the duration of hospitalization (up to 8 days) if managed medically. 1, 4
Statin Therapy
Start high-intensity statin therapy immediately, regardless of baseline cholesterol levels - this provides plaque stabilization and anti-inflammatory effects beyond LDL lowering. 1, 2
Risk Stratification and Timing of Invasive Strategy
The timing of coronary angiography depends on risk stratification:
Immediate Invasive Strategy (<2 hours) 1, 2
- Hemodynamic instability or cardiogenic shock
- Recurrent or refractory chest pain despite medical therapy
- Life-threatening arrhythmias or cardiac arrest
- Mechanical complications of MI
- Acute heart failure with refractory angina or ST deviation
Early Invasive Strategy (<24 hours) 1, 2
- Elevated troponin (this qualifies as high-risk regardless of GRACE score)
- Dynamic ST- or T-wave changes
- GRACE score >140
Delayed Invasive Strategy (25-72 hours) 1
- Diabetes mellitus
- Renal insufficiency (GFR <60 mL/min/1.73 m²)
- Reduced LV systolic function (EF <40%)
- GRACE score 109-140
Your patient with elevated troponin qualifies for early invasive strategy within 24 hours. 1, 2
Glycoprotein IIb/IIIa Inhibitors
Do NOT routinely administer GP IIb/IIIa inhibitors upstream (before angiography) - the EARLY ACS trial demonstrated increased bleeding without ischemic benefit. 1, 2
Consider GP IIb/IIIa inhibitors (eptifibatide, tirofiban, or abciximab) only at the time of PCI in high-risk patients with elevated troponin who are inadequately pretreated with P2Y12 inhibitors. 1
Special Populations
Patients with Renal Dysfunction (GFR <60 mL/min)
- Avoid LMWH or fondaparinux without dose adjustment - use unfractionated heparin or bivalirudin instead 5
- Continue aspirin 75-162 mg daily 5
- Use clopidogrel 300 mg loading, then 75 mg daily (ticagrelor and prasugrel dosing unchanged but monitor closely) 5
- Still proceed with invasive strategy if high-risk features present, but carefully weigh risk-benefit ratio in CKD stage 4-5 5
Patients with Atrial Fibrillation and Non-Obstructive CAD
This is a distinct scenario requiring different management:
- Initiate dual therapy with DOAC plus clopidogrel 75 mg daily for 1 month 6
- Avoid aspirin - triple therapy dramatically increases bleeding risk without proven benefit in non-obstructive CAD 6
- Transition to DOAC monotherapy after 1 month for long-term stroke prevention 6
Post-PCI Management
After successful PCI:
- Continue aspirin indefinitely 1, 2
- Continue P2Y12 inhibitor (ticagrelor or clopidogrel) for 12 months 1, 2
- Discontinue parenteral anticoagulation 1
- Discontinue GP IIb/IIIa inhibitor if used 1
Long-Term Secondary Prevention
Beyond antiplatelet therapy, ensure the following:
- ACE inhibitors or ARBs for patients with LVEF ≤40%, heart failure, hypertension, or diabetes 2
- Beta-blockers within 24 hours if not contraindicated 5
- High-intensity statin continued long-term with target LDL <70 mg/dL 2, 5
- Proton pump inhibitor to reduce GI bleeding risk with DAPT 6
Common Pitfalls to Avoid
- Do not delay angiography beyond 24 hours in patients with elevated troponin - this is a high-risk feature requiring early intervention 1, 2
- Do not use prasugrel before coronary anatomy is known - it is contraindicated if CABG is needed 1
- Do not use routine upstream GP IIb/IIIa inhibitors - this increases bleeding without benefit 1, 2
- Do not use LMWH in severe renal dysfunction (GFR <30 mL/min) without dose adjustment - switch to UFH 5
- Do not forget to assess CYP2C19 metabolizer status if using clopidogrel - poor metabolizers (2% of Whites, 4% of Blacks, 14% of Chinese) have significantly reduced antiplatelet effect 3
- Do not exceed 100 mg daily aspirin when using ticagrelor - higher doses reduce ticagrelor efficacy 1