Laboratory Testing in NSTEMI

Cardiac Biomarkers

• The European Society of Cardiology recommends measuring high-sensitivity cardiac troponin (hs-cTn) immediately at presentation with results available within 60 minutes of blood sampling, and serial measurements are mandatory to establish the diagnosis and guide antithrombotic therapy 1, 2, 3, 4
• A dynamic pattern of hs-cTn with ≥20% change between measurements distinguishes true NSTEMI from chronic troponin elevation, and at least one value above the 99th percentile combined with clinical evidence of ischemia confirms NSTEMI 1, 2, 4
• Higher hs-cTn levels correlate directly with increased mortality risk, and serial measurements help identify peak levels for risk stratification 2

Renal Function Assessment

• The European Heart Journal recommends measuring serum creatinine and calculating estimated glomerular filtration rate (eGFR) in all NSTEMI patients at presentation to guide anticoagulation dosing and risk stratification 1, 2
• Renal function is a key component of the GRACE risk score, and reduced eGFR independently predicts mortality and bleeding complications in NSTEMI 1, 2, 6, 7

Coagulation Parameters

• The American College of Cardiology recommends measuring baseline coagulation studies, including INR, PTT, and aPTT, before initiating anticoagulation therapy to identify patients at increased bleeding risk 6, 7
• Baseline coagulation parameters help identify patients who may benefit from fondaparinux over other anticoagulants, and antiplatelet therapy can be initiated even with elevated INR, but clinical judgment is required regarding the full antithrombotic regimen 6, 7

Glucose Assessment

• The European Heart Journal recommends measuring glucose at presentation in all NSTEMI patients to identify diabetic patients and guide long-term therapy, as acute hyperglycemia indicates worse prognosis regardless of diabetes history 2, 6, 7

Hepatic Function

• The American College of Cardiology recommends measuring baseline ALT and AST before initiating pharmacotherapy to identify contraindications and monitor for complications, although liver enzymes are not part of standard NSTEMI risk scores 2, 6, 7

Additional Laboratory Tests

• The European Society of Cardiology recommends considering BNP/NT-proBNP for enhanced risk stratification, as elevated BNP or NT-proBNP predicts death, acute heart failure, and atrial fibrillation development 1, 2, 3, 4
• A complete blood count, including hemoglobin, hematocrit, platelet count, and white blood cell count, provides additional prognostic information and helps identify patients at increased bleeding risk 2, 6, 7