Troponin
Overview
Troponin measures cardiac-specific proteins (troponin I or T) released into bloodstream following myocardial injury, serving as highly sensitive and specific biomarkers of cardiomyocyte damage. These regulatory proteins control actin-myosin interactions essential for cardiac muscle contraction. Elevated levels indicate acute myocardial infarction, myocarditis, heart failure exacerbation, or other cardiac injuries, while normal levels effectively rule out acute coronary syndrome; troponin is clinically indispensable for rapid diagnosis of myocardial infarction, risk stratification, and guiding urgent revascularization decisions in chest pain evaluation.
Clinical Use Cases
- Diagnosing acute myocardial infarction (AMI) in emergency settings.
- Risk stratification in acute coronary syndrome and heart failure.
- Detecting myocardial injury from myocarditis, takotsubo cardiomyopathy, or sepsis.
- Monitoring reperfusion success post-percutaneous coronary intervention.
- Evaluating type 2 myocardial infarction from demand ischemia.
Specimen Types
- Serum.
- Plasma (lithium heparin or EDTA).
Measurement Methods
- High-sensitivity cardiac troponin (hs-cTn) immunoassays.
- Chemiluminescent microparticle immunoassay.
- Point-of-care rapid assays.
Test Preparation and Influencing Factors
- No fasting required; serial measurements at 0, 3, and 6 hours optimal.
- Avoid hemolysis (false elevation).
- Renal failure, heart failure, tachyarrhythmias cause chronic elevations.
- Skeletal muscle injury minimally affects cardiac-specific assays.
- Biotin interference possible with streptavidin-biotin assays.
Synonyms
- Cardiac troponin I (cTnI).
- Cardiac troponin T (cTnT).
- High-sensitivity troponin (hs-cTn).