Blood Studies for Cardiovascular System I: Cardiac Biomarkers

Cardiac biomarkers are enzymes, proteins, and hormones released into the blood during cardiac cell injury. They aid in the management of myocardial necrosis and acute coronary syndrome.

First, cardiac troponins, such as troponins I and T, are the most precise and sensitive markers of myocardial injury.

Detectable within 4 to 6 hours post-injury, they remain elevated for 10 to 14 days, guiding immediate treatment and informing prognosis.

High-sensitivity troponin assays can detect troponins as early as 90 minutes post-injury.

Next, myoglobin, an oxygen-binding protein, is released within 1 to 3 hours, peaks at 12 hours, and quickly normalizes, aiding in early detection.

Finally, creatine kinase-myoglobin or CK-MB rises quickly after myocardial infarction, peaking within 12 to 24 hours and normalizing within 48 hours.

This rapid normalization makes CK-MB a valuable marker for detecting reinfarction if levels rise again after returning to baseline.