Biochemical Tests for Metabolic and Systemic Disorders

Myocardial Infarction: Cardiac Biomarkers

Myocardial infarction (MI), commonly known as a heart attack, is a life-threatening condition that occurs due to the obstruction of blood flow to the heart muscle. Accurate and early diagnosis is critical to managing patient outcomes, and biochemical markers play an essential role in this process.

Key Cardiac Biomarkers

Troponins (cTnI and cTnT)

• Highly sensitive indicators of myocardial injury.
• Elevated levels can be detected within 2–4 hours post-MI.
• Remain elevated for up to 10–14 days, aiding late diagnosis.

Creatine Kinase-MB (CK-MB)

• Specific to cardiac tissue but less sensitive than troponins.
• Rises within 4–6 hours post-MI, peaks at 12–24 hours.
• Returns to baseline within 48–72 hours, useful for reinfarction detection.

Myoglobin

• Rapidly released (within 1–3 hours) post-MI.
• Low specificity, but useful for early detection.
• Cleared quickly (within 24 hours).

Clinical Significance

Cardiac biomarkers provide valuable insights for diagnosing myocardial infarction, risk stratification, and guiding treatment decisions. Among them, troponins are the gold standard due to their superior sensitivity and specificity.