Which biomarker is most commonly used to diagnose MI?

Which biomarker is most commonly used to diagnose MI?

• A. Myoglobin
• B. CK-MB
• C. Troponin
• D. LDH

Answer: (C)

When diagnosing a myocardial infarction, you need a marker that signals heart muscle injury with high accuracy. Cardiac troponin, specifically troponin I or T, is the most commonly used because it is highly specific to heart tissue and highly sensitive to even small amounts of heart damage. This means troponin levels rise when the heart is injured and remain elevated for a longer period, allowing clinicians to detect MI even if the patient presents days later. Other markers can rise for various reasons—myoglobin appears early but isn’t heart-specific, LDH is older and nonspecific, and CK-MB is more cardiac-associated than total CK but not as sensitive or specific as troponin. Thus, troponin provides the most reliable indication of myocardial infarction.

When diagnosing a myocardial infarction, you need a marker that signals heart muscle injury with high accuracy. Cardiac troponin, specifically troponin I or T, is the most commonly used because it is highly specific to heart tissue and highly sensitive to even small amounts of heart damage. This means troponin levels rise when the heart is injured and remain elevated for a longer period, allowing clinicians to detect MI even if the patient presents days later. Other markers can rise for various reasons—myoglobin appears early but isn’t heart-specific, LDH is older and nonspecific, and CK-MB is more cardiac-associated than total CK but not as sensitive or specific as troponin. Thus, troponin provides the most reliable indication of myocardial infarction.