Which biomarker is most indicative of a myocardial infarction (MI) in a patient?

Troponin is considered the most indicative biomarker for myocardial infarction (MI) due to its high sensitivity and specificity for cardiac muscle injury. Troponin is a protein complex that is found in cardiac muscle, and it is released into the bloodstream when there is damage to the heart muscle, such as in the case of a myocardial infarction.

The elevation of troponin levels can be detected within a few hours after the onset of chest pain, and they can remain elevated for several days, making them an excellent indicator for diagnosing an MI. Additionally, the levels of troponin can correlate with the extent of myocardial injury, providing crucial information about the severity of the infarction.

While other biomarkers like CK-MB and myoglobin can also indicate myocardial injury, troponin is preferred because it is more specific to cardiac tissue. CK-MB levels can rise due to damage to other tissues, and myoglobin can increase in many non-cardiac conditions as well. C-reactive protein (CRP) is a marker of inflammation and is not specific to cardiac injury, making it less useful for diagnosing an MI.

Overall, troponin stands out as the most reliable biomarker for assessing myocardial infarction in clinical practice.