What laboratory test is most specific for diagnosing myocardial infarction?

Troponin levels are considered the most specific laboratory test for diagnosing myocardial infarction. Troponins are proteins found in cardiac muscle that play a crucial role in muscle contraction. When myocardial cells are damaged, such as during an infarction, troponin is released into the bloodstream.

The specific types of troponins often measured in clinical practice are troponin I and troponin T, both of which are specific to cardiac tissue. Their elevation indicates injury to the myocardial cells and is a strong marker for acute myocardial infarction, even appearing in the early phases after the incident.

Unlike other markers, such as creatine kinase (CK) which can be elevated in various muscle injuries or conditions, troponin is specific to the heart, making it a preferred biomarker in clinical settings for diagnosing myocardial infarctions. Additionally, troponin levels remain elevated longer than other markers, allowing for accurate diagnosis during the critical period post-event.

Other tests, like B-type natriuretic peptide (BNP), are more associated with heart failure rather than myocardial infarction. High-sensitivity C-reactive protein (hs-CRP) is a marker of inflammation and is used in assessing cardiovascular risk but does not have the specificity for