Which of the following cardiac markers is most sensitive for detecting an acute myocardial infarction?

Troponin is considered the most sensitive marker for detecting an acute myocardial infarction (AMI) due to its structural specificity and its role in cardiac muscle contraction. It is a protein complex that is released into the bloodstream when the heart muscle is damaged, making it highly specific to cardiac tissue.

Troponin levels begin to rise within a few hours of the onset of an acute myocardial infarction, peaking around 24 to 48 hours, and can remain elevated for several days, which enhances its utility in diagnosing myocardial infarctions even when they are not acute. This makes it a key biomarker in clinical practice for both detecting and managing heart attacks.

Comparatively, other markers like CK-MB and myoglobin have less sensitivity for diagnosing AMI. While CK-MB is also specific to cardiac tissue, it can rise in conditions other than heart attacks and tends to return to baseline more quickly. Myoglobin is an early marker that rises rapidly but is not specific to heart muscle, as it can also be released from skeletal muscle injury. The LD1/LD2 flip, while indicative of myocardial damage, is less commonly used in contemporary practice due to the availability and reliability of troponin testing.

The combination of sensitivity and specificity for cardiac