Which enzyme is more specific for acute myocardial infarction?

The enzyme that is more specific for acute myocardial infarction is CK-MB. Creatine Kinase-MB (CK-MB) is an isoenzyme of creatine kinase that is primarily found in cardiac muscle. During an acute myocardial infarction, cardiac muscle cells become damaged, leading to the release of CK-MB into the bloodstream.

While myoglobin is also released from damaged muscle and can indicate myocardial injury, it is not as specific for cardiac damage since it can be elevated in other conditions that affect muscle tissue. Total CK includes isoenzymes from various tissues, including skeletal muscle, which reduces its specificity for heart-related issues. Lactate dehydrogenase (LDH) can also be elevated in a variety of conditions, including liver and hemolytic diseases, and acts more as a late marker for myocardial infarction rather than a specific early indicator.

CK-MB is particularly valuable in the clinical setting for the diagnosis of myocardial infarction because its levels rise typically within 4-6 hours after the onset of chest pain, peak at around 24 hours, and return to baseline more rapidly than other markers, allowing for timely diagnosis and management. This time course and its specificity for cardiac tissue make CK-MB the enzyme of choice