What are they?
Cardiac Biomarkers are enzymes, proteins, and hormones that are associated with heart function, damage or failure. Some of the tests are specific for the heart while others are also elevated with skeletal muscle damage. Cardiac Biomarkers are used for diagnostic and prognostic purposes and are frequently ordered by doctors when someone comes into the Emergency Room complaining of symptoms, such as chest pain, pressure, nausea, and shortness of breath. These tests are ordered, along with other laboratory and non-laboratory tests, to detect heart failure (which is often a chronic, progressive condition affecting the ability of the heart to fill with blood and pump efficiently) and the acute coronary syndromes (ACS) as well as to help determine prognosis for people who have had a heart attack.
ACS is a group of symptoms that reflect a sudden decrease in the amount of blood and oxygen, also termed “ischemia,” reaching the heart. This decrease is frequently due to either a narrowing of the coronary arteries (Atherosclerosis or vessel spasm) or unstable plaques, which can cause a blood clot (thrombus) and blockage of blood flow. If the oxygen supply is low, it can cause Angina (pain); if blood flow is reduced, it can cause death of heart cells (called myocardial infarction or Heart Attack) and can lead to death of the affected heart muscle cells and to permanent damage and scarring of the heart.
The goal with Cardiac Biomarkers is to be able to detect the presence and severity of an acute heart condition as soon as possible so that appropriate treatment can be initiated. Cardiac Biomarkers must be available to the doctor 24 hours a day, 7 days a week with a rapid turn-around-time. Different biomarkers have different times that their levels rise, peak, and fall within the body, allowing them to be used not only to track the progress of a heart attack but to estimate when it began and to monitor for recurrence. There are only a few Cardiac Biomarkers that are being routinely used by physicians. Some have been phased out because they are not as specific as the marker of choice - troponin. Many other potential Cardiac Biomarkers are still being researched but their clinical utility has yet to be established.
Revision date: July 8, 2011
Last revised: by Jorge P. Ribeiro, MD