What are they?
Cardiac
biomarkers are substances that are released into the blood when the heart is damaged. Measurement of these biomarkers is used to help diagnose, evaluate, and monitor patients with suspected
acute coronary syndrome (ACS). The symptoms of ACS include chest pain, pressure, nausea, and/or shortness of breath. These symptoms are associated with
heart attacks and
angina, but they may also be seen with non-heart-related conditions. Increases in one or more cardiac biomarkers can identify patients with ACS, allowing rapid diagnosis and appropriate treatment of their condition.
ACS is caused by a sudden decrease in the amount of blood and oxygen reaching the heart. This decrease, also termed ischemia, is usually due to severe narrowing of the coronary arteries or a sudden blockage of blood flow through these arteries. A decrease in the supply of blood to the heart can cause angina (chest pain). When blood flow to the heart is blocked or significantly reduced, it can cause heart cells to die, triggering an acute myocardial infarction (AMI or heart attack). This can lead to death of the affected heart muscle and to permanent damage and scarring of the heart.
Cardiac biomarker tests are ordered to help detect the presence of ACS and to evaluate its severity as soon as possible so that appropriate therapy can be initiated. It is important to distinguish heart attack from angina, heart failure, or another condition because the treatments and monitoring requirements are different. For heart attacks, prompt medical intervention is crucial to minimize heart damage and future complications. Cardiac biomarker tests must be available to the doctor 24 hours a day, 7 days a week with a rapid turn-around-time. Some of the tests may be performed at the point of care (POC) – in the Emergency Room or at the patient’s bedside. Serial testing of one or more cardiac biomarkers is often done to ensure that a rise in their blood levels is not missed and to estimate the severity of a heart attack.
Only a few cardiac biomarker tests are routinely used by physicians. The current biomarker test of choice for detecting heart damage is troponin. Other cardiac biomarkers are less specific for the heart and may be elevated in skeletal muscle injury, liver disease, or kidney disease. Many other potential cardiac biomarkers are being researched, but their clinical utility has yet to be established.
Note: Cardiac biomarkers are not the same tests as those that are used to screen the general healthy population for their risk of developing heart disease. Those can be found under Cardiac Risk Assessment.
