What are cardiac biomarkers?
Cardiac biomarkers are substances that are released into the bloodstream when heart muscle is damaged or stressed. Measurement of these biomarkers is used to help diagnose, assess risk and manage people with the acute coronary syndrome (ACS), a potentially life-threatening condition characterised by the sudden onset of persistent pain in the chest, one or both arms, shoulders, stomach or jaw, shortness of breath, nausea, sweating and dizziness. The commonest cause of the syndrome is a heart attack (also called a myocardial infarction or MI) in which heart muscle cells die from insufficient blood flow caused by the narrowing or blockage of one of the heart's coronary arteries. However, similar symptoms may be caused by unstable angina and by other cardiac and non-cardiac conditions. Between 60% and 80% of patients taken to hospital with chest pain are found not to have had a heart attack.
Cardiac biomarker tests are requested immediately when a patient with symptoms of ACS is admitted to hospital as an emergency. Together with evidence from an electrocardiogram (ECG) and/or imaging investigations, increasing levels over time of a cardiac biomarker can help to identify those who have had a heart attack, allowing early treatment of their condition. Biomarker measurements are also used to assess the result of treatment with surgery (coronary angioplasty) or ‘clot-busting’ drugs. When the heart muscle’s blood supply is successfully restored, rapidly increasing amounts of biomarker are washed into the blood from damaged heart muscle.