What Are Cardiac Biomarkers?
Cardiac biomarkers are protein substances that are introduced into the blood circulation when there is heart damage or stress.
Purpose of Cardiac Biomarkers
These markers are used to help in the diagnosis of cardiac ischemia, cardiac injury, acute coronary syndrome (ACS), and other conditions that lead to decreased, insufficient blood supply to the heart.
Who Will Need the Cardiac Biomarker Test?
The symptoms of cardiac ischemia and ACS vary greatly in their presentation, yet often feature chest pain, breathlessness, queasiness, dizziness and profuse sweating. These symptoms may also be observed in non-cardiac conditions. Biomarker investigations help healthcare providers identify those who are at risk of having these conditions or aid them in swift diagnosis, treatment and patient monitoring, to differentiate cardiac and non-cardiac conditions.
The facility needed to test for these cardiac biomarkers is available 24/7 in Kauvery Hospital with a short turnaround time. POCT (point-of-care testing) is available for some of these tests, which are performed in the emergency department or near the bedside. Depending upon the clinical situation, follow-up testing is done to monitor or assess the severity.
Cardiac Biomarkers: The Tests
Precision in Every Beat: Markers Matter
Biomarkers primarily used for identifying any heart impairment are Troponin I, Troponin T and CK-MB. Other markers are less specific and can be elevated due to other causes, too.
Cardiac biomarker tests that are widely used include:
- Troponin (I or T): Most reliable of cardiac biomarkers. Their level increases in a few hours after cardiac damage and remains so for up to two weeks. The high-sensitivity troponin test can detect even lower levels of the same protein, which cannot be detected by the standard test. This test becomes positive at an early stage and may help diagnose heart events earlier. Further, even for people with stable angina or for people who display no symptoms of heart damage, the test will be positive. Many acute diseases are associated with elevated cTns.
- CK-MB: CK-MB is a type of protein enzyme found in the heart muscle. This increases during heart muscle damage, and its testing is used as an alternative when the troponin test is not available.
Some of the other biomarker tests are:
- hs-CRP: Highly sensitive C-reactive protein is produced by the liver, and increases in response to infection or inflammation. This is a marker of the atherosclerotic process, which leads to inflammation and is used in risk stratification.
- BNP (or NT-proBNP): It is used to detect and monitor heart failure, and also for prognosis to identify the likelihood of a condition recurring.
- Myoglobin
- Lactate dehydrogenase
Other laboratory investigations used in risk stratification to assess an individual’s risk for cardiac disease include total cholesterol, HDL, LDL, cholesterol/HDL ratio, non-HDL, lipoprotein A, apolipoprotein A, apolipoprotein B and homocysteine.
Other Investigations:
There are also other tests which enable doctors to assess the heart’s size, shape and function. Heart rhythm changes, damaged tissues and blocked blood vessels can be identified with these tests. They include:
- Chest x-ray
- Electrocardiogram
- Coronary angiography
- Echocardiogram
- Cardiac stress test
Prevention of Cardiovascular Disease: Healthy Heart, Wealthy Life
- Healthy food habits: Including more fruits, vegetables, whole grains, beans, lean meat, fish and low-fat dairy in diet.
- Reducing intake of salt, sugar, refined carbohydrates and saturated fat.
- Performing regular physical exercise and maintaining a healthy weight.
- Quitting smoking.
- Limiting intake of alcohol.
- Managing stress with healthy measures.
- Getting quality sleep.
- Undergoing regular health check-ups.
- Controlling associated medical conditions is crucial for maintaining heart health – this includes high blood pressure, high cholesterol, diabetes, and obesity.
Dr Subha Palaneeswari M
Consultant Biochemistry,
Kauvery Hospital, Chennai
