When is a Cardiac Marker Test Done?

Cardiac markers are myocardial markers that have the ability to diagnose cardiac injury, including myocardial infarction and myocardial microinjury.

In recent years, the risk factors that can predict heart disease, especially coronary heart disease, have been used as cardiac markers, such as high-sensitivity C-reactive protein, the number of peripheral blood monocytes, the ratio of high-density lipoprotein to low-density lipoprotein, Chlamydia pneumoniae antibody, thrombus precursor protein, fibrinogen, and so on.

1. When should the cardiac marker test be performed?

All diseases that may cause heart injury should always observe the list of cardiac markers, such as coronary heart disease, hypertension, myocarditis, cardiomyopathy, cor pulmonale, cardiac insufficiency and other diseases that damage the myocardium. Besides, taking drugs that damage the myocardium need to observe cardiac markers as well.

The cardiac marker test that can detect minor damage to the heart include myoglobin and troponin.

In addition, for older people, people with cardiovascular disease risk factors such as hyperlipidemia and obesity should also often observe some examination items with predictive value for the risk of coronary heart disease, such as high-sensitivity C-reactive protein, the ratio of high-density lipoprotein to low-density lipoprotein, fibrinogen, etc.

2. What is the clinical significance of the results of the major cardiac marker test?

Creatine kinase (CK), creatine kinase isoenzyme (CKMB), aspartate aminotransferase (GOT/AST), lactate dehydrogenase (LDH), hydroxybutyrate dehydrogenase (HDBD): they are mainly used for the diagnosis of myocardial infarction and also have good diagnostic significance for myocarditis. But they are less sensitive to myocardial injury caused by other causes.

Myoglobin and troponin: these two items are new items for the cardiac marker test that have only started in recent years. They have good specificity and sensitivity, and can be detected at an earlier time of onset, which has great advantages.

Myoglobin can be detected in the blood 1.5 to 2 hours after the occurrence of acute myocardial infarction (that is, the onset of chest pain), and it reaches a peak in 4 to 6 hours. Therefore, this project is especially suitable for early diagnosis of myocardial infarction.

And because of the high sensitivity of this project, this IVD kit can detect small myocardial damage, so the cardiac marker test has good diagnostic value for myocarditis, hypertensive myocardial damage, heart failure, pulmonary heart disease, myocardial damage, etc.

Troponin appears in the blood later than myoglobin after myocardial infarction, about 3 to 6 hours after the chest pain occurs, but it is the item with the highest myocardial injury specificity, so it has a decisive diagnostic value.

Like myoglobin, the cardiac marker test has diagnostic significance for myocardial injury caused by other causes or diseases. However, it takes a long time for troponin to disappear in the blood. Therefore, it is more valuable for patients with a long time of onset and can be used as an observation index of the condition.

High-sensitivity C-reactive protein (hsCRP): hsCRP is an independent prognostic index for incidence rate and mortality of coronary heart disease, angina pectoris, acute myocardial infarction. And the combination of troponin can evaluate its risk.

The clinical significance of hsCRP is great. Generally speaking, people with hsCRP more than 3mg/L should be given necessary early preventive treatment or behavioral guidance. If the cardiac marker test is combined with blood lipid test, its clinical significance is greater.