Causes of high troponin

The normal functioning of muscles throughout our body is inseparable from a regulatory protein called troponin. For certain diseases, such as myocardial damage, troponin acts as a marker. Once the troponin value increases, it indicates that there may be a certain disease in the body. We must have a full understanding of this phenomenon so that we can make a preliminary judgment. So, what causes high troponin levels? Let’s take a closer look at it below.

Troponin (Tn) is a regulatory protein for muscle tissue contraction. It is located on the thin filaments of contractile proteins and plays an important regulatory role in muscle contraction and relaxation. It contains three subtypes: fast-response type, slow-response type and cardiac troponin (cTn). The first two are related to skeletal muscle, while cardiac troponin only exists in cardiomyocytes. It is a complex composed of three subunits: troponin T (cTn), troponin I (cTnI), and troponin C (cTnC). cTnT and cTnI are cardiomyocyte-specific antigens that are degraded from myocardial fibers when cardiomyocytes are damaged. Increased cTn in serum reflects damage to myocardial cells, and its specificity and sensitivity are higher than the myocardial enzyme spectrum commonly used in the past.

Troponin is a marker of myocardial injury and necrosis and has important clinical significance for the diagnosis and risk stratification of acute myocardial infarction. Elevated troponin values ​​indicate myocardial damage, which can be seen in acute myocardial infarction, unstable angina, pulmonary infarction, heart failure and other diseases that cause myocardial damage, such as pancreatitis and connective tissue diseases. The higher the value, the wider the range of damage. In patients with acute myocardial infarction, it begins to be released within 3 to 6 hours, reaches a peak within 10 to 24 hours, and the time to return to normal is 10 to 15 days and 5 to 7 days for cTnT and cTnI, respectively; elevated levels may also occur in some patients with renal insufficiency.

Elevated troponin combined with evidence of ischemia is helpful for the early diagnosis and treatment of type I myocardial infarction; understanding the changing pattern of elevated troponin is helpful for the differential diagnosis of elevated troponin. In case of transient myocardial damage caused by strenuous exercise, tachycardia, acute pulmonary embolism, etc., cTn may increase transiently and return to normal within 1 to 2 days; the increase in cTn caused by heart failure is chronic. These characteristics are helpful in distinguishing it from myocardial infarction.