Troponin complex is a complex of proteins that participates in the regulation of muscle contraction. It consists of cardiac troponin I (cTnI), cardiac troponin T (cTnT), and slow skeletal/cardiac troponin C (TnC), which are associated in the ratio of 1:1:1 in a functionally active unit (1). In the heart muscle cells, troponin I and troponin T are presented by the specific cardiac isoforms cTnI and cTnT, respectively. This in turn makes it possible to use them as specific biomarkers of myocardial infarction and cardiovascular diseases (1).
Troponin complex as a marker in diagnostics
Acute myocardial infarction (AMI) causes the damage of heart muscle and the release of troponin complex into the blood of patients where it can be detected by measuring its components: either cTnI or cTnT using cTnI or cTnT assays, respectively (2). The fragments of cTnI and cTnT are also released from the damaged myocardium and they can be detected by the same assays. Both the cTnI and cTnT proteins are currently widely used as the guideline-recommended markers of AMI (3-6) and myocardial injury associated with postoperative myocardium trauma, chemotherapy cardiotoxicity, and many other diseases related to cardiac muscle injury.