Cardiac troponins I (cTnI) and T (cTnT) are established biomarkers of acute myocardial infarction (AMI). Together with troponin С (TnC), they form a ternary troponin complex (ITC-complex) that represents a significant portion of troponins released into the bloodstream following cardiomyocyte necrosis.

Modern immunodiagnostic systems utilize various types of blood samples to measure cardiac troponins. The impact of commonly used anticoagulants such as sodium citrate, heparin and EDTA, on the integrity of the ITC-complex in the samples remains unclear. To address this, Hytest scientists have conducted extensive studies, that were compiled in the latest article ‘Influence of Anticoagulants on the Dissociation of Cardiac Troponin Complex in Blood samples’, and published on August 16, 2024, in the International Journal of Molecular Sciences.

In this article, our scientists investigated how the native ITC-complex behaves when incubated in buffer solutions, serum, or citrate, heparin and EDTA plasmas at various temperatures. The results showed that ITC-complex is mostly stable in the first 24 hours of in vitro incubation in these matrixes at room temperature or at +4 °C but dissociates to form IC-complex and free cTnT at 37 °C. IC-complex further dissociates in heparin and EDTA plasmas at 37 °C to form free TnC. It was also shown that in serum and EDTA plasma cTnT and cTnI undergo partial proteolysis after in vitro incubation at 37 °C. Additionally, anti-troponin autoantibodies that are present in blood of some people impede the dissociation of cTnT from the ITC-complex and appear to enhance its stability in the blood samples.

The study describes the in vitro stability of troponin complex in various conditions and indicates that dissociation of troponin complex may take place both in damaged myocardium and in circulation. These insights can aid in the accurate interpretation of cardiac troponin tests.

Since 1994, Hytest has systematically studied the biochemical and immunochemical properties of cardiac troponins and has developed comprehensive antibody selection strategies for cTnI and cTnT assay development, backed by a strong scientific foundation. For more detailed information, please refer to the full article and our Troponins Booklet.