Diagnostic Role and Methods of Detection of Cardiac Troponins: An Opinion from Historical and Current Points of View

Abstract

Abstract: The laboratory methods for the determination of cardiac troponins (cTnI, cTnT) used nowadays are extremely diverse, which has a significant impact on our understanding of the biology and di¬agnostic the value of cTnI and cTnT as biomarkers. The main classifica¬tion of methods for the determination of cTnI and cTnT is based on the sensitivity of the immunoassay. Low- and moderately sensitive detec¬tion methods are known to be relatively low sensitive, which leads to a relatively late confirmation of cardiomyocyte death. Due to new highly sensitive methods used for the determination of cTnI and cTnT, designated as highly or ultrasensitive immunoassays (hs-TnT and hs-TnT), we received new, revised data about the biology of cardiac tro¬ponin molecules. In particular, it became clear that they can be considered products of normal myocardium metabolism since hs-TnT and hs-TnT are detected in almost all healthy patients. It also turned out that hs-TnT and hs-TnT are differ by gender (in men, troponin con¬centration in the blood is higher than in women), age (in elderly pa¬tients, the levels of troponins are higher than in young ones) and circadian cycles (morning concentrations of troponins are higher than in the evening). A large variety of methods for determining cTnI and cTnT, differing in their diagnostic capabilities, creates the need for tests to perform an unbiased assessment of the analytical charac¬teristics of each method. This review focuses on the most pressing is¬sues related to the discussion of the biological characteristics of cardiac troponin and the analytical characteristics of troponin immunoassays from a historical and contemporary point of view.