Cardiac Troponins: Analytical Characteristics and Diagnostic Capabilities of Modern (High-sensitive) Determination Methods

Abstract

Cardiovascular diseases have a leading role in terms of morbidity, mortality, and disability of the population, causing significant socio-economic damage to all countries of the world. This circumstance requires researchers to constantly seek for new biomarkers and improve methods for determining existing biomarkers, and search for new therapeutic targets to improve diagnostic and treatment strategies. Recently, there have been some important changes in laboratory diagnostics of patients with acute coronary syndrome, due to the introduction into the routine practice of new high and ultrasensitive methods for the determination of biomarkers of injury, specific to cardiac muscle tissue, namely cardiac troponins. A key advantage of highly sensitive immunochemical assays is the ability to detect cardiac troponins in the early stages of myocardial infarction. This allows making the optimal decision on the early choice and conduct of reperfusion therapy, which significantly improves the further prognosis of patients. Among the most significant generally recognised disadvantages of highly sensitive determination methods are low specificity and a huge variety of troponin immunoassays. The decrease in specificity is reflected in the fact that cardiac troponins are no longer considered the “gold standard” of diagnosis related to Acute Myocardial Infarction (AMI) (irreversible ischaemic damage to cardiomyocytes). As a result, any damage to the myocardium, even insignificant and reversible under physiological state (physical activity, stress) and several pathological conditions, can lead to an increase in serum levels of cardiac troponins and affect the accuracy of the diagnosis. Each method for the determination of cardiac troponins, among the existing wide variety of troponin immunoassays, possesses different analytical characteristics, and detects different concentrations of troponins in the same patient. This article provides a view of current data on the biology of cardiac troponins, and defines the analytical characteristics of new high-sensitive methods for the determination of cardiac troponins.