On the potential effect of circadian rhythms of cardiac troponins on the diagnosis of acute myocardial infarction

Abstract

Methods for the determination of cardiac troponins have been significantly improved, facilitating further advancement of the therapeutic and diagnostic process of the cardiovascular diseases case management. In particular, acceleration of the acute myocardial infarction testing (early diagnostic algorithms: 0-1 h, 0-3 h) enabled earlier detection and choice of the optimal treatment tactics. At the same time, with the increased sensitivity in the laboratory test results interpretation, there emerged a necessity to take into account some additional factors that may affect the concentration of cardiac troponins in blood serum. Several recent studies have reported the existence of circadian rhythms in cardiac troponins. This article aims to discuss the possible mechanisms of how circadian rhythms of cardiac troponins develop and their influence on the diagnosis of acute myocardial infarction.

Cardiac Troponins: Contemporary Biological Data and New Methods of Determination

“…The increased activity of these systems in the morning is necessary for a healthy person to maintain the optimal period of wakefulness; however, these systems can have an additional adverse effect on the state of the CVS both in normal and in pathological conditions. 36,71 For example, according to several studies, the size of the necrosis zone and the levels of cardiomarkers also have similar circadian features, exhibiting maximum values in the morning. 72,73 It is also quite remarkable that the peak activity of the above systems practically coincides with the peak levels of cardiac troponins in the morning, which is further evidence in favor of the mechanisms of this formation of hs-cTnI and hs-cTnT circadian rhythms.…”

“…Additionally, unfavorable family history and lipid profile (significant increase of total cholesterol and low-density lipoproteins) were indicative of AMI. At the same time, ECG, Echo-CG and coronarography showed no signs of Figure 1 Main groups of causes of increased cTnI and cTnT that are not associated with AMI, according to 33,36…”

“…As an exception to this rule, a group of causes of falsepositive increases in cTnI and cTnT can be noted, which includes cross-reactions of diagnostic anti-cTnI and anti-cTnT antibodies with skeletal troponins, the influence of heterophilic antibodies, alkaline phosphatase, biotin, hemolysis, ictericity and lipemia. 33,36 In general, the main reasons for the increase in cTnI and cTnT, which are not directly related to AMI, can be divided into three groups (Figure 1).…”

“…61 According to some reports, circadian rhythms may have a potential impact on the accuracy of early diagnosis of AMI and screening for CVD. 36 For example, hs-cTnI and hs-cTnT levels that naturally change throughout the day can be erroneously interpreted as diagnostically significant abnormalities. In one clinical case described by van der Linden, 70 the diagnostically significant influence of circadian rhythms on the early diagnosis of AMI was demonstrated using diagnostic algorithms developed by the European Society of Cardiology.…”

“…In one clinical case described by van der Linden, 70 the diagnostically significant influence of circadian rhythms on the early diagnosis of AMI was demonstrated using diagnostic algorithms developed by the European Society of Cardiology. 30,36,71 The exact mechanisms for the formation of circadian features in cardiac troponin concentrations have not been established, but it can be assumed that it is associated with circadian features of other human systems that, to varying degrees, adversely affect the cardiovascular system (CVS). Sympathoadrenal, renin-angiotensin-aldosterone, hypothalamic-pituitary-thyroid systems, and hemostasis system components are among such adverse factors affecting the cardiovascular system.…”