Cardiac Troponins in Dogs and Cats

Abstract

Cardiac troponins are sensitive and specific markers of myocardial injury. The troponin concentration can be thought of as a quantitative measure of the degree of injury sustained by the heart, however, it provides no information on the cause of injury or the mechanism of troponin release. Conventionally, the cardiac troponins have been used for diagnosis of acute myocardial infarction in humans and have become the gold standard biomarkers for this indication. They have become increasingly recognized as an objective measure of cardiomyocyte status in both cardiac and noncardiac disease, supplying additional information to that provided by echocardiography and ECG. Injury to cardiomyocytes can occur through a variety of mechanisms with subsequent release of troponins. Independent of the underlying disease or the mechanism of troponin release, the presence of myocardial injury is associated with an increased risk of death. As increasingly sensitive assays are introduced, the frequent occurrence of myocardial injury is becoming apparent, and our understanding of its causes and importance is constantly evolving. Presently troponins are valuable for detecting a subgroup of patients with higher risk of death. Future research is needed to clarify whether troponins can serve as monitoring tools guiding treatment, whether administering more aggressive treatment to patients with evidence of myocardial injury is beneficial, and whether normalizing of troponin concentrations in patients presenting with evidence of myocardial injury is associated with reduced risk of death.

Evaluation of a sensitive cardiac troponin I assay as a screening test for the diagnosis of hypertrophic cardiomyopathy in cats

“…Furthermore, NT‐proBNP predominantly is secreted in response to myocardial stretch as well as volume and pressure overload, whereas cTnI is a marker of myocardial injury itself and thus might be more suitable in cats with HCM. On the other hand, cTnI, like NT‐proBNP, can be influenced by various noncardiac diseases that sometimes cause greater increases in the cTnI concentration than do primary cardiac diseases themselves . Therefore, further diagnostic evaluation is required if increased biomarker concentrations are identified.…”

“…The difference between our cutoff and that determined in a previous study might be explained by the different grading system and exclusion criteria used in our study. Because impaired renal function, hyperthyroidism, and hypertension cause increases in cTnI, we excluded such cats from our study. However, the previous study included cats with concomitant chronic kidney disease and used higher blood pressure and higher serum T4 concentration as exclusion criteria.…”

“…Finally, we did not evaluate the effect of comorbidities on our test results. Various cardiac and noncardiac diseases can influence cTnI concentration . However, the presence of unknown comorbidities in an apparently healthy population of cats is a general limitation for the use of biomarkers as a screening test.…”

Associations among echocardiography, cardiac biomarkers, insulin metabolism, morphology, and inflammation in cats with asymptomatic hypertrophic cardiomyopathy

“…However, in our study, cardiac markers NTproBNP and cTnI were significantly increased and associated with the echocardiographic measures of HCM, as described previously for NTproBNP . This finding suggests that the cats in these studies suffered from cardiac pathology, with cardiomyocyte stretch and injury, and a thus physiological variation of heart size was less likely. Another possible mechanism is cardiomyopathy and increased LV wall thickness associated with hypersomatotropism .…”

The occurrence of cardiac abnormalities in canine steroid‐responsive meningitis arteritis

“…Cardiac troponin I (cTnI) is extensively used as a marker of cardiac myocyte damage in dogs but has been shown to be non-specific, increasing in various cardiac and non-cardiac conditions (Langhorn & Willesen 2016). Left ventricular systolic dysfunction, pericardial effusion and increased cTnI have been reported in five dogs with SRMA (Covey & Connolly 2018).…”