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

Abstract

Background Hypertrophic cardiomyopathy (HCM) is the most common cardiac disease in cats. However, most cats are not diagnosed until they develop congestive heart failure, arterial thromboembolism (ATE), or sudden cardiac death. Thus, an affordable screening test for early detection of HCM is desirable. Hypothesis/Objectives Evaluation of a sensitive cardiac troponin I (cTnI) assay as a screening test for HCM in cats and determination of a cutoff for its early detection. Animals One hundred sixty‐six client‐owned cats (male, n = 97) of various breeds were evaluated and classified using echocardiography as being healthy (n = 87), equivocal (n = 15), or having HCM (mild, n = 16; moderate, n = 10; severe, n = 34) or ATE (n = 4). Methods All cats were prospectively evaluated by echocardiography, and serum cTnI concentration was determined using the currently most sensitive assay (Siemens ADVIA Centaur TnI‐Ultra). Results The median cTnI concentration was significantly different between study groups ( P < .000001). A cutoff of 0.06 ng/mL provided good discrimination between healthy cats and cats with HCM (sensitivity, 91.7%; specificity, 95.4%; area under the curve [AUC], 0.95; 95% confidence interval [CI], 0.899‐0.978). Even for asymptomatic cats with HCM, sensitivity and specificity for a cutoff of >0.06 ng/mL remained high at 87.8% and 95.4%, respectively (AUC, 0.93; 95% CI, 0.864‐0.964). Conclusions and clinical importance Cardiac troponin I can be used as a sensitive and specific screening test for the diagnosis of HCM in otherwise healthy cats (cutoff, >0.06 ng/mL). However, echocardiography is needed to confirm the diagnosis.

ACVIM consensus statement guidelines for the classification, diagnosis, and management of cardiomyopathies in cats

“…Measuring circulating cardiac troponin‐I (cTnI) concentrations can help discriminate between cardiac and noncardiac causes of respiratory distress (LOE medium), but only when results can be obtained rapidly . High‐sensitivity assays for human cTnI might be considered for differentiating between normal cats and cats with subclinical HCM when cardiac disease is suspected (LOE medium) . In addition, cTnI also might be considered for its prognostic value, because an increased circulating cTnI concentration is associated with increased risk of cardiovascular death independent of LA size (LOE high) …”

Occurrences of heart disease in apparently healthy cats in Klang Valley, Malaysia

“…Besides on that, a variety of different methods and measurements for assessment has been continuously investigated in both healthy and affected cats [ 20 – 22 ]. Cardiac biomarkers have been used, but negative test results may not rule out, but a positive test result is a reliable indication of cardiomyopathy [ 23 – 25 ]. Hence, echocardiography remains superior in providing a definitive diagnosis [ 2 , 11 , 20 ].…”

An overview of the current genetic and phenotypical selection strategies to reduce the prevalence of feline hypertrophic cardiomyopathy

“…Cardiac biomarkers, such as N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI), are an attractive screening tool because of their low cost and easy use. However, there is some overlap in the concentrations of such biomarkers between healthy cats and cats with asymptomatic HCM (Fox et al, 2011;Hertzsch et al, 2019). Furthermore, increased levels of cardiac biomarkers can also be caused by other diseases, as has been shown for chronic kidney disease (Porciello et al, 2008), hyperthyroidism (Sangster et al, 2014) and hypertension (Bijsmans et al, 2017) in cats.…”