Evaluation of some cardiac biomarkers in cats with primary and secondary cardiomyopathies.

Cardiomyopathies (CMs) are one of the most predominant disorders in cats. Cardiac biomarkers can offer an economical alternative for the initial diagnosis of CM in comparison to the more costly echocardiography. This study aimed to assess the diagnostic accuracy of cardiac troponin I (cTnI), creatine kinase MB (CK-MB), N-terminal pro-brain natriuretic peptide (NT-proBNP), mid-regional pro-adrenomedullin (MR-proADM), and galectin-3 (Gal-3) in detection of feline CMs. The study included 78 cats classified into 3 groups based on clinical examination, echocardiography, and analysis of serum cardiac biomarkers, renal function, and total thyroxine. Group I (apparently healthy cats, n = 16), group II (cats with primary CM, n = 37), and group III (cats with secondary CM, n = 25). Sensitivity, specificity, positive and negative predictive values, receiver operating characteristic curves were used to identify area under the curve and the corresponding cut-off value for each cardiac biomarker. Pearson's correlation coefficient was also assessed. NT-proBNP, CK-MB, and Gal-3 were increased in groups II and III compared to group I. Meanwhile, cTnI was higher in group II than group III and MR-proADM was increased in group II only. NT-proBNP, cTnI, and CK-MB revealed moderate to strong positive correlations and the best diagnostic accuracy when compared to echocardiography, showcasing the benefits of multi-biomarker use. In conclusion, NT-proBNP, cTnI, CK-MB, and CK-RI exhibited the highest efficacy, and cTnI was able to statistically distinguish between primary and secondary CMs. In the absence of echocardiography, these biomarkers could be taken into account during the preliminary assessment for CM.