Cardiac biomarkers in Maine Coon cats genetically tested for hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common feline heart disease and is responsible for high morbidity and mortality rates. Sarcomere disorganization in the affected myocardium of cats with HCM is related to the myosin binding protein C (MYBPC3) gene mutation. The plasma concentration of cardiac biomarkers such as atrial aminoterminal natriuretic peptide (NT-proANP) and Type B aminoterminal natriuretic peptide (NT-proBNP) released, respectively, by atrial and ventricular myocardium secondary to wall stress; cardiac troponin I (cTnI), released secondary to myocardial injury; and type 1 endothelin (ET-1), a potent vasoconstrictor peptide have been increasingly used for evaluation of human heart disease which are increased in patients with heart failure (HF). HCM is diagnosed by the presence of segmental or diffuse cardiac hypertrophy (CH) through conventional echocardiography. This study enrolled 57 Maine Coon cats screened for mutation (M) that were assigned to four groups: GIA with M and with CH (n= 4); GIB with M and without CH (n= 10); GIIA without M and with CH (n= 5); GIIB without M and without CH (n= 38) and evaluated by conventional echocardiography and cardiac biomarkers NT-proANP, NT-proBNP, cTnI and ET-1 measurements. The prevalence of the mutation in this study was 24.56%. Statistically significantly differences were observed in NT-proBNP among GIA and GIIB groups and among GIA and GIB groups; and in cTnI between GIA and GIIB groups. When considering only mutation and CH presence or absence, higher values of NT-proBNP were found in CH cats, and higher values of cTnI in those with mutation. Based on proposed methodology, cut-off value to NT-proBNP considering CH presence of 189.9 pmol/L had a sensitivity of 77.8%, specificity of 81.3%, predictive positive value of 43,8% and predictive negative value of 95,1% and the cut-off value of 0.015 ng/mL for cTnI considering mutation presence had a sensitivity of 64.3%, specificity of 81.4%, predictive positive value of 52,9% and predictive negative value of 87,5%. This study opened new perspectives to studies related to cTnI and MYBPC3 mutation. (AU)