Cardiac biomarkers N-terminal fragment of the prohormone B-type natriuretic peptide and cardiac troponin I for characterization of the cardiac disease phenotype of the English Bull Terrier

The N-terminal fragment of prohormone B-type natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI) contribute information regarding cardiac load and function and myocardial injury, respectively, to the clinical work-up of dogs with heart disease. The English bull terrier (BT) has a predisposition to a complex cardiac phenotype. This prospective case-control study aimed to further characterize this phenotype through cardiac biomarker evaluation. Fifteen healthy BT (group 1) and 50 BT with various heart disease presentations (groups 2-4) were included. The main presentations were MVD (45 dogs) and MS (13 dogs). 16/50 dogs had echocardiographic evidence of cardiac remodeling: 7 with either increased left atrial (LA) or left ventricular (LV) volumes (group 3) and 9 with increased LA and LV volumes (group 4). Cardiac biomarkers were not significantly different between dogs with disease subtypes MVD or MS versus dogs with other disease presentations. When evaluated in relation to remodeling, median NT-proBNP and cTnI in group 4 (1004 pmol/L, 0.09 ng/mL) were significantly higher than in group 1 (257 pmol/L, 0.02 ng/mL), group 2 (300 pmol/L, 0.026 ng/mL) and group 3 (250 pmol/L, 0.02 ng/mL). There was significant discriminatory ability for both biomarkers between group 4 and groups 1, 2 or 3. Furthermore, cTnI significantly differentiated dogs with any degree of remodeling (groups 3 + 4) from those without (groups 1 + 2). The cardiac disease phenotype of the BT is not associated with a unique cardiac biomarker profile. Rather, biomarker levels are similar to those reported in other breeds with valvular heart disease.