The diagnostic accuracy of different natriuretic peptides in the investigation of canine cardiac disease.
OBJECTIVE
We aimed to validate and determine the accuracy of a new sandwich ELISA for canine N-terminal pro-B-type natriuretic peptide (NT-proBNP) in the discrimination of canine patients with cardiac disease from those with respiratory disease and to determine the effect of confounding variables on NT-proBNP concentrations.


METHODS
Validation studies for the new assay were undertaken. Concentrations of N-terminal atrial natriuretic peptide (NT-proANP) and NT-proBNP in both ethylenediaminetetraacetic acid (EDTA) plasma and serum were estimated in samples from 77 dogs at a laboratory blinded to the clinical status of the patient. The diagnostic accuracy of the each sample type and test was evaluated using receiver operating characteristic curves. The effect of age, gender and indicators of renal function was evaluated using a multivariate regression analysis.


RESULTS
Concentrations of NT-proBNP in both serum and plasma accurately discriminated dogs with respiratory disease from those with cardiac disease, with an optimum cut-off concentration of 210 pmol/l. NT-proBNP concentrations were unaffected by sample type. Increasing creatinine concentration is associated with increasing concentration of NT-proBNP. Age and gender were not found to have significant effects on natriuretic peptide concentrations in this population.


CONCLUSIONS
Canine NT-proBNP appears to be a useful marker of the presence of cardiac disease, although concentrations must be interpreted in the light of the patient's renal function.
Boswood
A
A
Department of Veterinary Clinical Sciences, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK.
Dukes-McEwan
J
J
Loureiro
J
J
James
R A
RA
Martin
M
M
Stafford-Johnson
M
M
Smith
P
P
Little
C
C
Attree
S
S
D000367:Age Factors; D000818:Animals; D009320:Atrial Natriuretic Factor; D015415:Biomarkers / Q000097:blood; D003937:Diagnosis, Differential; D004283:Dog Diseases / Q000097:blood* / Q000175:diagnosis; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000592:standards / Q000662:veterinary*; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis / Q000662:veterinary*; D007668:Kidney / Q000502:physiology; D008297:Male; D015999:Multivariate Analysis; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood; D012372:ROC Curve; D015203:Reproducibility of Results; D012140:Respiratory Tract Diseases / Q000097:blood / Q000175:diagnosis / Q000662:veterinary*; D012680:Sensitivity and Specificity; D012737:Sex Factors
D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor