Distinguishing cardiac and noncardiac dyspnea in 48 dogs using plasma atrial natriuretic factor, B-type natriuretic factor, endothelin, and cardiac troponin-I.

BACKGROUND

It is challenging to differentiate congestive heart failure (CHF) from noncardiac cause of dyspnea.

HYPOTHESIS

Circulating concentrations of atrial natriuretic peptide (NT-proANP), B-type natriuretic peptide (BNP), endothelin-I (ET-1), and cardiac troponin-I (cTnI) can be used to help distinguish between cardiac and noncardiac causes of dyspnea in dogs.

ANIMALS

Forty-eight client-owned dogs admitted to a veterinary teaching hospital for respiratory distress.

METHODS

Blood samples from patients were prospectively obtained. The etiology of dyspnea was determined by using physical examination, thoracic radiographs, and echocardiography.

RESULTS

CHF was diagnosed in 22 dogs, and dyspnea of noncardiac origin (noHD group) was diagnosed in 26 dogs. Analyses revealed significant difference between groups for NT-proANP (geometric mean, 95% confidence [CI]; no HD: 0.26 nmol/mL, 95% CI 0.17-1.09; CHF: 1.38 nmol/mL, 95% CI 1.09-1.74 nmol/mL; P < .0001), BNP (noHD: 12.18 pg/mL, 95% CI 10.91-16.17 pg/mL; CHF: 34.97 pg/mL, 95% CI 23.51-52.02 pg/mL; P < .0001), and ET-1 (noHD: 0.32 fmol/mL, 95% CI 0.23-0.46 fmol/mL; CHF: 1.26 fmol/mL, 95% CI 0.83-1.91 fmol/mL; P < .0001). Plasma cTnI concentrations were not significantly different between groups (noHD: 0.29 ng/mL, 95% CI 0.12-0.72 ng/mL; CHF: 0.42 ng/mL, 95% CI 0.18-0.97, P = .53). Receiver operating curves indicated areas under the curve for NT-proANP, BNP, and ET-1 of 0.946, 0.886, and 0.849, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Plasma NT-proANP, BNP, and ET-1, but not cTnI, appear useful for distinguishing between dogs with cardiac and noncardiac causes of dyspnea, with plasma NT-proANP having the highest sensitivity (95.5%) and specificity (84.6%).