N-terminal pro B-type natriuretic peptide and left ventricular diameter independently predict mortality in dogs with mitral valve disease.

OBJECTIVES: To determine whether natriuretic peptide concentrations would predict all cause mortality in dogs with degenerative mitral valve disease.
METHODS: One hundred dogs with naturally occurring degenerative mitral valve disease were prospectively recruited for this longitudinal study. Analysis of outcome was undertaken for 73 dogs for which the outcome was known. Dogs underwent physical examination, electrocardiography and echocardiography. Natriuretic peptide concentrations were measured by Enzyme-linked immunosorbent assay. The ability of natriuretic peptide concentrations, clinical, electrocardiographic and echocardiographic data, to predict all cause mortality was determined using univariable and multivariable Cox proportional hazards analyses.
RESULTS: Thirty dogs died during the period of follow-up. Two variables were independently predictive of all cause mortality; these were the normalised left ventricular end-diastolic diameter and the N-terminal pro B-type natriuretic peptide concentration. An increase of the left ventricular end-diastolic diameter by 0.1 increased the hazard of all cause mortality by 20% (95% confidence interval: 4 to 37%, P=0.01) and a 100 pmol/l increase in N-terminal pro B-type natriuretic peptide increased the hazard by 7% (95 confidence interval: 2 to 11%, P=0.003). CLINICAL SIGNIFICANCE: N-terminal pro B-type natriuretic peptide concentration and left ventricular end-diastolic diameter are significantly and independently predictive of all cause mortality in dogs with degenerative mitral valve disease.