Journal Scan: The potential prognostic value of NT-proBNP assays in cats with congestive heart failure

Can serial NT-proBNP measurements give you a glimpse into a cat's future? (Shutterstock)Why they did it

Assays of N-terminal pro-B-type natriuretic peptide (NT-proBNP) has been used in veterinary medicine as single-point with a variety of applications in veterinary medicine. This includes helping in the diagnosis of subclinical and occult cardiac disease and differentiating cardiac and respiratory disease processes in cats. In people, changes in NT-proBNP concentrations during treatment for heart failure have been found to be indicative of long-term prognosis. The authors in this study sought to determine if the same applied to cats.

What they did

Thirty-one cats with congestive heart failure were enrolled and completed the study. Cats with hypertension, hyperthyroidism or renal failure were excluded. Within four hours of admission to the hospital, blood was drawn for a NT-proBNP concentration. Treatment for heart failure was initiated and further NT-proBNP concentrations were measured at time of discharge and at re-evaluation seven to 10 days after discharge. Owners were then contacted by phone every three months for an update until the cat died or was euthanized.

What they found

Cat with a larger percentage decrease than the median in NT-proBNP concentration from admission to discharge had a significantly longer survival time than cats with a smaller percentage decrease than the median. In people, a > 30% decrease has been found to be a significant marker, but in this study that was not found to be significant. Median survival time for cats with the larger percentage decrease in NT-proBNP concentration was 182 days, while median survival time for cats with a smaller percentage decrease was 60 days.

Take-home points

Decrease in NT-proBNP concentration can be an important prognostic factor in determining survival time for cats with congestive heart failure. A larger decrease in NT-proBNP concentration after treatment is a positive prognostic factor. Unfortunately, at this time specific levels of decrease could not be determined as definitively prognostic. However, with a larger study sample size it is likely specific guidelines can be established.

Pierce KV, Rush JE, Freeman LM, et al. Association between survival time and changes in NT-proBNP in cats treated for congestive heart failure. J Vet Intern Med 2017;31:678-684.

Link to abstract: https://www.ncbi.nlm.nih.gov/pubmed/28370373