Biologic variability of N-terminal pro-brain natriuretic peptide in adult healthy cats

Abstract

Objectives The biologic variability of N-terminal pro-brain natriuretic peptide (NT-proBNP) and its impact on diagnostic utility is unknown in healthy cats and those with cardiac disease. The purpose of this study was to determine the biologic variation of NT-proBNP within-day and week-to-week in healthy adult cats. Methods Adult cats were prospectively evaluated by complete blood count (CBC), biochemistry, total thyroxine, echocardiography, electrocardiography and blood pressure, to exclude underlying systemic or cardiac disease. Adult healthy cats were enrolled and blood samples were obtained at 11 time points over a 6 week period (0, 2 h, 4 h, 6 h, 8 h, 10 h and at weeks 2, 3, 4, 5 and 6). The intra-individual (coefficient of variation [CV]) biologic variation along with index of individuality and reference change values (RCVs) were calculated. Univariate models were analyzed and included comparison of the six different time points for both daily and weekly samples. This was followed by a Tukey's post-hoc adjustment, with a P value of <0.05 being significant. Results The median daily and weekly CV for the population were 13.1% (range 0-28.7%) and 21.2% (range 3.9-68.1%), respectively. The index of individuality was 0.99 and 1 for daily and weekly samples, respectively. The median daily and weekly RCVs for the population were 39.8% (range 17.0-80.5%) and 60.5% (range 20.1-187.8%), respectively. Conclusions and relevance This study demonstrates high individual variability for NT-proBNP concentrations in a population of adult healthy cats. Further research is warranted to evaluate NT-proBNP variability, particularly how serial measurements of NT-proBNP may be used in the diagnosis and management of cats with cardiac disease.

Investigation of an N‐Terminal Prohormone of Brain Natriuretic Peptide Point‐of‐Care ELISA in Clinically Normal Cats and Cats With Cardiac Disease

“…The remaining 53 cats were used for analysis. Thirty‐eight were client‐owned cats that presented to the University of Florida Cardiology Service for cardiac evaluation, and 15 were apparently healthy cats recruited as part of another study . There were 3 intact females, 16 spayed females, 2 intact males, and 32 neutered males.…”

“…Cats with severe concurrent systemic disease based on history, physical examination, and diagnostic testing done at the discretion of the attending clinician also were excluded. Fifteen of the apparently healthy cat samples were obtained as part of another study . The study was approved by the University of Florida Institutional Animal Care and Use Committee, and written consent to participate in the study was obtained from owners.…”

“…Cats were considered free of cardiac disease (normal group) if they did not have any color flow or spectral Doppler abnormalities, had normal left ventricular internal diameter in diastole and left ventricular internal diameter in systole, the left ventricular end diastolic caudal wall dimension and interventricular septal thickness at diastole both were <6.0 mm, the left atrium: aorta ratio in short axis (linear dimension) was <1.5, and there was no evidence of arrhythmias on a 6‐lead ECG or auscultation. Cats were diagnosed with various forms of cardiomyopathy (abnormal group) based on criteria described in a previous study with the attending cardiologist being responsible for the final classification of disease presence and severity. Cats with cardiac disease were classified as hypertrophic cardiomyopathy (HCM) or restrictive/unclassified cardiomyopathy (R/UCM), or as having noncardiomyopathic forms of cardiac disease (valvular disease, arrhythmias).…”

Association between Survival Time and Changes inNT‐proBNPin Cats Treated for Congestive Heart Failure

“…Median daily and weekly coefficient of variation for NT‐proBNP in adult healthy cats with no underlying cardiac disease was 13.1 and 21.2%, respectively 47. Therefore, if variability is similar or greater in cats with CHF than it is in healthy cats, it could have further impacted the results.…”

“…Median daily and weekly coefficient of variation for NT-proBNP in adult healthy cats with no underlying cardiac disease was 13.1 and 21.2%, respectively. 47 Therefore, if variability is similar or greater in cats with CHF than it is in healthy cats, it could have further impacted the results. In people, the week-to-week variation for BNP and NT-proBNP concentrations can vary up to 60%, and reported day-to-day variation for NT-proBNP concentrations is 26% in healthy people and 27% in patients with stable heart failure.…”