# Analytical Validation of a Novel Point‐Of‐Care Quantitative Immunoassay for Feline N‐Terminal Pro‐Brain Natriuretic Peptide

## TL;DR

A new point-of-care test for measuring a heart-related protein in cats was validated for accuracy and reliability.

## Contribution

The study provides the first independent analytical validation of the Vcheck V200 assay for feline NT-proBNP.

## Key findings

- The assay showed acceptable precision with low to moderate within-day and within-week variability.
- The assay was linear over a wide range and compared well with a commercial test with minimal bias.
- Icteric samples invalidated the assay, while hemolysis and lipemia had no effect.

## Abstract

Point‐of‐care testing (POC) is widely utilized for rapid results for many different analytes. A new feline‐specific N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) quantitative assay (Vcheck V200, Bionote Inc) is currently available but has not undergone independent validation.

To validate the Vcheck POC quantitative assay for feline NT‐proBNP.

Validation was performed in accordance with the American Society for Veterinary Clinical Pathology guidelines utilizing serum samples from 62 cats. Precision was determined for low (50–100 pmol/L), mid (101–300 pmol/L), and high (> 301 pmol/L) pools short‐term (20 repetitions) and long‐term (5 repetitions each day for 5 days). Linearity, methods comparison, interference testing, and sample stability were evaluated.

The within‐day coefficients of variability (CV) were low pool = 12.6%, mid pool = 10.4%, and high pool = 8.7%. The within‐week CV was low pool = 9.9%, mid pool = 14.9%, and high pool = 6.9%. The assay was linear over the analytical range of 53–1488 pmol/L (R
2 = 0.99, p < 0.0001). Paired samples between the feline Cardiopet NT‐proBNP (IDEXX) and Vcheck assays demonstrated a mean difference of 11 pmol/L (2.3%), p = 0.38, between assays with minimal constant or proportional bias. Hemolysis and lipemia did not affect assay performance, while all icteric samples were invalid. Significantly lower values were identified in samples after 2 and 4 h when stored at 20°C and 4°C, respectively.

The Vcheck V200 has acceptable precision, accuracy, and compares favorably with commercially available assays and is a viable POC quantitative assay for feline NT‐proBNP.