Interlaboratory variation for NT-proBNP among Swedish laboratories in an external quality program 2011-2021

Area of Science:

• Clinical Chemistry
• Biomarker Analysis
• Cardiovascular Diagnostics

Background:

• N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a key biomarker for diagnosing heart failure.
• Established clinical decision limits for NT-proBNP vary based on clinical context (acute vs. chronic) and international guidelines.
• Limited standardization across different NT-proBNP assay methods poses a challenge for consistent patient management.

Purpose of the Study:

• To assess the analytical variability of NT-proBNP assays from different manufacturers.
• To evaluate the impact of method standardization on clinical decision-making for heart failure.
• To identify the need for improved standardization in NT-proBNP testing.

Main Methods:

• Analysis of external quality assessment data for NT-proBNP from Equalis (Sweden) between 2011-2021.
• Categorization of data by manufacturer and comparison of median values to consensus medians.
• Calculation of coefficient of variation (CV%) for each manufacturer across different NT-proBNP concentration levels.

Main Results:

• Roche assays showed median results closest to the consensus median.
• Total CV for NT-proBNP levels between 0-500 ng/L ranged from 4% to 27%.
• Significant inter-manufacturer variability was observed, with some methods yielding results substantially above or below the consensus median (e.g., Siemens, Abbott).

Conclusions:

• The introduction of new NT-proBNP methods since 2017 has decreased inter-manufacturer agreement.
• Clinical guidelines, often based on specific assay methods (e.g., Roche), may not account for current method-related biases.
• A common calibrator and standardized reference materials are essential to improve NT-proBNP assay harmonization and ensure reliable clinical application.