Cut-off on brain natriuretic peptide (BNP): is current Danish practice appropiate?
N Hornung, M F Moeller, L LylloffAbstract
Background
BNP is a key biomarker for excluding chronic heart failure (HF) in primary care. Studies recommend age-stratified cut-off values, which have been introduced in other European countries. Guidelines are unclear on this matter and although an age dependency is recognized in Denmark, a uniform cut-off (≤29 pmol/L) is applied for all ages and both genders. This practice may lead to false positive results causing misinterpretation and excessive use of other more expensive diagnostic tools. This is unsustainable, particularly in primary care settings where BNP is used to exclude HF in patients with a variety of unspecific symptoms.
Purpose
To investigate if patterns of BNP results on patients from primary care support age- and genderstratified BNP cut-offs, in order to improve diagnostic accuracy in Denmark.
Methods
BNP test results from August 2023 to December 2025 requested by general practices were extracted from the regional business Intelligence portal. Results from subjects with more than one measurement were excluded, in order to avoid bias from repeated testing, and to exclude results where follow up was found necessary. Data were stratified by age and gender to assess distribution patterns and potential thresholds.
Results
3110 BNP results were included. The percentage of results above current cut-off (≤29 pmol/L) increased with increasing age: 2,8 % (age 18 – 59 years); 7,8 % (age 60 – 69 years); 26,6 % (age 70 – 79 years); 51,8 % (≥80 years). The manufacturer of the assay suggests differentiated cut-offs, both regarding age and gender, which are partly introduced in other laboratories. When applying our data to these cut-offs, the fraction of positive results were less, starting at 2,1 % in the youngest group (18 - 44 years) increasing to 18,6 % for subjects ≥75 years. It also showed that females had fewer positive results than males (males: 2,2 % - 34,3 %; females: 1,9 % - 16,0 %).
Conclusion
The data show a clear dependency of BNP levels on both age and gender, based on results from non-hospitalized subjects. Although clinical data are not included in the assessment, the findings strongly support the need for reconsideration of the Danish cut-off in favor of age and gender adjusted thresholds.