NT-proBNP reference and cut-off values should be adjusted to patient’s age in clinical practice — results of national representative survey POLSENIOR 2

BACKGROUND: According to the guidelines of the European Society of Cardiology and American Heart Association, natriuretic peptides can be used as an initial diagnostic test, especially when echocardiography is not immediately available. The problem, however, is the lack of precise data on reference values for natriuretic peptide levels, especially in the elderly. AIMS: Purpose of the study was to assess the reference values of N-terminal pro-B-type natriuretic peptide (NT-proBNP) for elderly patients. METHODS: The PolSenior 2 study conducted from 2018-2020 included 5983 people 60+ years old. People who had increased NT-proBNP level with diagnosed heart failure, atrial fibrillation, advanced kidney disease, hyperthyroidism inflammation or were receiving eplerenone, spironolactone, furosemide, torasemide or anticoagulants were excluded. Finally, 2981 people were included in the analysis. The respondents were divided into age groups covering 10-year ranges and the NT-proBNP values were analyzed. RESULTS: Mean age was 71.6 years (standard deviation 8) with 51.6% being women. Only in the youngest age group (60-69 years) there were significant differences in NT-proBNP values between women and men (median 93 [52-162] ng/l vs. 62 [35-116] ng/l, respectively, P < 0.001). In each subsequent (older) age group, the level of NT-proBNP was significantly higher than in the previous one - 134 (73-260) ng/l in respondents aged 70-79, 231 (121-418) ng/l in 80-89 age group and 446 (288-766) in respondents 90+ years old. CONCLUSIONS: The level of NT-proBNP increases significantly with age and the assessment of NT-proBNP level should be age adjusted. Using NT-proBNP cut-off points among elderly patients may lead to unnecessary diagnostics and treatment.