Chronic kidney disease, anemia and low iron are related to increased NTproBNP levels in hospitalized HFrEF patients
L Mikic, J Stevic, I Dupor, M Jankovic, J Stanisic, M Babic, D Popovic, B Jasovic, N Markovic NikolicAbstract
Introduction
In the latest ESC Guidelines for the diagnosis and treatment of heart failure, NTproBNP has been recognized as substantial laboratory diagnostic marker. N-terminal pro-B-type natriuretic peptide is a stable degradation product of the active B-type natriuretic peptide, that is produced mainly by cardiomyocytes in response to stretching impulse. Despite being a great diagnostic marker of heart failure, the levels of NTproBNP vary depending on cardiac and non-cardiac conditions.
Aim
We wanted to evaluate what are the variables that correlate the most with NTproBNP levels in our population of hospitalized patients with heart failure and reduced ejection fraction (HFrEF).
Methods
We evaluated medical histories of 245 HFrEF patients hospitalized from March 2023 until November 2024. We focused our analysis on parameters related to the most common comorbidities – coronary disease, anemia, sideropenia, chronic kidney disease (CKD), atrial fibrillation (AF), chronic obstructive pulmonary disease (COPD) and type 2 diabetes mellitus (T2DM). We collected both numerical (NTproBNP, hemoglobin concentration, estimated glomerular filtration rate - eGFR, serum Fe) and categorical data (the presence of the comorbidity). For statistical analysis we used Spearman’s Rank correlation test and Mann Whitney U test.
Results
In our patient population (n=245, males 65.53%, mean age 68.48+-10.4 years), out of all analyzed variables, the strongest negative correlation was found between NTproBNP levels and eGFR (rho -0.3989, p<0.01), followed by serum Fe (rho – 0.3791, p<0.01) and hemoglobin concentration (rho -0.3417, p<0.01). There was statistically significant difference of NTproBNP levels in groups with the presence of selected comorbidities - CKD, anemia, coronary disease, COPD and right heart failure (defined as TAPSE / tricuspid annular plane systolic excursion <16mm), in relation to a group without a certain comorbidity. There was no difference found in relation to sex, T2DM and interestingly with the presence of AF.
Conclusion
Glomerular filtration rate, serum iron and hemoglobin concentration showed to be inversely correlated to NTproBNP levels. Comorbidities can be attributing factors for cardiac decompensation, however in CKD the mechanism of increased NTproBNP is probably related mostly by the elimination reduction, thus the high levels can be interpreted incorrectly.