NT-proBNP Levels in Hemodialysis Patients: Unrelated to Interdialytic Weight Gain, Limited in Detecting Left Ventricular Systolic Dysfunction, but May Identify Atrial Fibrillation

Background: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is released in response to increased cardiac wall stress and is used as a biomarker for volume overload and heart failure (HF). It is also elevated in atrial fibrillation (AF) and inflammation. However, in hemodialysis (HD) patients, its interpretation is complicated by reduced renal clearance, large fluid shifts between dialysis sessions, and chronic inflammation. Methods: In 123 HD patients, we examined the relationship between NT-proBNP and interdialytic weight gain, HF with preserved ejection fraction (HFpEF), left ventricular systolic dysfunction (LVSD), and AF, as well as the impact of inflammation. Clinical characteristics, laboratory data, and echocardiography (within three months) were evaluated, while serum NT-proBNP and calprotectin levels were measured by ELISA. Results: NT-proBNP showed no association with interdialytic weight gain and did not identify HFpEF. Inflammatory markers (C-reactive protein and calprotectin) correlated positively with NT-proBNP. Multivariable analysis demonstrated that LVSD, AF, and inflammation remained independent predictors of NT-proBNP levels. Although NT-proBNP levels were higher in LVSD, its diagnostic performance was poor (AUC 0.627). In contrast, NT-proBNP was significantly elevated in patients with AF and showed good diagnostic performance (AUC 0.801). Conclusions: In HD patients, NT-proBNP is not correlated with interdialytic weight gain, performs poorly as a marker of LVSD, but may serve as a useful marker of AF.