Clinical implications of the blood urea nitrogen/creatinine ratio in heart failure and their association with haemoconcentration

• Main Authors: Yasumori Sujino, Shintaro Nakano, Jun Tanno, Yasuyuki Shiraishi, Ayumi Goda, Atsushi Mizuno, Yuji Nagatomo, Takashi Kohno, Toshihiro Muramatsu, Shigeyuki Nishimura, Shun Kohsaka, Tsutomu Yoshikawa, for the West Tokyo Heart Failure Registry Investigators
• Format: Article
• Language: English
• Published: Wiley 2019-12-01
• Series: ESC Heart Failure
• Subjects: Acute decompensated heart failure; Blood urea nitrogen/creatinine ratio; Haemoconcentration; Haemodilution
• Online Access: https://doi.org/10.1002/ehf2.12531

Abstract Aims The blood urea nitrogen (BUN)/creatinine ratio is a strong prognostic indicator in patients with acute decompensated heart failure (ADHF). However, the clinical impact of a high BUN/creatinine ratio at discharge with respect to renal dysfunction, neurohormonal hyperactivity, and different responsiveness to decongestion therapy remains unclear. Herein, we examined (i) the predictive value of a high BUN/creatinine ratio at discharge and (ii) its haemoconcentration‐dependent effects, in patients with ADHF. Methods and results The West Tokyo Heart Failure registry was a multicentre, prospective cohort registry‐based study that enrolled patients hospitalized with a diagnosis of ADHF. The endpoint was post‐discharge all‐cause death. Based on the degree of haemoconcentration, patients (n = 2090) were divided into four subcategories. In multivariate proportional hazard analyses, a higher BUN/creatinine ratio was independently associated with higher all‐cause mortality in the total population and in the extreme haemodilution (ΔHaemoglobin ≤ −0.9 g/dL) and haemoconcentration (0.8 g/dL ≤ ΔHaemoglobin) subcategories, but not in the modest haemodilution/haemoconcentration subcategories. Conclusions A higher BUN/creatinine ratio at discharge was independently associated with higher post‐discharge all‐cause mortality in patients with ADHF. The predictive value of a high BUN/creatinine ratio at discharge was haemoconcentration dependent and may be an unfavourable predictor in patients showing excessive haemoconcentration and haemodilution, but not in those showing modest haemoconcentration/haemodilution.