title: Serum sodium concentration, blood urea nitrogen, and outcomes in patients hospitalized for acute decompensated heart failure.
abstract: BACKGROUND
  This study investigated the association of a low serum sodium and elevated blood urea nitrogen (BUN) with outcomes in acute decompensated heart failure (HF) patients.
  
  
  METHODS
  Of the 4842 patients enrolled in the Acute Decompensated Heart Failure Syndromes (ATTEND) registry, 4438 patients discharged after hospitalization for acute decompensated HF were investigated to assess the association of a low serum sodium and/or elevated BUN at discharge with all-cause mortality. The patients were divided into four groups based on serum sodium (>136 or ≤136mEq/l) and BUN (<25 or ≥25mg/dl) at discharge. The median follow-up period after discharge was 517 (381-776) days.
  
  
  RESULTS
  According to multivariate analysis, a low serum sodium (≤136mEq/l) or an elevated BUN (≥25mg/dl) was significantly associated with a higher risk of all-cause death compared with patients who had neither (hazard ratio [HR], 1.53; 95% confidence interval [CI], 1.22 to 1.94; P<0.001 and HR, 1.44; 95% CI, 1.19 to 1.73; P<0.001, respectively). Patients with both low serum sodium and elevated BUN had a higher risk of all-cause death relative to patients with neither (HR, 2.64; 95% CI, 2.17 to 3.20; P<0.001) and also relative to patients with either low serum sodium alone or elevated BUN alone (HR, 1.72; 95% CI, 1.36 to 2.18; P<0.001 and HR, 1.84; 95% CI, 1.53 to 2.21; P<0.001, respectively).
  
  
  CONCLUSIONS
  These findings demonstrated that a low serum sodium and an elevated BUN may be additive risk factors for postdischarge mortality in acute decompensated HF patients.
authors: Division of Cardiology, Sekikawa Hospital, Tokyo, Japan. Electronic address: kkajimoto@gmail.com.
authors: Katsuya
authors: K
authors: Kajimoto
authors: Department of Cardiology, Tokyo Women's Medical University, Tokyo, Japan.
authors: Yuichiro
authors: Y
authors: Minami
authors: Internal Medicine, Cardiology, and Intensive Care Unit, Nippon Medical School Musashi-Kosugi Hospital, Kanagawa, Japan.
authors: Naoki
authors: N
authors: Sato
authors: Department of Internal Medicine, Nippon Medical School, Tokyo, Japan.
authors: Teruo
authors: T
authors: Takano
mesh_terms: D000368:Aged; D001806:Blood Urea Nitrogen; D003404:Creatinine / Q000097:blood; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis / Q000401:mortality / Q000628:therapy; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge / Q000706:statistics & numerical data; D012042:Registries / Q000706:statistics & numerical data; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012964:Sodium / Q000097:blood*; D013223:Statistics as Topic; D016019:Survival Analysis
chemical_list: D012964:Sodium; D003404:Creatinine
keywords: Blood urea nitrogen; Heart failure; Outcomes assessment; Serum sodium