title: Prognostic value of serial measurements of blood urea nitrogen in ambulatory patients with chronic heart failure.
abstract: BACKGROUND
  Elevated blood urea nitrogen (BUN) in chronic heart failure (CHF) patients may represent increased neurohormonal activation. The purpose of this work was to evaluate the prognostic value of BUN and its variation in ambulatory patients with stable CHF.
  
  
  METHODS
  In a retrospective analysis we included 241 outpatients with stable CHF (NYHA class I-III). We evaluated patients at baseline and at 6 months, then they have been followed for one year. The population was divided in four groups according to the median value of BUN at baseline and BUN change (percentage) at 6 months (group 1 BUN <25.2 mg/dL and variation <3.4%, group 2 BUN <25.2 mg/dL and ≥3.4 %, group 3 BUN ≥25.2 mg/dL and <3.4%, group 4 BUN ≥25.2 mg/dL and ≥3.4%). During a median follow-up of one year, 3 (1.3%) patients died and 49 (20.3%) were hospitalized due to worsening heart failure HF.
  
  
  RESULTS
  The Kaplan-Meier curve showed that group 3 and group 4 had worse prognosis compared with group 1 and 2 and that a greater change in BUN, was associated with a further worsening of the prognosis (group 4). Multivariable models confirmed that cardiovascular mortality and HF hospitalizations were more frequent in patients who had an increase of BUN (HR 1.011 [IC 95% 1.002-1.021]; P=0.015).
  
  
  CONCLUSIONS
  In ambulatory patients with stable chronic heart failure the increment of BUN is associated with increased cardiovascular mortality and heart failure hospitalizations at one-year.
authors.affiliation: Division of Cardiology, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University and Civil Hospitals of Brescia, Brescia, Italy - lombardi.carlo@alice.it.
authors.forename: Carlo
authors.initials: C
authors.lastname: Lombardi
authors.forename: Valentina
authors.initials: V
authors.lastname: Carubelli
authors.forename: Riccardo
authors.initials: R
authors.lastname: Rovetta
authors.forename: Anna I
authors.initials: AI
authors.lastname: Castrini
authors.forename: Enrico
authors.initials: E
authors.lastname: Vizzardi
authors.forename: Ivano
authors.initials: I
authors.lastname: Bondei
authors.forename: Edoardo
authors.initials: E
authors.lastname: Sciatti
authors.forename: Alessandra
authors.initials: A
authors.lastname: Manerba
authors.forename: Erika
authors.initials: E
authors.lastname: Benlodi
authors.forename: Savina
authors.initials: S
authors.lastname: Nodari
authors.forename: Marco
authors.initials: M
authors.lastname: Metra
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001806:Blood Urea Nitrogen; D002423:Cause of Death; D016009:Chi-Square Distribution; D002908:Chronic Disease; D018450:Disease Progression; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology; D006760:Hospitalization; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013318:Stroke Volume; D013997:Time Factors; D015854:Up-Regulation; D016277:Ventricular Function, Left
chemical_list: D015415:Biomarkers