title: Serum blood urea nitrogen and long-term mortality in acute ST-elevation myocardial infarction.
abstract: BACKGROUND
  Renal dysfunction is associated with increased mortality in acute coronary syndromes and other cardiovascular diseases. The prognostic value of kidney dysfunction has been investigated using creatinine-based measures of renal function. Few data are available on the prognostic significance of blood urea nitrogen (BUN), a sensitive marker of hemodynamic alterations and renal perfusion.
  
  
  METHODS
  The relationship between estimated glomerular filtration rate (eGFR), BUN on admission and changes in BUN during hospital course and long-term mortality was evaluated in 1507 patients with acute ST-elevation myocardial infarction (STEMI).
  
  
  RESULTS
  During a median follow-up of 27 months (range, 12 to 44 months), 281 patients (18.6%) died. In multivariable Cox regression models, elevated BUN (>or=25 mg/dL) at admission was an independent predictor of mortality after adjustments for clinical variables and eGFR (adjusted hazard ratio [HR] 1.7; 95% confidence interval [CI] 1.2-2.3, P=0.0015). Similar results were obtained for elevated BUN/creatinine ratio (>or=25) at admission (adjusted HR 2.0; 95% CI 1.4-2.8; P<0.0001). An increase in BUN 50% above admission value occurred in 260 of patients (17.3%) during hospital course, and was associated with increased risk of mortality after adjustments of clinical variables, eGFR and BUN on admission (HR, 1.7 95% CI 1.3-2.2; P<0.0001).
  
  
  CONCLUSIONS
  Elevated BUN and BUN/creatinine ratio on admission are independent predictors of long-term mortality in patients with STEMI. An increase in BUN level during hospital course portends adverse outcome independent of eGFR and BUN on admission.
authors.affiliation: Department of Cardiology Rambam Medical Center, and Rappaport Medical School, Haifa, Israel. daronson@tx.technion.ac.il
authors.forename: Doron
authors.initials: D
authors.lastname: Aronson
authors.forename: Haim
authors.initials: H
authors.lastname: Hammerman
authors.forename: Rafael
authors.initials: R
authors.lastname: Beyar
authors.forename: Sergey
authors.initials: S
authors.lastname: Yalonetsky
authors.forename: Michael
authors.initials: M
authors.lastname: Kapeliovich
authors.forename: Walter
authors.initials: W
authors.lastname: Markiewicz
authors.forename: Alexander
authors.initials: A
authors.lastname: Goldberg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001806:Blood Urea Nitrogen; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000401:mortality*; D011446:Prospective Studies
chemical_list: D015415:Biomarkers