title: Extremely elevated BNP in acute heart failure: Patient characteristics and outcomes.
abstract: BACKGROUND
  We explored the clinical characteristics and outcomes of patients with acute systolic heart failure (HF) and extremely elevated admission B-type natriuretic peptide (BNP).
  
  
  METHODS
  Extremely elevated BNP was defined if BNP level was >85th percentile of the study cohort (i.e. >1694pg/mL). Our objectives were to find characteristic features that identify patients with extremely elevated BNP, to compare the degree of congestion in both groups and to study post-discharge outcomes.
  
  
  RESULTS
  347 patients (mean age 56years, 74% males) were divided into two groups based on whether BNP was extremely elevated (n=53) or not (n=294). Those with extremely elevated BNP were older (P=0.004), with a lower body mass index (P<0.0001), higher blood urea nitrogen (P=0.01), higher creatinine (P=0.005), lower cardiac output (P<0.0001) and lower cardiac index (P=0.001). With regards to signs of congestion, both groups had no significant difference in the frequency of rales (P=0.454), peripheral edema (P=0.397), jugular venous distension (P=0.396), positive hepatojugular reflux (P=0.083), S3 gallop (P=0.107), mean pulmonary capillary wedge pressure (P=0.351), and right atrial pressure (P=0.310). Both groups had similar frequency of rehospitalization for HF (P=0.939), nonetheless, patients with extremely elevated BNP had longer hospital stay during initial (P=0.014), or subsequent hospitalization (30days: P=0.01, 180days: P=0.008). 6-month all-cause-mortality was higher in patients with extremely elevated BNP (P=0.008), although death due to pump failure was not (P=0.921). Cox proportional hazard analysis revealed that extremely elevated admission BNP is an independent predictor of 6-month all-cause-mortality (hazard ratio 1.857, 95% CI=1.074-3.208, P=0.027) after adjustment for known predictors of post-discharge mortality in HF.
  
  
  CONCLUSIONS
  Extremely elevated admission BNP did not match the degree of congestion nor was a predictor of rehospitalization due to HF. It was associated with decreased COP, prolonged hospital stay, and increased 6-month all-cause-mortality.
authors.affiliation: Internal Medicine Department, Mercy Medical Center, Clinton, IA, United States. Electronic address: hesham.omar@apogeephysicians.com.
authors.forename: Hesham R
authors.initials: HR
authors.lastname: Omar
authors.affiliation: Division of Cardiovascular Medicine, Linda and Jack Gill Heart Institute, University of Kentucky, Lexington, KY, United States.
authors.forename: Maya
authors.initials: M
authors.lastname: Guglin
mesh_terms: D000328:Adult; D000368:Aged; D001806:Blood Urea Nitrogen; D015992:Body Mass Index; D005260:Female; D006333:Heart Failure / Q000378:metabolism / Q000473:pathology*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D020097:Natriuretic Peptide, Brain
keywords: B-Type natriuretic peptide; Congestion; Extreme BNP elevation; Heart failure