title: N-terminal pro-B-type natriuretic peptide levels and early outcome after cardiac surgery: a prospective cohort study.
abstract: BACKGROUND
  N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a powerful predictor of cardiovascular outcome in many circumstances. There are, however, limited data regarding the utility of NT-proBNP or BNP levels in patients undergoing cardiac surgery. The current study assesses the ability of NT-proBNP to predict early outcome in this setting.
  
  
  METHODS
  One thousand and ten patients undergoing non-emergent cardiac surgery were recruited prospectively. Baseline clinical details were obtained and the European System for Cardiac Operative Risk Evaluation (EuroSCORE) and Parsonnet score were calculated. Preoperative NT-proBNP levels were measured using the Roche Elecsys assay. The primary endpoint was 30 day mortality.
  
  
  RESULTS
  Median NT-proBNP levels were 624 ng litre(-1) among patients who died within 30 days of surgery (n=29), compared with 279 ng litre(-1) in survivors [odds ratio (OR) 1.03 per 250 ng litre(-1), 95% confidence interval 1.01-1.05, P=0.001). NT-proBNP levels remained predictors of 30 day mortality in models including either the additive EuroSCORE (OR 1.03 per 250 ng litre(-1), P=0.01), the logistic EuroSCORE (OR 1.03 per 250 ng litre(-1), P=0.004), or the Parsonnet score (OR 1.02 per 250 ng litre(-1), P=0.04). Levels of NT-proBNP were also predictors of prolonged (>1 day) stay in the intensive care unit (OR 1.03 per 250 ng litre(-1), P<0.001) and of a hospital stay >1 week (OR 1.07 per 250 ng litre(-1), P<0.001). They remained predictive of these outcomes in regression models that included either the EuroSCORE or the Parsonnet score and in a model that included all study variables.
  
  
  CONCLUSIONS
  NT-proBNP levels predict early outcome after cardiac surgery. Their prognostic utility is modest-but is independent of traditional indicators and conventional risk prediction scores.
authors.affiliation: Health Services Research Unit, University of Aberdeen and Aberdeen Royal Infirmary, Aberdeen AB25 2ZD, UK. b.h.cuthbertson@abdn.ac.uk
authors.forename: B H
authors.initials: BH
authors.lastname: Cuthbertson
authors.forename: B L
authors.initials: BL
authors.lastname: Croal
authors.forename: D
authors.initials: D
authors.lastname: Rae
authors.forename: P H
authors.initials: PH
authors.lastname: Gibson
authors.forename: J D
authors.initials: JD
authors.lastname: McNeilly
authors.forename: R R
authors.initials: RR
authors.lastname: Jeffrey
authors.forename: W Cairns
authors.initials: WC
authors.lastname: Smith
authors.forename: G J
authors.initials: GJ
authors.lastname: Prescott
authors.forename: K G
authors.initials: KG
authors.lastname: Buchan
authors.forename: H
authors.initials: H
authors.lastname: El-Shafei
authors.forename: G A
authors.initials: GA
authors.lastname: Gibson
authors.forename: G S
authors.initials: GS
authors.lastname: Hillis
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures / Q000401:mortality; D001026:Coronary Artery Bypass; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011300:Preoperative Care / Q000379:methods; D011379:Prognosis; D012606:Scotland / Q000453:epidemiology; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain