title: NT-proBNP independently predicts long term mortality after acute exacerbation of COPD - a prospective cohort study.
abstract: BACKGROUND
  Cardiovascular disease is prevalent and frequently unrecognized in patients with chronic obstructive pulmonary disease (COPD). NT-proBNP is an established risk factor in patients with heart failure. NT-proBNP may also be released from the right ventricle. Thus serum NT-proBNP may be elevated during acute exacerbations of COPD (AECOPD). The prognostic value of NT-proBNP in patients hospitalized with AECOPD is sparsely studied. Our objective was to test the hypothesis that NT-proBNP independently predicts long term mortality following AECOPD.
  
  
  METHODS
  A prospective cohort study of 99 patients with 217 admissions with AECOPD. Clinical, electrocardiographic, radiological and biochemical data were collected at index and repeat admissions and analyzed in an extended survival analysis with time-dependent covariables.
  
  
  RESULTS
  Median follow-up time was 1.9 years, and 57 patients died during follow-up. NT-proBNP tertile limits were 264.4 and 909 pg/mL, and NT-proBNP in tertiles 1 through 3 was associated with mortality rates of 8.6, 35 and 62 per 100 patient-years, respectively (age-adjusted log-rank p<0.0001). After adjustment for age, gender, peripheral edema, cephalization and cTnT in a multivariable survival model, the corresponding hazard ratios for dying were 2.4 (0.95-6.0) and 3.2 (1.3-8.1) (with 95% confidence intervals in parentheses, p-value for trend 0.013).
  
  
  CONCLUSIONS
  NT-proBNP is a strong and independent determinant of mortality after AECOPD.
authors.affiliation: Division of Medicine, Akershus University Hospital and Institute of Clinical Medicine, University of Oslo, Oslo, Norway. a.d.hoiseth@medisin.uio.no
authors.forename: Arne Didrik
authors.initials: AD
authors.lastname: Høiseth
authors.forename: Torbjørn
authors.initials: T
authors.lastname: Omland
authors.forename: Tor-Arne
authors.initials: TA
authors.lastname: Hagve
authors.forename: Pål H
authors.initials: PH
authors.lastname: Brekke
authors.forename: Vidar
authors.initials: V
authors.lastname: Søyseth
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000175:diagnosis / Q000401:mortality*; D012720:Severity of Illness Index; D015996:Survival Rate; D013997:Time Factors
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain