title: Predicting mortality and hospital admission in patients with COPD: significance of NT pro-BNP, clinical and echocardiographic assessment.
abstract: OBJECTIVE
  To quantify the ability of N-terminal pro-brain natriuretic peptide (NT pro-BNP) to predict mortality and hospitalization in patients with chronic obstructive airways disease (COPD).
  
  
  METHODS
  Prospective single-centre observational study of 140 consecutive patients aged at least 18 years with COPD between 27 March 2004 and 28 February 2008 (median follow-up 3.9 years).
  
  
  RESULTS
  Sixty-five (46%) men, 26 (19%) O2 therapy, 115 (82%) smokers, 38 (27%) patients receiving diuretics, 15 (11%) left-ventricular ejection fraction less than 45%. Median [interquartile range (IQR)] NT pro-BNP concentration 16.2 (25.4) pmol/l. NT pro-BNP was higher in those with a dilated left atrium (P<0.001), aortic stenosis (P=0.02), left-ventricular systolic dysfunction (P=0.027), right ventricular impairment (P=0.011), atrial fibrillation (P<0.001), patients receiving diuretics (P=0.010) and angiotensin-converting enzyme (ACE) inhibitors (P=0.006). One-year mortality and hospitalization rates were 2.9 and 25.4%. The median (IQR) time to hospitalization and length of first hospital stay: 383.5 (605) and 4.0 (7.0) days. NT pro-BNP was an excellent discriminator of right-ventricular impairment (C statistic=0.90) and predicted survival (highest quartile versus lowest quartile relative risk=3.02, P=0.001), but not hospital admission. After adjustment this association was not significant.
  
  
  CONCLUSIONS
  NT pro-BNP predicts survival, but not hospital admission in patients with COPD. The ability of NT pro-BNP to independently predict death or hospitalization is superseded by the presence of a dilated left atrium, aortic stenosis and left-ventricular systolic dysfunction.
authors.affiliation: Centre for Epidemiology and Biostatistics, University of Leeds, Leeds, UK. c.p.gale@leeds.ac.uk
authors.forename: Chris P
authors.initials: CP
authors.lastname: Gale
authors.forename: John E S
authors.initials: JE
authors.lastname: White
authors.forename: Alan
authors.initials: A
authors.lastname: Hunter
authors.forename: Jane
authors.initials: J
authors.lastname: Owen
authors.forename: Jane
authors.initials: J
authors.lastname: Allen
authors.forename: Josie
authors.initials: J
authors.lastname: Watson
authors.forename: Ian
authors.initials: I
authors.lastname: Holbrook
authors.forename: Nigel P
authors.initials: NP
authors.lastname: Durham
authors.forename: Maurice P
authors.initials: MP
authors.lastname: Pye
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood / Q000000981:diagnostic imaging / Q000209:etiology* / Q000401:mortality / Q000628:therapy; D016009:Chi-Square Distribution; D015150:Echocardiography, Doppler; D004739:England; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010343:Patient Admission; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000150:complications* / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain