title: Brain natriuretic peptide testing for angina in a rapid-access chest pain clinic.
abstract: BACKGROUND
  Patients complaining of chest pain are frequently referred to secondary care, although the majority have pain of non-cardiac origin.
  
  
  OBJECTIVE
  To investigate whether B-type natriuretic peptide (BNP) levels are predictive of a diagnosis of non-cardiac pain.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Consecutive patients (n = 296) presenting to a rapid-access chest pain clinic (RACPC) received the usual clinical assessment plus near-patient BNP testing, with the assessor blinded to the result. After clinical assessment (including exercise stress testing if clinically indicated), pain was diagnosed likely/definitely cardiac or non-cardiac.
  
  
  RESULTS
  Median BNP was higher in those diagnosed with likely/definite cardiac chest pain (26.5 vs. 8 pg/ml) (p < 0.0001, Wilcoxon rank sum test). The odds ratio for cardiac pain in those with BNP <20 pg/ml was 0.25 (95%CI 0.14-0.47) (p < 0.0005); adjusting for age and sex reduced this to 0.41 (95%CI 0.20-0.83) (p = 0.01). The area under the curve (AUC) for the model including BNP, age and sex was 0.70. With BNP as a continuous variable, the AUC for the same model was 0.72.
  
  
  CONCLUSIONS
  In typical patients presenting to a RACPC, those with a BNP < or =20 pg/ml were significantly less likely to be diagnosed with cardiac pain. Near-patient BNP testing may have a role as a 'rule out test' for angina in patients presenting to a RACPC.
authors.affiliation: Cardiovascular Medicine, Charing Cross Hospital, Fulham Palace Road, London. s.connolly@imperial.ac.uk
authors.forename: S B
authors.initials: SB
authors.lastname: Connolly
authors.forename: T
authors.initials: T
authors.lastname: Collier
authors.forename: R
authors.initials: R
authors.lastname: Khugputh
authors.forename: D
authors.initials: D
authors.lastname: Tataree
authors.forename: K
authors.initials: K
authors.lastname: Kyereme
authors.forename: S
authors.initials: S
authors.lastname: Merritt
authors.forename: A D
authors.initials: AD
authors.lastname: Struthers
authors.forename: K F
authors.initials: KF
authors.lastname: Fox
mesh_terms: D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000097:blood / Q000175:diagnosis*; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D002637:Chest Pain / Q000175:diagnosis; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D018710:Pain Clinics; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain