title: B-type natriuretic peptide signal peptide (BNPsp) in patients presenting with chest pain.
abstract: OBJECTIVE
  We assessed the ability of B-type natriuretic peptide signal peptide (BNPsp) to assist with the identification of patients with myocardial infarction (MI) and unstable angina pectoris (UAP).
  
  
  METHODS
  We studied 505 patients who presented to hospital within 4h of onset of chest pain suspicious of ACS. Blood samples were drawn at 0, 1, 2 and 24h from presentation and assayed for BNPsp, NT-proBNP, TnI and high sensitivity TnT. The ability of BNPsp and other markers to diagnose acute myocardial infarction (MI) and unstable angina pectoris (UAP) and predict subsequent events within one year was assessed. Statistical analysis was made using ROC AUC in SPSS, v.22.
  
  
  RESULTS
  Receiver operator area under the curve (AUC) data for the discrimination of MI was 0.69 for BNPsp and 0.97 for troponin, with BNPsp failing to add to troponin. However, in non-MI patients, BNPsp had discriminative power for UAP (p<0.05), and when combined with presentation values of NT-proBNP, white cell count and potassium into a unique parameter (UARatio), generated an AUC of 0.76 for UAP in patients with normal ECG results (p<0.001). In non-MI patients, the UARatio was significantly predictive of subsequent stroke (AUC=0.70, p<0.05) and heart failure (AUC=0.82, p<0.01) within one year.
  
  
  CONCLUSIONS
  In patients with chest pain, BNPsp is predictive of MI but is not a useful adjunct to troponin. However, the ability of BNPsp, in conjunction with NT-proBNP and key analytes, to diagnose UAP and other ischemic syndromes merits further investigation.
authors.affiliation: Christchurch Heart Institute, Department of Medicine, University of Otago, Christchurch, New Zealand. Electronic address: chris.pemberton@otago.ac.nz.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Pemberton
authors.affiliation: Department of Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: Chris M
authors.initials: CM
authors.lastname: Frampton
authors.affiliation: Department of Cardiology, Christchurch Hospital, New Zealand.
authors.forename: Sally
authors.initials: S
authors.lastname: Aldous
authors.affiliation: Department of Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: Mark
authors.initials: M
authors.lastname: Bailey
authors.affiliation: Department of Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: Joanna
authors.initials: J
authors.lastname: Young
authors.affiliation: Christchurch Heart Institute, Department of Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: Richard
authors.initials: R
authors.lastname: Troughton
authors.affiliation: Department of Emergency Medicine, Christchurch Hospital, New Zealand.
authors.forename: Martin
authors.initials: M
authors.lastname: Than
authors.affiliation: Christchurch Heart Institute, Department of Medicine, University of Otago, Christchurch, New Zealand; Cardiovascular Research Institute, National University of Singapore, Singapore.
authors.forename: Mark
authors.initials: M
authors.lastname: Richards
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood*; D002637:Chest Pain / Q000150:complications / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain
keywords: Acute coronary syndromes; BNP; Chest pain; Signal peptide; Unstable angina