title: No firm association between N-terminal pro-brain natriuretic peptide and percentage of pulmonary vascular obstruction in patients with acute pulmonary embolism.
abstract: BACKGROUND
  High concentrations of N-terminal-pro-brain natriuretic peptide (NT-proBNP) are found in patients with right ventricular overload. Right ventricular overload may be the result of large perfusion defects in patients with pulmonary embolism (PE). NT-proBNP levels are associated with poorer outcome in patients with acute PE. Likewise, the percentage of pulmonary vascular obstruction (PVO) has shown to be a prognostic parameter for outcome in PE-patients. We postulated that NT-proBNP is associated with the amount of perfusion defects, expressed as the PVO, on perfusion scintigraphy.
  
  
  METHODS
  We included 85 consecutive patients in whom the diagnosis PE was confirmed by ventilation-perfusion scintigraphy. PVO was calculated in all patients. NT-proBNP concentrations were measured at presentation. We plotted the logarithm of NT-proBNP versus the PVO. The strength of the estimated association between NT-proBNP and the PVO was expressed by R2.
  
  
  RESULTS
  Eighteen percent of the variation in PVO could be explained by NT-proBNP. A positive association becomes apparent for NT-proBNP values above 200 pg/mL, with an increase in PVO of 6.3% (95% Confidence Interval 2.0 to 10.6), with every doubling of NT-proBNP.
  
  
  CONCLUSIONS
  There is an association between NT-proBNP concentrations and PVO, although this relation is quite weak. Some patients with low NT-proBNP values can have a high PVO, which might be relevant for outcome. Therefore, we advise caution in risk stratification and not to focus on NT-proBNP, without involving the clinical condition.
authors.affiliation: Department of Internal Medicine, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands. m.j.agterof@umcutrecht.nl
authors.forename: M J
authors.initials: MJ
authors.lastname: Agterof
authors.forename: R E G
authors.initials: RE
authors.lastname: Schutgens
authors.forename: J F
authors.initials: JF
authors.lastname: Verzijlbergen
authors.forename: M M C
authors.initials: MM
authors.lastname: van Buul
authors.forename: E A M
authors.initials: EA
authors.lastname: Tromp
authors.forename: M J C
authors.initials: MJ
authors.lastname: Eijkemans
authors.forename: R
authors.initials: R
authors.lastname: van der Griend
authors.forename: D H
authors.initials: DH
authors.lastname: Biesma
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000097:blood*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011379:Prognosis; D011655:Pulmonary Embolism / Q000097:blood* / Q000150:complications; D018497:Ventricular Dysfunction, Right / Q000097:blood; D055815:Young Adult
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain