title: The role of plasma D-dimers concentration in the exclusion of pulmonary embolism.
abstract: OBJECTIVE
  To determine the role of four ELISA D-dimer assays in the exclusion of pulmonary embolism.
  
  
  METHODS
  Blinded comparison using pulmonary angiography and/or lung scintigraphy as a reference method.
  
  
  METHODS
  A secondary and tertiary referral centre.
  
  
  METHODS
  Consecutive patients with suspected pulmonary embolism underwent lung scintigraphy, followed by angiography if a non-diagnostic result was obtained. Comorbid conditions resulting in elevated plasma D-dimer levels were defined a priori. Cut-off levels for 100% sensitivity was determined. A decision-analytic model was used to determine effectiveness and costs in the management pulmonary embolism.
  
  
  METHODS
  The exclusion efficacy of the various assays at a sensitivity of 100% and cost-effectiveness.
  
  
  RESULTS
  A total of 179 patients were included (78 inpatients and 101 outpatients; 74 patients had comorbid conditions). Pulmonary embolism could be adequately excluded in between 8% and 18% of all patients, an in between 3% and 7% and 11% and 27% of inpatients and outpatients, respectively, depending on the assay used. D-dimer assays could exclude pulmonary embolism in <5% of patients with comorbid conditions, whereas this increased to 14-32% in outpatients without comorbid conditions. A cost-effectiveness analysis showed a cost reduction of 10% at a specificity of 30%, largely due to a 28% decrease in angiography requirements. Furthermore, for every 2% decrease to sensitivity, one per 1000 evaluated patients would die as a result of inadequately treated pulmonary embolism.
  
  
  CONCLUSIONS
  D-dimer ELISA assays may have a role in the exclusion of pulmonary embolism in symptomatic outpatients, where the application may reduce angiography by 30% and costs by 10%.
authors.affiliation: Centre for Haemostasis, Thrombosis, Atherosclerosis and Inflammation Research, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: E J
authors.initials: EJ
authors.lastname: van Beek
authors.forename: B E
authors.initials: BE
authors.lastname: Schenk
authors.forename: B C
authors.initials: BC
authors.lastname: Michel
authors.forename: B
authors.initials: B
authors.lastname: van den Ende
authors.forename: D P
authors.initials: DP
authors.lastname: Brandjes
authors.forename: Y T
authors.initials: YT
authors.lastname: van der Heide
authors.forename: P M
authors.initials: PM
authors.lastname: Bossuyt
authors.forename: R
authors.initials: R
authors.lastname: Büller H
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D000933:Antifibrinolytic Agents / Q000032:analysis*; D015331:Cohort Studies; D003362:Cost-Benefit Analysis; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000175:diagnosis*; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity
chemical_list: D000933:Antifibrinolytic Agents; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D