title: PO-29 - Age-adjusted D-dimer cutoff level increases the number of cancer patients in who pulmonary embolism can be safely excluded without CT-PA imaging: The ADJUST-PE cancer substudy.
abstract: BACKGROUND
  Patients with cancer frequently present with suspected pulmonary embolism (PE). The D-dimer test is less useful to rule out PE in cancer patients due to a lower specificity, whereas the safety of the combination of a clinical decision rule (CDR) and D-dimer test to rule out PE in these patients is unclear. In the general population, use of an age-adjusted cutoff for D-dimer in combination with a CDR has been shown to improve specificity in the diagnosis of PE.
  
  
  OBJECTIVE
  We prospectively analysed the safety and efficacy of the age-adjusted D-dimer (defined as age×10 in patients >50 years) combined with CDR for the exclusion of PE in patients with cancer.
  
  
  METHODS
  We conducted a multicenter multinational prospective management outcome study in 19 centers in Belgium, France, The Netherlands and Switzerland, the ADJUST-PE study, to validate an age-adjusted D-dimer cut-off in patients with suspected PE. The performance of the age-adjusted D-dimer cut-off and CDR was compared between patients with and without cancer. The primary outcome was the rate of adjudicated thromboembolic events during three-month follow-up.
  
  
  RESULTS
  Of the 3,324 patients with suspected PE, 429 (12.9%) patients had cancer. Cancer patients were older and more often had surgery or immobilisation. The prevalence of PE was 108/429 (25.2%) in cancer patients and 522/2894 (18%) in patients without cancer, p<0.001. Among cancer patients with an unlikely CDR, 27/274 (9.9%) had a D-Dimer <500 μg/L as compared with 19.7% using the age-adjusted D-dimer cut-off; in patients without cancer, these rates were 30.1% and 41.9%, respectively. The percentage of cancer patients in whom PE could be excluded based on CDR and age-adjusted D-dimer doubled from 6.3% to 12.6%. None of these cancer patients had a venous thromboembolic event during three-month follow-up, thus the failure rate was 0.0% (95% CI 0.0-6.9%).
  
  
  CONCLUSIONS
  Compared with the usual cut-off, the age-adjusted D-dimer cut-off doubles the proportion of patients with cancer in whom PE can be safely excluded by CDR and D-dimer without need for CTPA imaging.
authors.affiliation: Dept. of Vascular Medicine, University Medical Center Groningen, University of Groningen, The Netherlands.
authors.forename: I T
authors.initials: IT
authors.lastname: Wilts
authors.affiliation: Health Research Institute, Ottawa, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Le Gal
authors.affiliation: Dept. of Thrombosis and Hemostasis, Leiden University Medical Center, The Netherlands.
authors.forename: P L
authors.initials: PL
authors.lastname: den Exter
authors.affiliation: Dept. of Vascular Medicine, Amsterdam Medical Center, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: van Es
authors.affiliation: Health Research Institute, Ottawa, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Carrier
authors.affiliation: Dept. of Thrombosis and Hemostasis, Leiden University Medical Center, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Planquette
authors.affiliation: Dept. of Vascular Medicine, Amsterdam Medical Center, The Netherlands.
authors.forename: H R
authors.initials: HR
authors.lastname: Büller
authors.affiliation: Division of Angiology and Hemostasis, Geneva University Hospital and Faculty of Medicine, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Righini
authors.affiliation: Service de pneumologie et de soins intensifs, Hôpital Européen Georges Pompidou, Paris, France.
authors.forename: M V
authors.initials: MV
authors.lastname: Huisman
authors.affiliation: Dept. of Vascular Medicine, University Medical Center Groningen, University of Groningen, The Netherlands.
authors.forename: P W
authors.initials: PW
authors.lastname: Kamphuisen