title: Is ischaemia-modified albumin a test for venous thromboembolism?
abstract: OBJECTIVE
  Patients with symptoms of deep vein thrombosis (DVT) and pulmonary embolism (PE) commonly present to the emergency department (ED). The aim of this study was to assess the role of ischaemia-modified albumin (IMA) testing in the diagnosis of venous thromboembolism (VTE).
  
  
  METHODS
  This was a prospective diagnostic cohort study. Inpatients and ED patients >16 years of age investigated for PE or DVT at a single hospital were eligible for study consent. Blinded IMA analysis was performed on the first blood sample taken from each patient. Patients underwent reference standard investigation for PE or DVT, including 3-month follow-up. Receiver operating characteristic (ROC) curves were constructed for IMA and the IMA:albumin ratio in the diagnosis of all VTE, PE and DVT. A sensitivity analysis was performed.
  
  
  RESULTS
  452 patients were consented and investigated for DVT, and 354 patients were consented and investigated for PE (806 in total). 348 patients investigated for PE had IMA testing as did 195 of the first 199 DVT patients. VTE prevalence was 19.7%. The IMA:albumin ratio performed better than IMA alone. The area under the ROC curve (AUC) for IMA:albumin in all VTE was 0.60 (95% CI 0.54 to 0.66), in DVT 0.56 (95% CI 0.46 to 0.65) and in PE 0.63 (95% CI 0.56 to 0.71). In ED patients with symptoms of PE, the AUC for IMA:albumin was 0.69 (95% CI 0.60 to 0.78).
  
  
  CONCLUSIONS
  IMA testing cannot be used alone to diagnose DVT or PE, although there is a moderate association with PE in ED patients.
authors.affiliation: Thrombosis Department, The Ottawa Hospital, 1053 Carling Avenue, Ottawa, ON K1Y 4E9, Canada. kerstinhogg@manchester.ac.uk
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hogg
authors.forename: Edward
authors.initials: E
authors.lastname: Hinchliffe
authors.forename: Shonagh
authors.initials: S
authors.lastname: Halsam
authors.forename: Alex
authors.initials: A
authors.lastname: Valkov
authors.forename: Fiona
authors.initials: F
authors.lastname: Lecky
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000097:blood; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012709:Serum Albumin / Q000032:analysis*; D054556:Venous Thromboembolism / Q000097:blood / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; D012709:Serum Albumin