title: Tandem measurement of D-dimer and myeloperoxidase or C-reactive protein to effectively screen for pulmonary embolism in the emergency department.
abstract: OBJECTIVE
  The hypothesis was that the tandem measurement of D-dimer and myeloperoxidase (MPO) or C-reactive protein (CRP) could significantly decrease unnecessary pulmonary vascular imaging in emergency department (ED) patients evaluated for pulmonary embolism (PE) compared to D-dimer alone.
  
  
  METHODS
  The authors measured the sequential combinations of D-dimer and MPO and D-dimer and CRP in a prospective sample of ED patients evaluated for PE at two centers. Patients were followed for 90 days for venous thromboembolism (VTE, either PE or deep venous thrombosis [DVT]), which required the consensus of two of three blinded physician reviewers.
  
  
  RESULTS
  The authors enrolled 304 patients, 22 with VTE (7%; 95% confidence interval [CI] = 5% to 10%). The sensitivity and specificity of a D-dimer alone (cutoff > or = 500 ng/mL) were 100% (95% CI = 85% to 100%) and 59% (95% CI = 53% to 65%), respectively, and was followed by pulmonary vascular imaging negative for PE in 38% (115/304; 95% CI = 32% to 44%). The combination of either a negative D-dimer, or MPO < 22 mg/dL, had a sensitivity of 100% and specificity of 73% (95% CI = 67% to 78%). Thus, tandem measurement of D-dimer and MPO would have decreased the frequency of subsequent negative pulmonary vascular imaging from 38% to 25% (95% CI of the difference of -13% = -5% to -20%). The combination of CRP and D-dimer would not have significantly improved the rate of negative imaging.
  
  
  CONCLUSIONS
  The tandem measurement of D-dimer and MPO would have significantly decreased negative pulmonary vascular imaging compared with D-dimer alone and should be validated prospectively.
authors.affiliation: Department of Emergency Medicine, Carolinas Medical Center,, Charlotte, NC, USA.
authors.forename: Alice M
authors.initials: AM
authors.lastname: Mitchell
authors.forename: Kristen E
authors.initials: KE
authors.lastname: Nordenholz
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kline
mesh_terms: D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism*; D003952:Diagnostic Imaging / Q000706:statistics & numerical data; D004636:Emergency Service, Hospital; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009195:Peroxidase / Q000097:blood*; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000097:blood* / Q000175:diagnosis*; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D002097:C-Reactive Protein; D009195:Peroxidase