title: D-dimer and thrombin-antithrombin III complexes in patients with clinically suspected pulmonary embolism.
abstract: One hundred and fifty-six consecutive patients with clinically suspected pulmonary embolism (PE) had blood drawn to measure levels of D-dimer and thrombin-antithrombin (TAT) complexes and underwent ventilation/perfusion (V/Q) lung scanning and bilateral impedance plethysmography (IPG); pulmonary angiography was performed in 10 patients. Patients were classified as: PE-positive (positive pulmonary angiography or high probability lung scan or non-high probability lung scan and abnormal IPG) or, PE-negative (normal lung scan or normal pulmonary angiography) or PE-unlikely (non-high probability lung scan and normal serial IPG and absence of venous thromboembolism in follow-up). Thirty patients were classified as PE-positive, 64 as PE-negative and 62 patients as PE-unlikely. PE-positive patients were treated with anticoagulants, whereas PE-negative and PE-unlikely patients were not. PE-unlikely patients were followed for 3 months with repeat IPG and clinical evaluation for the occurrence of venous thromboembolism. The sensitivities, specificities, positive predictive values and negative predictive values of the D-dimer and TAT complex assays were calculated for patients classified as PE-positive and PE-negative. In addition, the prevalences of normal D-dimer and TAT complex assays were calculated for PE-unlikely patients. Cutoffs of 300 ng/ml for D-dimer and 3.5 micrograms/ml for TAT complexes provided sensitivities of 96% for both assays, negative predictive values of 97% for D-dimer and 96% for TAT complexes and specificities of 52% for D-dimer and 51% for TAT complexes. The specificities of the assays were higher in patients without comorbid conditions and in outpatients.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Demers
authors.forename: J S
authors.initials: JS
authors.lastname: Ginsberg
authors.forename: M
authors.initials: M
authors.lastname: Johnston
authors.forename: P
authors.initials: P
authors.lastname: Brill-Edwards
authors.forename: A
authors.initials: A
authors.lastname: Panju
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000990:Antithrombin III / Q000378:metabolism*; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D010447:Peptide Hydrolases / Q000378:metabolism*; D011655:Pulmonary Embolism / Q000097:blood* / Q000175:diagnosis* / Q000188:drug therapy; D012680:Sensitivity and Specificity
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C046193:antithrombin III-protease complex; C036309:fibrin fragment D; D000990:Antithrombin III; D006493:Heparin; D010447:Peptide Hydrolases