Diagnostic value of D-dimer in outpatients with suspected deep venous thrombosis receiving oral anticoagulation.
D-dimer has proved a useful diagnostic tool for the exclusion of deep venous thrombosis (DVT). The objective of this paper was to evaluate the diagnostic performance of a diagnostic algorithm combining clinical probability and D-dimer in outpatients receiving oral anticoagulant treatment (OAT) similar to those regularly applied to nonanticoagulated individuals. We enrolled 70 outpatients on OAT who presented with clinically suspected DVT; a standard diagnostic algorithm including clinical evaluation using the modified Wells score and a quantitative immunoturbidimetric D-dimer assay (STA Liatest D-Di; Diagnostica Stago, Asniéres sur Seine, France) was used. A 3-month follow-up period was applied for those patients in whom DVT was initially excluded. The prevalence of DVT was 18.5% (13/70); four of the diagnoses were made during the 3-month follow-up period. The sensitivity, specificity and negative predictive value of D-dimer were 69.2% (95 confidence interval, 42.4-87.3), 47.4% (95% confidence interval, 35.0-60.1) and 87.1% (95% confidence interval, 71.1-94.9), respectively. In conclusion, D-dimer is of limited value in outpatients on OAT presenting with clinically suspected DVT and should be omitted in such individuals; these patients should always undergo compression venous ultrasound, and repeat ultrasonography within 1 week might be warranted in cases with an initial negative examination.
Aguilar
Carlos
C
Department of Haematology, Hospital General Santa Bárbara, Soria, Spain. caraguilar@excite.com
Del Villar
Valentín
V
D000465:Algorithms; D000925:Anticoagulants / Q000627:therapeutic use*; D003933:Diagnosis; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis* / Q000592:standards; D006801:Humans; D010045:Outpatients; D011237:Predictive Value of Tests; D015995:Prevalence; D012680:Sensitivity and Specificity; D020246:Venous Thrombosis / Q000175:diagnosis*
D000925:Anticoagulants; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D