Exclusion of venous thromboembolism: evaluation of D-Dimer PLUS for the quantitative determination of D-dimer.
The objective of this study was to evaluate if D-Dimer PLUS (Dade Behring, USA), a rapid fully automated assay, could be used as an initial screening test in the diagnosis of venous thromboembolism (VTE). Samples from 274 consecutive symptomatic patients with suspected pulmonary embolism (n=229; 79% outpatients, 21% inpatients), deep venous thrombosis (n=37; 84% outpatients, 16% inpatients) or suspected for both complications (n=8) were tested with this D-dimer assay with a Sysmex CA-1500 Coagulation Analyzer. Clinical probability for pulmonary embolism (PE) or deep venous thrombosis (DVT) was staged according to a pretest risk score proposed by Wells. Final diagnosis of PE and/or DVT was established by spiral-computed tomography of the pulmonary arteries or compression ultrasonography, respectively. PE was diagnosed in 13.5% of the patients, whereas DVT was confirmed in 17.7% of the patients. The optimal cut-off value for exclusion of venous thromboembolism was 130 mug/l, and sensitivity, specificity and negative predictive value (NPV) were 95.0% (95% CI: 92.4-97.6), 30.4% (95% CI: 25.0-35.8) and 97.2% (95% CI: 95.2-99.2), respectively. In fact, two patient with PE were missed using D-Dimer PLUS; both cases were outpatients. In conclusion, this assay appears to be safe when implemented in an algorithm based on clinical assessment, D-dimer concentration, and radiological diagnostic techniques to stratify the risk for PE or DVT. However, higher sensitivities and negative predictive values were claimed in the scarce published reports for the D-Dimer PLUS assay than found in this study.
Vermeer
H J
HJ
Department of Haematology, The Hague, The Netherlands. h.vermeer@leyenburg-ziekenhuis.nl
Ypma
P
P
van Strijen
M J L
MJ
Muradin
A A
AA
Hudig
F
F
Jansen
R W
RW
Wijermans
P W
PW
Gerrits
W B J
WB
D015331:Cohort Studies; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000097:blood / Q000175:diagnosis; D012372:ROC Curve; D011933:Reagent Kits, Diagnostic / Q000706:statistics & numerical data*; D012680:Sensitivity and Specificity; D013923:Thromboembolism / Q000097:blood / Q000175:diagnosis*; D020246:Venous Thrombosis / Q000097:blood / Q000175:diagnosis*
D005338:Fibrin Fibrinogen Degradation Products; D011933:Reagent Kits, Diagnostic; C036309:fibrin fragment D