Negative D-dimer result to exclude recurrent deep venous thrombosis: a management trial.
BACKGROUND
All of the available diagnostic tests for deep venous thrombosis (DVT) have limitations for excluding acute recurrent DVT. Measurement of plasma d-dimer by using an automated quantitative assay may be useful as a rapid exclusion test in patients with suspected recurrent DVT.


OBJECTIVE
To test the safety of withholding additional diagnostic testing and heparin treatment in patients who have a negative d-dimer result at presentation (using the automated quantitative assay STA-Liatest D-di), regardless of their symptoms.


METHODS
Prospective cohort study.


METHODS
Academic medical center in the United States.


METHODS
300 consecutive patients with suspected recurrent DVT.


METHODS
Patients underwent d-dimer testing at presentation. In patients with negative D-dimer results, heparin therapy was withheld, and no further diagnostic testing for DVT was done as part of the initial evaluation. Patients with positive D-dimer results underwent compression ultrasonography.


METHODS
The primary outcome measure was a diagnosis of new symptomatic venous thromboembolism confirmed by diagnostic testing during the 3-month follow-up period.


RESULTS
Of the 300 study patients, the d-dimer result was negative at presentation in 134 patients (45%; negative cohort) and positive at presentation in 166 patients. Of the 166 patients, compression ultrasonography documented new DVT in 54 patients. Compression ultrasonography findings were normal in 79 patients and were inconclusive in 33 patients. After 3 months of follow-up, 1 of 134 patients in the negative cohort had confirmed venous thromboembolism (0.75% [95% CI, 0.02% to 4.09%]). Venous thromboembolism on follow-up could not be definitively excluded in 5 patients with recurrent leg symptoms and in 1 patient who died. If these patients are considered to have venous thromboembolism, the incidence during the 3-month follow-up period would be 6.0% (CI, 2.6% to 11.4%) (8 of 134 patients).


CONCLUSIONS
There is no accepted diagnostic reference standard for recurrent DVT. The precision of the estimate of the incidence of venous thromboembolism on follow-up and the generalizability to settings other than an academic health center should be evaluated.


CONCLUSIONS
Measurement of plasma d-dimer by using the automated quantitative assay STA-Liatest D-di seems to provide a simple method for excluding acute recurrent DVT in symptomatic patients.
Rathbun
Suman W
SW
Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA. suman-rathbun@ouhsc.edu
Whitsett
Thomas L
TL
Raskob
Gary E
GE
D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D005500:Follow-Up Studies; D006403:Hematologic Tests / Q000592:standards*; D006801:Humans; D012008:Recurrence; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000401:mortality
D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D