A randomized trial of diagnostic strategies after normal proximal vein ultrasonography for suspected deep venous thrombosis: D-dimer testing compared with repeated ultrasonography.

Abstract

BACKGROUND:

With suspected deep venous thrombosis and normal results on proximal vein ultrasonography, a negative d-dimer result may exclude thrombosis and a positive D-dimer result may be an indication for venography.

OBJECTIVE:

To evaluate and compare the safety of 2 diagnostic strategies for deep venous thrombosis.

DESIGN:

Randomized, multicenter trial.

SETTING:

Four university hospitals.

PATIENTS:

810 outpatients with suspected deep venous thrombosis and negative results on proximal vein ultrasonography.

INTERVENTIONS:

Erythrocyte agglutination D-dimer testing followed by no further testing if the result was negative and venography if the result was positive (experimental) or ultrasonography repeated after 1 week in all patients (control).

MEASUREMENTS:

Symptomatic deep venous thrombosis diagnosed initially and symptomatic venous thromboembolism during 6 months of follow-up.

RESULTS:

Nineteen of 408 patients (4.7%) in the D-dimer group and 3 of 402 patients (0.7%) in the repeated ultrasonography group initially received a diagnosis of deep venous thrombosis (P < 0.001). During follow-up of patients without a diagnosis of deep venous thrombosis on initial testing, 8 patients (2.1% [95% CI, 0.9% to 4.0%]) in the D-dimer group and 5 patients (1.3% [CI, 0.4% to 2.9%]) in the repeated ultrasonography group developed symptomatic venous thromboembolism (difference, 0.8 percentage point [CI, -1.1 to 2.9 percentage points]; P > 0.2). Venous thromboembolism occurred in 1.0% (CI, 0.2% to 2.8%) of those with a negative D-dimer result.

LIMITATIONS:

Seventy patients (8.6%) deviated from the diagnostic protocols, and 9 patients (1.1%) had inadequate follow-up.

CONCLUSION:

In outpatients with suspected deep venous thrombosis who initially had normal results on ultrasonography of the proximal veins, a strategy based on D-dimer testing followed by no further testing if the result was negative and venography if the result was positive had acceptable safety and did not differ from the safety of a strategy based on withholding anticoagulant therapy and routinely repeating ultrasonography after 1 week.

• Authors: Clive Kearon, Jeffrey S Ginsberg, James Douketis, Mark A Crowther, Alexander G Turpie, Shannon M Bates, Agnes Lee, Patrick Brill-Edwards, Terri Finch, Michael Gent
• Journal: Annals of internal medicine (Ann Intern Med) Vol. 142 Issue 7 Pg. 490-6 (Apr 05 2005) ISSN: 1539-3704 [Electronic] United States
• PMID: 15809460 (Publication Type: Clinical Trial, Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Fibrin Fibrinogen Degradation Products

Topics

• Female
• Fibrin Fibrinogen Degradation Products (analysis)
• Follow-Up Studies
• Humans
• Leg (blood supply)
• Male
• Middle Aged
• Ultrasonography, Doppler
• Veins (diagnostic imaging)
• Venous Thrombosis (diagnosis, diagnostic imaging)