Serial proximal vein ultrasonography + D-dimer = whole-leg Doppler for suspected leg DVT

Clinical Question

Is serial 2-point proximal vein ultrasonography plus D-dimer testing as accurate as whole-leg Doppler ultrasonography in the evaluation of adults with suspected symptomatic deep venous thrombosis?

Bottom Line

This study found the currently recommended management strategy of serial 2-point proximal vein ultrasonography plus D-dimer testing to have a similar complication rate as immediate whole-leg Doppler ultrasonography for patients with first episode suspected deep venous thrombosis (DVT). These results should be reassuring to clinicians who evaluate patients with suspected DVT in medical centers that do not have immediate access to the newest whole-leg color-coded Doppler ultrasonography technology. (LOE = 1b)

Reference

Bernardi E, Camporese G, Buller HR, et al, for the Erasmus Study Group. Serial 2-point ultrasonography plus D-dimer vs whole-leg color-coded Doppler ultrasonography for diagnosing suspected symptomatic deep vein thrombosis. A randomized controlled trial. JAMA 2008;300(14):1653-1659.  [PMID:18840838]

Study Design

Randomized controlled trial (single-blinded)

Funding

Foundation

Allocation

Concealed

Setting

Emergency department

Synopsis

Current guidelines recommend that adults presenting with suspected first episode deep venous thrombosis (DVT) with normal proximal vein compression ultrasonography undergo retesting in 1 week to detect initially undiagnosed calf DVT extending to the proximal veins, unless the initial D-dimer test result is also normal. Color-coded Doppler ultrasonography can scan the entire deep venous system negating the need for additional testing. However, this new technology requires special equipment and experienced operators that are not always available in all centers. In addition, whether prompt detection of calf DVT with whole-leg scanning reduces morbidity and mortality from DVT is uncertain. These investigators randomly assigned (concealed allocation assignment) 2098 eligible consecutive outpatients presenting with a first episode of suspected symptomatic DVT of the lower extremities to 1 of 2 management strategies: (1) Ultrasonography of the proximal vein only, followed by D-dimer testing if normal (2-point strategy). Patients with normal D-dimer levels were not treated and underwent no further testing; patients with abnormal D-dimer levels underwent repeat ultrasonography at 1 week or earlier if clinically indicated; or (2) Whole-leg color-coded Doppler ultrasonography only. Individuals assessing outcomes remained masked to management group assignment. Twenty-two percent of patients randomized to the 2-point strategy (n = 217) had abnormal findings at the initial work-up and underwent anticoagulation. Of the 828 patients with a normal ultrasound, 256 patients had an abnormal D-dimer level and underwent a second ultrasound scanning; 14 of these were subsequently diagnosed with a proximal DVT and were anticoagulated. The remaining 814 patients without a diagnosis of DVT remained untreated and underwent 3-month follow-up. Similarly, 26% of patients randomized to receive the whole-leg ultrasonography (n = 278) had abnormal findings at presentation (213 proximal vein DVT, 65 calf DVT) and underwent anticoagulation; the remaining 775 untreated patients with normal results underwent 3-month follow-up. Complete follow-up occurred for more than 99% of patients. Symptomatic venous thromboembolism occurred equally during the 3-month follow-up period in the 2-point and whole-leg strategy groups (incidence = 0.9%; 95% CI, 0.3% - 1.8% and 1.2%; 0.5%-2.2%, respectively). There were no DVT/pulmonary embolism-related deaths in either group.