Combined use of clinical assessment and d-dimer to improve the management of patients presenting to the emergency department with suspected deep vein thrombosis (the EDITED Study)

Abstract

Please see also Oswald C. T. et al. The use of the D-dimer in emergency room patients with suspected deep vein thrombosis: a test whose time has come. This issue, pp. 635±636.Summary. Suspected deep vein thrombosis (DVT) is a common problem facing emergency physicians. Timely diagnostic testing must be performed to accurately identify patients with DVT. The purpose of this study was to evaluate the safety and effectiveness of a management strategy that combined consideration of clinical pretest probability and a D-dimer test to evaluate patients presenting to the emergency department with suspected deep vein thrombosis (DVT). A prospective cohort study was performed in the emergency departments of four tertiary care institutions involving 1075 patients with suspected DVT. An emergency physician determined the pretest probability for DVT to be low, moderate, or high using an explicit clinical model. A blood sample was taken for D-dimer testing. Subsequent investigations (compression ultrasound, venography) were performed based upon the pretest probability and the D-dimer result. Patients considered at low pretest probability with negative D-dimer had no further diagnostic testing performed. All patients in whom the diagnosis of DVT was excluded by the algorithm did not receive anticoagulant therapy and were followed up for 90 days for the development of proximal DVT or pulmonary embolism. Overall, 195 (18.1%; 95% CI 15.9% to 20.6%) of 1075 patients were con®rmed to have proximal DVT. Of the 882 patients who had proximal DVT excluded during the initial evaluation period using the algorithms, four (0.5%; 95% CI 0.1% to 1.2%) were subsequently diagnosed with proximal DVT in the follow-up period, including three patients in the low pretest probability group (1.0%; 95% CI 0.2% to 2.1%) who had normal D-dimer and no additional diagnostic testing performed. None of the 882 patients (0%: 95% CI 0% to 0.5%) developed pulmonary embolism in the follow-up period. A diagnostic strategy for the evaluation of patients with suspected DVT based on pretest probability and D-dimer is safe and feasible in the emergency department setting.

Laboratory Markers in the Diagnosis of Venous Thromboembolism

“…5 Recently, a multicenter prospective cohort study examining the safety and effectiveness of a comprehensive strategy integrating a clinical risk assessment score, D-dimer testing, and compression ultrasonography in patients presenting to the emergency department with symptoms suggestive of DVT was published. 6 Through a published commentary on this article, Oswald suggested that the diagnostic strategy employed in this study was successful. 7 Of the 882 individuals in whom proximal DVT was excluded during initial evaluation, only 4 patients (0.5%) were subsequently diagnosed with proximal DVT and none developed pulmonary emboli (PE) during 90 days of follow-up.…”

“…7 Of the 882 individuals in whom proximal DVT was excluded during initial evaluation, only 4 patients (0.5%) were subsequently diagnosed with proximal DVT and none developed pulmonary emboli (PE) during 90 days of follow-up. 6 However, the results section of the original article reveals that an additional 5 patients with calf vein thrombosis were missed on the initial evaluation. In addition, Anderson used only compression ultrasonography, which would be unacceptable in many vascular laboratories in the United States.…”

“…9 Prevention of these complications can be achieved only by diagnosing and treating all leg thrombi. In a study conducted by Anderson,6 when the D-dimer assay alone was used to detect proximal DVT, the overall sensitivity was 82.6% with a specificity of 70%. These numbers are not good enough to justify using the D-dimer test alone for VTE diagnosis.…”

Ultrasonography and Diagnosis of Venous Thromboembolism

“…[22][23][24][25][26][27] The utility of algorithms in the diagnosis of DVT, however, depends on the availability of diagnostic testing, the expertise of the technologists performing the ultrasound examinations, the patient population, the cost and reimbursement of the different tests, and the interpretation of the results. What might be feasible for one institution may not be applicable to another, and each group should determine their own approach with some objective validation.…”

“…However, there have been some rigorously performed cohort studies that have incorporated algorithms utilizing clinical pretest probability in combination with ultrasonography and/or D-dimer testing. [22][23][24][25][26][27] …”