Safety and feasibility of a diagnostic algorithm combining clinical probability, d-dimer testing, and ultrasonography for suspected upper extremity deep venous thrombosis: a prospective management study.

Background: Although well-established for suspected lower limb deep venous thrombosis, an algorithm combining a clinical decision score, D-dimer testing, and ultrasonography has not been evaluated for suspected upper extremity deep venous thrombosis (UEDVT). Objective: To assess the safety and feasibility of a new diagnostic algorithm in patients with clinically suspected UEDVT. Design: Diagnostic management study. (ClinicalTrials.gov: NCT01324037) Setting: 16 hospitals in Europe and the United States. Patients: 406 inpatients and outpatients with suspected UEDVT. Measurements: The algorithm consisted of the sequential application of a clinical decision score, D-dimer testing, and ultrasonography. Patients were first categorized as likely or unlikely to have UEDVT; in those with an unlikely score and normal D-dimer levels, UEDVT was excluded. All other patients had (repeated) compression ultrasonography. The primary outcome was the 3-month incidence of symptomatic UEDVT and pulmonary embolism in patients with a normal diagnostic work-up. Results: The algorithm was feasible and completed in 390 of the 406 patients (96%). In 87 patients (21%), an unlikely score combined with normal D-dimer levels excluded UEDVT. Superficial venous thrombosis and UEDVT were diagnosed in 54 (13%) and 103 (25%) patients, respectively. All 249 patients with a normal diagnostic work-up, including those with protocol violations (n = 16), were followed for 3 months. One patient developed UEDVT during follow-up, for an overall failure rate of 0.4% (95% CI, 0.0% to 2.2%). Limitations: This study was not powered to show the safety of the substrategies. D-Dimer testing was done locally. Conclusion: The combination of a clinical decision score, D-dimer testing, and ultrasonography can safely and effectively exclude UEDVT. If confirmed by other studies, this algorithm has potential as a standard approach to suspected UEDVT.