Cohort study of prediction of venous thromboembolism in emergency department patients with extremity symptoms.

Abstract Despite diagnostic algorithms, the best pathway to identify venous thromboembolism (VTE) in emergency departments (ED) needs to be defined. We evaluated symptoms, background, and laboratory data in 27,647 ED patients presenting with pain, swelling, or other symptoms from the extremities, and identified predictors of VTE diagnosis within one year. Predictors of a clinical decision to perform phlebography, ultrasound, or computer tomography (CT) angiography of pelvic, lower, or upper extremity veins, CT of pulmonary arteries, or pulmonary scintigraphy at the ED or within 30 days, and the results of such investigations were also evaluated. A total of 3,195 patients (11.6%) were diagnosed with VTE within one year. In adjusted analysis of patients in whom all laboratory data were available, a d-dimer value ≥0.5 mg/l (odds ratio [OR]: 2.602; 95% confidence interval [CI]: 1.894-3.575; p<0.001) at the ED and a previous diagnosis of VTE (OR: 6.037; CI: 4.465-8.162; p<0.001) independently predicted VTE. Of diagnosed patients, 2,355 (73.7%) had undergone imaging within 30 days after the ED visit and 1,730 (54.1%) were diagnosed at this examination. Lower age (OR: 0.984; CI: 0.972-0.997; p=0.014), higher blood hemoglobin (OR: 1.023; CI: 1.010-1.037; p<0.001), C-reactive protein (OR: 2.229; CI: 1.433-3.468; p<0.001), d-dimer (OR: 8.729; CI: 5.614-13.574; p<0.001), and previous VTE (OR: 7.796; CI: 5.193-11.705; p<0.001) predicted VTE on imaging. In conclusion, analysis of 27,647 ED patients with extremity symptoms confirmed the importance of well-established risk factors for VTE. Many patients developing VTE within one year had initial negative imaging, highlighting the importance of continued symptom vigilance.