To evaluate the implementation of the European Society of Cardiology (ESC) guidelines concerning the diagnostic management of deep vein thrombosis (DVT) in emergency departments (ED); and to estimate the additional financial cost and the increase in the time spent in the ED if the guidelines are not followed.

Retrospective, bi-centric study including all patients directly admitted or referred to the ED for a suspected isolated DVT, between April 1, 2019, and July 30, 2019. The diagnostic management was compared to the 2017 ESC's guidelines.

107 patients were included, 13 had DVT (12%) and three had superficial venous thrombosis (3%). A total of 26 patients (24%) had a diagnostic management according to guidelines. In 72 patients (67%), no assessment of clinical probability score was found. Among the 35 patients in whom a clinical probability score was calculated, 5 patients had an unnecessary D-dimer assay and 2 patients had unjustified imaging. The median time spent in the ED was 185minutes when the recommendations were followed, and 250minutes when they were not (P=0.317). The total estimated additional cost was €232.20.

The rate of adherence to the guidelines is low, mainly due to the absence of calculation of a clinical probability. This leads, in addition to the risk of diagnostic error, to an increase in the time spent in the EDs and inappropriate use of the technical platform, resulting in additional costs of care.