Clinical use and safety of empiric anticoagulation during diagnostic work-up for deep vein thrombosis.

BACKGROUND

Previous studies suggest the safety of empiric anticoagulation administered to patients with suspected deep vein thrombosis (DVT) before the work-up is completed. However, the safety of such practice has not been thoroughly studied in the primary care setting.

OBJECTIVES

To describe the clinical use and safety of empiric low molecular-weight heparin (LMWH) in patients evaluated for suspected DVT in the prehospital, primary care setting.

METHODS

Patients evaluated for suspected DVT between February 2015 and November 2018 in the Emergency Department at Østfold Hospital, Norway, were eligible for inclusion. Pattern of use of empiric LMWH was evaluated regarding the type of anticoagulant agent and dosage (therapeutic vs sub-therapeutic). Safety, defined as major and clinically relevant non-major bleeding (CRNMB) events, and development of pulmonary embolism (PE) after the initiation of empiric therapy, was assessed in all patients receiving empiric anticoagulation 48 h post-enrolment.

RESULTS

Of the 1653 patients referred to Østfold Hospital with suspected DVT, 328 patients (19.8%) received LMWH. Of these, 54 (16.5%) received therapeutic doses, 232 (70.7%) sub-therapeutic doses, whereas 42 (12.8%) received unknown doses. Enoxaparin was prescribed to 303 patients (94.2%), while 25 patients (7.6%) received dalteparin. DVT was confirmed in 69 patients (21.0%). No major bleeding events or deaths occurred. Two patients (0.6%) experienced CRNMB events. None of the patients developed PE after the initiation of empiric therapy.

CONCLUSIONS

Most patients received sub-therapeutic doses of empiric LMWH. Bleeding complications were low, indicating that empiric anticoagulation was safe. Empiric anticoagulation was often prescribed irrespective of the pre-test probability score and the bleeding risk.Trial registration: ClinicalTrials.gov identifier: NCT02486445.