Anticoagulant therapies for acute venous thromboembolism: a comparison between those discharged directly from the emergency department versus hospital in two Canadian cities

Objective: To compare the characteristics/management of acute venous thromboembolism (VTE) for patients either discharged directly from the emergency department (ED) or hospitalised throughout a year within two urban cities in Canada.

Design: Retrospective medical record review.

Setting: Hospitals in Edmonton, Alberta (n=4) and Regina, Saskatchewan (n=2) from April 2014 to March 2015.

Participants: All patients discharged from the ED or hospital with acute deep vein thrombosis or pulmonary embolism (PE). Those having another indication for anticoagulant therapy, pregnant/breast feeding or anticipated lifespan <3 months were excluded.

Primary and secondary outcomes: Primarily, to compare proportion of patients receiving traditional therapy (parenteral anticoagulant±warfarin) relative to a direct oral anticoagulant (DOAC) between the two cohorts. Secondarily, to assess differences with therapy selected based on clot burden and follow-up plans postdischarge.

Results: 387 (25.2%) and 665 (72.5%) patients from the ED and hospital cohorts, respectively, were included. Compared with the ED cohort, those hospitalised were older (57.3 and 64.5 years; p<0.0001), more likely to have PE (35.7% vs 83.8%) with a simplified Pulmonary Embolism Severity Index (sPESI) ≥1 (31.2% vs 65.2%), cancer (14.7% and 22.3%; p=0.003) and pulmonary disease (10.1% and 20.6%; p<0.0001). For the ED and hospital cohorts, similar proportions of patients were prescribed traditional therapies (72.6% and 71.1%) and a DOAC (25.8% and 27.4%, respectively). For the ED cohort, DOAC use was similar between those with a sPESI score of 0 and ≥1 (35.1% and 34.9%, p=0.98) whereas for those hospitalised lower risk patients were more likely to receive a DOAC (31.4% and 23.8%, p<0.055). Follow-up was most common with family physicians for those hospitalised (51.5%), while specialists/VTE clinic was most common for those directly discharged from the ED (50.6%).

Conclusions: Traditional and DOAC therapies were proportionately similar between the ED and hospitalised cohorts, despite clear differences in patient populations and follow-up patterns in the community.