Safety and efficacy of apixaban and rivaroxaban in obese patients with acute venous thrombosis/embolism

Introduction Direct oral anticoagulants (DOACs) have significant advantages over vitamin K antagonists in the treatment of venous thromboembolism and as prophylaxis against recurrence. However, there is inadequate data to support the safety and efficacy of DOACs in the morbidly obese, and warfarin treatment is currently recommended by the International Society of Hemostasis and Thrombosis for this population. Materials and Methods We performed a retrospective review of outcomes in 499 patients with BMI ≥ 40 kg/m2 admitted from January 2013 to January 2020 with acute venous thromboembolism (VTE) and treated with either rivaroxaban (n=296) or apixaban (n=203). Results There were 38 (7.6%) bleeding and clotting events within 60 days of the initiation of DOACs, of which 35 (7.0%) were bleeding events and 3 (0.6%) were clotting events. Patients treated with rivaroxaban had more bleeding episodes (23, 7.8% vs. 12, 5.9%) and higher mortality (21, 7.1% vs. 13, 6.4%) compared with those treated with apixaban; however, these differences were not statistically significant (p=.427 and p=.764, respectively). Most of the bleeding occurred in the genitourinary and gastrointestinal tracts. Conclusions Our study indicates that apixaban and rivaroxaban are not associated with an increase in VTE recurrence in the morbidly obese; however, bleeding rates were slightly higher in the rivaroxaban group compared to the apixaban group.