LAUSR

Background Rivaroxaban is a first-line option for the management of venous thromboembolism (VTE). However, limited data are available regarding its effectiveness in morbidly obese patients. Objective To evaluate rates of thrombosis and bleeding in morbidly obese patients receiving rivaroxaban or warfarin for VTE. Methods A multicenter, retrospective cohort study was conducted to compare rates of bleeding and thrombosis in patients receiving rivaroxaban versus warfarin for acute VTE. Patients were included if they were older than 18 years and had a body mass index (BMI) greater than 40 kg/m2 or weight greater than 120 kg. The primary effectiveness outcome was hazard of VTE recurrence; the primary safety outcome was hazard of major bleeding. Patients were followed for up to 12 months. Results A total of 1281 patients were identified for acute VTE and were included in this study with 487 patients receiving rivaroxaban and 785 receiving warfarin. The average cohort age was 57.6 ± 14.6 years, and the average weight was 136.4 ± 27.2 kg. After controlling for confounding factors, the use of rivaroxaban was not associated with an increased hazard of VTE events when compared with warfarin (hazard ratio [HR] = 0.69, 95% confidence interval [CI]: 0.42-1.08, P = 0.12) or major bleeding (HR = 1.29, 95% CI: 0.66-2.30, P = 0.52). Conclusion and Relevance No difference was observed in obese patients with weight >120 kg or BMI >40 kg/m2 receiving rivaroxaban or warfarin for VTE treatment in hazard of VTE or major bleeding. Either agent may be considered an appropriate treatment option in this population.