Multi-center retrospective study evaluating the efficacy and safety of apixaban versus warfarin for treatment of venous thromboembolism in patients with severe obesity

Study Objective Direct oral anticoagulants are the standard of care for venous thromboembolism (VTE) treatment. These agents are recommended regardless of patient weight and body mass index (BMI). However, there remains limited evidence supporting the use of apixaban in patients with severe obesity with a BMI >= 40 kg/m(2) or weight >= 120 kg. The purpose of this study was to evaluate the efficacy and safety of apixaban for VTE in patients with a BMI >= 40 kg/m(2) or weight >= 120 kg. Design This multi-center, retrospective study compared the use of apixaban versus warfarin in patients with severe obesity for the treatment of VTE between January 1, 2012, and December 31, 2019. Patients were identified by diagnosis codes for acute VTE and a weight >= 120 kg or BMI >= 40 kg/m(2). The primary efficacy outcome was time to recurrence of VTE within 12 months, and the primary safety outcome was time to major bleeding within 12 months. Secondary outcomes included incidence of recurrent VTE, major bleeding, clinically relevant non-major bleeding (CRNMB), all-cause mortality, number of total hospital encounters, and switch in anticoagulant. Main Results A total of 1099 patients were included in the study. Of these, 314 patients received apixaban and 785 received warfarin. The mean weight and BMI were 137 kg and 46 kg/m(2), respectively. Time to recurrent VTE was significantly longer in those treated with apixaban compared to warfarin (p = 0.018). After controlling for confounding factors, apixaban use was associated with a reduced risk of recurrent VTE compared to warfarin (hazard ratio [HR] = 0.54, 95% confidence interval [CI]: 0.29-0.97, p = 0.04). There were no significant differences in major bleeding, CRNMB, or all-cause mortality between groups. Conclusion In patients with a BMI >= 40 kg/m(2) or weight >= 120 kg, apixaban appears to be effective and safe for the treatment of VTE.