Treatment of atrial fibrillation and venous thromboembolism with factor Xa inhibitors in severely obese patients.

Background: A paucity of data exists to support the use of factor (F)Xa inhibitors in severely obese patients with a weight of ≥150 kg or body mass index (BMI) of ≥50 kg/m².

Objectives: The purpose of this study was to evaluate whether FXa inhibitors are as safe and effective as warfarin for the treatment of atrial fibrillation (AF) and/or venous thromboembolism (VTE) in individuals with a BMI of ≥50 kg/m² and/or weight of ≥150 kg.

Methods: This was a multicenter retrospective cohort study of severely obese adult patients with AF and/or VTE treated with a FXa inhibitor or warfarin. The primary effectiveness outcome was composite odds of stroke, systemic embolism, or VTE; the primary safety outcome was odds of major bleeding. Secondary outcomes included incidence of stroke or systemic embolism, VTE, major bleeding, clinically relevant nonmajor bleeding, all-cause mortality, change in anticoagulation, and total number of hospital encounters. Outcomes were assessed for 12 months following initiation of study drug.

Results: A total of 1736 patients were included. The mean weight and BMI of the overall cohort were 164.4 kg and 54.6 kg/m², respectively. There was no difference in odds of stroke, systemic embolism or VTE (odds ratio, 1.005; 95% CI, 0.6-1.68), or major bleeding (odds ratio, 0.9; 95% CI, 0.47-1.7) between groups.

Conclusion: These data suggest that apixaban and rivaroxaban are safe and effective alternatives to warfarin for the treatment of AF and/or VTE in individuals with a BMI of ≥50 kg/m² and/or weight of ≥150 kg.