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 Xa inhibitors in severely obese patients with a weight ≥ 150kg or BMI ≥ 50 kg/m2 .

OBJECTIVES: The purpose of this study is to evaluate whether factor Xa 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 ≥ 50 kg/m2 and/or weight ≥ 150 kg.

PATIENTS / METHODS: This was a multicenter retrospective cohort study of severely obese adult patients with AF and/or VTE treated with a factor Xa inhibitor or warfarin. The primary effectiveness outcome was a 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 non-major 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 1,736 patients were included. The mean weight and BMI of the overall cohort was 164.4 kg and 54.6 kg/m2 , respectively. There was no difference in odds of stroke, systemic embolism or VTE (OR 1.005, 95% CI 0.6 - 1.68) or major bleeding (OR 0.9, 95% CI 0.47 - 1.7) between groups.

CONCLUSIONS: 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 ≥ 50 kg/m2 and/or weight ≥ 150 kg.