Effectiveness and safety of apixaban and rivaroxaban for acute venous thromboembolism therapy in patients with extremes in bodyweight

Objectives To investigate the association of extremes in bodyweight (EBW) and outcomes in patients with acute venous thromboembolism (VTE). Recurrent VTE, major bleeding, and clinically relevant non-major bleeding were compared between patients with bodyweight <60 kg, 60-120 kg, and >120 kg. Methods Consecutive patients enrolled in the Mayo Clinic VTE Registry (03/28/2013-8/31/2019) with acute VTE were followed prospectively. Patient status was assessed in person, by mailing a written questionnaire, or by a scripted phone interview. Results Among 2577 patients with weight ranging from 27.0 kg to 263.2 kg, 2123 (82%) had a bodyweight between 60 and 120 kg, 223 (8.7%) had bodyweight < 60 kg, and 230 (8.9%) had bodyweight >120 kg. Patients with bodyweight <60 kg treated with DOACs had higher 3- and 6-month incidence of major bleeding compared to the bodyweight 60-120kg group (4.4% vs 1.1%,P = .03, and 4.4% vs 1.4%,P = .05, respectively). Patients with bodyweight >120 kg and cancer on rivaroxaban had higher VTE recurrence compared to bodyweight 60-120kg group (P = .01). Conclusions Treatment of acute VTE is associated with a higher incidence of bleeding in patients with bodyweight 120 kg on rivaroxaban.