Absorption of apixaban following metabolic and bariatric surgery: is reluctance still warranted?

Background: Absorption of apixaban, a direct oral anticoagulant (DOAC), may be impaired after metabolic and bariatric surgery (MBS). The Dutch guideline advises switching to vitamin K antagonists (VKA), while patients prefer the use of DOACs. Apixaban is not regularly prescribed after MBS due to a lack of evidence regarding its efficacy and safety. Objectives: This study aimed to evaluate the efficacy and safety of apixaban after MBS. Methods: In this retrospective cohort study, chronic DOAC users who received preoperative and postoperative consultation and used apixaban (5 mg twice daily) after MBS with available anti-Xa levels were included. The outcomes were incidence rate of postoperative bleeding and thromboembolic events, number of patients switching to VKA, and percentage of anti-Xa peak levels within the expected on-therapy range up to 1 year postoperatively. Results: Of the 97 included patients, 63.9% were female, median age was 57 years (range, 51-61 years), and median preoperative body mass index was 43.2 kg/m² (range, 39.5-46.8 kg/m²), DOAC use was mostly indicated because of atrial fibrillation (59.8%), and 71.1% underwent Roux-en-Y gastric bypass. No thromboembolic events or major bleeds occurred, and 1 clinically relevant non-major bleeding was observed (incidence rate, 0.61; 95% CI, 0.02-3.38 per 100 patient-years). One patient switched to VKA, and 91.1% of patients had postoperative anti-Xa peak levels within expected on-therapy range. Conclusion: In this population of chronic DOAC users, apixaban with consultation including regular anti-Xa peak level measurements seems safe and effective after MBS. However, future prospective research in a larger population with longer follow-up is needed to confirm these results.