Absorption of apixaban following metabolic 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 to switch 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. Therefore, this study aimed to evaluate the efficacy and safety of apixaban after MBS.

Methods: In this retrospective cohort study, chronic DOAC users who received pre 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 one year postoperative.

Results: Of the 97 included patients, 63.9% were female, median age was 57 years [51-61], and preoperative BMI 43.2 kg/m [39.5-46.8], DOAC 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 one 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.