Original article| Volume 19, ISSUE 3, P222-230, March 2023

Download started.


Outcomes with direct-acting oral anticoagulants in patients with a history of bariatric surgery: a retrospective cohort study

Published:September 21, 2022DOI:



      Patients who undergo bariatric surgery have major physiologic changes in their gastrointestinal tract, which can theoretically alter drug absorption and pharmacokinetics. This is especially concerning for drugs with a narrow therapeutic index, as small changes in absorption can have significant effects on safety and efficacy. One class of interest is direct-acting oral anticoagulants (DOACs), for which there is a paucity of data in this population.


      To characterize the use of DOACs (apixaban, dabigatran, rivaroxaban) in patients with a history of bariatric surgery and incidence of clotting and bleeding events.


      Public healthcare system/university hospital, United States.


      This retrospective cohort study included adult patients who were prescribed a DOAC for the prophylaxis or treatment of venous thromboembolism or for stroke and systemic embolism prevention in atrial fibrillation between January 2011 and December 2018.


      A total of 191 patients with a history of bariatric surgery were included. Clotting events occurred in 11 of 191 patients (5.8%) receiving DOAC therapy, with a calculated clotting rate of 3.9 clots per 100 person-years. Bleeding events occurred in 42 of 191 patients (22%) receiving a DOAC, with a calculated bleeding rate of 17.1 bleeds per 100 person-years. The use of rivaroxaban versus apixaban was associated with a statistically significant increased risk of bleeding in patients with a history of bariatric surgery.


      In this retrospective cohort of bariatric surgery patients receiving DOACs, we found clotting rates consistent with expected rates and bleeding rates above expected rates based on historical data. We also found an increased risk of bleeding in rivaroxaban users compared with apixaban users. Careful evaluation of bleeding risks in bariatric surgery patients is encouraged.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Surgery for Obesity and Related Diseases
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Concors S.J.
        • Ecker B.L.
        • Maduka R.
        • et al.
        Complications and surveillance after bariatric surgery.
        Curr Treat Options Neurol. 2016; 18: 5
      1. American Society for Metabolic and Bariatric Surgery (ASMBS) [Internet]. Newberry, FL: The Association; [updated 2021 Mar; cited 2022 Jan 24]. Estimate of bariatric surgery numbers, 2011–2019 [about 2 screens]. Available from:

        • Bland C.M.
        • Miller Quidley A.
        • Love B.L.
        • Yeager C.
        • McMichal B.
        • Bookstaver P.B.
        Long-term pharmacotherapy considerations in the bariatric surgery patient.
        Am J Health-Syst Pharm. 2016; 73: 1230-1242
        • Martin K.A.
        • Lee C.R.
        • Farrell T.M.
        • Moll S.
        Oral anticoagulant use after bariatric surgery: a literature review and clinical guidance.
        Am J Med. 2017; 130: 517-524
        • Nasser M.F.
        • Jabri A.
        • Fandhi S.
        • Rader F.
        Oral anticoagulant use in morbid obesity and post bariatric surgery: a review.
        Am J Med. 2021; 134: 1465-1475
        • Hakeam H.
        • Al-Sanea N.
        Effect of major gastrointestinal tract surgery on the absorption and efficacy of direct acting oral anticoagulants (DOACs).
        J Thromb Thrombolysis. 2017; 43: 343-351
        • Domienik-Karlowicz J.
        • Pruszczyk P.
        The use of anticoagulants in morbidly obese patients.
        Cardiol J. 2016; 23: 12-16
        • Kröll D.
        • Stirnimann G.
        • Vogt A.
        • et al.
        Pharmacokinetics and pharmacodynamics of single doses of rivaroxaban in obese patients prior to and after bariatric surgery.
        Br J Clin Pharmacol. 2017; 83: 1466-1475
        • Moore K.T.
        • Kröll D.
        Influences of obesity and bariatric surgery on the clinical and pharmacologic profile of rivaroxaban.
        Am J Med. 2017; 130: 1024-1032
        • Rottenstreich A.
        • Barkai A.
        • Arad A.
        • Raccah B.H.
        • Kalish Y.
        The effect of bariatric surgery on direct-acting oral anticoagulant drug levels.
        Thromb Res. 2017; 163: 190-195
        • Martin K.A.
        • Beyer-Westendorf J.
        • Davidson B.L.
        • Huisman M.V.
        • Sandset P.M.
        • Moll S.
        Use of direct oral anticoagulants in patients with obesity for treatment and prevention of venous thromboembolism: updated communication from the ISTH SSC Subcommittee on Control of Anticoagulation.
        J Thromb Haemost. 2021; 19: 1874-1882
        • Lip G.Y.N.
        • Banerjee A.
        • Boriani G.
        • et al.
        Antithrombotic therapy for atrial fibrillation: CHEST Guideline and Expert Panel Report.
        Chest. 2018; 154: 1121-1201
        • Kaatz S.
        • Ahmad D.
        • Spyropoulos A.C.
        • et al.
        Definition of clinically relevant non-major bleeding in studies of anticoagulants in atrial fibrillation and venous thromboembolic disease in non-surgical patients: communication from the SSC of the ISTH.
        J Thromb Haemost. 2015; 13: 2119-2126
        • Harris P.A.
        • Taylor R.
        • Thielke R.
        • Payne Gonzalez N.
        • Conde J.C.
        Research electronic data capture (REDCap): A metadata-driven methodology and workflow process for providing translational research informatics support.
        J Biomed Inform. 2009; 42: 377-381
      2. R Project [homepage on the Internet]. R Foundation for Statistical Computing, Vienna, Austria2014 ([cited 2022 Jan 15]. Available from:)
        • Srivastava K.
        • Patel N.
        • Tabbara M.
        • et al.
        Thromboembolism, bleeding and mortality incidence of direct oral anticoagulants versus warfarin postbariatric surgery.
        Am J Med. 2021; 134: 1403-1412
        • Hanarz M.
        • Gołąb A.
        • Plicner D.
        • Undas A.
        Direct oral anticoagulants in patients with atrial fibrillation following bariatric surgery: a single center experience.
        Kardiol Pol. 2021; 79: 1378-1381
        • DeCamillo D.
        • Haymart B.
        • Barnes G.
        Adverse event in pts taking apixaban or rivaroxaban who have undergone bariatric surgery: a retrospective case series.
        J Thromb Thrombolysis. 2022; 53: 601-606
        • Hendricks A.K.
        • Zieminski J.J.
        • Yao X.
        • et al.
        Safety and efficacy of oral anticoagulants for atrial fibrillation in patients after bariatric surgery.
        Am J Cardiol. 2020; 136: 76-80
        • Grainger B.
        • Holloway R.
        • Merriman E.
        • et al.
        Evidence of impaired dabigatran absorption following laparoscopic Roux-en-Y gastric bypass surgery: the Auckland regional experience (2011-2018).
        Br J Haematol. 2020; 191: e67-e69
        • Nasser M.F.
        • Khaled Z.
        • Jabri A.
        • Karim S.
        The importance of use of appropriate anticoagulant in atrial fibrillation after gastric bypass surgery.
        Heart Rhythm Case Rep. 2021; 7: 354-356
        • Kok T.
        • deBoer H.
        • Witteman B.
        • Hovens M.
        • van Luin M.
        • Monajemi H.
        Anti-Xa levels in morbidly obese patients using apixaban or rivaroxaban, before and after bariatric surgery.
        Obes Surg. 2022; 32: 607-614
        • Steele K.E.
        • ProkopowiczGP
        • Canner J.P.
        • et al.
        The APB study: apixaban pharmacokinetics in bariatric patients before to 1 year after vertical sleeve gastrectomy or Roux-en-Y gastric bypass.
        Surg Obes Relat Dis. 2022; 18: 594-603
        • Klok F.A.
        • Kooiman J.
        • Huisman M.V.
        • Konstantinides S.
        • Lankeit M.
        Predicting anticoagulant-related bleeding in patients with venous thromboembolism: a clinically oriented review.
        Eur Respir J. 2015; 45: 201-210
        • Kirchhof P.
        • Haas S.
        • Amarenco P.
        • et al.
        Impact of modifiable bleeding risk factors on major bleeding in patients with atrial fibrillation anticoagulated with rivaroxaban.
        J Am Heart Assoc. 2020; 9e009530
        • Susmallian S.
        • Danoch R.
        • Raskin B.
        • et al.
        Assessing bleeding risk in bariatric surgeries: a retrospective analysis study.
        Dig Dis. 2020; 38: 449-457
        • Shea B.
        • Motamedi S.M.K.
        • Mustafa R.
        • et al.
        Managing therapeutic anticoagulation in bariatric surgery patients.
        Surg Endosc. 2021; 35: 4779-4785
        • Lazzati A.
        • Chatellier G.
        • Katsahian S.
        Readmissions after bariatric surgery in France, 213-2016: a nationwide study on administrative data.
        Obes Surg. 2019; 29: 3680-3689
        • Patel H.K.
        • Khorana A.K.
        Anticoagulation in cancer patients: a summary of pitfalls to avoid.
        Curr Oncol Rep. 2019; 21: 18
        • Skottheim I.B.
        • Stormark K.
        • Christensen H.
        • et al.
        Significantly altered systemic exposure to atorvastatin acid following gastric bypass surgery in morbidly obese patients.
        Clin Pharmacol Ther. 2009; 86: 311-318
        • Abraham N.S.
        • Noseworthy P.A.
        • Yao X.
        • Sangaralingham L.R.
        Gastrointestinal safety of direct oral anticoagulants: a large population-based study.
        Gastroenterology. 2017; 152: 1014-1022
        • Dawwas G.K.
        • Brown J.
        • Dietrich E.
        • Park H.
        Effectiveness and safety of apixaban versus rivaroxaban for prevention of recurrent venous thromboembolism and adverse bleeding events in patients with venous thromboembolism: a retrospective population-based cohort analysis.
        Lancet Haematol. 2019; 6: e20-e28
        • Cohen A.T.
        • Hamilton M.
        • Mitchell S.A.
        • et al.
        Comparison of the novel oral anticoagulants apixaban, dabigatran, edoxaban, and rivaroxaban in the initial and long-term treatment and prevention of venous thromboembolism: systematic review and network meta-analysis.
        PLoS One. 2015; 10e0144856