Direct oral anticoagulants after bariatric surgery—What is the evidence?

BACKGROUND: Obesity is a global epidemic and bariatric surgery is used with increasing frequency to treat its complications. The extent to which bariatric surgery alters the efficacy, safety, and pharmacokinetics of direct oral anticoagulants (DOACs) is unknown. AIMS: In this review, we summarize the evidence supporting the use of DOACs after bariatric surgery and apply our findings to resolve several clinical cases. MATERIALS & METHODS: We systematically searched MEDLINE, EMBASE, Cochrane Library, CINAHL and ClinicalTrials.gov from January 1, 2000, to June 15, 2021 for randomized and non-randomized studies evaluating the use of DOACs for any indication after bariatric surgery. Two reviewers independently screened titles, abstracts, and full-text articles. Clinical and pharmacokinetic outcomes were pooled by random-effects meta-analysis with inverse variance weighting. We used the Newcastle-Ottawa scale to assess risk of bias in non-randomized studies and assessed the certainty of evidence with GRADE. RESULTS: From 2519 records, we included 28 studies (n = 3229 patients): no randomized trials, 7 cohort studies, 6 case series, and 15 case reports. Incidence rates for arterial thromboembolism, venous thromboembolism and major bleeding were: 0.73 (95% confidence interval [CI]: 0.01-5.10), 2.45 (95% CI: 0.40-7.94), and 3.40 (95% CI: 0.80-9.36) events per 100 patient-years, respectively. The pooled proportion of peak direct oral anticoagulant drug levels within the expected range was 58% (95% CI: 39%-74%). CONCLUSION: There appears be substantial risk of DOAC malabsorption after bariatric surgery that could affect clinical outcomes, however the certainty of evidence was very low. PROSPERO: CRD42020202636.