Clinician Article

Oral Anticoagulant Use in Patients with Morbid Obesity: A Systematic Review and Meta-Analysis.

  • Wang TF
  • Carrier M
  • Fournier K
  • Siegal DM
  • Le Gal G
  • Delluc A
Thromb Haemost. 2021 Aug 16. doi: 10.1055/a-1588-9155. (Review)
PMID: 34399433
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  • Family Medicine (FM)/General Practice (GP)
    Relevance - 6/7
    Newsworthiness - 6/7
  • General Internal Medicine-Primary Care(US)
    Relevance - 6/7
    Newsworthiness - 6/7
  • Cardiology
    Relevance - 6/7
    Newsworthiness - 5/7
  • Hemostasis and Thrombosis
    Relevance - 6/7
    Newsworthiness - 4/7
  • Internal Medicine
    Relevance - 4/7
    Newsworthiness - 5/7


OBJECTIVES: Obesity is associated with increased risks of atrial fibrillation (AF) and venous thromboembolism (VTE) for which anticoagulation is commonly used. However, data on the efficacy and safety of oral anticoagulants in patients with morbid obesity are limited.

METHODS: We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs) for AF or VTE in patients with morbid obesity.

RESULTS: We included three randomized controlled trials (5 studies) and 18 observational studies in adult patients with a body weight =120 kg, body mass index =40 kg/m2, or classified as morbid obesity who received DOACs or VKAs for AF or VTE (N = 77,687). The primary efficacy outcome was stroke/systemic embolism or recurrent VTE, and the primary safety outcome was major bleeding. DOACs were associated with a pooled incidence rate of stroke/systemic embolism of 1.16 per 100 person-years, compared to 1.18 with VKAs. The incidence of recurrent VTE on DOACs was 3.83 per 100 person-years, compared to 6.81 on VKAs. In both VTE and AF populations, DOACs were associated with lower risks of major bleeding compared to VKAs. However, all observational studies had moderate to serious risks of bias.

CONCLUSION: Patients with morbid obesity on DOACs had similar risks of stroke/systemic embolism, lower rates of recurrent VTE, and major bleeding events compared to those on VKAs. However, the certainty of evidence was low given that studies were mostly observational with high risk of confounding.

Clinical Comments


This systematic review and meta-analysis, by including three randomized controlled trials (5 studies) and 18 observational studies, investigated the efficacy and safety outcomes of oral anticoagulant in patients with morbid obesity (body weight >120 kg, body mass index>40 kg/m). The pooled result was demonstrated by incident rate of DOAC and VKA, which was very different from traditional approach to present comparative outcomes given the follow-up durations differed among studies.

Family Medicine (FM)/General Practice (GP)

The level of evidence remains low given that studies were mostly observational at this meta-Analysis. The efficacy and safety of oral anticoagulants in patients with severe obesity are limited. Receiving DOACs compared to VKAs result in less major bleeding, and both seems to be a good choice in Morbid Obesity.

General Internal Medicine-Primary Care(US)

Assuming no publication bias, then it's nice to see that DOACS may be more effective with similar bleeding.

Hemostasis and Thrombosis

This systematic review and meta-analysis shows that DOACs and VKAs have equivalent effectiveness and safety in morbidly obese patients with AF or VTE. The level of certainty of this conclusion is low based on the quality of studies included in the analysis. Since there is no "danger signal" in the individual studies nor in their aggregate, practitioners may prescribe DOACs in this patient population with a degree of confidence. This is buttressed by the current ISTH guidelines relating to the morbidly obese.

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