Background: Obesity is associated with increased risks of venous thromboembolism (VTE) and atrial fibrillation (AF) for which anticoagulation is commonly used.
Aims: We conducted a systemic review and meta-analysis to evaluate the efficacy and safety of direct oral anticoagulants (DOACs) or vitamin K antagonists (VKA) in the treatment of VTE or AF in patients with morbid obesity.
Methods: We searched the electronic databases including MEDLINE, Embase, Scopus, and Cochrane Central Register of Controlled Trials from inception. We included randomized controlled trials (RCTs) and observation studies which reported outcomes of interest in adult patients with weight ≥ 120 kg, BMI ≥ 40 kg/m2, or classified as morbid obesity by ICD codes who received DOACs or VKA for VTE or AF. The primary efficacy outcome was VTE recurrence in VTE population and stroke or systemic embolism in AF population, and the primary safety outcome was major bleeding. We calculated the pooled annual incidence rates of outcomes and compared DOAC with VKA by incidence rate ratio using R software (version 4.0.3). The quality of studies was assessed by ROBINS-I and Cochrane RoB 2 tools.
Results: Fifteen studies (3 RCTs and 12 observational studies) with 68,250 morbidly obese patients were included for meta-analysis. Nine studies involved VTE population and 10 involved AF. Table 1 summarized the incidence rates of outcomes. VKA was associated with a numerically higher rate of recurrent VTE compared to DOAC in VTE population. In both populations, DOAC was associated with significantly lower risks of major bleeding compared to VKA. However, all observational studies had moderate to serious risks of bias. Patients prescribed VKA were commonly reported to have more co-morbidities.
| Population | Anticoagulant | Recurrent venous thromboembolism or stroke/systemic thrombosis | Major bleeding | ||
| Incidence rate per 100 person-years (95% CI) |
Incidence rate ratio (95% CI) |
Incidence rate per 100 person-years (95% CI) |
Incidence rate ratio (95% CI) |
||
| Venous thromboembolism | Direct oral anticoagulants | 3.83 (3.08-4.76) | 0.78 (0.48-1.27) | 1.63 (1.17-2.28) | 0.72 (0.54-0.96) |
| Vitamin K antagonists | 6.81 (5.53-8.37) | 2.97 (1.21-7.27) | |||
| Atrial fibrillation | Direct oral anticoagulants | 1.16 (0.86-1.59) | 0.96 (0.78-1.16) | 2.74 (1.68-4.48) | 0.75 (0.59-0.96) |
| Vitamin K antagonists | 1.18 (0.67-2.08) | 3.61 (1.78-7.31) | |||
The incidence rates and incidence rate ratios of thrombotic and bleeding outcomes
Conclusions: Patients with morbid obesity on fixed-dose DOAC did not appear to have worse outcomes compared to VKA. However, the strength of evidence remained low given that results were mostly observational with high risk of confounding.
To cite this abstract in AMA style:
Wang T-, Carrier M, Fournier K, Siegal D, Le Gal G, Delluc A. Oral Anticoagulant Use in Patients with Morbid Obesity: A Systemic Review and Meta-analysis [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/oral-anticoagulant-use-in-patients-with-morbid-obesity-a-systemic-review-and-meta-analysis/. Accessed October 1, 2023.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/oral-anticoagulant-use-in-patients-with-morbid-obesity-a-systemic-review-and-meta-analysis/