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

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 >= 120kg, body mass index >= 40kg/m (2) , 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.