Safety and Efficacy of Oral Anticoagulants for Atrial Fibrillation in Patients After Bariatric Surgery

Anticoagulation management is challenging in bariatric surgery patients, due to altered gastrointestinal anatomy and potentially reduced absorption. Few studies have evaluated clinical outcomes in this population. The objective of this study was to compare the efficacy and safety of oral anticoagulants in patients with and without a history of bariatric surgery. A retrospective, matched cohort study was conducted, utilizing data from the OptumLabs Data Warehouse. Patients ≥18 years old, with nonvalvular atrial fibrillation (NVAF), and treated with an oral anticoagulant between January 1, 2010 and December 31, 2018 were included. Outcomes were compared between bariatric and nonbariatric surgery patients. Secondary analysis compared warfarin to the direct oral anticoagulants (DOAC) in the bariatric cohort. The primary efficacy outcome was the rate of ischemic stroke and systemic embolism and the primary safety outcome was major bleeding. A total of 1,673 bariatric surgery and 155,619 nonbariatric surgery patients were identified. There was no significant difference in the rate of ischemic stroke or systemic embolism (0.83 vs 1.32 per 100 person years; Hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.31 to 1.22; p = 0.17) or major bleeding (5.30 vs 4.87 per 100 person years; HR 1.05, 95% CI 0.80 to 1.37; p = 0.73) between bariatric and nonbariatric surgery patients. In bariatric surgery patients alone, efficacy and safety were similar with warfarin compared with the DOACs. Results of this study suggest that bariatric surgery patients are not at an increased thrombotic or bleeding risk when using oral anticoagulants for NVAF. DOACs may be a reasonable alternative to warfarin.