(41) Effectiveness and Safety of Warfarin Use After Bariatric Surgery in Patients with Atrial Fibrillation and Venous Thromboembolism: A Real-World Analysis

Saturday, August 27, 2022

8:00 AM – 6:00 PM CEST

Location: Hall C

Publication Number: 715

Presenting Author(s)

Abdullah Abdulaziz Alalwan
– Assistant Professor of Pharmacoepidemiology and Drug Safety, Qassim University, Saudi Arabia, Riyadh, Al Riyadh, Saudi Arabia

Co-Author(s)

Jeffrey Friedman, MD, FACS
– UF Health Bariatric Surgery Center - Shands Hospital, UF Health Surgical Specialists – Shands Hospi, UF Health Bariatric Surgery Center, Department of Surgery, University of Florida, Gainesville, Florida, USA, FL, United States
Haesuk Park
– University of Florida, University of Florida, Gainesville, Florida, United States
Richard Segal, PhD
– Department of Pharmaceutical Outcomes and Policy, College of Pharmacy, University of Florida, United States

Background: There are limited data regarding warfarin use in bariatric surgery population. The effectiveness and safety profile of warfarin after bariatric surgery remains unclear.

Objectives: we aim to compare the effectiveness and safety of warfarin in atrial fibrillation and venous thromboembolism (VTE) patients who received bariatric surgery vs. non-bariatric surgery patients.

Objectives: we aim to compare the effectiveness and safety of warfarin in atrial fibrillation and venous thromboembolism (VTE) patients who received bariatric surgery vs. non-bariatric surgery patients

Methods: A retrospective cohort analysis was conducted using data from Truven MarketScan Commercial and Medicare supplemental claims databases from 2005, to 2015. We compared the effectiveness and safety outcomes in adult warfarin users (≥18 years) who underwent bariatric surgery to those who did not undergo bariatric surgery. We examined the incidence of stroke, Transient Ischemic Attack (TIA), VTE, and major and minor bleeding. We performed Cox proportional hazard models to evaluate the risk of effectiveness and safety outcomes and propensity score inverse probability of treatment weighting was used to adjust for baseline demographic, confounders, and clinical characteristics.

Results: We assessed a total of 677,320 patients who met the study inclusion criteria. The adjusted risk of stroke for bariatric surgery group was [adjusted hazard ratios (aHRs) 0.57 (95% CI, 0.46 – 0.70), VTE [aHR 0.65 (95% CI, 0.62 – 0.68)] and TIA [aHR, 0.70 (95% CI, 0.55 – 0.89)] compared to non-bariatric surgery patients. In safety outcomes assessment, bariatric surgery group showed insignificant risk for intracranial hemorrhage and gastrointestinal hemorrhage compared to non-bariatric surgery group [aHR, 1.33 (95% CI, 0.94 – 1.86)] and [aHR 1.01 (95% CI, 0.80 – 1.30)] compared with non-bariatric surgery group, respectively.

Conclusions: Warfarin use seems to be effective when used after bariatric surgery patients. Although the safety composite outcomes were in favor of warfarin users who received bariatric surgery, there was insignificant difference in the risk of major and minor bleeding in the two groups. Further longitudinal studies are needed to assess long-term findings of warfarin use in bariatric surgery population.