Anticoagulant Use and the Risk of Thromboembolism and Bleeding in Postoperative Atrial Fibrillation After Noncardiac Surgery

Abstract

BackgroundAn effective and safe oral anticoagulation (OAC) strategy for patients with new postoperative AF (POAF) after noncardiac surgery remains unclear. We aimed to determine the association between OAC use and 1) thromboembolic events and 2) major bleeding in patients with POAF after noncardiac surgery. MethodsA retrospective cohort (1999-2015) was used to identify patients with new POAF after inpatient noncardiac surgery. Initiation of OAC was defined as prescription of an OAC within 30 days following hospital discharge. Times to first hospital admission or emergency department visit for a thromboembolic or major bleeding event were compared using Cox proportional hazards models. ResultsWe identified 22,007 patients with new POAF after inpatient noncardiac surgery. The majority of patients had intermediate (CHA2DS2-VASc 2-3: 45%) to high (CHA2DS2-VASc ≥ 4: 42%) thromboembolic risk. During a mean follow-up of 4 years, a total of 1099 (5%) thromboembolic and 3250 (15%) bleeding events occurred. Compared with patients not on anticoagulation, anticoagulation did not reduce the risk for thromboembolic events (adjusted hazard ratio [aHR] 0.89, 95% CI 0.73-1.07). In patients initiated on anticoagulation, there was an association with a higher risk for major bleeding (aHR 1.14, 95% CI 1.04-1.25). ConclusionsIn patients with new POAF after noncardiac surgery, anticoagulation was not associated with a reduction in long-term thromboembolic events; however, this was accompanied by an overall increased risk for major bleeding. Future prospective clinical studies are needed to better address the role for anticoagulation therapy in the setting of POAF after noncardiac surgery to understand the efficacy and safety of treatment.