Anticoagulant use and the risk of thromboembolism and bleeding in post-operative AF following non-cardiac surgery

Abstract Background An effective and safe anticoagulation (OAC) strategy for new post-operative AF (POAF) after non-cardiac surgery patients remains unclear. We aimed to determine the association between OAC use and 1) thromboembolic events and 2) major bleeding in patients with POAF after non-cardiac surgery. Methods A retrospective cohort (1999-2015) was used to identify patients with new POAF after inpatient non-cardiac surgery. Initiation of OAC was defined as prescription of an OAC within 30 days following hospital discharge. Time to first hospital admission or emergency department visit for a thromboembolic or major bleeding event were compared using Cox proportional hazards models. Results We identified 22,007 patients with new POAF after inpatient non-cardiac surgery. The majority of patients were intermediate (CHA 2DS2‐VASc 2-3, 45%) to high thromboembolic risk (CHA2DS2VASc: ≥4, 42%). During a mean follow up of 4 years, a total of 1099 (5%) thromboembolic and 3250 (18%) bleeding events occurred. Compared to patients not on anticoagulation, anticoagulation did not reduce the risk for thromboembolic events (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: 1.2, 95% CI: 1.1-1.32). Conclusion In patients with new POAF after non-cardiac 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.