Challenges in anticoagulation for atrial fibrillation

Abstract

This thesis explores the management of anticoagulation therapy in patients with atrial fibrillation (AF) and cancer, and in patients with AF and a high-bleeding risk. An increasing body of evidence has shown that cancer confers additional risks for bleeding and thrombosis in patients with AF. The studies included in this thesis show that patients with AF and cancer experience high rates of thromboembolisms and bleeding complications, with the extent of risk depending on cancer type. Moreover, around 10% of AF patients with cancer permanently discontinue anticoagulant treatment, while nearly 40% of patients experience one or more anticoagulant interruptions during the course of cancer. These interruptions were associated with high rates of bleeding and thromboembolic complications. In patients with AF and a high-bleeding risk, it is unknown whether a bleeding risk score could identify patients in whom dose reduction would provide a reasonable option. The post-hoc analyses in the RE-LY and ENGAGE AF-TIMI 48 trials included in this thesis demonstrated that dose reduction of dabigatran or edoxaban in patients deemed at high risk of bleeding by the AF-BLEED score resulted in fewer bleeding, but at the expense of a numerically smaller increase of ischemic stroke.