Antithrombotic therapy in atrial fibrillation: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy
- DE Singer
Chronic warfarin anticoagulation is commonly used to prevent thromboembolism in patients with atrial fibrillation or venous thromboembolism, and in the management of patients with mechanical heart valves. Interruption of long-term anticoagulation therapy for elective, planned urologic procedures in these patients creates a complex situation in which competing risks of thrombosis and hemorrhage must be managed; when anticoagulation is withheld patients are at risk of thrombosis, and when it is restarted they are at risk of hemorrhage. Patients at a high risk of thrombosis are typically given bridging therapy with heparin to reduce the amount of time without anticoagulation. Outcomes from bridging therapy are influenced by patient characteristics, including the risk of thromboembolism from underlying medical conditions and the risk of perioperative bleeding, and by characteristics of the procedures themselves. The safety and efficacy of different approaches are not well documented. Data regarding periprocedural anticoagulation management of urology patients is limited and principally describes outcomes related to transurethral prostate surgery. Results from these studies indicate that various strategies of anticoagulation interruption and bridging therapy result in low frequencies of thromboembolism, but variable rates of hemorrhage. Patients on anticoagulation therapy who are due to undergo invasive urologic procedures that have a low risk of developing thromboembolism can discontinue warfarin 4–5 days before the procedure, and resume it postprocedure. Bridging therapy to prevent thrombosis is necessary for patients at a higher risk of developing thromboembolism. Future research should develop strategies to maintain low rates of thrombosis but reduce the frequency of postoperative hemorrhage.