Background: Hyperthyroidism and atrial fibrillation (AF) are both common in the Australian community, and often encountered in general practice.
Objective: This article discusses the risk of AF and thromboembolism in hyperthyroidism, the role of antithrombotic therapy in this setting, and appropriateness and safety of various antithrombotic agents in thyroid disease.
Discussion: Prevention of thromboembolism is an important consideration in the care of patients with AF and hyperthyroidism. However, the evaluation of thromboembolic risk and management in this setting is challenging. Thyroid disease results in a pro-coagulant state via disruption of coagulation pathways and alters the pharmacodynamics of anticoagulants. Currently, guidelines regarding anticoagulation in AF do not incorporate hyperthyroidism as an additional risk factor. Until further evidence becomes available, we recommend warfarin as the oral anticoagulant of choice in thyroid disease because of ease of monitoring and reversibility.