Epidemiology, prognosis and challenges in the management of Hyperthyroidism-related Atrial Fibrillation

Abstract

Atrial fibrillation (AF) is a common condition with a global estimated prevalence of 60 million cases, and the most common cardiac complication of hyperthyroidism, occurring in 5-15% of overtly hyperthyroid patients. Additionally, subclinical hyperthyroidism and high-normal free T4 have been associated with an increased risk in the development of AF. Hyperthyroidism-related AF is a reversible cause of AF and the majority of patients spontaneously revert to sinus rhythm in 4-6 months during or after restoration of euthyroidism. Therefore, restoring thyroid function is an indispensable element in hyperthyroidism-related AF management. Rate control with beta-blockers consists another first-line therapy, reserving rhythm control in cases of persistent hyperthyroidism-related AF. It is still controversial whether hyperthyroidism is an independent risk factor of stroke in nonvalvular AF. As a result, initiating anticoagulation should be guided by the clinical thrombo-embolic risk score CHA2DS2-VASc score in the same way it is applied in patients with non- hyperthyroidism related AF. Treatment with the novel direct oral anticoagulants appears to be as beneficial and maybe safer than warfarin in patients with hyperthyroidism-related AF. In this review, we address the epidemiology, prognosis and diagnosis of hyperthyroidism-related AF and we discuss the management strategies and controversies in patients with hyperthyroidism-related AF.