Abstract 14539: Incidence, Risk Factors, Natural History, and Outcomes of Atrial Fibrillation in Patients With Graves’ Disease

Abstract

Background: Hyperthyroidism is associated with atrial fibrillation (AF) with a reported prevalence of 16-60%. However, risk factors for onset of AF with hyperthyroidism are not well defined. We sought to identify patients with hyperthyroidism most likely to develop AF. Methods: We reviewed the medical records of 1371 consecutive patients with GD evaluated at our clinic between 2009 and 2019. GD-related AF was defined as AF diagnosed up to 30 days before or at any time after Grave’s disease (GD). Spontaneous recovery was defined as sinus rhythm after attainment of euthyroidism without the need for pharmacologic or electrical cardioversion. Outcomes of major cardiovascular events, all-cause mortality, and cardiac hospitalizations were compared between cases and controls (GD without AF) matched 1:1 for age, gender, and history of coronary artery disease. Results: AF occurred in 140 patients with an incidence of 10.2%. Older age (RR 1.63 per 10 years, p <0.001), male gender (RR 2.06, p < 0.001), overt hyperthyroidism (RR 2.48, p = 0.002), COPD (RR 2.14, p =0.006), and higher BMI (RR 1.03 per unit, p=0.023) were independent risk factors for AF. Spontaneous AF recovery occurred in 44 of 128 (34.6%) patients with adequate follow up. The multivariate risk factor for failed recovery was the presence of heart failure (HF) (OR =3.52, p= 0.004). GD patients with AF had higher rates of cardiac hospitalizations (Figure) that persisted even after adjusting to HF presence (27.9% vs 2.9%, p < 0.001). Conclusion: Risk factors for AF in GD are similar to those in the general population, although overt hyperthyroidism conferred the highest risk. These data argue for careful monitoring of GD patients with multimorbidity who may be at high risk of developing AF.