Risk of atrial fibrillation in patients with differentiated thyroid cancer: a nationwide population-based analysis

Thyroid hormone suppression therapy (THST) is widely used for long-term management of differentiated thyroid cancer (DTC). However, studies have suggested that THST may increase the risk of atrial fibrillation (AF) in patients with DTC. We aimed to evaluate whether the risk of AF in patients with DTC differs according to treatment modality.

This retrospective cohort study used data from the Korean National Health Information Database between 2006 and 2019. We included 113,791 patients with DTC and age- and sex-matched 455,188 controls. The risk of AF was assessed according to the following treatment modalities: lobectomy or total thyroidectomy with or without radioactive iodine therapy (RAIT). A Cox proportional hazards model was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs).

Patients with DTC had a two-fold higher risk of incident AF than controls (HR, 2.07; 95% CI, 1.98-2.17). All the treatment groups showed a higher risk of AF than the control group. Patients with DTC who underwent total thyroidectomy without RAIT (HR, 2.20; 95% CI, 2.06-2.34) or with RAIT (HR, 2.07; 95% CI, 1.95-2.20) had a higher risk of AF in contrast to those who underwent lobectomy (HR, 1.93; 95% CI, 1.72-2.15).

Patients with DTC had an increased risk of incident AF. The risk of AF was higher in patients with DTC who underwent total thyroidectomy than those who underwent lobectomy alone. For long-term management of patients with DTC, increased vigilance is required for AF screening, particularly in this high-risk group.