Patients with differentiated thyroid cancer had a two-fold higher risk of incident atrial fibrillation than controls, with the risk being higher in those who underwent total thyroidectomy than those who underwent lobectomy alone.
Key Findings
Results
Patients with differentiated thyroid cancer had a significantly higher risk of incident atrial fibrillation compared to matched controls.
HR of 2.07 (95% CI, 1.98–2.17) for AF in DTC patients versus controls
Study included 113,791 patients with DTC and 455,188 age- and sex-matched controls
Data drawn from the Korean National Health Information Database between 2006 and 2019
A Cox proportional hazards model was used to compute hazard ratios and 95% confidence intervals
Results
All treatment modality groups (lobectomy, total thyroidectomy with or without RAIT) showed a higher risk of AF than the control group.
Lobectomy group: HR 1.93 (95% CI, 1.72–2.15)
Total thyroidectomy without RAIT: HR 2.20 (95% CI, 2.06–2.34)
Total thyroidectomy with RAIT: HR 2.07 (95% CI, 1.95–2.20)
Each treatment group was compared against matched controls, not against each other
Results
Patients with DTC who underwent total thyroidectomy had a higher risk of AF than those who underwent lobectomy alone.
Total thyroidectomy without RAIT had an HR of 2.20 (95% CI, 2.06–2.34) versus lobectomy HR of 1.93 (95% CI, 1.72–2.15)
Total thyroidectomy with RAIT had an HR of 2.07 (95% CI, 1.95–2.20) versus lobectomy HR of 1.93 (95% CI, 1.72–2.15)
The study design was a retrospective cohort using nationwide population-based data
The authors note this finding has implications for long-term management and AF screening strategies in DTC patients
Methods
The study population was a large nationwide cohort of differentiated thyroid cancer patients identified from a Korean national database spanning over a decade.
113,791 DTC patients were included with a 1:4 matching ratio yielding 455,188 controls
Matching was performed by age and sex
Data covered the period from 2006 to 2019
Treatment modalities assessed included lobectomy, total thyroidectomy without RAIT, and total thyroidectomy with RAIT
Background
Thyroid hormone suppression therapy is widely used in the long-term management of differentiated thyroid cancer and has been suggested to increase AF risk.
THST is described as 'widely used for long-term management of differentiated thyroid cancer'
Prior studies have suggested THST may increase the risk of AF in DTC patients
The study aimed to evaluate whether AF risk differs according to treatment modality
Increased vigilance for AF screening is recommended, 'particularly in this high-risk group'
Heo J, Sohn S, Kim Y, Cho S. (2026). Risk of atrial fibrillation in patients with differentiated thyroid cancer: a nationwide population-based analysis.. The Korean journal of internal medicine. https://doi.org/10.3904/kjim.2025.129