Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Clinical Trials / Outcomes D-PO01 - Featured Poster Session (ID 11) Poster

D-PO01-153 - Increased Risk Of Ischemic Stroke Or Systemic Embolism In Patients With Hyperthyroidism-related Nonvalvular Atrial Fibrillation: A Korean Nationwide Cohort Study (ID 941)


Background: Atrial fibrillation (AF) associated with hyperthyroidism is often considered to be transient. The long-term risks of ischemic events by hyperthyroidism-related AF is poorly identified.
Objective: We aimed to evaluate the long-term risk of ischemic stroke/systemic embolism (SSE) of hyperthyroidism-related AF.
Methods: Using a Korean National Health Insurance Service database between 2005 and 2016, we identified 615,724 new-onset, nonvalvular AF aged ≥18 years with oral anticoagulation naïve. Among them, 20,773 AF patients were associated with hyperthyroidism. After 3:1 propensity score matching, SSE was compared between hyperthyroidism-related and non-related AF groups (‘nonthyroidal AF’).
Results: During median follow-up of 5.9 years, compared with nonthyroidal AF, hyperthyroidism-related AF had increased risk of SSE (hazard ratio [HR] 1.13; 95% confidence interval [CI] 1.07-1.19; P<0.001). The risk of SSE was 36% higher in hyperthyroidism-related AF than in nonthyroidal AF within 1 year from AF diagnosis (HR 1.36; 95% CI 1.24-1.50 P<0.001), and was similar with nonthyroidal AF beyond 1 year (HR 1.03; 95% CI 0.97-1.11; P=0.312). The risk of SSE was significantly decreased in treated hyperthyroidism patients (HR 0.64; 95% CI 0.58-0.70 P<0.001).
Conclusion: The risk of SSE of hyperthyroidism-related AF was higher than nonthyroidal AF, especially within 1 year after AF diagnosis, and was reduced by treatment of hyperthyroidism. Patients with hyperthyroidism-related AF are at high risk of stroke when initially diagnosed and require regular follow-up with appropriate anticoagulation and prompt treatment of hyperthyroidism.