Background: We aimed to evaluate the long-term risk of ischemic stroke/systemic embolism of hyperthyroidism-related AF. Methods: This retrospective population-based cohort study included records of 1,034,099 atrial fibrillation patients between 2005 and 2016 from the Korean National Health Insurance Service database. After exclusion, we identified 615,724 oral anticoagulation-naïve patients aged ≥18 years with new-onset non-valvular atrial fibrillation, of whom 20,773 had hyperthyroidism-related atrial fibrillation. After 3:1 propensity score matching, ischemic stroke and systemic embolism occurrences were compared between hyperthyroidism-related and non-hyperthyroidism-related (“nonthyroidal”) atrial fibrillation patients. Results: After exclusion, we identified 615,724 oral anticoagulation-naïve AF patients of whom 20,773 had hyperthyroidism-related AF. Median follow-up duration was 5.9 years. Hyperthyroidism-related AF patients had significantly higher risks of ischemic stroke and systemic embolism than nonthyroidal AF patients (1.83 vs 1.62 per 100-person year, hazard ratio[HR], 1.13; 95% confidence interval[CI], 1.07 to 1.19; P < 0.001). This risk was 36% higher in hyperthyroidism-related than in nonthyroidal AF patients within 1 year of atrial fibrillation diagnosis (3.65 vs 2.67 per 100-person year, HR, 1.36; 95% CI, 1.24 – 1.50; P < 0.001). This difference was also observed in the CHA2DS2-VASc score subgroup analysis. The risk of ischemic stroke and systemic embolism significantly decreased in patients treated for hyperthyroidism (HR, 0.64; 95% CI, 0.58 to 0.70; P < 0.001). Conclusions: Hyperthyroidism-related AF patients have high risks of ischemic stroke and systemic embolism like nonthyroidal AF, especially when initially diagnosed. This risk is reduced by treating hyperthyroidism.
Bibliographical noteFunding Information:
Dr. Gregory Y.H. Lip has served as a consultant for Bayer/Janssen, BMS/Pfizer, Biotronik, Medtronic, Boehringer Ingelheim, Novartis, Verseon, and Daiichi-Sankyo and as a speaker for Bayer, BMS/Pfizer, Medtronic, Boehringer Ingelheim, and Daiichi-Sankyo. No fees were directly received personally. Dr. Boyoung Joung has served as a speaker for Bayer, BMS/Pfizer, Medtronic, and Daiichi-Sankyo, and has received research funding from Medtronic and Abbott. No fees were directly received personally. The other authors have no conflict of interest.
This research was supported by a grant of Patient-Centered Clinical Research Coordinating Center (PACEN) funded by the Ministry of Health & Welfare, Republic of Korea (grant number : HI19C0481, HC19C013, HI15C1200) and Korea-UK grant (HI19C0622). The funding sources were not involved in the study design and data collection, analysis, or interpretation.
All Science Journal Classification (ASJC) codes
- Cardiology and Cardiovascular Medicine