Long-term Effect of Thyrotropin-binding Inhibitor Immunoglobulin on Atrial Fibrillation in Euthyroid Patients

Jung-Chi Hsu; Kang-Chih Fan; Ting-Chuan Wang; Shu-Lin Chuang; Ying-Ting Chao; Ting-Tse Lin; Kuan-Chih Huang; Lian-Yu Lin; Lung-Chun Lin

doi:10.1016/j.eprac.2024.03.391

Long-term Effect of Thyrotropin-binding Inhibitor Immunoglobulin on Atrial Fibrillation in Euthyroid Patients

Endocr Pract. 2024 Apr 2:S1530-891X(24)00474-9. doi: 10.1016/j.eprac.2024.03.391. Online ahead of print.

Authors

Jung-Chi Hsu¹, Kang-Chih Fan², Ting-Chuan Wang³, Shu-Lin Chuang³, Ying-Ting Chao³, Ting-Tse Lin⁴, Kuan-Chih Huang⁵, Lian-Yu Lin⁶, Lung-Chun Lin⁴

Affiliations

¹ Division of Cardiology, Department of Internal Medicine, National Taiwan University Hopistal Jinshan Branch, New Taipei City, Taiwan; Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan.
² Division of Endocrinology and Metabolism, Department of Internal Medicine, National Taiwan University Hospital Hsinchu Branch, Hsinchu City, Taiwan.
³ Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan.
⁴ Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan; Cardiovascular Center, National Taiwan University Hospital, Taipei, Taiwan; Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
⁵ Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan; Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Hsin-Chu Branch, Hsinchu, Taiwan. Electronic address: 100643rv4d@gmail.com.
⁶ Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan; Cardiovascular Center, National Taiwan University Hospital, Taipei, Taiwan; Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Master's Program in Smart Medicine and Health Informatics, NTU, Taipei, Taiwan.

PMID: 38574890
DOI: 10.1016/j.eprac.2024.03.391

Abstract

Objective: Individuals with hyperthyroidism are at an increased risk of atrial fibrillation (AF), but the association between autoantibodies and AF or cardiovascular mortality in individuals who have returned to normal thyroid function remains unclear.

Methods: The study utilized electronic medical records from National Taiwan University Hospital between 2000 and 2022. Each hyperthyroidism patient had at least 1 thyrotropin-binding inhibiting immunoglobulin (TBII) measurement. The relationship between TBII levels and the risk of AF and cardiovascular mortality was assessed using multivariable Cox regression models and Kaplan-Meier survival analysis.

Results: Among the 14 618 enrolled patients over a 20-year timeframe, 173 individuals developed AF, while 46 experienced cardiovascular mortality. TBII values exceeding 35% were significantly associated with an elevated risk of AF for both the first TBII (hazard ratio {HR} 1.48 [1.05-2.08], P = .027) and mean TBII (HR 1.91 [1.37-2.65], P < .001). Furthermore, after free T4 levels had normalized, a borderline association between first TBII and AF (HR 1.59 [0.99-2.56], P = .056) was observed, while higher mean TBII increased AF (HR 1.78 [1.11-2.85], P = .017). Higher first and mean TBII burden continued to significantly impact the incidence of cardiovascular mortality (HR 6.73 [1.42-31.82], P = .016; 7.87 [1.66-37.20], P = .009). Kaplan-Meier analysis demonstrated that elevated TBII levels increased the risk of AF and cardiac mortality (log-rank P = .035 and .027, respectively).

Conclusion: In euthyroid individuals following antithyroid treatment, elevated circulating TBII levels and burden are associated with an elevated risk of long-term incident AF and cardiovascular mortality. Further reduction of TBII level below 35% will benefit to clinical outcomes.

Keywords: Graves’ disease; antithyroid treatment; atrial fibrillation; hyperthyroidism; thyrotropin-binding inhibitor immunoglobulin (TBII).