Data_Sheet_2_The Association Between Subclinical Thyroid Dysfunction and Recurrence of Atrial Fibrillation After Catheter Ablation.docx

ObjectiveThe aim of this study was to evaluate the association between subclinical thyroid dysfunction and the recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA).
MethodsWe examined the association between subclinical thyroid dysfunction and the recurrence of AF at a large university-affiliated cardiac arrhythmia center in China. Data were collected from consecutive patients who underwent RFCA for AF, excluding those with a history of hypothyroidism, hyperthyroidism, or ongoing medical treatment for hypothyroidism or hyperthyroidism, biochemically defined overt thyroid disease, and long-term use of amiodarone before admission. The primary end point was the recurrence of AF in a time-to-event analysis. We compared outcomes in patients who had subclinical hyperthyroidism or hypothyroidism with those who had euthyroid state, using a multivariable Cox model with inverse probability weighting and propensity score matching.
ResultsIn all, 93 patients were excluded from 435 consecutive patients who underwent RFCA for AF. Of the remaining 342 patients for the analysis, the prevalence of subclinical hyperthyroidism and subclinical hypothyroidism were 26 (7.6%) and 41 (12.0%), respectively; during a median follow-up of 489 days, 91 patients (26.6%) developed a primary end point event. In the main analysis of the multivariable Cox model, only subclinical hyperthyroidism [hazard ratio: 3.07, 95% confidence interval (CI): 1.54–6.14] was associated with an increased risk of end point event after adjusting for potential confounders. However, the association between subclinical hypothyroidism and the end point event was not significant (hazard ratio: 0.66, 95% CI: 0.31–1.43). Results were consistent either in multiple sensitivity analyses or across all subgroups of analysis. Compared with individuals with free triiodothyronine (fT3) in the lowest quintile, those with fT3 in the highest quintile had an HR of 2.23 (95% CI: 1.16–4.28) for recurrence of AF. With the increase of thyroid-stimulating hormone (TSH), a reduction in the risk of recurrence of AF was detected in the adjusted model, and the hazard ratio (HR) per standard deviation (SD) increase was 0.82 (95% CI: 0.68–0.98).
ConclusionIn this retrospective cohort study involving patients who underwent RFCA for AF, patients with subclinical hyperthyroidism were associated with a markedly higher prevalence of recurrence of AF, whereas patients with subclinical hypothyroidism had a similar recurrence rate of AF compared to those with the euthyroid state.

研究目的：本研究旨在评估亚临床甲状腺功能异常与心房颤动（Atrial Fibrillation, AF）射频导管消融（Radiofrequency Catheter Ablation, RFCA）术后复发的相关性。
研究方法：本研究在中国某大型大学附属心律失常中心开展，探讨亚临床甲状腺功能异常与心房颤动射频导管消融术后复发的关联。研究数据来源于因心房颤动接受射频导管消融的连续入组患者，排除既往有甲状腺功能减退症、甲状腺功能亢进症病史，或正在接受甲状腺功能减退/亢进药物治疗者，以及经生化检查确诊为显性甲状腺疾病、入院前长期使用胺碘酮的患者。本研究的主要终点为事件发生时间分析中的心房颤动复发。采用逆概率加权多变量Cox模型及倾向得分匹配法，对比亚临床甲状腺功能亢进症、亚临床甲状腺功能减退症患者与甲状腺功能正常者的预后结局。
研究结果：本研究共纳入435例因心房颤动接受射频导管消融的连续患者，其中93例被排除。剩余342例患者纳入分析，亚临床甲状腺功能亢进症患病率为7.6%（26例），亚临床甲状腺功能减退症患病率为12.0%（41例）。中位随访489天期间，共有91例（26.6%）患者出现主要终点事件。多变量Cox模型的主要分析显示，在校正潜在混杂因素后，仅亚临床甲状腺功能亢进症[风险比（Hazard Ratio, HR）：3.07，95%置信区间（Confidence Interval, CI）：1.54~6.14]与终点事件风险升高显著相关；而亚临床甲状腺功能减退症与终点事件的关联未达到统计学显著性（HR：0.66，95%CI：0.31~1.43）。多项敏感性分析及所有亚组分析均得到一致结果。与游离三碘甲状腺原氨酸（Free Triiodothyronine, fT3）最低五分位组患者相比，fT3最高五分位组患者的心房颤动复发风险比为2.23（95%CI：1.16~4.28）。在校正模型中，随着促甲状腺激素（Thyroid-Stimulating Hormone, TSH）水平升高，心房颤动复发风险呈降低趋势，每1个标准差（Standard Deviation, SD）升高对应的HR为0.82（95%CI：0.68~0.98）。
研究结论：这项针对心房颤动射频导管消融患者的回顾性队列研究显示，亚临床甲状腺功能亢进症患者的心房颤动复发率显著升高，而亚临床甲状腺功能减退症患者的心房颤动复发率与甲状腺功能正常者无显著差异。