Thyroid Function and Risk of Atrial Tachyarrhythmia Occurrence after Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation

Abstract

Backgrounds: Recent evidence demonstrated that serum free thyroxine (FT4) concentration was independently associated with the development of atrial fibrillation (AF), even in euthyroid persons with TSH levels in the normal range. We examined the impact of thyroid function on the risk of recurrent and newly developed atrial tachyarrythmias after catheter ablation for AF. Methods: This study included 156 consecutive patients with paroxysmal AF who underwent initial pulmonary vein antral isolation with elimination of dormant conduction induced by isoproterenol and adenotriphosphate injection. Patients with prior or current thyroid dysfunction were excluded. We examined the occurrence of documented recurrent or newly developed atrial tachyarrhythmia after the ablation. Results: After a mean follow-up of 27 months, 12.2% (19/156) of the studied subjects had AF recurrence. Although the AF recurrence rates of the highest FT4 quartile tended to be higher, there was no significant difference in recurrence rates among those quartiles. Patients with newly developed atrial tachycardia/flutter had significantly higher serum FT4 level and lower serum thyroid-stimulating hormone. The higher FT4 level was significantly associated with newly documented atrial tachycardia/flutter. Conclusions: Patients with high-normal thyroid function were not at an increased risk of AF recurrence but associated with newly developed atrial tachycardia/flutter after catheter ablation.