High‐Normal Thyroid‐Stimulating Hormone Shows a Potential Causal Association With Arrhythmia Recurrence After Catheter Ablation of Atrial Fibrillation

Abstract

BackgroundHypothyroidism has been shown to contribute to enhanced atrial arrhythmogenesis, resulting in atrial fibrillation (AF) development in animal models and clinical populations. We aimed to elucidate whether high thyroid‐stimulating hormone (TSH) levels are related to outcomes of catheter ablation of AF.Methods and ResultsOf 477 consecutive patients who underwent first‐time pulmonary vein isolation–based radiofrequency catheter ablation of AF, 456 with TSH above the lower limit of the normal range (age, 65.5±9.9 years; men, 73.9%; paroxysmal AF, 56.8%) were analyzed for this study. Atrial tachyarrhythmia recurrence for 3 years was compared across groups with hypothyroidism (n=23) and TSH quartile groups with euthyroidism (normal‐range TSH levels, n=433). Atrial tachyarrhythmia recurrence occurred in 179 patients (39%) after the first session. Patients with hypothyroidism had increased recurrence compared with patients with normal TSH levels (crude hazard ratio, 3.14 after the last session; P=0.001). When focusing on patients with normal TSH levels, recurrence‐free survivals after both the first and last sessions were significantly reduced in euthyroid patients with the highest quartile of TSH levels (quartile 4) compared with others (quartiles 1–3). Cox regression analysis identified high TSH levels as an independent predictor of atrial tachyarrhythmia recurrence after both the first (adjusted hazard ratio, 1.51; P=0.018) and last (adjusted hazard ratio, 1.86; P=0.023) sessions. The difference was more pronounced in patients with paroxysmal AF than in those with nonparoxysmal AF.ConclusionsNot only hypothyroidism but also high‐normal TSH levels may be an independent predictor of atrial tachyarrhythmia recurrence after catheter ablation of AF.

High-Normal Thyroid Function and Recurrence of Atrial Fibrillation after Catheter Ablation: A Prospective Observational Study

“…Wei et al [17] also suggested that TSH was not an independent predictor of LA arrhythmia recurrence in their population, which is consistent with our results. In contrast, Morishima et al [9] demonstrated that patients with high TSH levels, even on the high-end of the normal range, could be exposed greater to a risk of AF recurrence in a Japanese population. In the report of Morishima et al [9], patients with a history of thyroid diseases or medications for thyroid diseases were not excluded.…”

“…In contrast, Morishima et al [9] demonstrated that patients with high TSH levels, even on the high-end of the normal range, could be exposed greater to a risk of AF recurrence in a Japanese population. In the report of Morishima et al [9], patients with a history of thyroid diseases or medications for thyroid diseases were not excluded. Although TSH reflects the status of the thyroid, it is influenced by drugs and nonthyroidal disease [18].…”

Pro-Arrhythmic Signaling of Thyroid Hormones and Its Relevance in Subclinical Hyperthyroidism

“…Moreover, TH affect the outcomes after an invasive treatment of AF. Accordingly, high circulating T 3 , as well as high-normal T 4 or lower TSH levels, have been associated with AF recurrence after an arrhythmogenic foci ablation [23,[88][89][90][91]. Free T 4 levels influence the success rate of ablation procedures even in the normal range.…”

Influence of thyroid-stimulating hormone on the recurrence after radiofrequency ablation for atrial fibrillation

“…First of all, it is achieved by isolation of pulmonary veins (PVs), which usually function as sources of AF, causing premature contractions. Electrical isolation of PVs has been shown to be up to approximately 80 % successful in significantly reducing the frequency and duration of AF in patients who do not tolerate AF [9][10][11][12].…”

“…Some studies suggest a close association of hypothyroidism history with the occurrence of AF in patients. However, there is very little data in the literature on the effect of thyroid hormone levels on the effectiveness of RFA [5,9,[13][14][15][16][17][18][19][20].…”