Pulmonary vein isolation in patients with paroxysmal AF and previous amiodarone-induced hyperthyroidism yielded a lower single-procedure arrhythmia-free rate compared to controls (30% vs 62.5%, P=0.01).
Case-Control (n=60)
No
Does a history of amiodarone-induced hyperthyroidism reduce the success rate of pulmonary vein isolation in patients with paroxysmal atrial fibrillation?
Patients with paroxysmal AF and a history of amiodarone-induced hyperthyroidism have a lower success rate after a single pulmonary vein isolation procedure and a higher incidence of PV-unrelated tachycardias, though overall freedom from tachyarrhythmias is similar after repeat ablations.
Absolute Event Rate: 30% vs 62.5%
p-value: p=0.01
INTRODUCTION: Many patients with atrial fibrillation (AF) receive amiodarone. Amiodarone-induced hyperthyroidism (AIH) may develop as a complication. We hypothesized that pulmonary vein (PV) isolation in patients with paroxysmal AF and history of AIH may yield a lower success rate. METHODS AND RESULTS: Among 704 patients who underwent AF ablation in our center between 2007 and 2010, we identified 20 patients (mean age 58.3 ± 5.0 years; 11 males) with paroxysmal AF and overt AIH in the past. The control group consisted of 40 patients with amiodarone-refractory AF and no thyroid dysfunction. All patients underwent circumferential PV isolation. During redo procedures all tachycardias were targeted for ablation. During a 12-month follow-up, in the AIH group 6 (30%) patients were arrhythmia free after a single procedure, in comparison to 25 (62.5%) controls (P = 0.01). Atrial tachycardia (AT) was registered in 7 (35%) AIH patients and in 1 (2.5%) control patient (P = 0.001). AF recurred in 10 (50%) AIH versus 15 (37.5%) control patients (P = 0.2). Redo ablation was performed in 7 (35%) AIH patients and in 3 (7.5%) non-AIH patients (P = 0.01). During a redo procedure a PV-unrelated tachycardia was diagnosed in 5 (25%) AIH patients (vs 0 in the controls, P = 0.003). After the last performed ablation, 12 (60%) AIH patients and 28 (70%) controls had no recurrence, P = 0.56. AIH was an independent predictor of ATs. CONCLUSION: PV isolation alone has a lower efficacy for preventing recurrence in paroxysmal AF in AIH patients. After repeat ablations, overall freedom from tachyarrhythmias is similar to patients with no history of thyroid dysfunction.
Mikhaylov et al. (Wed,) conducted a case-control in Paroxysmal Atrial Fibrillation (n=60). Pulmonary vein isolation in patients with previous amiodarone-induced hyperthyroidism vs. Pulmonary vein isolation in patients with amiodarone-refractory AF and no thyroid dysfunction was evaluated on Arrhythmia-free after a single procedure (p=0.01). Pulmonary vein isolation in patients with paroxysmal AF and previous amiodarone-induced hyperthyroidism yielded a lower single-procedure arrhythmia-free rate compared to controls (30% vs 62.5%, P=0.01).