ECE2014 Poster Presentations Thyroid (non-cancer) (125 abstracts)
1Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland; 2Nuclear Medicine Department, Medical University of Warsaw, Warsaw, Poland; 3Department of Computer Science and Statistics, Poznan University of Medical Sciences, Poznan, Poland.
Introduction: Radioiodine (RAI) therapy is a standard procedure in therapy of hyperthyroidism. However, the use of RAI in euthyroid patients requiring chronic administration of amiodarone (AM), in a case of lacking efficacy of other antiarrhythmic drugs might be controversial.
Objective: The aim of the study was to assess the safety and efficacy of an AM therapy prior to treatment with radioiodine therapy in euthyroid patients with permanent atrial fibrillation (PAF), who were treated for hyperthyroidism in the past.
Patients and methods: This was a retrospective observational study. Patients were assessed at baseline and 2, 6, 8, and 12 months after RAI therapy. 17 euthyroid patients with PAF were qualified to the RAI (female/male 3/14; range age from 65 to 87, median 71 years). The patients required chronic administration of AM as a prophylaxis against sudden death.
Results: Each patient received an ablative dose of 800 MBq (22 mCi) of 131I. At the baseline and the time of observation no side effects of the therapy and no signs of drug intolerance were observed. Subclinical hyperthyroidism occurred in 2 (11.8%) cases after 2 months of RAI and 5 weeks of AM administration. In this situation RAI therapy was repeated. Three patients (17.6%) after 6 months and another 2 (11.8%) after 8 months required submission of additional dose of 131I due to amiodarone induced thyrotoxicosis (AIT). Twelve patients (70.6%) returned to spontaneous sinus rhythm within 2 months. Fourteen patients (82.4%) had sinus rhythm during follow-up after 6 and 12 months of treatment.
Conclusions: Prevention of RAI therapy before including AM in euthyroid patients (but previously hyperthyroid), with PAF when other antiarrhytmic drugs are ineffective may be a method of choice. This is particularly important for patients who will require permanent AM administration as a life-saving drug.