Thyroidectomy for amiodarone-induced thyrotoxicosis: Mayo Clinic experience

Context: Amiodarone-induced thyrotoxicosis (AIT) is a difficult diagnostic and management challenge, especially during severe thyrotoxicosis accompanied by cardiovascular compromise. Objective: To evaluate thyroidectomy for the management of AIT. Design: Retrospective cohort study of adults with noncongenital heart disease with AIT after > 3 months of amiodarone who underwent thyroidectomy from 1 November 2002 to 31 December 2016. Setting: Referral center. Patients: The group was comprised of 17 patients. Main Outcome Measures: Thyroid function, left ventricular ejection fraction (LVEF), and surgical complications were the main outcome measures. Results: Patients had median age of 60 years, 82.4% were male, and 47% had systolic heart failure. At diagnosis, median TSH was 0.005 mIU/L, median free T4 was 3.25 ng/dL, and total T3 was 198.5 ng/dL. We classified five patients as type 1 and type 2 and two patients as mixed; five patients remained undefined. The most common surgical indications were medically refractory disease, worsening cardiac status, and severe thyrotoxicosis requiring prompt resolution. Within 1 week post-thyroidectomy, median TSH was 0.565 mIU/L, and free T4 was 1.8 ng/dL. Median LVEF improved by 8% in patients with systolic heart failure. Seven patients had a complication within 30 days postsurgery (rehospitalization, n = 4; cervical hematoma, n = 2; recurrent arrhythmia, n = 2; symptomatic hypocalcemia, n = 1; death, n = 1). A larger thyroid gland was a risk factor for complications. Conclusions: Thyroidectomy resulted in rapid resolution of thyrotoxicosis. Its complication rate was higher than for non-AIT indications but lower than previously reported in a similar population of highrisk surgical patients.