Thyroidectomy for Amiodarone-Induced Thyrotoxicosis: Mayo Clinic Experience

Abstract

ContextAmiodarone-induced thyrotoxicosis (AIT) is a difficult diagnostic and management challenge, especially during severe thyrotoxicosis accompanied by cardiovascular compromise.ObjectiveTo evaluate thyroidectomy for the management of AIT.DesignRetrospective 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.SettingReferral center.PatientsThe group was comprised of 17 patients.Main Outcome MeasuresThyroid function, left ventricular ejection fraction (LVEF), and surgical complications were the main outcome measures.ResultsPatients 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.ConclusionsThyroidectomy 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 high-risk surgical patients.

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“…[61][62][63] Thyroidectomy remains a valuable option for AIT management, particularly for patients with suboptimal response to medical therapy and high risk for cardiac complications. 67 A higher prevalence of overt hypothyroidism (22.7%) as compared to controls (4.1%, p: 0.02) was found in TM patients 3 months after starting amiodarone, while the prevalence of subclinical hypothyroidism was similar in amiodarone-treated (18.2%) and untreated (15%) TM patients. 63 Overt hypothyroidism resolved spontaneously after amiodarone withdrawal in one case, while the remaining TM patients were maintained euthyroid on amiodarone by L-thyroxine administration.…”

“…68 In conclusion, clinicians should keep in mind the possibility of development of thyroid disorders in patients on treatment with amiodarone even after several years of use. Although it is difficult to decipher the specific factors contributing to the successful management in patients with AIT, Kotwal et al 67 suggested that the outcome of these patients is most likely derived from the coordinated efforts of endocrinologists, thyroid surgeons, cardiologists, anesthesiologists, and members of all of collaborating teams.…”

Amiodarone-Induced Thyrotoxicosis After Total Thyroidectomy for Metastatic Follicular Thyroid Cancer

“…Amiodarone is a benzofuranic, iodine-rich antiarrhythmic drug (class III) that causes thyroid dysfunction in 15 to 20% of patients (1). In each 200-mg tablet, there is 75 mg of iodine (37% of the amiodarone mass) of which approximately 10% of the iodine is released as free iodide daily.…”

“…Radioactive iodine can be used where thioamide drugs have been used initially to render an individual with AIT type 1 euthyroid, but who is unable to come off the oral agents. In more resistant cases, thyroidectomy may be an option (1,4).…”

Amiodarone-induced thyrotoxicosis type 2: predictors and treatment options

“…Хирургическое вмешательство позволяет быстро устранить тиреотоксикоз. Такой подход считается безопасным для пациентов с тяжелыми нарушениями ритма сердца, которым невозможна отмена Ам, а быстрое восстановление эутиреоза консервативными методами недостижимо [65,66].…”