[Total thyroidectomy in patients with amiodarone-induced hyperthyroidism: when does the risk of conservative treatment exceed the risk of surgery?]

Cardiac evaluation in amiodarone-induced thyroid dysfunction with suspected cardiac ischemia?: a case report and review of the literature

BACKGROUND

Amiodarone-induced thyroid dysfunction (AIT) is a side-effect associated with the use of Amiodarone for the treatment of refractory arrythmias. Resulting hyperthyroidism can precipitate cardiac complications, including cardiac ischemia and myocardial infarction, although this has only been described in a few case reports.

CASE PRESENTATION

We present here a clinical scenario involving a 66-year-old male Caucasian patient under Amiodarone for atrial fibrillation, who developed AIT. In the presence of dyspnea, multiple cardiovascular risk factors and ECG abnormalities, a transthoracic echocardiogram was performed, showing inferobasal hypokinesia. This led to further investigations through a cardiac PET-CT, where cardiac ischemia was suspected. Ultimately, the coronary angiography revealed no abnormalities. Nonetheless, these extensive cardiologic investigations led to a delay in initiating an emergency endovascular revascularization for acute-on-chronic left limb ischemia. Although initial treatment using Carbimazole was not successful after three weeks, the patient reached euthyroidism after completion of the treatment with Prednisone so that eventually thyroidectomy was not performed. Endovascular revascularization was finally performed after more than one month.

CONCLUSIONS

We discuss here cardiac abnormalities in patients with AIT, which may be due to relative ischemia secondary to increased metabolic demand during hyperthyroidism. Improvement of cardiac complications is expected through an optimal AIT therapy including medical therapy as the primary approach and, when necessary, thyroidectomy. Cardiac investigations in the context of AIT should be carefully considered and may not justify delaying other crucial interventions. If considered mandatory, diagnostic procedures such as coronary angiography should be preferred to functional testing.

Short review: novel concepts in the approach to patients with amiodarone-induced thyrotoxicosis

INTRODUCTION

Amiodarone-induced thyrotoxicosis is associated with high morbidity and mortality rates. The approach to this condition is widely variable across different medical specialists and even among expert endocrinologists. As a matter of fact, the approach to amiodarone-induced thyrotoxicosis has always been considered difficult, due to diagnostic uncertainties easily resulting in missteps, and therapeutic challenges easily resulting in unresponsiveness or slow-responsiveness to the administered drugs.

PURPOSE

Our purpose is to review novelties emerged during the last years about this condition, with the aim to provide novel insights on the diagnostic and therapeutic management of this challenging condition.

Early surgery: a favorable prognosticator in amiodarone-induced thyrotoxicosis-a single-center experience with 53 cases

Fewer than 100 cases of amiodarone-induced thyrotoxicosis (AIT) managed surgically have been reported worldwide. This study aims to assess the outcome of thyroidectomy under general anesthesia in a relatively large case series. A retrospective analysis of the clinical records of 53 patients who underwent thyroidectomy for AIT between 1995 and 2019 was conducted. There were 48 (90%) males and 5 females with an average age of 63.7 years. Type 1 and 2 AIT were present in 35 (66%) and 18 (34%) of patients, respectively. The mean preoperative ejection fraction (EF) was 45 ± 13%. Salvage surgery was performed in 6 (11%) patients due to decompensating heart failure and/or malignant arrhythmias. 35 (66%) patients underwent urgent surgery due to a predicted late response to medical therapy and/or the need to discontinue it. Elective surgery was performed in the remainder. A considerable improvement in mean EF occurred 12 months post-surgery (44% vs. 49%; p < 0.001). The overall survival rate following thyroidectomy was 96% at 12 months, and 83% at 5 years. No survival differences were observed based on systolic function. Cardiac-specific mortality was 11%, and these patients demonstrated a considerably shorter survival post-surgery compared to those who died of a non-cardiac cause (27 ± 18 vs. 77.5 ± 54 months; p < 0.05). Total thyroidectomy can be safely performed under general anesthesia despite severe cardiac disease. It considerably improves cardiac function and confers a survival advantage. Therefore, it should be considered early in the treatment plan of select cases.