Total Thyroidectomy in Patients with Amiodarone-Induced Thyrotoxicosis and Severe Left Ventricular Systolic Dysfunction

Abstract

Patients with amiodarone-induced thyrotoxicosis (AIT) and left ventricular (LV) systolic dysfunction have a high mortality rate. Usually, medical therapy is the first choice for AIT patients, whereas the role of the thyroidectomy is unsettled. The objective of the study was to evaluate the effect of a total thyroidectomy on cardiac function and survival of AIT patients with severe LV systolic dysfunction. This was a retrospective cohort study. The study was conducted at a tertiary university center. All AIT patients (n=24; nine patients with type 1 AIT, 15 patients with type 2 AIT) referred to the Department of Endocrinology and submitted to a total thyroidectomy at the Department of Surgery, both at the University of Pisa, during the years 1997-2010. The intervention was a total thyroidectomy. LV ejection fraction (EF) after the thyroidectomy and survival in December 2011 were measured. All enrolled patients had previously undergone to medical treatment for AIT, as appropriate, without achieving euthyroidism. Patients with moderate to severe LV systolic dysfunction (EF<40%, group 1, n=9) or with mild systolic dysfunction (40%≤EF≤50%, group 2, n=5) were compared with patients with normal systolic function (EF>50%, group 3, n=10). Two months after thyroidectomy, under levothyroxine replacement therapy, LVEF improved in patients with LV systolic dysfunction, particularly in those of group 1, in whom it increased from 28.2±7.2 to 38.3±6% (P=0.007). On the contrary, LVEF did not significantly change in group 3 (from 57.1±3.0 to 59.8±6.6%, P=0.242). The mean follow-up was 67±42 months. No death occurred during and 2 months after surgery. One death occurred in one patient of group 1, 30 months after the thyroidectomy, due to acute myocardial infarction. No patient had relevant complications of thyroidectomy. Total thyroidectomy, by rapidly restoring euthyroidism, may improve cardiac function and reduce the risk of mortality in AIT patients with severe LV dysfunction.