RESUMO
CONTEXT: 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. OBJECTIVE: 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. DESIGN: This was a retrospective cohort study. SETTINGS: The study was conducted at a tertiary university center. PATIENTS: 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. INTERVENTION: The intervention was a total thyroidectomy. MAIN OUTCOME MEASURE: LV ejection fraction (EF) after the thyroidectomy and survival in December 2011 were measured. RESULTS: 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. CONCLUSIONS: Total thyroidectomy, by rapidly restoring euthyroidism, may improve cardiac function and reduce the risk of mortality in AIT patients with severe LV dysfunction.
