Endocrine Abstracts

Introduction: Thyroid dysfunction is relatively common in amiodarone treated subjects, partly because of its high iodine content. The benefits of surveillance, early identification and management of such thyroid dysfunction have been established. We undertook a retrospective case notes audit of all amiodarone treated subjects in our hospital to evaluate thyroid surveillance and outcome.

Methods: All patients treated with amiodarone between 2001 and 2004 were identified. Data obtained included demographic status, indication for amiodarone therapy, documentation of baseline thyroid status, surveillance during follow up and management of thyroid dysfunction.

Results: During the study period 83 patients (median age 72 years) were treated with amiodarone. The majority had documented cardiovascular comorbidities (43% coronary heart disease; 20% heart failure; 9% stroke; 8% valvular disease). Amiodarone was used as a first line agent for ventricular arrhythmias but mainly as second line for supraventricular arrhythmias. 16 patients were followed up for <1 month and 34 patients were followed up for >6 months (Range 0–106 months). There were 24 deaths mainly outside our follow up.

During follow up, 46/83(55%) patients did not have their thyroid profile (TFT) checked 6 monthly for 2 years. Baseline TFT was not checked in 20 patients (seven never had a TFT check). Of the discharged patients, there was no record of advice to the family practitioner regarding thyroid surveillance.

Thyroid dysfunction developed in 24% (six thyrotoxicosis; five hypothyroidism; nine subclinical disease). Two thyrotoxic patients with missed diagnosis achieved spontaneous euthyroidism and one had exacerbation of arrhythmia. Two patients (one with missed diagnosis) died of unrelated postoperative complications. Only one patient was referred to the endocrinologists. Three patients were treated with carbimazole and none with steroids. Subtype differentiation of amiodarone-induced thyroxicity was not performed in any subject. All hypothyroid patients were treated appropriately with thyroxine.

Conclusion: This audit confirms that thyroid surveillance of amiodarone treated subjects and the management of thyroid dysfunction in them is clearly inadequate. There is a need for physician education and early referral to endocrine physicians.