Agranulocytosis and acute coronary syndrom in apathetic hyperthyreoidism

INTRODUCTION Tissue expose to excessive levels of circulating thyroid hormones results in thyrotoxicosis. In most cases, thyrotoxicosis is due to hyper-activity of the thyroid gland. Cardiovascular and myopathic manifestations are predominant clinical features in most hyperthyroid patients, aged 60 years and older. Some of patients have apathetic hyperthyreoidism which presents with weight loss, small goiter, severe depression and without clinical features of increased sympathetic activity [3, 6]. About 50% of patients with cardiovascular manifestations have no evidence of underlying heart disease. Cardiac problems resolve when euthyreoid state is established [3]. Three treatment modalities are available in hyperthyreodism, namely medicament therapy, surgery and radioactive iodine. Antithyroid drug therapy complications, can be mild such as rash, which is managed without cessation of therapy by antihistamines administration. On the other hand, very serious complications such as agranulocytosis, necessitate immediate discontinuation of the medication and appropriate treatment. Although extremely rear, it is life-threatening with highly variable recovery time. CASE REPORT A 62-year-old woman with recurrent hyperthyroidism was admitted after treatment of agranu locytosis due to antithyroid drugs in another institution with G-CSF. The patient presented with clinical features of apathetic hyperthyroidism with extremely elevated thyroid hormone levels (total and free T4) and suppressed TSH. Radioactive iodine (5 mCi) was administered after increased thyroid uptake was confirmed. Echocardiography on admission was normal. ECG revealed moderately inverted T waves in standard and V1, V2 precordial leads. Laboratory analysis revealed mild normocytic anemia with normal white blood cell count, hypokaliemia and normal concentration of creatine phosphokinase lactic dehidrogenase and mildly elevated aspartate transaminase in sera. Chest X-ray was consistent with pulmonary emphysema. Because the worsening of ECG changes she was transferred to Coronary unit. The diagnosis of non-Q myocardial infarction was confirmed and treatment with nitrates and beta-adrenergic antagonists was instituted. Four weeks later she became euthyroid and coronarography was performed. Subepicardial coronary arteries were normal (Figure 1). She was dismissed, and still euthyroid three months later. DISCUSSION Agranulocytosis is very rare but very serious complication of antithyroid drug therapy. It can be detected in about 0.1 -1 % patients during the first three months of treatment. Sudden appea