Endocrine Abstracts

Introduction: Cardiothyreosis is the consequence of the effects of excess free thyroid hormones on the vascular wall and myocardium. This complication is the most serious aspect of hyperthyroidism. Rhythm disorders and heart failure are the most frequently noted. The prevalence of coronary insufficiency is lower. The aim of this study is to evaluate the characteristics of coronary insufficiency in patients with hyperthyroidism.

Method: This is a retrospective descriptive study including six patients among a hundred patients who were followed for hyperthyroidism and cardiothyreosis, during a period of 20 years, in the Endocrinology department of Hedi Chaker Hospital in Sfax. These six patients had coronary insufficiency related to cardiothyreosis.

Results: The prevalence of coronary insufficiency in cardiothyreosis was 6%. All six patients were male, with a mean age of 44.16 years [extremes: 25-61]. The majority were aged ≤ 35 years (4 cases). They had no personal history of cardiovascular pathology except hypertension for one patient. The etiology of hyperthyroidism was Graves’ disease in 2 cases, Hashimoto’s thyroiditis in 2 cases, toxic multi-nodular goiter and iodine overload. The mean TSH level was 0.054 µIU/ml [extremes: 0.01 - 0.19 µIU/ml], FT4 was 54.36 pmol/l [extremes: 31.3 - 71.43 pmol/l]. No cases of subclinical hyperthyroidism were reported. The diagnosis of hyperthyroidism was concomitant with the diagnosis of cardiothyreosis in 5 patients and delayed in one patient. Tachycardia was present in all patients with a mean heart rate of 101.2 bpm. The different forms of coronary syndrome were objectified, ranging from unstable angina to myocardial infarction with or without necrosis Q wave. Coronary angiography reports of 4 patients were obtained: they showed arterial occlusion in 2 cases and a healthy coronary network in the other 2 cases. Coronary insufficiency was always associated with one or more of the other types of cardiothyreosis. Rhythm disorders were present in 5 cases (atrial fibrillation in 4 cases and atrial extrasystoles in one case). Systolic ejection fraction was low in all patients with a mean of 35.83% [extremes: 20-55%]. 2 patients had died in major heart failure. The others had not developed new coronary events after obtaining euthyroidism.

Conclusion: The risk of coronary insufficiency during hyperthyroidism is well established. Less common than rhythm disorders and heart failure, it is usually associated with them. Early diagnosis and adequate treatment of hyperthyroidism would prevent this complication.