The Effect of Coronary Angiography on Thyroid Function (Kermanshah 2002)

Introduction: During the angiography of coronary vessels a great amount of  iodine mixed with radio-contrasts enter the body, and if autonomic centers exist in thyroid it causes hyperthyroidism. This can be dangerous in patients with Cronary Artery Disease (CAD). This study aimed to determine the effect of a radio-contrast used in coronary angiohraphy on thyroid’s function in patients referring to Imam Ali Hospital of Kermanshah (2002).

Materials and Methods: In this clinical–trial study 80 available patients referring for coronary angiography were selected. They had not used Iodine-containing medicines or drugs which have effect on thyroid’s function. First the history and careful physical examination of patients were taken. In case of having goiter,they were classified according to WHO classification. The patients thyroid's function were tested in two stages; before angiography and after it. All those who had hypothyroidism or hyperthyroidism before angiography, were excluded. The average iodine present in radio-contrast was 375 mg/ml (16% Graphine) The- pair test was done to analyze the data.

Results: Four patients with thyroid dysfunction befor angiography were excluded,and 13 patients(17.1%) of 76 patients (29 females,47 males) developed hyperthyroidism. 61/54% of them had overt hyperthyroidism and the rest had subclincal hyperthyroidism. Seven of them were females and six were males, in other words 24.19% of women and 12.8% of men had iatrogenic hyperthyroidism. 55.9% were over 60y. And the rest were younger. 77% of them received over 70cc of iodine contrasts.

Conclusion: Coronary angiography with iodine radio-contrasts had a significant  effect on thyroid’s function and in the first few weeks after the angiography,it causes hyperthyroidism. This complication can be dangerous in patients with CAD. Therefore, the thyroid’s function in patients with CAD over 60y  after the angiography  with radio-contrast should be carefully inspected.