Silent thyroid function abnormalities in patients undergoing coronary angiography

Abstract

Background: Iodine is an essential element in the formation of thyroid hormones, the body may encounter situations in which high iodine load occur in the body like doing the contrast studies using the iodine-containing contrast media. In most people, this iodine load is well-tolerable; however, in some others, this may result in derangements in the thyroid function, from which hyperthyroidism is the most common. Objective: The objective of the study is to determine the subclinical changes in the thyroid functions in a cohort of patients with coronary artery disease (CAD) undergoing coronary angiography (CAG) and/or percutaneous coronary intervention (PCI). Materials and Methods: In this pilot study, a total of 101 patients with CAD undergoing CAG and/or PCI were recruited during the year 2018. All cases had normal thyroid function tests including (thyroid-stimulating hormone [TSH], free T4, and free T3) preprocedural. Six weeks after CAG/PCI serum TSH, free T4 and T3 were assessed again. Results: No significant differences were observed in levels of TSH, free T4, and free T3 between preprocedures (CAG/PCI) and after 6 weeks with P values (0.645, 0.135, and 0.807), respectively. In addition, no difference was found between the subgroup of CAG versus PCI. Conclusion: In euthyroid patients undergoing CAG/PCI minimal changes could occur in thyroid function. However, these changes are of limited significance in the short term.