Short-Term Effects of Coronary Angiographic Contrast Agents on Thyroid Function

Abstract

Objective: To determine the effect of two iodine-containing contrast agents used for coronary angiography on subsequent thyroid hormone concentrations. Methods: We prospectively studied thyroid function in 56 patients, with no previous history of thyroid disease and normal findings on thyroid examinations, who underwent nonemergent cardiac catheterization. Thyroid hormone concentrations were assessed at baseline and at day 1 and day 7 after administration of a radiographic iodinated contrast agent (Renografin or Omnipaque). Results: Use of Omnipaque and Renografin was not associated with significant changes in thyroid-stimulating hormone, total thyroxine, triiodothyronine resin uptake, free thyroxine index, or total triiodothyronine. Three patients had slightly increased thyroid-stimulating hormone concentrations at 7 days after angiography. Conclusion: Administration of iodinated contrast agents for cardiac catheterization does not result in hyperthyroidism in patients with previously normal findings on thyroid examination.

A Review: Radiographic Iodinated Contrast Media-Induced Thyroid Dysfunction

“…In contrast, an Italian study of over 1700 patients reported a low incidence of hyperthyroidism of 1.9% after coronary angiography (43). Similarly, hyperthyroidism was not seen in a US study of 56 patients who underwent coronary angiography (44). The low rate of contrast-induced hyperthyroidism in the Italian study, conducted in an iodine-deficient region, was likely due to the use of antithyroid medications and/or radioactive iodine ablation before contrast exposure.…”

Acute Painful Thyroiditis and Thyrotoxicosis after PCI – a Case Study

“…Hence, the usual knowledge on that particular problem is rather insufficient and studies considering this clinical entity are relatively scarce. Two studies in Germany and the USA showed that only a small proportion of patients after coronary angiography or computed tomography scan develop subclinical hypothyroidism 11,12 . It is usually established approximately 1 week after the examination.…”

2021 European Thyroid Association Guidelines for the Management of Iodine-Based Contrast Media-Induced Thyroid Dysfunction

“…The most rapid (hours to days) effect of pharmacologic doses of iodine is to inhibit organification of iodide, thereby diminishing hormone biosynthesis (Wolff-Chaikoff effect) and decreasing thyroglobulin proteolysis, thereby decreasing thyroid hormone secretion [3, 5]. The resulting small decrease in serum T4 and T3 levels causes a compensatory, transient increase in TSH concentrations [44, 45]. After the acute phase, normal thyroid hormone synthesis resumes, even with continued excess iodide exposure, a phenomenon described as the escape from the acute Wolff-Chaikoff effect.…”