Dexamethasone premedication safe for Adrenal Vein Sampling in patients with iodine contrast media allergy

CANADA: According to a study published in the Journal of the Endocrine Society, adrenal vein sampling with dexamethasone premedication is safe and effective for subtyping primary aldosteronism and can treat lateralized primary aldosteronism postoperatively.

It is debatable how to prepare individuals with iodine contrast media (ICM) allergies for adrenal vein sampling (AVS), which is necessary to determine the cause of their confirmed primary aldosteronism's (PA) excess aldosterone. Regular premedication with high-dose prednisone may affect the aldosterone to cortisol ratios, making it more difficult to detect lateralized aldosterone excess.

"Adrenal venous sampling, which necessitates injection of contrast media to determine location of adrenal veins, is the best method to accurately classify PA into primarily lateralized or bilateral illness. As a result, performing AVS on individuals who have an iodine contrast medium (ICM) allergy is difficult," the researchers wrote.

In order to conduct AVS on patients with ICM, the authors of the study sought to assess the effectiveness and safety of premedication with high-dose dexamethasone.

For this purpose, the history of ICM allergy was retrospectively examined in 177 consecutive patients with confirmed PA who received bilateral simultaneous basal and post-ACTH bolus AVS at the center between January 2010 and December 2020. In place of the customary 50 mg of prednisone, a total of 7 patients (4%) who had previously experienced allergic reactions to ICM received 3 doses of 7.5 mg dexamethasone as a premedication. Throughout the course of the study, a number of assays were used to measure plasma aldosterone concentration (PAC), with the most recent being the DIAsource Aldosterone radioimmunoassay kit.

Key results of the study:

• None of the 7 patients experienced any severe adverse reactions.
• The basal and post-ACTH selectivity index were respectively > 2 and > 5 bilaterally in all patients despite acceptable blood cortisol suppression after dexamethasone, indicating appropriate cannulation of both adrenal veins.
• 3 patients throughout the AVS trial had bilateral source, but 4 patients had lateralized ratios (A/C ratio > 2 basally and > 4 post-ACTH).
• The 3 patients who underwent unilateral adrenalectomy for lateralized source and contralateral suppression and who had sufficient follow-up information had their PA cured on average 58 months after surgery.

When determining the cause of aldosterone excess in individuals with primary aldosteronism and iodine contrast media allergy, Adrenal Vein Sampling utilizing dexamethasone premedication is secure and reliable, concluded the authors.

To validate the efficacy of premedication with dexamethasone to perform Adrenal Vein Sampling in patients with iodine contrast media allergy, prospective multicenter collaborative trials including a greater number of patients might be helpful.

REFERENCE

Nada Younes, Eric Therasse, Isabelle Bourdeau, André Lacroix, Successful Adrenal Vein Sampling Using Dexamethasone Premedication in Patients With Iodine Contrast Media Allergy, Journal of the Endocrine Society, Volume 6, Issue 8, August 2022, bvac093, https://doi.org/10.1210/jendso/bvac093