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Primary aldosteronism (PA) causes 15%–25% of cases of drug-resistant hypertension and is associated with a markedly increased risk of both cardiovascular and cerebrovascular disease -- especially stroke.

Adrenal vein sampling (AVS) with continuous synthetic ACTH infusion is the gold standard assay to distinguish unilateral from bilateral adrenal sources of autonomous aldosterone secretion and, as such, is crucial for disease management: unilateral adrenal etiologies of PA may be surgically resected, whereas bilateral sources are better managed with medications (potassium-sparing diuretics or aldosterone receptor antagonists).

However, intravenous contrast media (ICM) is needed in this procedure, posing a problem for patients with a severe allergy to ICM. The use of exogenous glucocorticoids like prednisone can affect measurements of serum cortisol and may also influence adrenal cortisol secretion, precluding their use in AVS.

In a study in the , Younes and colleagues describe the successful use of dexamethasone administered at 6 PM and midnight the night before and at 6 AM the morning of the procedure in a small series of seven patients with contrast media allergy undergoing AVS for PA, rendering very accurate results while not compromising on safety. Dexamethasone has a much higher anti-inflammatory potency than prednisone and suppresses the hypothalamic-pituitary-adrenal (HPA) axis while not interfering with modern chemiluminescence-based cortisol assays.

This well done and long-awaited study demonstrates that AVS utilizing continuous ACTH infusion can still be reliably and safely performed when using dexamethasone as premedication for ICM allergy and could potentially open up an avenue for the rational design of AVS protocol in patients with severe ICM allergy.

Darius Schneider, MD, PhD, practices endocrinology in La Jolla, California.

Read the study here and a Q&A with a study coauthor here.