Results of bilateral adrenal venous sampling (AVS) in the patient with primary aldosteronism who had a CT scan and AVS radiographs
In a 37-year-old woman with poorly controlled hypertension and primary aldosteronism who had a CT scan and AVS radiographs: The cortisol concentrations from the adrenal veins and inferior vena cava are used to confirm successful catheterization; the ratio of adrenal vein cortisol to inferior vena cava is typically more than 10:1 when the protocol for continuous cosyntropin infusion is followed. Dividing the plasma aldosterone concentrations (PACs) of the right and left adrenal veins by the respective cortisol concentrations corrects for the dilutional effect of blood from the inferior phrenic vein flowing into the left adrenal vein; these quotients are termed cortisol-corrected aldosterone ratios. In patients with aldosterone-producing adenoma (APA), the mean cortisol-corrected aldosterone ratio (the ratio of APA-side PAC/cortisol concentration to normal adrenal PAC/cortisol concentration) is 18:1. A cutoff for the cortisol-corrected aldosterone ratio from high side to low side of more than 4:1 is used to indicate unilateral aldosterone excess. The lateralization ratio in this patient of 20.5:1 is consistent with a right adrenal APA.