Ability of calculated right adrenal vein aldosterone levels to identify the aldosterone-overproducing side in patients with primary aldosteronism undergoing adrenal venous sampling

Backgroud Adrenal venous sampling (AVS) is a gold standard procedure to determine the dominant side of aldosterone secretion in patients with primary aldosteronism. Unsuccessful cannulation of right adrenal vein (RAV) is a common problem in performing AVS. Objective To use calculated aldosterone concentration in the RAV (cAldo RAV ) for identifying the dominant side of aldosterone secretion. Design Retrospective study, 2011-2023. Methods Based on the assumption that cortisol production from both adrenal glands is equal, aldosterone concentration in the RAV was calculated by using the data from left adrenal vein (LAV) and inferior vena cava. The aldosterone concentration in the LAV (Aldo LAV ) compared to the cAldo RAV (Aldo LAV :cAldo RAV ratio) was then used to determine the dominant side of aldosterone secretion in patients with primary aldosteronism. Results Of 117 patients with successful AVS, 95 (81.2%) had concordant results between adrenal imaging and AVS study and were used as the gold standard for studying diagnostic performance. The Aldo LAV :cAldo RAV ratio with the cutoff values of ≥3 and ≤0.33 could identify unilateral diseases (left-sided and right-sided disease, respectively) with 93.8% sensitivity and 100% specificity. In 22 patients who had discordant results between adrenal imaging and standard AVS interpretation, 11 had concordant results when using the Aldo LAV :cAldo RAV ratio. Conclusions The Aldo LAV :cAldo RAV ratio can determine the dominant side of aldosterone secretion with high sensitivity and specificity. It can not only be used for patients with unsuccessful cannulation of RAV but also increase the concordance rate in those who have discordance between adrenal imaging and standard AVS interpretation.