In patients with primary aldosteronism (PA), adrenal venous sampling (AVS) is performed to determine the presence of unilateral or bilateral adrenal disease. Verification of catheter positioning within the left (LAV) and right (RAV) adrenal veins by comparison of AV and inferior vena cava (IVC) cortisol levels can be variable. The objective of this study was to determine the utility of AV epinephrine levels in assessing successful AV cannulation. This was a single institution, retrospective review of patients who underwent AVS with cosyntropin stimulation for PA between 2009-2018. Successful cannulation of the AV was defined by an AV/IVC cortisol ratio (selectivity index; SI) ≥3:1. Epinephrine thresholds to predict catheter placement in the AV were determined using logistic regression. The calculated epinephrine thresholds were compared to previously published thresholds. AVS was performed on 101 consecutive patients and based on the SI, successful cannulation of the LAV and RAV occurred in 98 (97%) and 91(90%) patients respectively. The calculated optimal epinephrine threshold to predict AV cannulation was 364 pg/mL (sensitivity 92.1% and specificity 94.6%) and the calculated optimal AV/IVC ER threshold was 27.4, (sensitivity 92.1% and specificity 91.3%). Among the 14 patients with failed AV cannulation, 3 would have been considered to have successful AVS using AV epinephrine levels >364 pg/mL and AV/IVC ER >27.4 thresholds. Routinely obtaining two RAV samples as well as AV and IVC epinephrine levels during AVS may prevent unnecessary repeat AVS in patients with failed adrenal vein cannulation based on cortisol-based SI <3:1.
