[An exploratory study on new indicators of AVS in the typing diagnosis of primary aldosteronism]

Objective: To explore the value of metanephrine, normetanephrine, and some steroid hormones in the assessment of adrenal venous sampling (AVS). Methods: This retrospective study enrolled 101 patients with primary aldosteronism who underwent AVS at Peking Union Medical College Hospital between June 1, 2021, and October 1, 2024. Multiple hormones, including aldosterone, cortisol, metanephrine, normetanephrine and steroid hormone profiles, were measured in samples from the inferior vena cava and bilateral adrenal veins during AVS. Selectivity index and lateralization index were calculated based on the levels of different hormones to determine successful AVS cannulation (selectivity index≥2) and aldosterone hypersecretion lateralization (lateralization index≥2). Patients who underwent unilateral adrenalectomy were followed for at least 6 months. Clinical and biochemical outcomes were assessed according to the Primary Aldosteronism Surgical Outcome (PASO) criteria, with biochemical remission defined as achieving complete or partial biochemical remission postoperatively. The efficacy of different hormones relative to cortisol for calculating selectivity index and lateralization index was evaluated for subtype classification. Results: The age at diagnosis of the enrolled patients was (50.5±9.6) years, including 77 males. Regarding the selectivity index, five hormones including metanephrine, normetanephrine, androstenedione, 17α-hydroxypregnenolone, and dehydroepiandrosterone demonstrated significantly higher selectivity index compared to cortisol (all P<0.05). Based on the cortisol-derived selectivity index, AVS cannulation was unsuccessful in 8 patients; using the five indices, unsuccessful cannulation occurred in 2, 2, 3, 4, and 5 patients, respectively. Based on postoperative follow-up, 55 patients were identified as having unilateral surgically relievable primary aldosteronism. In identifying these patients, the performance of metanephrine, normetanephrine, androstenedione, 17α-hydroxypregnenolone, and dehydroepiandrosterone was non-inferior to cortisol, correctly identifying 95% (52/55), 93% (51/55), 91% (50/55), 87% (48/55), and 89% (49/55) of cases, respectively. However, among these patients, there were no statistically significant differences in the success rate of intubation in AVS and the ability to identify patients with unilateral primary aldosteronism between the five indicators and cortisol (all P>0.05). Using cortisol-based lateralization as the reference standard, androstenedione and dehydroepiandrosterone both achieved an accuracy of 90% (84/93) for determining the lateralized side, while 17α-hydroxypregnenolone, normetanephrine, and metanephrine achieved accuracies of 89% (83/93), 81% (74/93), and 80% (73/93), respectively. Conclusion: Metanephrine, normetanephrine, androstenedione, 17α-hydroxypregnenolone and dehydroepiandrosterone could increase the success rate of intubation in AVS, with a high ability to identify patients with unilateral primary aldosteronism, and are expected to replace cortisol as new indicators of AVS.