Metanephrines-corrected adrenal vein sampling in primary aldosteronism concurrent with autonomous cortisol secretion

Whether metanephrines (MNs)-corrected indices in adrenal venous sampling (AVS) would be useful in subtyping primary aldosteronism (PA) concurrent with autonomous cortisol secretion (ACS) remains unclear.

This retrospective study included PA patients concurrent with (PA/ACS) or without (isolated PA) ACS who underwent AVS. Firstly, optimal cut-offs for the metanephrine-based selectivity index (SI_MN) and normetanephrine-based SI (SI_NMN) were determined using cortisol-corrected SI (SI_cort≥2) as the reference in the isolated PA group. Subsequently, the accuracy of MNs-corrected indices was evaluated in the PA/ACS group.

130 isolated PA patients and 65 PA/ACS patients were included. In isolated PA, the optimal cut-off values of SI_MN and SI_NMN were 3.4 and 1.6, respectively. Eleven PA/ACS patients had unsuccessful cannulation (SI_cort<2), of whom, the diagnoses of 8 and 6 patients were rescued by SI_MN and SI_NMN, respectively. Using lateralization index (LI) ≥ 4 to diagnose unilateral PA, 28 out of 65 PA/ACS were identified by cortisol- or NMN-corrected indices, and five more patients were identified by MN-corrected indices. Among 25 PA/ACS patients with a final subtyping diagnosis based on post-surgery outcomes, 52.0% (13/25) were correctly identified by both cortisol- and MNs-corrected indices. In the remaining 12 patients, four were correctly identified by MNs-corrected indices, one was correctly identified by cortisol-corrected indices alone, two were judged as unsuccessful cannulation by SI and all three indicators were wrongly subtyped in the five patients.

For patients with PA/ACS, MN-corrected AVS serves as a complementary approach to cortisol-corrected AVS.