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

Purpose: 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.

Methods: 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) and normetanephrine-based SI (SI) were determined using cortisol-corrected SI (SI≥2) as the reference in the isolated PA group. Subsequently, the accuracy of MNs-corrected indices was evaluated in the PA/ACS group.

Results: 130 isolated PA patients and 65 PA/ACS patients were included. In isolated PA, the optimal cut-off values of SI and SI were 3.4 and 1.6, respectively. Eleven PA/ACS patients had unsuccessful cannulation (SI<2), of whom, the diagnoses of 8 and 6 patients were rescued by SI and SI, 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.

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