Impact of autonomous cortisol secretion on adrenal venous sampling with and without ACTH stimulation in patients with primary aldosteronism.

The impact of autonomous cortisol secretion (ACS) on adrenal venous sampling (AVS) in patients with primary aldosteronism (PA) remains uncertain. This study aimed to evaluate the effects of ACS on success and lateralization of AVS. From the Japan Primary Aldosteronism Study-II, 872 PA patients with adrenal nodular lesions on computed tomography (CT) who underwent a 1-mg dexamethasone suppression test (DST) were included. ACS was defined as a post-DST cortisol level ≥1.8 μg/dL. AVS success was assessed using selectivity index (cutoff value 2 without, 5 with ACTH-stimulation), and lateralization was determined using lateralization index (cutoff value 2 without, 4 with ACTH-stimulation). Among 872 patients, 283 (32.4%) had ACS. After ACTH-stimulation, AVS success rate was significantly lower in ACS group than in non-ACS group (84.8% vs. 91.0%, p < 0.01), while no significant difference was observed before ACTH-stimulation. Among 524 patients with successful AVS both before and after ACTH-stimulation, 161 (30.7%) had ACS. The proportion of unilateral results did not differ significantly between ACS and non-ACS groups either with or without ACTH. Concordance between AVS and CT laterality was significantly lower in ACS group only without ACTH-stimulation (44.1% vs. 61.7%, p < 0.01). In patients with post-DST cortisol ≥5 μg/dL, reverse AVS-CT laterality was significantly more frequent than in those with cortisol <1.8 μg/dL both with and without ACTH-stimulation. In conclusion, ACS was associated with a lower AVS success rate with ACTH-stimulation, had no impact on rate of unilateral results, but reduced AVS-CT concordance, especially in patients with higher post-DST cortisol levels.