Clinical implications of aldosterone responsiveness to adrenocorticotropic hormone stimulation in two major subtypes of primary aldosteronism

Objective This study examined differences in aldosterone responsiveness to adrenocorticotropic hormone (ACTH) between the unilateral aldosterone-producing adenoma (APA) and bilateral idiopathic hyperaldosteronism (IHA) subtypes of primary aldosteronism (PA) and the impacts on vascular function and treatment outcomes.Methods This retrospective study enrolled 97 patients with PA (63 with APA and 34 with IHA) who underwent adrenal venous sampling (AVS) with ACTH stimulation. During AVS, baseline and ACTH-stimulated plasma aldosterone concentration (PAC) and cortisol levels were also assessed. Vascular function was assessed by measuring flow-mediated dilation (FMD). APA tissues were analyzed for KCNJ5 mutations.Results Among 97 patients with PA, those with APA showed higher baseline and ACTH-stimulated plasma aldosterone concentration levels, which correlated inversely with FMD. In patients with IHA, the logarithmic difference between PAC measurements before and after ACTH stimulation correlated positively with the blood pressure-normalization effect after mineralocorticoid receptor antagonist (MRA) therapy, with a cutoff value of 2.140 for predicting treatment response.Conclusion These findings suggest that ACTH-stimulated aldosterone may offer a useful marker for personalized management of PA, particularly in assessing vascular health and guiding MRA treatment.