Verification of the screening criteria of the ACTH-stimulating test for predicting aldosterone producing adenoma in primary aldosteronism

Abstract

Adrenal venous sampling (AVS) is essential for the subtype diagnosis of primary aldosteronism (PA); however, it requires a respectable technique and effort. To avoid unnecessary AVS for bilateral PA, we used the adrenocorticotropic hormone-stimulating test (AST) to narrow the unilateral PA before AVS. Here, the efficacy of the criteria was verified in two sets of patients with PA, namely, the nonselected and selected groups. In the nonselected group, patients referred for PA evaluation were mostly admitted to our hospital and underwent AVS if they had positive reactions for at least one of the AST, captopril challenge test, and furosemide upright test. In the selected group, the referred patients underwent AST in the outpatient office, and those who met our criteria were preferentially subjected to AVS. Additionally, some applicants underwent AVS. Of the 43 nonselected patients, only nine (20.9%), 32 (74.4%), and two (4.7%) were diagnosed with unilateral PA, bilateral PA, and considered normal, respectively. Three of the nine unilateral PAs and six of the 32 bilateral PAs did not meet our criteria. In the selected group, 34 patients were screened for AST levels using the new aldosterone measurement method, chemiluminescent enzyme immunoassay, and 14 patients were subjected to AVS. Following AVS, eight of nine patients (88.9%) who met our AST criteria were diagnosed with unilateral PA; conversely, all five patients who did not meet the criteria were diagnosed with bilateral PA (predictive accuracy 92.9%). In conclusion, initial screening with AST appears efficient even in a practical setting for refining unilateral AP before AVS and reducing significant number of patients with bilateral PA from unnecessary AVS.