Randomization and Procedures
hyperplasia, inferior vena cava, AVS failure
DISEASE, HYPERPLASIA, ATYPICAL ADENOMA
Patients were randomly assigned to either the ACTH-stimulated or non–ACTH-stimulated group. The randomization method is presented in the eMethods in Adrenal venous sampling was performed by 2 experienced endocrinologists (S.Y., Z.D.) between 8 Cannulation was considered successful when the selectivity index, namely, the plasma cortisol concentration (PCC) in the adrenal vein divided by the PCC in the inferior vena cava (IVC), was 3 or greater with ACTH stimulation or 2 or greater without ACTH stimulation. The ratio of plasma aldosterone concentration (PAC) to PCC on the side with the higher ratio divided by the contralateral PAC-PCC ratio is defined as the lateralization index (LI). Lateralization of aldosterone excess was defined as an LI of 4 or greater irrespective of ACTH use. Patients with an LI between 2 and 4 together with contralateral suppression (the PAC-PCC ratio of the nondominant side was less than the PAC-PCC ratio of the IVC) or CT showing a typical adenoma on the dominant side were also considered to have lateralized disease. Patients with an LI less than 2 or of 2 to 4 without meeting the above criteria were diagnosed as having BPA.In case of technical AVS failure or a bilateral PAC-PCC ratio lower in adrenal venous blood than peripheral blood, adrenalectomy was recommended if the patient met 1 of the following sets of criteria: (1) unilateral nodule (diameter, ≥1 cm) identified on CT, no observable nodules or hyperplasia on the contralateral adrenal gland, and PAC of 20 ng/dL or greater, plasma renin concentration (PRC) less than 3.2 pg/mL, and serum potassium level ≤3.5 mEq/L