ObjectiveAccurate assessment of the localization of aldosterone-producing adenomas (APAs) is essential for the treatment of primary aldosteronism (PA). Although adrenal venous sampling (AVS) is the standard method of reference for subtype diagnosis in PA, controversy exists concerning the criteria for interpretation. This study aimed to determine better indicators that can reliably predict subtypes of PA. 

MethodRetrospective analysis in single-cohort including 209 patients with PA who were subjected to AVS. 82 patients whose plasma aldosterone concentrations (PAC) were normalized after surgery were histopathologically or genetically diagnosed with APA. The accuracy of image findings was compared to AVS results. Receiver operating characteristic (ROC) curve analysis between the operated and no apparent laterality groups was performed using AVS parameters and loading test for diagnosis of PA. 

Result The agreement between image findings and AVS results was 56.3%. ROC curve analysis revealed that lateralization index (LI) after ACTH stimulation cutoff value was 2.40, with 98.8% sensitivity and 97.1% specificity. The contralateral suppression index (CSI) cutoff value was 1.19, with 98.0% sensitivity and 93.9% specificity. All patients over the LI and CSI cutoff values exhibited unilateral subtypes. Among the loading test, the best classification accuracy was achieved using the PAC reduction rate after saline infusiontest (SIT) >33.8%, which yielded 87.2% sensitivity or PAC after SIT <87.9 pg/mL 86.2% specificity for predicting bilateral PA. 

ConclusionThe combined criterion of the PAC reduction rate and PAC after SIT may determine a subset of patients with APA who should be performed AVS for validation.