The US Endocrine Society guideline on detection, diagnosis, and management of PA has recommended that, instead of proceeding directly to subtype classification, patients who screen positive for PA by demonstrating elevated plasma aldosterone/renin ratio levels should undergo further testing to definitively confirm or exclude the diagnosis.7 This approach recognizes the possibility that elevated aldosterone/renin ratio values may represent false positives and permits identification of individuals who, by testing negative (PA excluded), can be spared from having to undergo adrenal venous sampling, which is expensive, technically difficult and invasive. The guideline, however, has so far regarded available evidence as insufficient to recommend any one of the 4 testing procedures in common use (oral sodium loading, saline infusion suppression testing [SIT], fludrocortisone suppression testing [FST], and captopril challenge) over the others.
