• Adrenal venous sampling (AVS) is the gold standard for primary aldosteronism (PA).
• Biochemical and radiographic tests do not reliably distinguish aldosterone-producing adenoma (APA) from bilateral hyperaldosteronism (BHA).
• There is ample evidence for high accuracy of AVS. It is an essential diagnostic step in most patients to distinguish between unilateral and bilateral adrenal aldosterone hypersecretion (Young WF, et al. Surgery. 2004;136(6):1227-35).
• Rapid cortisol assays improve the success rate of AVS for PA. A study revealed that the success rate for the control period was 73% (22/30 studies). After incorporating rapid cortisol assay, the success rate increased to 97% (29/30 studies).
• PASO criteria – Williams et al created consensus criteria for clinical and biochemical outcomes and follow-up of adrenalectomy for unilateral PA. Complete clinical success was achieved in 37% patients, and partial clinical success in 47%; complete biochemical success was seen in 94% patients. Female patients were more likely to have complete clinical success. Younger patients had a higher likelihood of complete clinical success. Higher levels of preoperative medication predicted less complete clinical success. (Williams TA, et al. Lancet Diabetes Endocrinol. 2017;5(9):689-99).
• Aldosterone-producing cell clusters (APCCs) are a contributor to PA.
• Conn-Shing syndrome – Large adrenal adenomas sometimes produce both aldosterone and cortisol. In a study of 174 patients with PA (103 unilateral adenomas, 71 bilateral adrenal hyperplasias), 162 healthy controls, 56 patients with endocrine inactive adrenal adenoma, 104 patients with mild subclinical and 47 with clinically overt adrenal cortisol excess, PA patients had significantly increased cortisol that resolved with surgery (Arlt W, et al. JCI Insight. 2017;2(8):e93136).

PASO criteria - Establishes a standardized criteria for PA.