Primary aldosteronism is the most common secondary cause of hypertension, affecting 10% of hypertensive patients. Adrenal vein sampling (AVS) is the current gold standard for distinguishing unilateral from bilateral disease, thereby guiding surgical versus medical intervention respectively. However, using cortisol to confirm successful cannulation is challenging, due to its long half-life and potential co-secretion by aldosterone-producing adenomas, which can lead to misinterpretation.

Htut et al. have examined the diagnostic utility of plasma metanephrines as an alternative to cortisol for assessing the success of cannulation and the lateralisation of aldosterone secretion. In their series of 131 unstimulated AVS procedures performed by a single operator, a metanephrine-based selectivity index (i.e. to confirm successful cannulation) cut-off value >3 achieved 99% sensitivity and 100% specificity. An aldosterone/metanephrine lateralisation index >4 indicated unilateral disease with 94% sensitivity and 96% specificity.

Based on these findings, the authors recommend incorporating metanephrine measurements to enhance diagnostic accuracy and reduce the risk of missing unilateral disease, particularly in cases with aldosterone–cortisol co-secreting adenomas.

Read the full article in Clinical Endocrinology https://doi.org/10.1111/cen.15277