Endocrine Abstracts

Background: Primary aldosteronism is identified in approximately 10% of hypertensive all-comers. Adrenal vein sampling (AVS) allows localization of aldosterone production, identifying cases where unilateral adrenalectomy can be curative. Unfortunately, AVS is technically challenging.

Methods: Data from AVS procedures performed in BC were extracted from the SunQuest laboratory information system in Vancouver Coastal Health. Cortisol and aldosterone levels from adrenal vein (AV) and inferior vena cava (IVC) samples, as previously measured by tandem mass spectrometry, were analyzed using established cutoffs for selectivity and lateralization.

Results: From 9 March 2011 to 28 January 2016, 216 AVS procedures were identified. Successful bilateral cannulation was confirmed in 174 cases (81%). Failure of right, left, and bilateral AV cannulation occurred in 27, 4, and 11 cases, respectively. Of successful procedures, secretion was right-lateralized in 30%, left-lateralized in 34%, bilateral in 32%, and equivocal in 4%. Analysis of unilateral AV results could predict lateralization. Suppression of aldosterone, defined as post-stimulation (aldosterone/cortisol)_AV/(aldosterone/cortisol)_IVC <1.2, predicted contralateral autonomous aldosterone secretion with sensitivity of 84.8%, specificity of 95.3%, and accuracy of 92.0%. Excessive aldosterone production, defined as pre-stimulation (aldosterone/cortisol)_AV >20, predicted ipsilateral autonomous aldosterone secretion with sensitivity of 54.1%, specificity of 94.9%, and accuracy of 81.9%.

Conclusion: AVS results from a single AV can predict lateralization with a high degree of specificity and accuracy. In the right clinical context, this may limit the need for repeat AVS in cases of unilateral failed cannulation.