Endocrine Abstracts

Objective: Recent guidelines promote adrenal venous sampling (AVS) as the reference test to document lateralised aldosterone hypersecretion in primary aldosteronism (PA). However, there are wide discrepancies between institutions in the criteria used. Our objective was to evaluate their consequences on the interpretation of AVS results.

Design and methods: All 506 AVS performed from 01/2001 to 03/2009 in our institution were included. Results were interpreted using the criteria reported in papers from four experienced institutions where Cosyntropin is not infused during AVS (Brisbane, Padua, Paris, and Turin). AVS were classified as: i) unsuccessful if they did not meet the criterion of selectivity; ii) left or iii) right if successful and meeting the lateralisation criterion on the considered side; iv) bilateral otherwise. When multiple samples were available from at least one side, we compared the classification induced by the two most extreme lateralisation ratios from all possible combinations of right and left selective samples.

Results: The proportion of AVS classified as unsuccessful was almost five times higher with the strictest criteria than with the least strict (18 vs 4%). The proportion of AVS classified as lateralised was more than twice higher with the least stringent criteria than with the most stringent (60 vs 26%).

Multiple samples where available from at least one side in 147 AVS. Patients with more than one selective sample were classified differently with the two most extreme samples combinations in 16% (Brisbane) to 18% (Padua) of cases (Fisher’s P=0.75).

Conclusion: Different sets of criteria currently used in experienced institutions translate into extremely heterogeneous classifications, and hence surgical decisions, for PA patients. AVS cannot be regarded as a gold standard until the most appropriate procedure and diagnostic criteria have been defined. Large and well-designed studies, preferably multicentre, are needed to resolve this issue.