Differences between left adrenal vein sampling sites revealed with segmental sampling in primary aldosteronism

OBJECTIVES: To clarify the differences between two left sampling sites (left adrenal central vein [LCV] and common trunk [CMT], conjunction with LCV and inferior phrenic vein) and their impact on adrenal venous sampling (AVS) in primary aldosteronism by analyzing the results of segmental AVS (sAVS). METHODS: We retrospectively analyzed a final cohort of 432 patients who underwent cosyntropin-stimulated sAVS from 2017 to 2020. Hormone levels in the LCV and the CMT were compared. Subtype diagnosis was based on the lateralization index with LCV and CMT sampling (a cutoff value of 4) and sAVS after excluding patients with a selectivity index (SI) <3. RESULTS: Compared with the LCV, CMT sampling showed significantly lower aldosterone and cortisol levels and a higher proportion of cases with an SI of <3 (2.8% vs 0.5%, p = 0.025) and <5 (6.9% vs 0.5%, p < 0.001), while the aldosterone-to-cortisol ratio and the lateralization index were not significantly different. Subtyping of both sites was concordant in 94.7% (393/415) and discordant in the remainder, which included left and right aldosterone-producing adenoma and idiopathic hyperaldosteronism cases referring to the sAVS. There was no significant difference between the concordance rate of the two sampling sites based on the sAVS diagnosis. CONCLUSIONS: LCV sampling meets the SI criteria for successful AVS more frequently compared with CMT sampling, but neither was better than the other in terms of diagnosis under conditions of meeting the criteria. ADVANCES IN KNOWLEDGE: LCV sampling would decrease the number of cases judged as AVS failure.