Adrenal vein sampling: accuracy of earlier sampling post adrenocorticotropic hormone (ACTH) administration

Aim: Multiple studies recommend sampling at least 15-30-minutes post administration of ACTH. The aim of this retrospective study was to determine the impact on adrenal vein sampling (AVS) result interpretation when obtaining post-ACTH blood samples earlier, at 5- and 10-minutes, compared to the standard 15-30 minutes. Materials and methods: All consecutive adult patients who underwent AVS using the simultaneous sampling method between August 2023 and March 2024 were included. The differences in adrenal vein aldosterone and cortisol levels at 5- and 10-minutes were compared to the referenced 15-minute samples. Results: A total of 46 AVS studies were included. On average, there was an 11- and 9-fold increase in the SI between the pre- and post-ACTH samples on the right and left respectively, indicating appropriate adrenal vein cannulation. Most of the percentage differences between the levels of cortisol and aldosterone at 5- and 10-minutes compared to those at 15-minutes were within 1 standard deviation from the median. There was no significant difference in LI or overall lateralisation between the 5-minute (paired t-test P = 0.18) and the 10-minute sample (paired t-test P = 0.61) compared to the 15-minute sample. The LI at 5-minutes and 10 minutes demonstrated strong correlation with that at 15-minutes. There was one exception where the LI of the 5- and 10-minute samples were discordant with the 15-minute sample, but concordant with the pre-ACTH sample. Conclusion: AVS can be a lengthy and technically challenging procedure. Being able to sample much earlier post-ACTH may help improve procedural efficiency, reduce procedural risks and minimize patient discomfort.