A stress reaction affects assessment of selectivity of adrenal venous sampling and of lateralization of aldosterone excess in primary aldosteronism

Background: A stress reaction involving increased cortisol release, which has not been documented thus far, might affect the assessment of selectivity of catheterization during adrenal venous sampling (AVS). Objective: To investigate whether an ACTH-driven cortisol release occurs during AVS and whether it influences the assessment of selectivity by the step-up of cortisol (plasma cortisol concentrations, PCC) between the adrenal vein blood (PCCSIDE) and the inferior vena cava (PCCIVC), e.g. the selectivity index (SI). Design and methods: We determined the SI in samples obtained simultaneously at starting AVS (t-15) and again after 15 min (t0) in 34 consecutive patients with proven aldosterone-producing adenoma. We then calculated the SI with PCCSIDE obtained at t-15 and at t0, and the PCCIVC values obtained at the different time point, thus simulating sequential AVS. Results: The PCCSIDE and the SI fell significantly from t-15 to t0 on both the sides. When PCCSIDE obtained at t-15 was combined with PCCIVC at t0, the SI values were higher than those obtained with simultaneously drawn samples. This led to label as selective more AVS studies than with bilaterally simultaneous data, especially when using higher cutoffs for the SI. Conclusions: A transient increase in cortisol release from both adrenal glands occurs in the majority of the patients who undergo AVS. This stress reaction can influence the assessment of both the selectivity of the catheterization during the sequential AVS technique and the lateralization of aldosterone excess.