MON-291 A Study Of Adrenal Venous Sampling In Primary Aldosteronism With Cortisol Autonomic Secretion

Abstract Disclosure: S. Konishi: None. M. Kometani: None. D. Aono: None. M. Kadono: None. S. Karashima: None. K. Furukawa: None. Y. Takeda: None. T. Yoneda: None. Background: In the subtype diagnosis of primary aldosteronism (PA) using adrenal venous sampling (AVS), cases with cortisol autonomous secretion may affect the interpretation of AVS results, such as a decrease in the aldosterone/cortisol ratio (A/C) in the adrenal vein on the cortisol-dominant side, a decrease in the Selectivity Index (SI) on the side opposite the cortisol-dominant side, and an effect on the Lateralized Ratio (LR) due to a decrease in A/C . The aim of this study was to analyze the results of AVS using the PA protocol from the perspective of the presence of cortisol autonomous secretion, and to evaluate the effects on SI and LR. Methods: We retrospectively analyzed 227 patients who underwent AVS (with ACTH stimulation by intravenous injection) for PA and 1 mg dexamethasone suppression test (1 mg DST) at Kanazawa University Hospital between 2011 and 2020. We divided them into three groups based on 1 mg DST cortisol (nmol/L) values: ≥138 (Group 1), 50-137 (Group 2), and <50 (Group 3) (13, 34, and 180 patients). Aldosterone was measured using the RIA method. The Mann-Whitney U test and chi-square test were used for statistical analysis. Results: The rates of achieving SI>2 before ACTH loading and SI>5 after ACTH loading were 53.8% and 84.6%, respectively, in Group 1, 76.3% and 88%, respectively, in Group 2, and 84% and 94%, respectively, in Group 3. SI before ACTH loading was significantly lower in Group 1 than in Group 3, but there was no significant difference between the other groups. LR was 19.0 and 18 .4, 15.7, 23.6 (Group 2) and 5.53, 4.35 (Group 3), and Group 2 before ACTH loading was significantly higher than Group 3, and Groups 1 and 2 after ACTH loading were significantly higher than Group 3. Conclusion: In the 1 mg DST non-suppression group, SI was found to decrease and LR to increase compared to the 1 mg DST suppression group. In the future, we will report the results of additional analyses of surgical cases. Presentation: Monday, July 14, 2025