SAT-720 Do Discordant Basal And Post Acth Lateralization Indexes In Adrenal Venous Sampling Affect Clinical And Biochemical Outcomes After Adrenalectomy In Primary Aldosteronism?

Abstract S. Larose: None. F. Benadada: None. J. Bejjani: None. M. Dorais: None. I. Bourdeau: None. A. Lacroix: None. E. Therasse: None. Objectives: Many primary aldosteronism (PA) patients present discordant lateralization indexes (LI) between basal and post-ACTH stimulated values during adrenal vein sampling (AVS). Primary study objective: to compare post-adrenalectomy clinical and biochemical outcomes of patients with concordant and discordant LI. Secondary objective: to identify other favorable post-adrenalectomy outcome predictors in AVS data. Materials and methods: retrospective cohort study including all PA patients who underwent bilateral, simultaneous basal and post-250 mcg ACTH bolus AVS (11-1990 to 06-2022). Post-adrenalectomy follow-up data (at 6-12 months) was available in 170 patients; 108 women, 62 men; median age 51.2 years (Q1:43.8- Q3:59.1). Clinical and biochemical outcomes following unilateral adrenalectomy were analyzed using PASO criteria and were compared between patients with concordant LI (basal and post-ACTH LI >= 4) or discordant LI (basal LI >= 4 and post-ACTH LI < 4 or basal LI < 4 and post-ACTH LI >= 4). The null hypothesis was tested with the Chi square test/ Fisher’s exact test. ROC curves were used to identify other potential favorable outcome predictors. Results: Complete biochemical cure and biochemical improvement rates in the 136 patients with concordant LI (respectively 84.4% and 91.2%) were significantly higher than in the 27 patients with discordant LI (respectively 48.2% and 63.0%), (p<0.001 for both comparisons). However, complete clinical cure and clinical improvement rates in concordant LI (respectively 33.1% and 83.1%) were not significantly higher than in discordant LI (respectively 22.2% and 74.1%), (p=0.27 for both comparisons). Among other potential clinical outcomes predictors, a basal LI >= 16.4 (sensitivity 65.2%, specificity 62.7%) and post-stimulation LI >= 16.1 (sensitivity 65.4%, specificity 71.2%) predicted complete clinical cure on ROC curves (p= 0.0009 and p<0.0001, respectively). Finally, basal contralateral aldosterone to peripheral aldosterone ratio (basal Ac/Ap) of =< 1.79 had the best sensitivity (57.7%) and specificity (67.8%) for complete clinical cure on ROC curves (p= 0.0021). Conclusions: After adrenalectomy, biochemical outcome was significantly better in PA patients with concordant than with discordant LI basal and post-ACTH stimulated AVS. However, LI and basal Ac/Ap are better predictors of clinical outcome than basal and post-stimulation AVS concordance. Saturday, June 1, 2024