6808 Effect of Corticosteroid Premedication on Adrenal Vein Sampling in Patients with Primary Aldosteronism and Iodine Contrast Allergy

Abstract Disclosure: S. Mohan: None. O.A. Shariq: None. J.C. Andrews: None. W.F. Young: None. Background: Adrenal vein sampling (AVS) is performed in patients with primary aldosteronism (PA) to subtype surgically curable unilateral disease. During AVS, iodinated contrast is used to confirm catheterization of adrenal veins for accurate sampling. However, in patients with severe contrast allergy, the optimal method of safely and effectively confirming localization is debatable. Premedication with oral corticosteroids has raised concern for suppression of cortisol and confounding of AVS results. We therefore investigated our experience of AVS after corticosteroid premedication in patients with PA and iodine contrast allergy. Methods: Patients with PA who underwent AVS at our center under continuous cosyntropin infusion (50 mcg/hr started 30 minutes before sampling) between September 1990 - October 2023 were identified. Individuals with documented allergy to iodinated contrast who received corticosteroid premedication were matched 1:1 for age and sex with control patients without contrast allergy or premedication. Baseline demographics, biochemical variables, AVS results, and follow-up data were compared between groups. Results: 1273 AVS studies were performed in 1255 patients with PA and 35 (2.8%) patients received corticosteroid premedication for contrast allergy. Methylprednisolone was used in 32 (91.4%) patients while dexamethasone was used in the rest. No patients experienced a severe breakthrough allergic reaction. Mean age was similar in cases vs. controls (53.9 vs. 54.1 years, P=0.92) with 16 females (45.7%) per group. There were no significant differences in baseline aldosterone-to-renin ratios (57.7 vs. 49.3, P=0.57) or daily defined doses of antihypertensives (5.5 vs. 4.4, P=0.21) between the two groups. Absolute cortisol levels (mcg/dL) from both adrenal veins (AV) and the inferior vena cava (IVC) were similar between cases and controls (right AV: 752.5 vs. 813.7, P=0.48; left AV: 527.2 vs. 462.7, P=0.33; IVC: 23.1 vs. 24.5, P=0.18). The ratio of cortisol in the corresponding AV to the IVC (selectivity index) was >5 in all patients, confirming appropriate cannulation, with similar mean selectivity indices between groups (right AV: 33.0 vs. 33.7, P=0.86; left AV: 22.8 vs. 19.0 P=0.17). Unilateral disease (indicated by a lateralization index >4) was present in 20 (57.1%) patients who received premedication compared with 16 (45.7%) controls (P=0.34). Surgery for unilateral disease was performed in 16 cases and 12 controls, with similar post-op day 1 aldosterone levels in both groups (3.8 vs. 3.3, P=0.36), consistent with surgical cure. Conclusion: In patients with PA and iodine contrast allergy, premedication with corticosteroids prior to cosyntropin-stimulated AVS does not significantly suppress cortisol levels or affect interpretation of AVS results, with comparable rates of disease subtyping and surgical outcomes when compared to a control group. Presentation: 6/3/2024