MON-285 Impact of Potassium-Sparing Diuretics on Adrenal Vein Sampling and Intervention Outcomes

Abstract Disclosure: N. Sharma: None. M. Neff: None. J. Lin: None. J. Foster: None. J. Sandhu: None. E. Hilborn: None. E. Garcia: None. Z.C. Hannoush: None. A. Ayala: None. S. Rodgers: None. Z. Miller: None. Introduction: Potassium-sparing diuretics (KSD), such as spironolactone and eplerenone, preserve serum potassium levels but elevate renin, altering the aldosterone-to-renin ratio (A:R). Adrenal vein sampling (AVS) differentiates unilateral aldosterone-producing adenomas from bilateral adrenal hyperplasia in primary aldosteronism. Ongoing KSD use during AVS may lower the lateralization index, complicating interpretation, and increasing misdiagnosis risk. Although guidelines recommend stopping KSD before AVS, issues like rebound hypokalemia may necessitate continued use. This study evaluates the effects of KSD on lab values, lateralization, and clinical outcomes in AVS patients. We hypothesize that KSD use during AVS does not significantly affect clinical outcomes. This study compares pre-procedure lab values, imaging, surgical, and BP outcomes in patients on vs. off KSD to refine AVS protocols. Methods: A retrospective study was conducted with 75 AVS patients, grouped by KSD use (30 on, 45 off). Pre-procedure labs, including serum sodium (Na), potassium (K), plasma aldosterone concentration (PAC), plasma renin concentration (PRC), and A:R, were collected. Blood pressure (BP) was measured before and after AVS-guided adrenalectomy. A Mann-Whitney U test analyzed K and BP changes within 3 months pre- and post-adrenalectomy. Statistical significance was p < 0.05. Results: Among 75 patients, 31 underwent adrenalectomy with 64.5% on KSD. The gender ratio was M:F = 2:3. Median age 59.0 (IQR 53.0-66.0), antihypertensive use 3.0 (IQR 2.0-4.0), pre-procedure Na 141.0 (IQR 139.0-142.0), pre K 4.0 (IQR 3.5-4.4), pre PAC 21.5 (IQR 15.25-34.25), A:R ratio 86.1 (IQR 55.58-98.90), pre adrenalectomy systolic BP 142.0 (IQR 126.0-154.0), pre diastolic BP 82.0 (IQR 75.0-90.0). Post adrenalectomy K median 4.7 (IQR 4.4-5.0), post systolic BP 131.0 (IQR 122.0-136.0), post diastolic BP 83.0 (IQR 71.0-87.0). Comparative analysis showed no significant change in K levels post-adrenalectomy for KSD vs non-KSD (p = 0.546). No significant BP changes were observed (systolic p = 0.67; diastolic p = 0.136). These findings indicate that while KSD may increase serum potassium levels, the impact is not significant. Conclusion: Our findings suggest that KSD use before AVS-guided adrenalectomy does not significantly alter potassium levels post-procedure and no significant differences were observed in systolic or diastolic BP outcomes, suggesting that KSD use does not impact the final clinical outcome post-adrenalectomy. Our study indicates that KSD use should not influence procedural decision-making, as its discontinuation does not alter post-surgical BP outcome. This challenges the necessity of strict pre-AVS discontinuation protocols, and further research is needed to assess whether current guidelines for AVS should be revised for patients needing ongoing KSD therapy. Presentation: Monday, July 14, 2025