THU568 The Impact of Surgical versus Medical Therapy on Renin Plasma Activity, Renal Function, and Hypertension Control in Patients with Primary Aldosteronism

Disclosure: S. Rolak: None. N. Venkatesan: None. R. Gregg Garcia: None. W.F. Young: None. I. Bancos: None. Background: Bilateral primary hyperaldosteronism (PA) is treated with mineralocorticoid receptor antagonist (MRA) therapy. However, the best way to monitor the success of MRA therapy is unclear. Aims: To compare the impact of curative adrenalectomy versus MRA therapy in patients with PA on plasma renin activity (PRA), renal function, and hypertension control. Methods: Single center retrospective study of patients with unilateral PA treated with adrenalectomy or bilateral PA treated with MRAs, 2017-2021. Patients underwent adrenal vein sampling to confirm laterality. Hypertension control was defined based on blood pressure measurements and the standardized hypertension daily dose (HDD). Minimum follow-up was defined as first nonsuppressed PRA or >1 month from therapy. Results: Of 73 patients, 53 underwent unilateral adrenalectomy for unilateral PA (median age 57, range 25-71 years, 36% women) and 20 had bilateral PA treated with MRA (median age 49, range 30-70 years, 70% women). At baseline, when compared to the bilateral PA, patients with unilateral PA had higher plasma aldosterone concentrations (median 31 ng/dL vs 19 ng/dL, P= 0.001), similarly suppressed PRA, and similar estimated glomerular filtration rate (eGFR). Uncontrolled hypertension (>130/90 mmHg) was seen in 40 (75%) of patients with unilateral PA and 14 (70%) patients with bilateral PA, despite a more intensive antihypertensive regimen in unilateral PA (median HDD 5, range 1-18 vs median HDD 3.5 in bilateral PA, range 0.5-9; P=0.016). Hypokalemia was present in 50 (94%) patients with unilateral PA and 15 (75%) in bilateral PA, P = 0.02.Following treatment, hyperkalemia developed in 10 (19%) patients post-adrenalectomy and in 2 (10%) patients treated with MRAs, P = 0.36. At a median follow up of 108 days, 24 (45%) patients treated with adrenalectomy and 16 (80%) patients treated with MRAs demonstrated PRA >1.5 ng/mL/hr, P = 0.008. eGFR decreased by at least 10 points in 15 (30%) patients treated with adrenalectomy vs in 11 (59%) patients treated with MRAs (P=0.033). Post-adrenalectomy, antihypertensive management lessened by a median of 2.5 HDD, while HDD increased in patients treated with MRAs by a median of 1.25, P<0.0001. Hypertension control improved, with a mean decrease in systolic blood pressure of -11 mmHg (95%CI -16.5-(-5.5)) without between group differences. Diastolic blood pressure decreased by a mean of -4.7 mmHg (95%CI -8.7-(-0.7)) in the adrenalectomy group but did not change in those treated with MRAs. Conclusions: Following curative adrenalectomy in unilateral PA, more than half of patients continue to have suppressed PRA. Despite less severe PA at baseline, patients treated with MRAs, as compared to those treated with adrenalectomy, demonstrate a higher prevalence of non-suppressed PRA, lower eGFR, similar hypertension control, and a more intense antihypertensive regimen during follow up. Presentation: Thursday, June 15, 2023