Abstract No. 386 Adrenal Vein Sampling Results and Surgical Outcomes in Patients with Non-suppressed Plasma Renin Activity

Patients with primary aldosteronism may present with an atypical biochemical profile. The purpose of this study is to describe adrenal vein sampling (AVS) and post-adrenalectomy outcomes in patients with non-suppressed plasma renin activity (PRA) and elevated aldosterone-to-renin ratio (ARR). The study sample included 23 patients with an ARR > 20 and PRA > 1 ng/mL/h ("non-suppressed group") who underwent AVS from 2006-2023. These patients were compared to a randomly selected cohort of 23 patients with an ARR > 20 and PRA < 0.6 ng/mL/h ("suppressed group") who underwent AVS during the same time period. Data regarding baseline clinical characteristics, lateralization indices from AVS, and outcomes after adrenalectomy were analyzed. AVS was technically successful in all 46 patients. The plasma aldosterone concentration in the non-suppressed group was significantly higher compared to the suppressed group (41.2 ng/dL vs. 24 ng/dL, p < 0.001). The ARR in the non-suppressed group was significantly lower compared to the suppressed group (29.9 vs. 109.5, p < 0.001). The proportion of patients in the non-suppressed group who had a lateralization index > 4 was lower than that in the suppressed group, although this did not reach significance (43% vs. 61%, p = 0.38). The mean lateralization index in the non-suppressed group trended lower compared to the suppressed group (8.7 vs. 16.6, p = 0.10). Within the non-suppressed group, patients who lateralized had a significantly higher ARR compared to those who did not (36.4 vs. 27.8, p = 0.04). The proportion of patients in the non-suppressed group who were able to decrease the number of medications in their antihypertensive regimen following adrenalectomy was similar to that of patients in the suppressed group who also underwent surgery (88% vs. 100%, p = 0.62). All hypokalemic patients in both the non-suppressed and suppressed groups who underwent adrenalectomy had normalization of their potassium levels following surgery. Nearly half of patients with non-suppressed PRA lateralized with AVS. The patients who did lateralize had similar blood pressure response and correction of hypokalemia following adrenalectomy, regardless of plasma renin activity. Therefore, patients with a non-suppressed PRA (greater than 1 ng/mL/h) should still be considered for AVS provided the ARR is elevated.