SUN-245 - Evaluation of Hyperaldosteronism in A US Cohort.

The Endocrine Society suggests that individuals with hypertension should be screened for primary aldosteronism (PA) with plasma aldosterone concentrations (PAC) and plasma renin [activity] (PRA). Those with a high probability of unilateral primary aldosteronism (UPA) should have a CT scan of the adrenals and adrenal vein sampling (AVS). Evidence-based trials on AVS for UPA from Europe and Asia do not include African Americans (AA) who have “salt sensitive” hypertension. We reviewed these guidelines in a US-based population. We performed post hoc analyses for predicting “high probability” of a UPA. AVS depends on the technical expertise to catheterize the right adrenal vein. We evaluated the positive predictive value (PPV) of RASI [Relative Aldosterone Secretion Index= Ratio of left AV Aldosterone (A)/Cortisol (C) vs inferior vena cava A/C] for localization of ipsilateral and contralateral UPA.

Methods: Data from a convenience sample were retrieved from an electronic health record (EHR) of patients who had PAC /PRA determinations from Jan 1, 2023, through Dec 31, 2024. We compared outcomes by binary logistic regression analysis (BLRA).

Results: There were 120 Whites (Wh) and 183 AA patients. Although AA vs Wh had similar PAC, AA had lower PRA (1.4± 2.42 vs 2.34 ± 3.4 ng/mL/h, P=0.004) and higher log transformed Aldosterone: Renin: Ratios (LnARR 2.71 ±1.45 vs 2.17 ±1.74, p=0.004). The higher LnARR in AA suggested a greater responsiveness of aldosterone to renin. LnARR progressed with increasing age (r=0.135, p< 0.001) and was consistently greater in AA. Three patients aged < 35, with PAC >20ng/dL, and a unilateral adrenal nodule >10mm (UAN10mm) were referred for surgery without AVS. Thirty-five underwent AVS after consensus of the patient and provider. Those who had AVS had higher PAC (44.7± 36.4 vs 11.6 ±11.1 ng/dL , p< 0.001) and lower PRA (0.34± 0.23 vs 1.97 ±2.94, ng/dL/h, p< 0.001) than those who did not have AVS. Of those who had AVS, 18 had UPA and 17 had bilateral adrenal hyperplasia (BAH). Post hoc BLRA showed the PPV for UPA was best defined by a composite score of baseline LnARR (p < 0.001) plus UAN10mm (p=0.001). Thus, for a LnARR of 6.25, the PPV for UPA was 90% with UAN10mm but only 34% without a nodule. In patients who had AVS, there was a PPV of 90% for an ipsilateral left UPA with a composite score of RASI (p=0.01) plus UAN10mm (p=0.08). A composite score of suppressed RASI (p=0.03) plus UAN10mm (p=0.08) had a lower PPV of 70% for a contralateral right UPA. Summary: In this US cohort, AA compared to Wh had an increased aldosterone responsiveness to renin as determined by LnARR, which increased with age, and was consistently greater in AA. An effective predictor for the PPV of UPA was a composite score of LnARR plus UAN10mm. In those who had AVS, a composite score of RASI with UAN10mm had a high PPV for a left sided UPA, but a composite score of suppressed RASI with UAN10mm was less reliable to predict a contralateral right UPA.

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