European Society of Endocrinology 2025 Criteria Double Primary Aldosteronism Detection in Hypertensive Patients: A Single-Center Retrospective Study

Objective: Primary aldosteronism is the most common cause of secondary hypertension, affecting up to 10% of hypertensive patients with disproportionate cardiovascular morbidity. The 2025 European Society of Endocrinology guidelines fundamentally revised diagnostic criteria by abandoning mandatory confirmatory testing in favor of a biochemical phenotype-driven approach. We compared primary aldosteronism prevalence and diagnostic performance using 2016 versus 2025 algorithms in hypertensive patients referred to a specialized center. Design and method: We retrospectively analyzed 137 consecutive patients referred for secondary hypertension work-up between June 2024 and June 2025. Plasma renin, aldosterone, and aldosterone-to-renin ratio were assessed before and after saline loading. Primary aldosteronism was defined according to 2016 criteria and 2025 criteria using locally validated thresholds. Results: rimary aldosteronism prevalence increased from 8.8% with 2016 criteria to 16.1% with 2025 criteria (p=0.009), representing a 92% relative increase. Diagnostic concordance reached 91.7% (k=0.61). Net reclassification improvement ranged from +148% to +175%. Newly diagnosed patients exhibited milder phenotypes with less severe/resistant hypertension (27% vs 73%, p=0.03), lower baseline aldosterone levels (95 vs 185 ng/L, p<0.001), and 82% negative saline infusion tests versus 18% in classical cases (p=0.002). Among 2025-diagnosed patients, 91% of newly identified cases showed intermediate lateralization probability, suggesting predominantly bilateral disease requiring medical management. The saline infusion test demonstrated a 50% false-negative rate. Despite this limitation, positive saline test remained the sole independent predictor of primary aldosteronism diagnosis (OR=3.25, 95%CI 1.22-8.67, p=0.019). Conclusions: The 2025 criteria nearly double primary aldosteronism detection by identifying milder phenotypes characterized by lower aldosterone levels and negative confirmatory tests. The high saline infusion test false-negative rate supports abandoning mandatory confirmatory testing. Implementation requires laboratory-specific threshold validation and prospective studies to confirm cardiovascular benefits of earlier identification.