Endocrine Society 2025 diagnostic criteria increase primary aldosteronism detection in hypertensive patients: a comparative study with 2016 guidelines

Primary aldosteronism (PA) is the most common cause of secondary hypertension, associated with disproportionate cardiovascular morbidity. The 2025 Endocrine Society (ES) guidelines revised diagnostic criteria, allowing diagnosis based on a biochemical triad (suppressed renin, elevated aldosterone and aldosterone-to-renin ratio, ARR) without mandatory confirmatory testing. We compared PA detection and diagnostic performance using ES 2016 versus ES 2025 algorithms in hypertensive patients referred to a specialized center. We retrospectively analyzed 137 consecutive patients referred for secondary hypertension work-up to Strasbourg University Hospital (June 2024 - June 2025). All underwent standardized hormonal evaluation and saline infusion testing (SIT). PA was defined according to ES 2016 (ARR >23 ng/mUI with aldosterone ≥200 ng/L, or 90–200 ng/L with positive saline test) and ES 2025 criteria with locally adapted thresholds (ARR >18.7ng/ng, renin ≤6.15 ng/L, aldosterone ≥75 ng/L). PA prevalence increased from 8.8% (n=12) with ES 2016 to 16.1% (n=22) with ES 2025 criteria (p=0.009). Diagnostic concordance was high (91.7%, κ=0.61). Net reclassification improvement ranged from +148% to +175%. Newly identified patients exhibited milder PA phenotypes with less severe/resistant hypertension (27% vs 73%, p=0.03), lower aldosterone levels (95 vs 185 ng/L, p<0.001), and predominantly negative SIT (82%). Despite a 50% false-negative rate, positive SIT remained the only independent predictor of PA diagnosis (OR=3.25, 95%CI 1.22-8.67, p=0.019). ES 2025 criteria increase PA detection by identifying milder forms not captured by previous algorithms. These findings support a phenotype-based diagnostic approach and question the systematic use of confirmatory testing. • ES 2025 criteria nearly doubled PA detection compared with ES 2016 • Diagnostic gain reflects a shift in case definition rather than ARR threshold changes • Newly identified patients show milder phenotypes with preserved aldosterone suppressibility • High false-negative rate of SIT supports reduced reliance on confirmatory testing