Scoring system for the diagnosis of bilateral primary aldosteronism in the outpatient setting before adrenal venous sampling

Summary Objective The only reliable method for subtyping primary aldosteronism (PA) is adrenal venous sampling (AVS), which is costly and time‐consuming. Considering the limited availability of AVS, it would be helpful to obtain information on the diagnosis of bilateral hyperaldosteronism (BHA) from routine tests. We aimed to establish new, simple criteria for outpatients to diagnose BHA from PA before AVS. Design We retrospectively analysed 82 patients who were diagnosed with PA and underwent AVS. Thirty‐seven patients were diagnosed with unilateral hyperaldosteronism (UHA), and 36 with BHA and nine were undetermined. Among the variables that were significantly different between UHA and BHA in the univariate analysis, we chose three variables to be included in multivariate logistic regression models and constructed a subtype prediction score. Results The subtype prediction score was calculated as follows: 3 points for no adrenal nodules on computed tomography imaging, 2 for serum potassium of ≥3·5 mmol/l and 2 for aldosterone‐to‐renin ratio of