[Re-validation of the prediction model for unilateral primary aldosteronism].

Objective

To re-evaluate the diagnostic efficacy of the Chongqing Primary Aldosteronism Study (CONPASS) model for unilateral primary aldosteronism (UPA).

Methods

This retrospective study included patients with primary aldosteronism (PA) who underwent subtyping via adrenal venous sampling, postoperative outcomes, or both, between April 2022 and June 2025 at the First Affiliated Hospital of Chongqing Medical University. The accuracy of the CONPASS model (comprising serum potassium ≤3.5 mmol/L, plasma aldosterone concentration ≥200 pg/ml, plasma renin concentration ≤5 mU/L, and a unilateral adrenal nodule ≥10 mm on CT) was assessed by calculating sensitivity, specificity, positive predictive value, negative predictive value, and the corresponding 95% confidence intervals (CI). The diagnostic efficacy of the CONPASS model was subsequently compared with that achieved using the Endocrine Society clinical practice guidelines-recommended approach (comprising typical clinical features, age <35 years, and a unilateral adrenal nodule >1 cm on CT).

Results

A total of 267 patients with a definitive subtyping diagnosis (151 with UPA and 116 with bilateral PA) were enrolled. The cohort comprised 145 females (54.3%), aged 25 to 76 years, with a median age of 51 years. The CONPASS model demonstrated a sensitivity of 31.8% (48/151) (95%CI 24.5%-39.9%) and a specificity of 98.3% (114/116) (95%CI 93.9%-99.8%). The predictive value was 96.0% (48/50) (95%CI 86.3%-99.5%), and negative predictive value was 52.5% (114/217) (95%CI 45.7%-59.3%). In comparison, application of the guideline-recommended criteria achieved a specificity of 100.0% (116/116) (95%CI 96.9%-100.0%) but a sensitivity of only 2.0% (3/151) (95%CI 0.4%-5.7%). This represents a significantly lower identification rate for UPA relative to the CONPASS model. Among the UPA patients correctly identified by the CONPASS model, 93.8% (45/48) were ≥35.

Conclusions

This study further validates the high diagnostic accuracy of the CONPASS model. Eliminating the age restriction present in current guideline criteria permits the identification of a larger proportion of UPA patients who are candidates for surgical intervention.