Endocrine Abstracts

Background: Adrenal venous sampling (AVS) is the gold standard to differentiate patients with unilateral primary aldosteronism (UPA) from those with bilateral disease (BPA).

Objective: The aim of this study was to evaluate the efficiency of using the online Integer scoring system in predicting BPA, as a possible surrogate for AVS.

Methods: We performed a retrospective analysis of 105 patients (66 female, median age at diagnosis 53 years (20-75)) treated for primary aldosteronism (PA) in our center between 2015 and 2022. AVS was bilaterally successful in 86 (82 %) patients. According to AVS 58 (55 %) patients were diagnosed as UPA, 37 (35 %) as BPA and in 10 (10 %) the result was inconclusive. The Integer score was calculated in 86 patients, 52 (60 %) diagnosed with UPA and 34 (40 %) with BPA according to AVS. It was based on serum potassium level, sex, imaging finding on CT, baseline plasma aldosterone concentration and baseline aldosterone to renin ratio. The result between 8 and 12 was considered as predictive for BPA.

Results: Of 34 patients diagnosed with BPA using the AVS, the Integer score was diagnostic in 9 of them, giving a positive predictive value of only 26 %. In 50 of 52 patients diagnosed with UPA using the AVS, the Integer score was less than 8, giving a negative predictive value of 96 %. The sensitivity of this scoring system was 82 % and specificity only 67 %.

Conclusion: Our results suggest that Integer scoring system is not applicable for PA subtype prediction in our center and that each center should determine their own score. To the extent that each center does not have a scoring system, AVS remains the only diagnostic method for subtyping PA.