PS-C22-6: PERFORMANCE OF PREDICTION ALGORITHM FOR THE SUBTYPE DIAGNOSIS OF PRIMARY ALDOSTERONISM WHICH WAS ADVOCATED IN THE JAPAN PRIMARY ALDOSTERONISM STUDY

Abstract

Objective: In the part of the Japan Primary Aldosteronism Study (JPAS), the prediction algorithm for the subtype diagnosis of primary aldosteronism (PA) was advocated and published in 2018 (Umakoshi.H et.al, J Clin Endocrinol Metab, 2018, 103(3):900–908). In the algorithm, patients with PA with bilateral normal results on CT and normokalemia likely have a low prior probability of a lateral form of PA in AVS (6.2%) and could be treated medically, whereas those with unilateral visible mass on CT and presence of hypokalemia have a high probability of a lateralized form of PA in AVS (70.6%). To validate the efficacy of the algorithm, we applied the algorithm for recent PA cases in our institute, Keio University hospital. Patients: A total of 77 patients with PA who underwent adrenal venous sampling (AVS) between November 2018 and October 2019 were enrolled in this study. They were classified into four groups according to CT findings and potassium status. Subtype diagnosis of PA was determined by AVS. Results: In our case, the prevalence for unilateral hyperaldosteronism on AVS was as follows: CT-negative with normokalemia, 7.9%; CT-positive with normokalemia, 15.4%; CT-negative with hypokalemia 22.2%, and CT-positive, 71.4%. The results were quite similar to the results in the previous report. In the algorithm, it was stated that AVS could be spared in patients with unilateral lesion on CT and hypokalemia if they were younger than 35 years, however, in our cases, there was one patient whose age was 30 with unilateral lesion on CT and hypokalemia and the AVS result of whom indicated bilateral PA. In the algorithm, it was also stated that AVS could be spared in patients with bilateral lesions on CT and normokalemia if plasma aldosterone concentration was less than 8 ng/dl and it was consistent in our cases. Conclusion: Overall, the prediction algorithm for the subtype diagnosis of PA developed in JPAS could be applied well in our recent PA cases.