Reassessment of the Adrenal Computed Tomography and Serum Potassium for Subtype Diagnosis of Primary Aldosteronism

Presentation Number: SUN 506
Date of Presentation: April 2nd, 2017

Hironobu Umakoshi*1, Mika Tsuiki1, Isao Kurihara2, Yoshiyu Takeda3, Norio Wada4, Takamasa Ichijo5, Takuyuki Katabami6, Yuichi Fujii7, Masakatsu Sone8, Koichi Yamamamoto9, Kohei Kamemura10, Hirotaka Shibata11, Toshihiko Yanase12, Junji Kawashima13, Katsutoshi Takahashi14, Tetsuya Tagami1, Mitsuhide Naruse15 and Jpas Group15
1National Hospital Organization Kyoto Medical Center, Kyoto, Japan, 2Keio University School of Medicine, Tokyo, Japan, 3Kanazawa University, Ishikawa, Japan, 4Sapporo City General Hospital, Sapporo, Japan, 5Saiseikai Yokohamashi Tobu Hospital, Yokohama, Japan, 6St Marianna University School of Medicine, Yokohama City Seibu Hospital, Yokohama-shi Kanagawa, Japan, 7Hiroshima General Hospital of West Japan Railway Company, Hiroshima, Japan, 8Kyoto University Graduate School of Medicine, Kyoto, Japan, 9Osaka University Graduate School of Medicine, Osaka, Japan, 10Akashi Medical Center, Akashi, Japan, 11Oita University, Yufu-city, Japan, 12Fukuoka University, Fukuoka, Japan, 13Kumamoto University, Kumamoto, Japan, 14The University of Tokyo, Tokyo, Japan, 15National Hospital Organization Kyoto Medical Center

Abstract

Background: Adrenal venous sampling (AVS) is considered to be the criterion standard for subtype diagnosis of primary aldosteronism (PA). However, the number of centers with successful AVS programs are limited because of technical difficulties, invasive nature of testing, and high cost of the procedure and hence AVS should be appropriately indicated in the diagnosis of PA.

Objective: Aim of the present study was to reassess the diagnostic significance of adrenal computed tomography (CT) and serum potassium concentration for subtype diagnosis in PA.

Design, Setting and Patients: A total of 1500 patients with PA who underwent adrenal CT and successful ACTH-stimulated AVS at 24 referral centers in Japan between 2006 and 2016 were studied. Unilateral lesion on CT was defined when the diameter of tumor was greater than 10 mm. Unilateral aldosterone excess on AVS was defined when lateralization index (aldosterone/cortisol dominant/aldosterone/cortisol non-dominant) was greater than 4. We evaluated the diagnostic accuracy of adrenal CT with and without hypokalemia in the subtype diagnosis of PA determined by AVS.

Results: On CT, unilateral adrenal lesion was identified in 43% of the patients, while bilateral adrenal lesion (bilateral tumor or normal adrenal gland) was identified in 57% of the patients. On AVS, 32% of the patients were diagnosed as unilateral subtype of PA and 68% of the patients were diagnosed as bilateral subtype of PA. Of the patients with unilateral adrenal lesion on CT, 50% of the patients were diagnosed as unilateral subtype by AVS. By contrast, of the patients with bilateral adrenal lesion on CT, only 12% of the patients were diagnosed as unilateral subtype of PA by AVS. In addition, percentage of the unilateral subtype by AVS was 70% in patients with unilateral lesion on CT and hypokalemia, 25% in patients with unilateral lesion on CT and normokalemia, 42% in patients with bilateral lesion on CT and hypokalemia, and 8% in patients with bilateral lesion and normokalemia.

Conclusions: The present results clearly demonstrated that CT findings are useful in predicting the probability of the subtype of PA. The unilateral subtype was less than 10% in patients with bilateral lesion on CT when serum potassium concentrations were normal. AVS should be strictly indicated in patients with bilateral lesion on CT and normal serum potassium concentrations.

 

Disclosure: MT: Investigator, ONO-Pharma. TK: Protocol review committee, ONO-Pharma, Investigator, ONO-Pharma. Nothing to Disclose: HU, IK, YT, NW, TI, YF, MS, KY, KK, HS, TY, JK, KT, TT, MN, JG