Importance of Contralateral Aldosterone Suppression During Adrenal Vein Sampling in the Subtype Evaluation of Primary Aldosteronism

Hironobu Umakoshi; Kanako Tanase-Nakao; Norio Wada; Takamasa Ichijo; Masakatsu Sone; Nobuya Inagaki; Takuyuki Katabami; Kohei Kamemura; Yuichi Matsuda; Yuichi Fujii; Tatsuya Kai; Tomikazu Fukuoka; Ryuichi Sakamoto; Atsushi Ogo; Tomoko Suzuki; Mika Tsuiki; Akira Shimatsu; Mitsuhide Naruse

Disclosures

Clin Endocrinol. 2015;83(4):462-467. 

In This Article

Abstract and Introduction

Abstract

Objectives Adrenal vein sampling (AVS) is the standard criterion for the subtype diagnosis in primary aldosteronism (PA). Although lateralized index (LI) ≥4 after cosyntropin stimulation is the commonly recommended cut-off for unilateral aldosterone hypersecretion, many of the referral centres in the world use LI cut-off of <4 without sufficient evidence for its diagnostic accuracy.

Aim The aim of the study was to establish the diagnostic significance of contralateral (CL) aldosterone suppression for the subtype diagnosis in patients with LI <4 in AVS.

Design and patients A retrospective multicentre study was conducted in Japan. Of 124 PA patients subjected to unilateral adrenalectomy after successful AVS with cosyntropin administration, 29 patients with LI < 4 were included in the study. The patients were divided into Group A with CL suppression (n = 16) and Group B (n = 13) without CL suppression. Three outcome indices were assessed after 6 months postoperatively: normalization/significant improvement of hypertension, normalization of the aldosterone to renin ratio (ARR) and normalization of hypokalaemia.

Results The normalization/significant improvement of hypertension was 81% in Group A and 54% in Group B (P = 0·2). The normalization of ARR was 100% in Group A and 46% in Group B (P = 0·004). Hypokalaemia was normalized in all patients of both groups. The overall cure rate of PA based on meeting all the three criteria was 81% in Group A and 31% in Group B (P = 0·01).

Conclusions In patients with PA, where the LI is <4 on AVS, CL suppression of aldosterone is an accurate predictor of a unilateral source of aldosterone excess. CL suppression data should be interpreted in conjunction with computed tomographic adrenal imaging findings to guide surgical management.

Introduction

Primary aldosteronism (PA) is the most common cause of curable endocrine hypertension, accounting for 5% to 10% of hypertensive patients.[1,2] The major subtypes of PA are unilateral aldosterone-producing adenoma (APA) and bilateral idiopathic hyperaldosteronism (BHA).[3] Adrenal vein sampling (AVS) is accepted as the standard reference method for subtype testing in PA because of its superiority to adrenal imaging modalities in its sensitivity and specificity.[4,5]

However, the decision criteria of AVS have not been fully established. Rossi et al.[6] demonstrated in the Adrenal Vein Sampling International Study (AVIS) a diversity of diagnostic criteria with the lateralization index (LI) being the most widely used criterion in subtype diagnosis of PA. In addition, two recent expert consensus statements on AVS reported that patients with LI ≥ 4 after cosyntropin stimulation have a certain diagnosis of unilateral aldosterone hypersecretion.[7,8] The majority of the referral centres in the world, however, on occasion use LI < 4 with insufficient evidence to support diagnostic specificity.[6] Some investigators have reported that contralateral (CL) suppression is useful for distinguishing between unilateral APA and BHA.[9,10] Although Monticone et al.[11] reported that CL suppression was not associated with postsurgical outcome in patients with LI ≥ 4, recent consensus statements reported that CL suppression could aid subtype diagnosis in patients with LI < 4.[8] However, there is currently insufficient evidence to establish the value of CL suppression relative to LI.

The aim of this study was to establish the diagnostic significance of CL suppression in patients with LI < 4. To this end, we investigated the relationships between CL suppression and postsurgical outcome in patients with PA.

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