We sought to measure the clinical benefits of adrenal venous sampling (AVS), a test recommended by guidelines for primary aldosteronism (PA) patients seeking surgical cure, in a large registry of PA patients submitted to AVS. Data of 1625 consecutive patients submitted to AVS in 19 tertiary referral centers located in Asia, Australia, Europe, and North America were collected in a large multicenter international registry. The primary end points were the rate of bilateral success, ascertained lateralization of PA, adrenalectomy, and of cured arterial hypertension among AVS-guided and non AVS-guided adrenalectomy patients. AVS was successful in 80.1% of all cases but allowed identification of unilateral PA in only 45.5% by the criteria in use at each center. Adrenalectomy was performed in 41.8% of all patients and cured arterial hypertension in 19.6% of the patients, 2-fold more frequently in women than men ( P <0.001). When AVS-guided, surgery provided a higher rate of cure of hypertension than when non-AVS-guided (40.0% versus 30.5%; P =0.027). Compared with surgical cases, patients treated medically needed more antihypertensive medications ( P <0.001) and exhibited a higher rate of persistent hypokalemia requiring potassium supplementation (4.9% versus 2.3%; P <0.01). The low rate of adrenalectomy and cure of hypertension in PA patients seeking surgical cure indicates suboptimal AVS use, possibly related to issues in patient selection, technical success, and AVS data interpretation. Given the better outcomes of AVS-guided adrenalectomy, these results call for actions to improve the diagnostic use of this test that is necessary for detection of surgical PA candidates. Clinical Trial Registration—: URL: http://www.clinicaltrials.gov . Unique identifier: NCT01234220.
20 September 2019 in The Journal of Clinical Endocrinology & Metabolism
Context: Adrenal venous sampling (AVS) is the key test for subtyping primary aldosteronism (PA), but its interpretation varies widely across referral centers and this can adversely affect the management of PA patients. Objectives: To investigate in a real-life study the rate of bilateral success and identification of unilateral aldosteronism and their impact on blood pressure outcomes in PA subtyped by AVS. Design and settings: In a retrospective analysis of the largest international registry of individual AVS data (AVIS-2 study), we investigated how different cut-off values of the selectivity index (SI) and lateralization index (LI) affected rate of bilateral success, identification of unilateral aldosteronism, and blood pressure outcomes. Results: AVIS-2 recruited 1625 individual AVS studies performed between 2000 and 2015 in 19 tertiary referral centers. Under unstimulated conditions, the rate of biochemically confirmed bilateral AVS success progressively decreased with increasing SI cut-offs; furthermore, with currently used LI cut-offs, the rate of identified unilateral PA leading to adrenalectomy was as low as <25%. A within-patient pairwise comparison of 402 AVS performed both under unstimulated and cosyntropin-stimulated conditions showed that cosyntropin increased the confirmed rate of bilateral selectivity for SI cut-offs ≥ 2.0, but reduced lateralization rates (P < 0.001). Post-adrenalectomy outcomes were not improved by use of cosyntropin or more restrictive diagnostic criteria. Conclusion: Commonly used SI and LI cut-offs are associated with disappointingly low rates of biochemically defined AVS success and identified unilateral PA. Evidence-based protocols entailing less restrictive interpretative cut-offs might optimize the clinical use of this costly and invasive test. (J Clin Endocrinol Metab XX: 0-0, 2020)
Purpose: Aldosterone-producing adenoma (APA) is the main curable cause of endocrine hypertension cause of primary aldosteronism (PA) and it is in up to 66% of all cases investigated with adrenal vein sampling (AVS). Mutations in the KCNJ5 potassium channel involve up to 70% of APA and cause the most florid PA phenotypes. The recent finding that macrolide antibiotics specifically inhibit in vitro the altered function of mutated KCNJ5 channels has opened new horizons for the diagnosis and treatment of APA with KCNJ5 mutations in that it can allow identification and target treatment of PA patients harbouring a mutated APA. Thus, we aimed at investigating if clarithromycin and roxithromycin, two macrolides that potently blunt mutated Kir3.4 channel function in vitro, affect plasma aldosterone concentration in adrenal vein blood during AVS and in peripheral blood, respectively, in PA patients with a mutated APA. Methods and design: We designed two proof of concept studies. In study A: consecutive patients with an unambiguous biochemical evidence of PA will be exposed to a single dose of 250 mg clarithromycin during AVS, to assess its effect on the relative aldosterone secretion index in adrenal vein blood from the gland with and without APA. In study B: consecutive hypertensive patients submitted to the work-up for hypertension will receive a single oral dose of 150 mg roxithromycin. The experimental endpoints will be the change induced by roxithromycin of plasma aldosterone concentration and other steroids, direct active renin concentration, serum K+, systolic and diastolic blood pressure. Discussion: We expect to prove that: (i) clarithromycin allows identification of mutated APA before adrenalectomy and sequencing of tumour DNA; (ii) the acute changes of plasma aldosterone concentration, direct active renin concentration, and blood pressure in peripheral venous blood after roxithromycin can be a proxy for the presence of an APA with somatic mutations.
The pulsatile secretion of adrenocortical hormones and a stress reaction occurring when starting adrenal vein sampling (AVS) can affect the selectivity and also the assessment of lateralization when sequential blood sampling is used. We therefore tested the hypothesis that a simulated sequential blood sampling could decrease the diagnostic accuracy of lateralization index for identification of aldosterone-producing adenoma (APA), as compared with bilaterally simultaneous AVS. In 138 consecutive patients who underwent subtyping of primary aldosteronism, we compared the results obtained simultaneously bilaterally when starting AVS (t-15) and 15 min after (t0), with those gained with a simulated sequential right-to-left AVS technique (R ⇒ L) created by combining hormonal values obtained at t-15 and at t0. The concordance between simultaneously obtained values at t-15 and t0, and between simultaneously obtained values and values gained with a sequential R ⇒ L technique, was also assessed. We found a marked interindividual variability of lateralization index values in the patients with bilaterally selective AVS at both time point. However, overall the lateralization index simultaneously determined at t0 provided a more accurate identification of APA than the simulated sequential lateralization indexR ⇒ L (P = 0.001). Moreover, regardless of which side was sampled first, the sequential AVS technique induced a sequence-dependent overestimation of lateralization index. While in APA patients the concordance between simultaneous AVS at t0 and t-15 and between simultaneous t0 and sequential technique was moderate-to-good (K = 0.55 and 0.66, respectively), in non-APA patients, it was poor (K = 0.12 and 0.13, respectively). Sequential AVS generates factitious between-sides gradients, which lower its diagnostic accuracy, likely because of the stress reaction arising upon starting AVS.