Subtyping of primary aldosteronism with adrenal vein sampling: Hormone- and side-specific effects of cosyntropin and metoclopramide

Aberrant hormone receptors regulate a wide spectrum of endocrine tumors

Aberrant G-protein coupled receptor (GPCR) expression is highly prevalent in cortisol-secreting primary bilateral macronodular adrenal hyperplasia (PBMAH) and unilateral adenomas. The aberrant expression of diverse GPCRs and their ligands play an important role in the over-function of various endocrine tumours. Examples include aberrant expression of MC2R, 5-HT4R, AVPR1A, LHCGR, and GnRHR in primary aldosteronism; GCGR, LHCGR, and 5-HT4R in phaeochromocytomas and paragangliomas; TRHR, GnRHR, GIPR, and GRP101 in pituitary somatotroph tumours; AVPR2, D2DR, and SSTR5 in pituitary corticotroph tumours; GLP1R, GIPR, and somatostatin receptors in medullary thyroid carcinoma; and SSTRs, GLP1R, and GIPR in other neuroendocrine tumours. The genetic mechanisms causing the ectopic expression of GIPR in cortisol-secreting PBMAHs and unilateral adenomas have been identified, but distinct mechanisms are implicated in other endocrine tumours. Development of functional imaging targeting aberrant GPCRs should be useful for identification and for specific therapies of this wide spectrum of tumours. The aim of this review is to show that the regulation of endocrine tumours by aberrant GPCR is not restricted to cortisol-secreting adrenal lesions, but also occurs in tumours of several other organs.

Effect of adrenocorticotropic hormone stimulation during adrenal vein sampling for the subtyping of primary aldosteronism: a prospective study

OBJECTIVE

Adrenal venous sampling (AVS) is key for primary aldosteronism subtype identification. However, the value of adrenocorticotropic hormone (ACTH) stimulation in AVS is still controversial.

METHODS

In this prospective study, we investigated the role of continuous ACTH infusion on the performance and interpretation of bilateral simultaneous AVS using a standard protocol in 59 primary aldosteronism patients. We analyzed the selectivity index and lateralization index in AVS pre and post-ACTH and estimated the prognosis of patients who underwent adrenalectomy with different cutoff points of lateralization index post-ACTH.

RESULTS

The confirmed success rate of bilateral adrenal vein catheterization increased from 84% pre-ACTH to 95% post-ACTH. Fifty percent of the patients had a decline in lateralization index post-ACTH, 30% of patients showed unilateral primary aldosteronism pre-ACTH but bilateral primary aldosteronism post-ACTH according to lateralization index at least 2 pre-ACTH and lateralization index at least 4 post-ACTH. The outcomes of the patients with primary aldosteronism after adrenalectomy indicated that all patients achieved clinical and biochemical success regardless of lateralization index at least 4 or less than 4 post-ACTH. Receiver operating characteristic curves showed that lateralization index cutoff 2.58 post-ACTH stimulation yielded the best threshold in lateralization with a sensitivity of 73.1% and a specificity of 92.9%.

CONCLUSION

ACTH stimulation increased the AVS success rates in patients with primary aldosteronism, reduced lateralization index in some cases and decreased the proportion of identified unilateral primary aldosteronism, resulting in some patients losing the opportunity for disease cure. Compared with lateralization index at least 4, a lower cutoff point of lateralization index at least 2.58 after ACTH stimulation has better accuracy of lateralization diagnosis.

Intraprocedural Cortisol Measurement Increases Adrenal Vein Cannulation Success Rate in Primary Aldosteronism: A Systematic Review and Meta-analysis

BACKGROUND

This study aimed to explore the effectiveness of intraprocedural cortisol measurement (IPCM) for the technical success rates of bilateral adrenal vein, right adrenal vein (RAV), and left adrenal vein (LAV) cannulation during adrenal vein sampling (AVS).

METHODS

Systematic searches of PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were performed from database inception to May 10, 2023, without any restrictions. We estimated the overall effect estimates of outcomes using the Mantel-Haenszel random-effects model. We conducted subgroup analyses, meta-regression, and sensitivity analysis to explore the possible sources of between-study heterogeneity.

RESULTS

In total, 3,485 patients from 11 studies (three prospective and eight retrospective) were enrolled. Bilateral selectivity in patients who underwent IPCM during AVS was significantly higher than that in patients who underwent a routine AVS procedure (84% vs. 64%, RR 1.42, 95% confidence interval [CI]: 1.27-1.59, P < 0.01), with significant heterogeneity (I2 = 68%). A 42% relative risk reduction in the failure rate of bilateral adrenal vein cannulation was found in the IPCM group. Moreover, pooled analysis showed a significant increase in the success rates of RAV cannulation (84% vs. 72%, RR 1.21, 95% CI 1.12-1.31, P < 0.01, I2 = 33%) and LAV cannulation (89% vs. 84%, RR 1.05, 95% CI 1.02-1.08, P < 0.01, I2 = 4%) when IPCM was implemented during the AVS procedure compared to the routine AVS procedure.

CONCLUSIONS

An IPCM-based strategy during AVS appears to have a significant beneficial effect on improving the success rate of bilateral cannulation, RAV cannulation and LAV cannulation.

Unilaterally Selective Adrenal Vein Sampling for Identification of Surgically Curable Primary Aldosteronism

BACKGROUND

Adrenal venous sampling is recommended for the identification of unilateral surgically curable primary aldosteronism but is often clinically useless, owing to failed bilateral adrenal vein cannulation.

OBJECTIVES

To investigate if only unilaterally selective adrenal vein sampling studies can allow the identification of the responsible adrenal.

METHODS

Among 1625 patients consecutively submitted to adrenal vein sampling in tertiary referral centers, we selected those with selective adrenal vein sampling results in at least one side; we used surgically cured unilateral primary aldosteronism as gold reference. The accuracy of different values of the relative aldosterone secretion index (RASI), which estimates the amount of aldosterone produced in each adrenal gland corrected for catheterization selectivity, was examined.

RESULTS

We found prominent differences in RASI values distribution between patients with and without unilateral primary aldosteronism. The diagnostic accuracy of RASI values estimated by the area under receiver operating characteristic curves was 0.714 and 0.855, respectively, in the responsible and the contralateral side; RASI values >2.55 and ≤0.96 on the former and the latter side furnished the highest accuracy for detection of surgically cured unilateral primary aldosteronism. Moreover, in the patients without unilateral primary aldosteronism, only 20% and 16% had RASI values ≤0.96 and >2.55.

CONCLUSIONS

With the strength of a large real-life data set and use of the gold reference entailing an unambiguous diagnosis of unilateral primary aldosteronism, these results indicate the feasibility of identifying unilateral primary aldosteronism using unilaterally selective adrenal vein sampling results.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01234220.

Role of Adrenal Vein Sampling in Guiding Surgical Decision in Primary Aldosteronism

Adrenal vein sampling (AVS) is recommended for subtyping primary aldosteronism (PA) to identify lateralized or bilateral sources of aldosterone excess, allowing for better decision-making in regard to medical or surgical management on a case-by-case basis. To date, no consensus exists on protocols to be used during AVS, especially concerning sampling techniques, the timing of sampling, and whether or not to use adrenocorticotropic hormone (ACTH) stimulation. Interpretation criteria for selectivity, lateralization, and contralateral suppression vary from one expert center to another, with some favoring strict cut-offs to others being more permissive. Clinical and biochemical post-operative outcomes can also be influenced by AVS criteria utilized to indicate surgical therapy.In this review, we reanalyze studies on AVS highlighting the recent pathological findings of frequent micronodular hyperplasia adjacent to a dominant aldosteronoma (APA) overlapping with bilateral idiopathic hyperaldosteronism (IHA) etiologies, as opposed to the less frequent unilateral single aldosteronoma. The variable expression of melanocortin type 2 receptors in the nodules and hyperplasia may explain the frequent discordance in lateralization ratios between unstimulated and ACTH- stimulated samples. We conclude that aldosterone values collected during simultaneous bilateral sampling, both at baseline and post-ACTH stimulation, are required to adequately evaluate selectivity, lateralization, and contralateral suppression during AVS, to better identify all patients with PA that can benefit from a surgical indication. Recommended cut-offs for each ratio are also presented.

Prognostic value of contralateral suppression on kidney function after surgery in patients with primary aldosteronism

BACKGROUND AND OBJECTIVE

Adrenalectomy for primary aldosteronism (PA) has been associated with decreased kidney function after surgery. It has been proposed that elimination of excess aldosterone unmasks an underlying failure of the kidney function. Contralateral suppression (CLS) is considered a marker of aldosterone excess and disease severity, and the purpose of this study was to assess the hypothesis that CLS would predict change in kidney function after adrenalectomy in patients with PA.

DESIGN AND PATIENTS

Patients with PA referred for adrenal venous sampling (AVS) between May 2011 and August 2021 and who were subsequently offered surgical or medical treatment were eligible for the current study.

RESULTS

A total of 138 patients were included and after AVS 85/138 (61.6%) underwent adrenalectomy while 53/138 (38.4%) were treated with MR-antagonists. In surgically treated patients the estimated glomerular filtration rate (eGFR) was reduced by 11.5 (SD: 18.5) compared to a reduction of 5.9 (SD: 11.5) in medically treated patients (p = .04). Among surgically treated patients, 59/85 (69.4%) were classified as having CLS. After adrenalectomy, patients with CLS had a mean reduction in eGFR of 17.5 (SD: 17.6) compared to an increase of 1.8 (SD: 12.8) in patients without CLS (p < .001). The association between CLS and change in kidney function remained unchanged in multivariate analysis. Post-surgery, 16/59 (27.1%) patients with CLS developed hyperkalemia compared to 2/26 (7.7%) in patients without CLS (p = .04).

CONCLUSION

This retrospective study found that CLS was a strong and independent predictor of a marked reduction of eGFR and an increased risk of hyperkalemia after adrenalectomy in patients with PA.

Adrenal androgens versus cortisol for primary aldosteronism subtype determination in adrenal venous sampling

OBJECTIVE

We examined if measurement of adrenal androgens adds to subtype diagnostics of primary aldosteronism (PA) under cosyntropin-stimulated adrenal venous sampling (AVS).

DESIGN

A prospective pre-specified secondary endpoint analysis of 49 patients with confirmed PA, of whom 29 underwent unilateral adrenalectomy with long-term follow-up.

METHODS

Concentrations of androstenedione, dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulphate (DHEAS) were measured during AVS in addition to aldosterone and cortisol. Subjects with lateralisation index (LI) of ≥4 were treated with unilateral adrenalectomy, and the immunohistochemical subtype was determined with CYP11B2 and CYP11B1 stains. The performance of adrenal androgens was evaluated by receiver operating characteristics (ROC) curve analyses in adrenalectomy and medical therapy groups.

RESULTS

During AVS, the correlations between cortisol and androstenedione, DHEA and DHEAS for LI and selectivity index (SI) were highly significant. The right and left side SIs for androstenedione and DHEA were higher (p < .001) than for cortisol. In ROC analysis, the optimal LI cut-off values for androstenedione, DHEA and DHEAS were 4.2, 4.5 and 4.6, respectively. The performance of these LIs for adrenal androgens did not differ from that of cortisol.

CONCLUSIONS

Under cosyntropin-stimulated AVS, the measurement of androstenedione and DHEA did not improve the cannulation selectivity. The performance of cortisol and adrenal androgens are confirmatory but not superior to cortisol-based results in lateralisation diagnostics of PA.

Mass spectrometry-based cortisol profiling during adrenal venous sampling reveals misdiagnosis for subtyping primary aldosteronism

OBJECTIVE

Primary aldosteronism (PA) is a common form of secondary hypertension. Adrenal venous sampling (AVS) is the gold standard for subtyping PA. This study aimed to determine whether there is a difference between immunoassays and liquid chromatography-mass spectrometry (LC-MS/MS) methods for measuring cortisol levels that affect the judgement of AVS.

DESIGN

This was a retrospective study.

PATIENTS

Included 72 patients who were diagnosed with PA and had undergone AVS.

MEASUREMENTS

Patients were grouped according to whether they received adrenocorticotropic hormone (ACTH) stimulation during AVS, and the cortisol results were measured using immunoassay and LC-MS/MS.

RESULTS

There were 48 patients in the without ACTH stimulation group and 24 in the post-ACTH stimulation group during AVS (bilateral adrenal vein cannulation success rate, 56.25% vs. 83.33%). ACTH stimulation was beneficial for increasing the success rate of AVS (p < .001). Immunoassays were linearly correlated with LC-MS/MS when cortisol concentrations were <1750 nmol/L (r = .959, p < .001). When cortisol concentrations were >17,500 nmol/L, no correlation was found between the two methods (p = .093). The two methods were consistent for the detection of cortisol for evaluating the success of cannulation for AVS. Five percent of patients showed discordant lateralization of aldosterone production according to the cortisol LC-MS/MS and immunoassay results in the without ACTH group, and 15% showed discordant lateralization in the post-ACTH group.

CONCLUSIONS

The immunoassay method can be used to determine whether cannulation is successful. The final decision for lateralization may be more appropriate based on LC-MS/MS results.

Subtype-specific trends in the clinical picture of primary aldosteronism over a 13-year period

OBJECTIVE

Primary aldosteronism has two main clinically and biologically distinct subtypes: unilateral aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH). We aimed to evaluate the changes of each subtype's clinical characteristics over a 13-year period.

METHODS

This retrospective study involved time-trend analyses to identify changes in the clinical features of APA and BAH at diagnosis (2006-2018). A nationwide database from 41 Japanese referral centers was searched, which identified 2804 primary aldosteronism patients with complete baseline information and adrenal venous sampling (AVS) data.

RESULTS

The proportion of patients with APA decreased from 51% in 2006-2009 to 22% in 2016-2018. Among the 1634 patients with BAH, trend analyses revealed decreases in hypertension duration (median 7--3 years; P < 0.01) and hypokalemia prevalence (18--11%; P < 0.01). However, among the 952 patients with APA, there were no significant changes in hypertension duration (median 8 years) and hypokalemia prevalence (overall 70%). Furthermore, the APA group had a trend towards increased use of multiple hypertensive drugs at diagnosis (30--43%; P < 0.01). When subtypes were reclassified according to the precosyntropin stimulation AVS data, APA patients tended to be diagnosed earlier and at milder forms, consistent with the trend in overall primary aldosteronism patients.

CONCLUSION

During 2006-2018, we identified marked subtype-specific trends in the clinical findings at the diagnosis of primary aldosteronism. Our results suggested that the emphasis on the implementing cosyntropin stimulation during AVS might lead to under-identification of APA, especially in patients with mild or early cases.

Adrenal Venous Sampling for Subtype Diagnosis of Primary Hyperaldosteronism

Adrenal venous sampling (AVS) is the key procedure for lateralization of primary hyperaldosteronism (PA) before surgery. Identification of the adrenal veins using computed tomography (CT) and intraoperative cortisol assay facilitates the success of catheterization. Although administration of adrenocorticotropic hormone (ACTH) has benefits such as improving the success rate, some unilateral cases could be falsely diagnosed as bilateral. Selectivity index of 5 with ACTH stimulation to assess the selectivity of catheterization and lateralization index (LI) >4 with ACTH stimulation for unilateral diagnosis is used in many centers. Co-secretion of cortisol from the tumor potentially affects the lateralization by the LI. Patients aged <35 years with hypokalemia, marked aldosterone excess, and unilateral adrenal nodule on CT have a higher probability of unilateral disease. Patients with normokalemia, mild aldosterone excess, and no adrenal tumor on CT have a higher probability of bilateral disease. Although no methods have 100% specificity for subtype diagnosis that would allow bypassing AVS, prediction of the subtype should be considered when recommending AVS to patients. Methodological standardization and strict indication improve diagnostic quality of AVS. Development of non-invasive imaging and biochemical markers will drive a paradigm shift in the clinical practice of PA.

Adrenal venous sampling with adrenocorticotropic hormone stimulation: A meta-analysis

BACKGROUND

This meta-analysis was performed to compare the effect of adrenal venous sampling with adrenocorticotropic hormone with that without adrenocorticotropic hormone in subjects with primary aldosteronism.

METHODS

A systematic literature search up to May 2020 was performed and 17 studies were detected with 1878 subjects who had adrenal venous sampling operations. They reported relationships between with and without adrenocorticotropic hormone stimulation during adrenal venous sampling in subjects with primary aldosteronism. We calculated the odds ratio (OR) with 95% confidence intervals (CIs), using the dichotomous method with a random- or fixed-effect model.

RESULTS

Adrenal venous sampling operations with adrenocorticotropic hormone stimulation had statistically significant lower incorrect lateralisation (OR, 0.57; 95% CI, 0.43-0.75, P < .001); lower unsuccessful cannulations in both adrenal veins (OR, 0.35; 95% CI, 0.21-0.58, P < .001); lower unsuccessful cannulations of left adrenal vein (OR, 0.10; 95% CI, 0.06-0.17, P < .001) and lower unsuccessful cannulations of right adrenal vein (OR, 0.25; 95% CI, 0.11-0.54, P < .001) compared with without adrenocorticotropic hormone stimulation in subjects with primary aldosteronism.

CONCLUSIONS

Adrenal venous sampling operations with adrenocorticotropic hormone stimulation had significantly lower incorrect lateralisation, unsuccessful cannulations in both adrenal veins, unsuccessful cannulations of the left adrenal vein and unsuccessful cannulations of the right adrenal vein compared with adrenal venous sampling operations without adrenocorticotropic hormone stimulation in subjects with primary aldosteronism. Larger prospective studies are recommended to confirm these findings.

Aldosterone-Regulating Receptors and Aldosterone-Driver Somatic Mutations

BACKGROUND

Somatic gene mutations that facilitate inappropriate intracellular calcium entrance have been identified in most aldosterone-producing adenomas (APAs). Studies suggest that angiotensin II and adrenocorticotropic hormone (ACTH) augment aldosterone production from APAs. Little is known, however, regarding possible variations in response to hormonal stimuli between APAs with different aldosterone-driver mutations.

OBJECTIVE

To analyze the transcript expression of type 1 angiotensin II receptors (AGTR1), ACTH receptors (MC2R), and melanocortin 2 receptor accessory protein (MRAP) in APAs with known aldosterone-driver somatic mutations.

METHODS

RNA was isolated from APAs with mutations in: KCNJ5 (n = 14), ATP1A1 (n = 14), CACNA1D (n = 14), and ATP2B3 (n = 5), and from normal adjacent adrenal tissue (n = 45). Transcript expression of MC2R, MRAP, AGTR1, aldosterone synthase (CYP11B2), 17α-hydroxylase/17,20-lyase (CYP17A1), and 11β-hydroxylase (CYP11B1) were quantified using quantitative RT-PCR and normalized to β-actin.

RESULTS

Compared to adjacent normal adrenal tissue, APAs had higher transcript levels of CYP11B2 (2,216.4 [1,112.0, 2,813.5]-fold, p < 0.001), MC2R (2.88 [2.00, 4.52]-fold, p < 0.001), and AGTR1 (1.80 [1.02, 2.80]-fold, p < 0.001]), and lower transcript levels of MRAP, CYP17A1, and CYP11B1 (0.28-0.36, p < 0.001 for all). MC2R and CYP11B2 transcripts were lower in APAs with KCNJ5 vs. other mutations (p < 0.01 for both). MC2R expression correlated positively with that of AGTR1 in APAs harboring KCNJ5 and CACNA1D mutations, and with MRAP expression in APAs harboring ATPase mutations.

CONCLUSIONS

While MC2R and AGTR1 are expressed in all APAs, differences were observed based on the underlying aldosterone-driver somatic mutations. In tandem, our findings suggest that APAs with ATPase-mutations are more responsive to ACTH than KCNJ5-mutated APAs.

Update: Selective adrenal venous sampling (AVS) - Indication, technique, and significance

BACKGROUND

 Primary aldosteronism (PA) is the most common detectable cause of secondary hypertension. The majority of patients have either an adrenal aldosterone-producing adenoma (APA) or bilateral adrenal hyperplasia (BAH) demanding different therapeutic approaches. Screening tests and imaging cannot reliably distinguish between a unilateral or bilateral PA.

METHODS

 This review article gives an overview concerning etiology, diagnostics, and therapeutic options of PA, and reviews the indication, the technique, and relevance of selective adrenal venous sampling (AVS) in the context of the current literature and the authors' experience.

RESULTS

 AVS can verify or exclude a unilaterally dominated secretion with a high success rate. Patients with PA and a unilateral APA can be treated curatively by adrenalectomy.

CONCLUSIONS

 AVS is an established diagnostic examination for differentiation of unilateral from bilateral adrenal disease in patients with PA.

KEY POINTS

· Selective adrenal venous sampling (AVS) is a safe, reliable, and minimally invasive method to detect a unilateral or bilateral adrenal adrenal gland disease.. · Verification of lateralization by AVS has direct therapeutic relevance for patients with primary aldosteronism (PA).. · AVS can be performed with low radiation exposure, without contrast medium, and with a high success rate when performed by an experienced interventional radiologist..

CITATION FORMAT

· Loberg C, Antoch G, Stegbauer J et al. Update: Selective adrenal venous sampling (AVS) - Indication, technique, and significance. Fortschr Röntgenstr 2021; 193: 658 - 666.

Utility of adrenocorticotropic hormone in adrenal vein sampling despite the occurrence of discordant lateralization

BACKGROUND

Adrenal vein sampling (AVS) is crucial for accurate lateralization of aldosterone excess but it is technically challenging due to the difficulty of adrenal vein cannulation. The use of adrenocorticotropic hormone (ACTH) to improve cannulation success is controversial and can lead to discordant lateralization outcomes.

OBJECTIVE

To evaluate the utility of ACTH in two centres with different levels of AVS expertise and formulate a strategy for interpreting discordant results.

DESIGN

A retrospective cross-sectional analysis of AVS results and postoperative patient outcomes.

SETTING

Two large tertiary hospitals with harmonized AVS protocols where adrenal venous samples are collected both before and after ACTH stimulation.

MEASUREMENTS

Cannulation success (measured by selectivity index, SI), lateralization (measured by lateralization index, LI) and postoperative biochemical cure.

RESULTS

Number of AVS procedures judged to have successful bilateral adrenal vein cannulation increased from 53% pre- to 73% post-ACTH. The increase in cannulation success was significantly higher in centre where AVS was performed by multiple radiologists with a lower basal success rate. In both centres, the proportion of cases deemed to display lateralization significantly decreased with the use of ACTH (70% pre- to 52% post-ACTH). Based on postoperative outcomes of patients with discordant results who underwent unilateral adrenalectomy, the combination of LI >3 pre-ACTH and LI >2 post-ACTH was predictive of a biochemical cure.

CONCLUSION

Adrenocorticotropic hormone can increase the rate of cannulation success during AVS at the expense of reduced lateralization. The criteria for lateralization should be carefully determined based on local data when ACTH is used.

Resolution of drug-resistant hypertension by adrenal vein sampling-guided adrenalectomy: a proof-of-concept study

Drug-resistant hypertension (RH) is a very high-risk condition involving many hypertensive patients, in whom primary aldosteronism (PA) is commonly overlooked. Hence, we aimed at determining if (1) adrenal vein sampling (AVS) can identify PA in RH patients, who are challenging because of receiving multiple interfering drugs; (2) AVS-guided adrenalectomy can resolve high blood pressure (BP) resistance to treatment in these patients.

Based on a pilot study we selected from 1016 consecutive patients referred to our Centre for ‘difficult-to-treat’ hypertension those with RH, for an observational prospective cohort study. We excluded those non-adherent to treatment (by therapeutic drug monitoring) and those with pseudo-RH (by 24-h BP monitoring), which left 110 patients who met the European Society of Cardiology/European Society of Hypertension (ESC/ESH) 2013 definition for RH. Of these patients, 77 were submitted to AVS, who showed unilateral PA in 27 (mean age 55 years; male/female 19/8). Therefore, these patients underwent AVS-guided laparoscopic unilateral adrenalectomy, which resolved RH in all: 20% were clinically cured in that they no longer needed any antihypertensive treatment; 96% were biochemically cured. Systolic and diastolic BP fell from 165/100 ± 26/14 mmHg at baseline, to 132/84 ± 14/9 mmHg at 6 months after surgery (P&lt;10−4 for both) notwithstanding the fall of number and defined daily dose (DDD) of antihypertensive drugs required to achieve BP control (P&lt;10−4 for both). A prominent regression of cardiac and renal damage was also observed.

Thus, the present study shows the feasibility of identifying PA by AVS in RH patients, and of resolving high BP resistance to treatment in these patients by AVS-guided adrenalectomy.

Subtyping of Primary Aldosteronism in the AVIS-2 Study: Assessment of Selectivity and Lateralization

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).

10 good reasons why adrenal vein sampling is the preferred method for referring primary aldosteronism patients for adrenalectomy

: Nowadays most patients diagnosed with surgically curable primary aldosteronism have small or micro aldosterone-producing adenoma or unilateral micronodular hyperplasia, which are undetectable with available imaging technologies. Therefore, a negative imaging test by no means excludes unilateral primary aldosteronism. Moreover, about 10% of the subjects above the age of 35 years have nonfunctioning adrenal tumors, regardless of being hypertensive or not, with a prevalence that raises with aging. Hence, the finding of an adrenal mass at imaging does not reliably detect the culprit of primary aldosteronism. On the other hand, when primary aldosteronism patients are selected for adrenalectomy on the basis of demonstration of lateralized aldosterone excess at adrenal vein sampling (AVS), close to 100% are biochemically cured from the hyperaldosteronism, about 45% are cured of arterial hypertension and an additional 52% are markedly improved in terms of blood pressure control. By contrast, patients referred for surgery based on imaging alone often fail to reach these successful outcomes, indicating that surgery was unnecessary or, even worse, performed on the wrong side. For these reasons, and because of the lack of accurate and widely available alternative methods, all current guidelines recommend that AVS be offered to all primary aldosteronism patients with only few exceptions, mainly in patients unable or unwilling to undergo surgery and those with germ-line mutations causing familial primary aldosteronism. The main argument against systematic use of AVS entails its suboptimal performance, partly justified by its intrinsic technical difficulty, and its limited availability. This led to propose skipping AVS strategies for predicting surgically curable primary aldosteronism, but success has been inconsistent. The most urgent standing issue is, therefore, not to find loopholes to avoid AVS, but rather to improve its use, which means improving the rate of AVS success, through formal training of interventionists, selection of appropriate cutoffs and exploitation of a standardized procedure.

The 2020 Italian Society of Arterial Hypertension (SIIA) practical guidelines for the management of primary aldosteronism

Background and aim

Considering the amount of novel knowledge generated in the last five years, a team of experienced hypertensionlogists was assembled to furnish updated clinical practice guidelines for the management of primary aldosteronism.

Methods

To identify the most relevant studies, the authors utilized a systematic literature review in international databases by applying the PICO strategy, and then they were required to make use of only those meeting predefined quality criteria. For studies of diagnostic tests, only those that fulfilled the Standards for Reporting of Diagnostic Accuracy recommendations were considered.

Results

Each section was jointly prepared by at least two co-authors, who provided Class of Recommendation and Level of Evidence following the American Heart Association methodology. The guidelines were sponsored by the Italian Society of Arterial Hypertension and underwent two rounds of revision, eventually reexamined by an External Committee. They were presented and thoroughly discussed in two face-to-face meetings with all co-authors and then presented on occasion of the 36th Italian Society of Arterial Hypertension meeting in order to gather further feedbacks by all members. The text amended according to these feedbacks was subjected to a further peer review.

Conclusions

After this process, substantial updated information was generated, which could simplify the diagnosis of primary aldosteronism and assist practicing physicians in optimizing treatment and follow-up of patients with one of the most common curable causes of arterial hypertension.

Adrenal Venous Sampling: Where Do We Stand?

Adrenal venous sampling is the gold standard test to identify surgically curable primary aldosteronism, but it is markedly underused in clinical practice being perceived as a technically challenging and invasive procedure and, moreover, as difficult to interpret. This review provides updated information on current indications to adrenal venous sampling and how to perform and interpret adrenal venous sampling.