Adrenal vein sampling in primary aldosteronism: towards a standardised protocol

Comparison of Adrenal Vein Sampling Methods for Subtyping of Primary Aldosteronism: A Retrospective Observational Study

PURPOSE

Although adrenal vein sampling (AVS) is the standard method for subtype diagnosis in patients with primary aldosteronism (PA), the methods used to sample the adrenal vein are not standardized. The aim of this study was to establish the optimal method for sampling the adrenal vein based on the pathological findings after surgery for PA.

METHODS

We enrolled 168 consecutive patients who were diagnosed to have PA and underwent AVS at our institution between 2019 and 2023. The impact of sampling by gentle negative pressure (GNP) on the accuracy of diagnosis of the PA subtype was compared with that of sampling by gravity, whereby blood flows out naturally.

RESULTS

AVS was performed successfully on both sides in 139 patients using the two sampling methods. Subtype diagnosis using the two sampling methods was concordant in 128 (92.1%) of the 139 patients and discordant in 11 (7.9%). Among the 11 patients with a discordant subtype diagnosis, unilateral adrenalectomy was performed in three with the right unilateral subtype by gravity and the bilateral subtype by GNP, one with the bilateral subtype by gravity and the right unilateral subtype by GNP, and one with the left unilateral subtype by gravity and the bilateral subtype by GNP. The pathological findings after surgery showed that the false-negative rate was 20% (1/5) with data obtained by the gravity method and 80% (4/5) with data obtained by the GNP method. Bilateral AVS took significantly longer when sampling was performed by the gravity method than when it was performed by GNP (p < 0.01).

CONCLUSIONS

The gravity method may be preferable to GNP for AVS in patients with PA.

Intraprotocol Adrenal Vein Sampling Inconsistencies in Primary Aldosteronism Lateralization

Background Primary aldosteronism can arise from one or both adrenal glands. Adrenal vein sampling (AVS) is the standard of care for identifying patients with lateralized primary aldosteronism who would benefit from surgery. Variability in AVS lateralization has been primarily attributed to cosyntropin use and lateralization index thresholds. Data regarding intraprotocol variability are lacking. Purpose To assess the rates of intraprotocol lateralization inconsistency during simultaneous AVS. Materials and Methods This retrospective cross-sectional study assessed patients with primary aldosteronism who underwent simultaneous AVS at a single tertiary referral center between January 2015 and December 2023. Six sets of adrenal vein and peripheral vein samples were obtained: three baseline samples obtained after cannulation, 5 minutes apart; and three samples obtained between 5 and 30 minutes after cosyntropin stimulation. Patients with successful cannulation and valid hormonal data at all six time points were included. A lateralization index (computed as the aldosterone-to-cortisol ratio between the two adrenal veins, with the highest number as numerator) of at least 4 was considered indicative of lateralized primary aldosteronism. The proportions of baseline and stimulated AVS sets within which one of three lateralization indexes provided different subtype results were assessed. Linear mixed-effects models were used to estimate the between- and within-patient hormonal and lateralization index variances. Results Of 402 patients (median age, 53 years; IQR, 45-63 years; 233 male) included, 129 patients (32.1%) had at least one lateralization index inconsistency. Of these 402 patients, 89 patients (22.1%) had lateralization inconsistencies within the baseline sets, 53 patients (13.2%) within cosyntropin-stimulated sets, and 13 patients (3.2%) in both baseline and cosyntropin-stimulated sets. The highest outlier prevalence occurred in the first (42 patients; 10.4%) and third (33 patients; 8.2%) baseline samples, with roughly twofold-lower rates in the first (23 patients; 5.7%) and last postcosyntropin stimulation samples (4.2%; 17 patients). The absolute change in baseline and cosyntropin-stimulated lateralization index (maximum-minimum lateralization index within a triplicate) was as high as 152.9 and 327.4, respectively. The highest hormonal variability was noted in the adrenal vein producing less aldosterone. Conclusion Almost a third of patients undergoing AVS in triplicate, both before and after cosyntropin stimulation, had intraprotocol discrepancies in lateralization results, with the highest variability occurring within samples obtained without cosyntropin stimulation. © RSNA, 2025 See also the editorial by Georgiades in this issue.

Resolution of paradoxical bilateral aldosterone suppression with mass spectrometry

OBJECTIVE

Adrenal vein sampling (AVS) is the standard-of-care for primary aldosteronism (PA) subtyping. Paradoxical bilateral aldosterone suppression (BAS), defined by lower aldosterone/cortisol ratio in both adrenal veins compared to peripheral circulation, has been reported in AVS studies, but the underlying causes remain poorly understood. We aimed to assess the prevalence of BAS in AVS without and with cosyntropin stimulation based on clinical immunoassays, and to probe the BAS results using liquid chromatography mass spectrometry (LC-MS/MS).

METHODS

We retrospectively assessed the BAS prevalence among patients with confirmed PA who underwent AVS in a referral center between 2015 and 2023. Simultaneous AVS was performed both before and after cosyntropin stimulation. LC-MS/MS quantitation of cortisol and aldosterone was performed in patients with serum available.

RESULTS

Of 402 patients, BAS was observed in 102 (25%): Pre-cosyntropin in 31, post-cosyntropin in 48 (including 10 who did not meet successful catheterization criteria in baseline samples), and both pre- and post- cosyntropin in 23. Paradoxically, AVS indicated lateralized PA in 36% and 43% of patients with BAS based on pre- and post-cosyntropin data, respectively. Using LC-MS/MS, BAS was not present in 42/53 (79%) patients with serum available. Compared to LC-MS/MS, immunoassays overestimated cortisol across the analytical range. In contrast, for aldosterone, immunoassays overestimated low concentrations, but underestimated high concentrations, such as those measured in adrenal veins.

CONCLUSIONS

Apparent BAS derives primarily from artifacts in clinical immunoassays. These data caution against assuming that aldosterone suppression indicates contralateral aldosterone lateralization in cases with partial adrenal vein catheterization failure.

Prevalence and main characteristics of primary aldosteronism in bilateral macronodular adrenal disease: a systematic review of the literature

CONTEXT

Bilateral macronodular adrenal disease (BMAD) typically presents with bilateral benign adrenocortical macronodules and variable cortisol excess. Anecdotal evidence suggests oversecretion of other adrenal steroids, including mineralocorticoids.

HYPOTHESIS

We hypothesized that primary aldosteronism (PA) can occur in BMAD, resulting in a distinct, more severe phenotype compared to BMAD with isolated cortisol hypersecretion or unilateral PA (uPA).

OBJECTIVE

To assess the prevalence and characteristics of PA in BMAD.

METHODS

We systematically reviewed case reports and series of BMAD patients with PA, following PRISMA guidelines. BMAD was defined by bilateral adrenal nodules ≥10 mm. PA diagnosis followed US or Japanese Endocrine Society guidelines. We compared these findings with 2 cohorts from LMU Hospital Munich: BMAD with isolated cortisol hypersecretion and uPA.

RESULTS

From 1018 articles, 18 representing 68 cases were included. Of these, 66 had BMAD with PA and 2 had BMAD with aldosterone precursor excess. The PA proportion in published BMAD series ranged from 2% to 43%. BMAD patients with PA were predominantly male (75%) and younger (median 51.5 years) than those with isolated cortisol hypersecretion (median 60.5 years, P < .01). Their median blood pressure was higher (170/100 mm Hg) compared to those with isolated cortisol hypersecretion (138/80 mm Hg) or uPA (153/94 mm Hg, P < .01). Treatment was only described in 28 cases, with 93% undergoing adrenalectomy. Clinical outcome was similar across groups post-treatment.

CONCLUSION

This review highlights the need for increased screening for PA in younger, hypertensive BMAD patients. Larger multicenter studies are needed to determine the association between these conditions, cardiovascular risk, and optimal treatment.

The value of targeted CXCR4 18F-AlF-NOTA-pentixafor PET/CT for subtyping primary aldosteronism

Objective

The study aimed to investigate the diagnostic value of 18F-AlF-NOTA-Pentixafor PET/CT in subtyping primary aldosteronism (PA).

Methods

This study enrolled 88 patients with PA or nonfunctional adenoma (NFA) for 18F-Pentixafor PET/CT scan. Of these, 20 patients underwent adrenal venous sampling (AVS), and 65 underwent adrenalectomy and postoperative follow-up.

Results

In 88 patients, 76 were diagnosed with unilateral PA (UPA), 4 were diagnosed with bilateral PA (BPA), and 8 were diagnosed with NFA, resulting in a total of 95 lesions. To identify UPA, visual analysis received a specificity of 94.12% and a sensitivity of 89.74%. The optimal cutoff values for SUVmax at 5.45, the lesion-to-normal adrenal ratio (LAR) at 1.43, and lesion-to-liver ratio (LLR) all yielded a specificity of 100% and a sensitivity of 79.49%, 83.33%, and 80.77%, respectively. In 15 adrenal lesions with similar uptake to contralateral and adjacent normal adrenal tissue (defined as warm lesions), 7 were confirmed as UPA, 4 were confirmed as BPA, and 4 were confirmed as NFA. Furthermore, among the 20 patients who underwent AVS, the concordance rate of AVS and PET/CT visual analysis for PA subtyping was 65.00%.

Conclusions

The CXCR4-targeted 18F-AlF-NOTA-pentixafor PET/CT is a valuable noninvasive tool for diagnosing UPA, demonstrating high sensitivity and specificity. More attention should be paid to warm adrenal lesions for their high diagnostic ambiguity probability.

Adrenal Vein Sampling for Primary Aldosteronism: Recommendations From the Australian and New Zealand Working Group

Adrenal vein sampling (AVS) is the current recommended procedure for identifying unilateral subtypes of primary aldosteronism (PA), which are amenable to surgery with the potential for cure. AVS is a technically challenging procedure usually undertaken by interventional radiologists at tertiary centres. However, there are numerous variations in AVS protocols relating to patient preparation, sampling techniques and interpretation which may impact the success of AVS and patient care. To reduce practice variations, improve the success rates of AVS and optimise patient outcomes, we established an Australian and New Zealand AVS Working Group and developed evidence-based expert consensus recommendations for the preparation, performance and interpretation of AVS. These recommendations can be used by all healthcare professionals in a multidisciplinary team who look after the diagnosis and management of PA.

A modified single-catheter approach for improving adrenal venous sampling in patients with primary aldosteronism

OBJECTIVES

Adrenal vein sampling (AVS) is an established procedure for assessing subtype patients with primary aldosteronism (PA). However, it is technically challenging, with high failure rates, which limits its application in clinical practice. Our study aimed to evaluate the safety and efficacy of a single-catheter modified approach for AVS.

METHODS

The clinical, angiographic, and procedural data of 182 consecutive patients who underwent AVS procedures between May 2020 and May 2023 were collected and analyzed. The single-catheter modified approach was performed as a single 5 F Tiger catheter with only one-time manual reshaping, which was recommended for sequential bilateral adrenal cannulations.

RESULTS

Of the 182 consecutive patients, 174 (95.6%) had successful bilateral adrenal cannulation. The single-catheter modified approach was successfully performed to cannulate the right adrenal vein in 176 (96.7%) patients, while another six (3.3%) patients needed at least a second manual reshaping for 5 F Tiger catheters. For left adrenal cannulation, a single-catheter modified approach was successfully used in 179 (98.4%) patients, whereas 5 F Tiger catheters with at least second-time manual reshaping were used in the remaining three (1.6%) patients. The procedural period was 15.6 ± 10.8 min, the fluoroscopy time was 4.2 ± 1.5 min, and the diagnostic contrast was 15.5 ± 4.8 mL. The incidence of procedure-related complications associated with AVS was 1.1%. The cumulative summation assessment illustrated that the learning curve for the operating procedure required up to 29 cases, indicating that the procedure time was shortened after 29 cases.

CONCLUSIONS

The single-catheter modified approach is an effective, safe, and feasible technique for AVS treatment. In particular, this improved method is not difficult for beginners with high technical success rates.

Typing diagnostic value of 68Ga-pentixafor PET/CT for patients with primary aldosteronism and unilateral nodules

PURPOSE

Our goal was to compare the lateralization of 68Ga-pentixafor PET/CT with adrenal vein sampling (AVS) in primary aldosteronism (PA) patients with unilateral lesions.

METHODS

We retrospectively enrolled 61 patients with PA and all patients showed unilateral nodular lesions on CT and underwent 68Ga-Pentixafor PET/CT. The general clinical data, imaging and AVS results were collected. The diagnostic efficiency of 68Ga-Pentixafor PET/CT imaging in PA patients was calculated by visual and semi-quantitative analysis to compare the consistency with AVS, and the correlation between CXCR4 express and 68Ga-Pentixafor uptake was performed.

RESULTS

The study included 42 unilateral PA (UPA) and 19 bilateral PA (BPA). The area under curve (AUC) of 68Ga-Pentixafor PET/CT to diagnosis UPA with 10 min maximum standardized uptake value (SUVmax) > 8.17 was 0.82 ([0.70-0.90], P < 0.001), and the sensitivity and specificity were 0.64 and 0.90, respectively. The maximal AUC of 68Ga-pentixafor PET/CT for the diagnosis UPA in patients with nodules with a diameter ≥1 cm was 0.87 ([0.73-0.95],P both <0.001,[10 min SUVmax=8.17 and 10 min mean standardized uptake value (SUVmean)=5.57]), and the sensitivity and specificity were 0.73 and 0.93, respectively. Unilateral adrenalectomy and significant CXCR4 expression were present in 32 UPA, including 27 aldosterone-producing adenoma and 5 idiopathic adrenal hyperplasia. Additionally, 68Ga-pentixafor uptake in adrenal lesions was significantly correlated with CXCR4 expression, and statistical differences in 68Ga-pentixafor uptake among IRS subgroups.

CONCLUSIONS

68Ga-Pentixafor PET/CT can be helpful for subtyping diagnosis of PA patients with unilateral adrenal nodular, showing significant potential in non-invasive PA classification.

Diagnosis of Primary Aldosteronism without Discontinuation of Interfering Antihypertensive Medications

PURPOSE OF REVIEW

One of the challenges in the diagnosis and management of primary aldosteronism (PA), the most common type of secondary hypertension with curative potential, is the modification of antihypertensive medications. We seek to explore whether these medications can be continued during the diagnostic process of PA to minimize the duration and risks associated with medication adjustments.

RECENT FINDINGS

We searched PubMed for eligible original literature between 1990 and 2024 using the following keywords: (screening) AND (primary aldosteronism); (confirmatory) AND (primary aldosteronism); (adrenal vein sampling) AND primary aldosteronism). Some recent studies support the feasibility of PA-related tests and even adrenal vein sampling (AVS) without the need to discontinue antihypertensive medications in certain cases. In this review, we propose a management approach that considers the specific effects of antihypertensive medications on the RAAS axis and the patient's disease phenotype. Based on this, we suggest a strategy that enables the diagnosis of PA in certain patients without discontinuing their antihypertensive medications.

Circulating miRNAs and Machine Learning for Lateralizing Primary Aldosteronism

BACKGROUND

Distinguishing between unilateral and bilateral primary aldosteronism, a major cause of secondary hypertension, is crucial due to different treatment approaches. While adrenal venous sampling is the gold standard, its invasiveness, limited availability, and often difficult interpretation pose challenges. This study explores the utility of circulating microRNAs (miRNAs) and machine learning in distinguishing between unilateral and bilateral forms of primary aldosteronism.

METHODS

MiRNA profiling was conducted on plasma samples from 18 patients with primary aldosteronism taken during adrenal venous sampling on an Illumina MiSeq platform. Bioinformatics and machine learning identified 9 miRNAs for validation by reverse transcription real-time quantitative polymerase chain reaction. Validation was performed on a cohort consisting of 108 patients with known subdifferentiation. A 30-patient subset of the validation cohort involved both adrenal venous sampling and peripheral, the rest only peripheral samples. A neural network model was used for feature selection and comparison between adrenal venous sampling and peripheral samples, while a deep-learning model was used for classification.

RESULTS

Our model identified 10 miRNA combinations achieving >85% accuracy in distinguishing unilateral primary aldosteronism and bilateral adrenal hyperplasia on a 30-sample subset, while also confirming the suitability of peripheral samples for analysis. The best model, involving 6 miRNAs, achieved an area under curve of 87.1%. Deep learning resulted in 100% accuracy on the subset and 90.9% sensitivity and 81.8% specificity on all 108 samples, with an area under curve of 86.7%.

CONCLUSIONS

Machine learning analysis of circulating miRNAs offers a minimally invasive alternative for primary aldosteronism lateralization. Early identification of bilateral adrenal hyperplasia could expedite treatment initiation without the need for further localization, benefiting both patients and health care providers.

Targeted liquid biopsy for brain tumors

Cerebrospinal fluid (CSF) is a promising source of molecular biomarkers in the detection and monitoring of brain malignancies. Unlike peripheral blood, where biomarker detection is hindered by the blood-brain barrier and the complex nature of biofluids, CSF offers a more direct and enriched source of tumor-derived markers, including circulating tumor DNA (ctDNA), microRNA (miRNA), proteins, and extracellular vesicles (EVs). These biomarkers, originating from brain tumor cells, are often more concentrated in CSF than in peripheral blood due to the proximity of CSF to the central nervous system (CNS). The presence of ctDNA in CSF is notably higher than in plasma, making CSF an advantageous medium for liquid biopsy in brain tumor patients. Traditional liquid biopsy approaches relying on peripheral venous blood samples often face challenges in detecting low concentrations of tumor-derived biomarkers. The direct contact of CSF with the CNS minimizes background noise, potentially enhancing the accuracy and sensitivity of diagnostic assays. Despite the barriers posed by the blood-brain barrier and other physiological factors that limit biomarker levels in the systemic circulation, CSF's unique position within the CNS allows for more effective biomarker collection. While peripheral blood remains the standard medium for liquid biopsy in oncology, the proximity of CSF to brain tumors suggests it may offer superior diagnostic capabilities. Emerging evidence from non-CNS malignancies indicates that collecting biofluids closer to the tumor site can significantly improve biomarker detection. Although this approach has been well-documented in other solid tumors, its application to CNS malignancies remains underexplored. This study hypothesizes that targeted blood sampling from CNS tumor-draining veins could similarly enhance biomarker detection, thereby increasing the sensitivity and efficacy of liquid biopsy techniques in diagnosing and monitoring brain malignancies.

Impact of Cortisol-Cosecretion on Adrenal Venous Sampling Results in Primary Aldosteronism: Study of 225 Cases

Background/Objectives: Mild autonomous cortisol secretion (MACS) can coexist with primary aldosteronism (PA). The purpose of our study was to evaluate whether (MACS) influences parameters analyzed during adrenal venous sampling (AVS) in patients with PA. Methods: Patients with PA from the SPAIN-ALDO Registry and the German Conn's Registry with available 1 mg-dexamethasone suppression test (DST) and AVS were included. MACS was defined as a post-DST cortisol > 1.8 µg/dL in the absence of specific signs and symptoms of Cushing's syndrome. Results: Two-hundred and twenty-five patients were included, 98 (43.6%) of whom had concomitant MACS. The mean age was 54 ± 10 years and 37.3% were women. AVS was performed by simultaneous catheterization of both adrenal veins and analysis of basal samples in 157 patients (69.8%), with both basal and post-ACTH samples in 15 patients (6.7%), and during continuous ACTH infusion in 53 patients (23.6%). AVS was considered technically unsuccessful in 40 cases (17.8%), suggesting unilateral secretion in 106 (47.1%) and bilateral secretion in 79 (35.1%). We did not find significant differences in the percentage of unilateral and bilateral results, cortisol, corrected aldosterone, or selectivity indices in the dominant and non-dominant veins, nor in the lateralization index or the contralateral suppression index between patients with and without MACS. They also had similar rates of surgical treatment and biochemical and clinical response. Conclusions: Although pathophysiological reasoning suggests that MACS could hinder AVS identification of unilateral forms of PA, our data suggest that such interference, if it exists, is of moderate clinical relevance.

Utility of Adrenal Vein Sampling With and Without Ultra-Low Dose ACTH Infusion in the Diagnostic Evaluation of Primary Aldosteronism

BACKGROUND

Adrenal vein sampling (AVS), integral to identifying surgically remediable unilateral primary aldosteronism (PA), is technically challenging and subject to fluctuations in cortisol and aldosterone secretion. Intra-procedural adrenocorticotropic hormone (ACTH), conventionally administered as a 250-μg bolus and/or 50 μg per hour infusion, increases cortisol and aldosterone secretion and can improve AVS success, but may cause discordant lateralisation compared to unstimulated AVS.

AIMS

To assess if AVS performed with ultra-low dose ACTH infusion causes discordant lateralisation.

METHODS

Here, we describe our preliminary experience using an ultra-low dose ACTH infusion AVS protocol. We retrospectively reviewed the results of consecutive AVS procedures (n = 37) performed with and without ultra-low dose ACTH (1-μg bolus followed by 1.25 μg per hour infusion).

RESULTS

Bilateral AV cannulation was successful in 70% of procedures pre-ACTH and 89% post-ACTH (p < 0.01). Sixty-nine percent of studies lateralised pre-ACTH and 55% post-ACTH, improving to 79% when both groups were combined. Lateralisation was discordant in 11 cases, including eight in which lateralisation was present only on basal sampling, and three in which lateralisation occurred only with ACTH stimulation.

DISCUSSION

Overall, the decrease in lateralisation rates with ACTH was higher than previously reported for some protocols utilising conventional doses of ACTH. Our results suggest that AVS performed with ultra-low dose ACTH can cause discordant lateralisation similar to AVS performed with conventional doses of ACTH.

CONCLUSION

Prospective studies directly comparing low and conventional dose ACTH AVS protocols and long-term patient outcomes are needed to help define the optimal ACTH dose for accurate PA subtyping.

Clinical prediction model for primary aldosteronism subtyping and special focus on adrenal volumetric assessment

PURPOSE

Our aim was to develop a prediction model based on a simple score with clinical, laboratory, and imaging findings for the subtype diagnosis of primary aldosteronism (PA). The contribution of adrenal volumetric assessment to PA subtyping was also investigated.

METHODS

Thirty-five patients with adequate cannulation in adrenal venous sampling (AVS) were included. Laboratory data, the saline infusion test (SIT), and the AVS results of patients with PA were retrospectively evaluated. Volumetric assessment was performed using magnetic resonance imaging (MRI) and the ratio of adrenal volumes was calculated after adjusting for gender- and side-specific mean reference values of both adrenal glands.

RESULTS

The AVS was consistent with unilateral PA in 49% and bilateral in 51% of the patients. Hypertension as a reason for work-up, the highest aldosterone/lowest potassium value higher than 12, the percentage of plasma aldosterone concentration (PAC) reduction after SIT by equal or less than 43.5%, the use of oral potassium replacement, unilateral disease at pre-AVS imaging, and a ratio of adjusted adrenal volumes equal to or below 1.7 were indicative of unilateral disease in univariate logistic regression analysis concerning the distinction of PA subtyping (p < 0.05). Multivariate logistic regression analysis also revealed that adrenal volumetric assessment has an impact on PA subtyping (p < 0.05). In the prediction model, when each of the six parameters that were significant in the univariate logistic regression analysis was assigned one point, < 4 predicted bilateral PA, whereas ≥ 4 predicted unilateral PA (AUC:0.92, p < 0.001).

CONCLUSION

This prediction model before AVS may serve as a convenient and practical approach, while an adjusted adrenal volumetric assessment can make a positive contribution to PA subtyping.

Temporal trends in clinical features of patients with primary aldosteronism over 20 years

Primary aldosteronism (PA) accounts for approximately 5-10% of hypertension cases. Over the past 20 years, the reported incidence of PA has increased due to widespread screening for secondary hypertension and imaging studies. We aimed to evaluate the temporal trends in the clinical characteristics and subtypes of PA. A total of 1064 patients with PA in two tertiary hospitals between 2000 and 2021 were categorized into three groups according to the year of diagnosis: 2000-2009, 2010-2015, and 2016-2021. The clinical characteristics of the patients over the three time periods were compared using a trend analysis. The age at diagnosis and sex of patients with PA did not change over 20 years. The proportion of patients with bilateral hyperaldosteronism (BHA) increased (11%, 25%, and 40%, P for trend <0.001). The proportion of hypokalemia (87%, 61%, and 40%) and plasma aldosterone concentration (36.0, 30.8, and 26.6 ng/dL) decreased (all P for trend <0.001). There was a trend toward an increased proportion of incidentally detected patients compared to clinically symptomatic patients (36%, 55%, and 61%, P for trend <0.001). The concordance rate of imaging and adrenal venous sampling results decreased (91%, 70%, and 57% P for trend <0.001). However, the proportion of patients with resistant hypertension and comorbidities did not differ. In conclusion, among patients with PA, patients with BHA and incidental detection have increased over 20 years, and more patients are likely to present with milder clinical symptoms and biochemical profiles.

Practical consensus for the treatment and follow-up of primary aldosteronism: a multidisciplinary consensus document

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension and is associated with a higher cardiometabolic risk than essential hypertension. The aim of this consensus is to provide practical clinical recommendations for its surgical and medical treatment, pathology study and biochemical and clinical follow-up, as well as for the approach in special situations like advanced age, pregnancy and chronic kidney disease, from a multidisciplinary perspective, in a nominal group consensus approach of experts from the Spanish Society of Endocrinology and Nutrition (SEEN), Spanish Society of Cardiology (SEC), Spanish Society of Nephrology (SEN), Spanish Society of Internal Medicine (SEMI), Spanish Radiology Society (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Society of Laboratory Medicine (SEQC(ML)), Spanish Society of Anatomic-Pathology and Spanish Association of Surgeons (AEC).

Selective venous sampling for secondary hypertension

Selective venous sampling (SVS), an invasive radiographic procedure that depends on contrast media, holds a unique role in diagnosing and guiding the treatment of certain types of secondary hypertension, particularly in patients who may be candidates for curative surgery. The adrenal venous sampling (AVS), in particular, is established as the gold standard for localizing and subtyping primary aldosteronism (PA). Throughout decades of clinical practice, AVS could be applied not only to PA but also to other endocrine diseases, such as adrenal Cushing syndrome (ACS) and Pheochromocytomas (PCCs). Notably, the application of AVS in ACS and PCCs remains less recognized compared to PA, with the low success rate of catheterization, the controversy of results interpretation, and the absence of a standardized protocol. Additionally, the AVS procedure necessitates enhancements to boost its success rate, with several helpful but imperfect methods emerging, yet continued exploration remains essential. We also observed renal venous sampling (RVS), an operation akin to AVS in principle, serves as an effective means of diagnosing renin-dependent hypertension, aiding in the identification of precise sources of renin excess and helping the selection of surgical candidates with renin angiotensin aldosterone system (RAAS) abnormal activation. Nonetheless, further basic and clinical research is needed. Selective venous sampling (SVS) can be used in identifying cases of secondary hypertension that are curable by surgical intervention. Adrenal venous sampling (AVS) and aldosterone measurement for classificatory diagnosis of primary aldosteronism (PA) are established worldwide. While its primary application is for PA, AVS also holds the potential for diagnosing other endocrine disorders, including adrenal Cushing's syndrome (ACS) and pheochromocytomas (PCCs) through the measurements of cortisol and catecholamine respectively. In addition, renal venous sampling and renin measurement can help to diagnose renovascular hypertension and reninoma.

Untargeted metabolomics reveals potential plasma biomarkers for diagnosis of primary aldosteronism using liquid chromatography-mass spectrometry

Metabolite profiling has the potential to comprehensively bridge phenotypes and complex heterogeneous physiological and pathological states. We performed a metabolomics study using parallel liquid chromatography-mass spectrometry (LC-MS) combined with multivariate data analysis to screen for biomarkers of primary aldosteronism (PA) from a cohort of 111 PA patients and 218 primary hypertension (PH) patients. Hydrophilic interaction chromatography and reversed-phase liquid chromatography separations were employed to obtain a global plasma metabolome of endogenous metabolites. The satisfactory classification between PA and PH patients was obtained using the MVDA model. A total of 35 differential metabolites were screened out and identified. A diagnostic biomarker panel was established using the least absolute shrinkage and selection operator (LASSO) binary logistic regression model and receiver operating characteristic analysis. Joint analysis with clinical indicators, including plasma supine aldosterone level, plasma orthostatic aldosterone level, body mass index, and blood potassium, revealed that the combination of metabolite biomarker panel and plasma supine aldosterone has the best clinical diagnostic efficacy.

Anatomy and anatomical variations of adrenal veins and its application to adrenal venous sampling

PURPOSE

Our aim was to study the anatomy of the left and right main adrenal veins (LAV and RAV) and to identify their anatomical variations in order to see the practical application of these findings to adrenal venous sampling (AVS).

METHODS

Our work is based on dissection of 80 adrenal glands from fresh corpses in the forensic medicine department. We studied the number, the drainage, the direction and the level of termination of the main adrenal veins.

RESULTS

The average length of the LAV was 21 mm. It ended in 100% of cases at the upper edge of the left renal vein with a mean connection angle of 70° and after an anastomosis with the lower phrenic vein in 36 cases(90%). The average length of the RAV was 9 mm. It ended in 100% of cases at the level of the retro hepatic inferior vena cava (IVC) mainly on its posterior face in 21 cases (53%) and on its right lateral border in 18 cases (45%). The mean angle of the RAV in relation to the vertical axis of the IVC was 40°, with extremes ranging from 15° to 90°.

CONCLUSIONS

AVS seems to be easier on the left than on the right side because of the greater length of the adrenal vein (21 mm vs. 9 mm) and a greater angle of connection (70° with the left renal vein vs. 40° with the IVC), which explains the lower success rate of cannulation and the more frequent occurrence of blood sample contamination on the right side.

Multifocal, Asymmetric Bilateral Primary Aldosteronism Cannot be Excluded by Strong Adrenal Vein Sampling Lateralization: An International Retrospective Cohort Study

BACKGROUND

Primary aldosteronism (PA) has been broadly dichotomized into unilateral and bilateral forms. Adrenal vein sampling (AVS) lateralization indices (LI) ≥2 to 4 are the standard-of-care to recommend unilateral adrenalectomy for presumed unilateral PA. We aimed to assess the rates and characteristics of residual PA after AVS-guided adrenalectomy.

METHODS

We conducted an international, retrospective, cohort study of patients with PA from 7 referral centers who underwent unilateral adrenalectomy based on LI≥4 on baseline and/or cosyntropin-stimulated AVS. Aldosterone synthase (CYP11B2) immunohistochemistry and next generation sequencing were performed on available formalin-fixed paraffin-embedded adrenal tissue.

RESULTS

The cohort included 283 patients who underwent AVS-guided adrenalectomy, followed for a median of 326 days postoperatively. Lack of PA cure was observed in 16% of consecutive patients, and in 22 patients with lateralized PA on both baseline and cosyntropin-stimulated AVS. Among patients with residual PA postoperatively, 73% had multiple CYP11B2 positive areas within the resected adrenal tissue (versus 23% in those cured), wherein CACNA1D mutations were most prevalent (63% versus 33% in those cured). In adjusted regression models, independent predictors of postoperative residual PA included Black versus White race (odds ratio, 5.10 [95% CI, 1.45-17.86]), AVS lateralization only at baseline (odds ratio, 8.93 [95% CI 3.00-26.32] versus both at baseline and after cosyntropin stimulation), and CT-AVS disagreement (odds ratio, 2.75 [95% CI, 1.20-6.31]).

CONCLUSIONS

Multifocal, asymmetrical bilateral PA is relatively common, and it cannot be excluded by robust AVS lateralization. Long-term postoperative monitoring should be routinely pursued, to identify residual PA and afford timely initiation of targeted medical therapy.

Treatment decision based on unilateral index from nonadrenocorticotropic hormone-stimulated and adrenocorticotropic hormone-stimulated adrenal vein sampling in primary aldosteronism

OBJECTIVE

Adrenal venous sampling (AVS) is recommended for identifying the subtype of primary aldosteronism before making a surgical treatment decision, but failed cannulation of one adrenal vein is common. To evaluate whether using results of one adrenal vein during AVS could accurately predict unilateral primary aldosteronism.

METHODS

A retrospective study was conducted in primary aldosteronism patients receiving bilaterally or unilaterally successful AVS. The aldosterone-cortisol ratio from the adrenal vein divided by the aldosterone-cortisol ratio from the inferior vena cava (IVC) was calculated as the AV/IVC index.

RESULTS

The study examined 455 patients with primary aldosteronism, including 347 patients with unilateral primary aldosteronism. Among them, 250 and 125 patients received non- adrenocorticotropic hormone (ACTH) and ACTH-stimulated AVS, respectively, and 80 patients received both forms of AVS. Under non-ACTH-stimulated AVS, AUC of the AV/IVC index to diagnose ipsilateral and contralateral primary aldosteronism were 0.778 and 0.924, respectively. The specificity was 100% for both, with sensitivities of 5 and 26%, respectively, when using cutoffs of 17.05 to diagnose ipsilateral primary aldosteronism and 0.15 to diagnose contralateral primary aldosteronism. When using cutoffs of 3.60 and 0.70, the specificity decreased, but if combined with CT results (ipsilateral or contralateral adrenal nodules larger than 10 mm), the specificity could be maintained at 99%, with sensitivities of 33 and 45%, respectively. Under ACTH-stimulated AVS, the AV/IVC index showed similar accuracy to diagnose ipsilateral and contralateral primary aldosteronism.

CONCLUSION

The unilateral AV/IVC index can be used to diagnose unilateral primary aldosteronism during AVS. Combining CT results can increase the accuracy further.

Strategies for subtyping primary aldosteronism

Adrenal venous sampling (AVS) is a crucial method for the lateralization of primary aldosteronism (PA). It is advised to halt the use of the patient's antihypertensive medications and correct hypokalemia prior to undergoing AVS. Hospitals equipped to conduct AVS should establish their own diagnostic criteria based on current guidelines. If the patient's antihypertensive medications cannot be discontinued, AVS can be performed as long as the serum renin level is suppressed. The Task Force of Taiwan PA recommends using a combination of adrenocorticotropic hormone stimulation, quick cortisol assay, and C-arm cone-beam computed tomography to maximize the success of AVS and minimize errors by using the simultaneous sampling technique. If AVS is not successful, an NP-59 (131 I-6-β-iodomethyl-19-norcholesterol) scan can be used as an alternative method to lateralize PA. We depicted the details of the lateralization procedures (mainly AVS, and alternatively NP-59) and their tips and tricks for confirmed PA patients who would consider to undergo surgical treatment (unilateral adrenalectomy) if the subtyping shows unilateral disease.

Epidemiology and diagnosis of primary aldosteronism. What have we learned from the SPAIN-ALDO registry?

PURPOSE

To summarize the available data on the prevalence, clinical repercussion, and diagnosis of primary aldosteronism (PA) and to discuss the SPAIN-ALDO registry's findings, which is the largest PA patient registry in Spain.

METHODS

A comprehensive review of the literature focused on the prevalence, clinical presentation and diagnosis of PA was performed.

RESULTS

PA is the most common cause of secondary arterial hypertension. In addition, PA patients have a higher cardio-metabolic risk than patients with essential arterial hypertension matched by age, sex, and blood pressure levels. However, despite its high prevalence and associated metabolic and cardiovascular complications, PA remains largely under-recognized, with less than 2% of people in at-risk populations ever tested. The diagnostic investigation is a multistep process, including screening, confirmatory testing, and subtype differentiation of unilateral from bilateral PA forms. Data from the SPAIN-ALDO registry have shed light on the cardiometabolic impact of PA and about the limitations in the PA diagnosis of these patients in Spain.

CONCLUSIONS

The most common cause of secondary hypertension is PA. One of the most challenging aspects of the diagnosis is the differentiation between unilateral and bilateral PA because adrenal venous sampling is a difficult procedure that should be performed in experienced centers. Data from the SPAIN-ALDO registry have provided important information on the nationwide management of this pathology.

The where, who and how of adrenal vein sampling in Australia and New Zealand

INTRODUCTION

Primary aldosteronism (PA) causes 10-15% of cases of hypertension, and it is increasingly recognised as being under-diagnosed. An interventional radiology procedure, adrenal vein sampling (AVS), is a necessary and important diagnostic procedure for complete workup of PA. There is an anticipated increase in demand for AVS as detection of PA improves. This study aims to describe the current landscape of AVS in Australia and New Zealand (NZ).

METHODS

Two surveys exploring AVS methodology and performance were conducted of (i) Endocrinology Unit Heads and (ii) interventional radiologists who perform AVS, at public hospitals with Endocrinology Units across Australia and NZ.

RESULTS

Responses were received from 48/53 Endocrinology Unit Heads (91%) and 35 radiologists from 26 sites (87% of AVS sites). AVS was provided at 28/48 Endocrinology sites (58%) across Australia and NZ. In Australia, sites were concentrated in Victoria, New South Wales and Queensland with none in the Northern Territory; in NZ, sites were more evenly distributed across the North and South Islands. AVS was performed by 1-2 dedicated radiologists at 24 sites, 2-3 radiologists at two sites and a rotating roster of radiologists at two sites. Responses to both surveys revealed significant variation in AVS methodology and interpretation of AVS results.

CONCLUSION

There is significant heterogeneity in the availability of AVS, the procedural details and the interpretation of results across Australia and NZ, which potentially impacts the quality of patient care and ability to scale up AVS capacity to meet increasing demand.

Diagnostic consistency between computed tomography and adrenal vein sampling of primary aldosteronism: leading to successful curative outcome after adrenalectomy; a retrospective study

BACKGROUND

Adrenal computed tomography (CT) is a useful tool for locating adrenal lesion in primary aldosteronism (PA) patients. However, adrenal vein sampling (AVS) is considered as a gold standard for subtype diagnosis of PA. The aim of this study was to investigate the consistency of CT and AVS for the diagnosis of PA subtypes and evaluate the concordance of surgical outcomes.

MATERIALS AND METHODS

This retrospective study included 264 PA patients having both CT and AVS. Diagnostic consistency between CT and AVS was accessed, and clinical and biochemical outcomes were evaluated at 6 months after adrenalectomy.

RESULTS

Of all, 207 (78%) had a CT unilateral lesion, 31 (12%) CT bilateral lesion, and 26 (10%) CT bilateral normal findings. Among the CT unilateral lesion group, 138 (67%) had ipsilateral AVS lateralization. For CT bilateral lesion and bilateral normal, AVS unilateral lateralization was found in 17 (55%) and 2 (8%), respectively. The consistency between CT lesion and AVS lateralization including CT unilateral with AVS ipsilateral, and CT bilateral lesion with AVS bilateral patients was 63.8% (152/238). Of 77 patients with available data out of 138 patients who underwent adrenalectomy with consistency between CT and AVS, the clinical success rate was 96%, for 17 inconsistency patients out of 22 patients who underwent adrenalectomy, the clinical success rate was 94% after adrenalectomy following the lateralization result of AVS.

CONCLUSION

CT is a useful tool to diagnose the adrenal lesion in PA patients. However, AVS is more sufficient to detect the unilateral PA subtype, which could provide curable treatment to surgical candidates of PA such that AVS can identify patients with contralateral PA in CT unilateral lesion and unilateral PA in CT bilateral lesion. The surgical outcome was successful when an adrenalectomy was performed according to the AVS lateralization result.

Developing the novel diagnostic model and potential drugs by integrating bioinformatics and machine learning for aldosterone-producing adenomas

Background: Aldosterone-producing adenomas (APA) are a common cause of primary aldosteronism (PA), a clinical syndrome characterized by hypertension and electrolyte disturbances. If untreated, it may lead to serious cardiovascular complications. Therefore, there is an urgent need for potential biomarkers and targeted drugs for the diagnosis and treatment of aldosteronism. Methods: We downloaded two datasets (GSE156931 and GSE60042) from the GEO database and merged them by de-batch effect, then screened the top50 of differential genes using PPI and enriched them, followed by screening the Aldosterone adenoma-related genes (ARGs) in the top50 using three machine learning algorithms. We performed GSEA analysis on the ARGs separately and constructed artificial neural networks based on the ARGs. Finally, the Enrich platform was utilized to identify drugs with potential therapeutic effects on APA by tARGseting the ARGs. Results: We identified 190 differential genes by differential analysis, and then identified the top50 genes by PPI, and the enrichment analysis showed that they were mainly enriched in amino acid metabolic pathways. Then three machine learning algorithms identified five ARGs, namely, SST, RAB3C, PPY, CYP3A4, CDH10, and the ANN constructed on the basis of these five ARGs had better diagnostic effect on APA, in which the AUC of the training set is 1 and the AUC of the validation set is 0.755. And then the Enrich platform identified drugs tARGseting the ARGs with potential therapeutic effects on APA. Conclusion: We identified five ARGs for APA through bioinformatic analysis and constructed Artificial neural network (ANN) based on them with better diagnostic effects, and identified drugs with potential therapeutic effects on APA by tARGseting these ARGs. Our study provides more options for the diagnosis and treatment of APA.

2023 Korean Endocrine Society Consensus Guidelines for the Diagnosis and Management of Primary Aldosteronism

Primary aldosteronism (PA) is a common, yet underdiagnosed cause of secondary hypertension. It is characterized by an overproduction of aldosterone, leading to hypertension and/or hypokalemia. Despite affecting between 5.9% and 34% of patients with hypertension, PA is frequently missed due to a lack of clinical awareness and systematic screening, which can result in significant cardiovascular complications. To address this, medical societies have developed clinical practice guidelines to improve the management of hypertension and PA. The Korean Endocrine Society, drawing on a wealth of research, has formulated new guidelines for PA. A task force has been established to prepare PA guidelines, which encompass epidemiology, pathophysiology, clinical presentation, diagnosis, treatment, and follow-up care. The Korean clinical guidelines for PA aim to deliver an evidence-based protocol for PA diagnosis, treatment, and patient monitoring. These guidelines are anticipated to ease the burden of this potentially curable condition.

Key to the Treatment of Primary Aldosteronism in Secondary Hypertension: Subtype Diagnosis

PURPOSE OF REVIEW

Primary aldosteronism (PA) is a leading global cause of secondary hypertension. Subtyping diagnosis of PA is the key to surgery, but accurate classification of PA is crucial but challenging in clinical diagnosis and treatment. The purpose of this review is to provide a summary of current literature and propose subtyping diagnosis flow chart to help us classify PA quickly and accurately.

RECENT FINDINGS

Early diagnosis and accurate typing are essential for the timely treatment and appropriate management of PA. For most patients, adrenal venous sampling (AVS) is the central choice for typing diagnosis, but AVS is invasive and difficult to promote effectively. CT can help identify unilateral typical adenomas in select patients to avoid AVS. New radionuclide imaging has shown value in the diagnosis and classification of PA, which distinguishes adrenocortical hyperplasia from adenoma and can replace AVS in some patients. Accurately diagnosing unilateral PA is crucial for determining the appropriate treatment strategy for PA. The simple flow chart of PA subtyping diagnosis based on the current literature needs to be verified and evaluated by follow-up researches.

Differences between left adrenal vein sampling sites revealed with segmental sampling in primary aldosteronism

OBJECTIVES

To clarify the differences between two left sampling sites (left adrenal central vein [LCV] and common trunk [CMT], conjunction with LCV and inferior phrenic vein) and their impact on adrenal venous sampling (AVS) in primary aldosteronism by analyzing the results of segmental AVS (sAVS).

METHODS

We retrospectively analyzed a final cohort of 432 patients who underwent cosyntropin-stimulated sAVS from 2017 to 2020. Hormone levels in the LCV and the CMT were compared. Subtype diagnosis was based on the lateralization index with LCV and CMT sampling (a cutoff value of 4) and sAVS after excluding patients with a selectivity index (SI) <3.

RESULTS

Compared with the LCV, CMT sampling showed significantly lower aldosterone and cortisol levels and a higher proportion of cases with an SI of <3 (2.8% vs 0.5%, p = 0.025) and <5 (6.9% vs 0.5%, p < 0.001), while the aldosterone-to-cortisol ratio and the lateralization index were not significantly different. Subtyping of both sites was concordant in 94.7% (393/415) and discordant in the remainder, which included left and right aldosterone-producing adenoma and idiopathic hyperaldosteronism cases referring to the sAVS. There was no significant difference between the concordance rate of the two sampling sites based on the sAVS diagnosis.

CONCLUSIONS

LCV sampling meets the SI criteria for successful AVS more frequently compared with CMT sampling, but neither was better than the other in terms of diagnosis under conditions of meeting the criteria.

ADVANCES IN KNOWLEDGE

LCV sampling would decrease the number of cases judged as AVS failure.

Surgery based on computed tomography images might be feasible for primary aldosteronism patients with visible unilateral adenoma

Primary aldosteronism (PA) with unilateral adrenal disease can be cured or improved by adrenalectomy. Adrenal venous sampling (AVS) is recommended to identify patients for surgical management. However, surgeries based on computed tomography (CT) images are only advocated for PA patients aged <35 with visible unilateral adenoma. Herein, we aimed to compare CT-based and AVS-based surgery outcomes for PA patients with visible unilateral adenomas for different age groups. A total of 178 PA patients who underwent unilateral adrenalectomy between June 2018 and January 2021 were included in the study based on CT (n = 54) or AVS (n = 124). Demographics, diagnostics, and follow-up data were retrospectively collected. Clinical and biochemical outcomes were analyzed according to Primary Aldosteronism Surgical Outcome (PASO) criteria at 1-year follow-up. Our results showed that complete clinical success (46.3% vs. 47.6%, p = 0.875) and complete biochemical success (88.8% vs. 91.9%, p = 0.515) were similar between the two groups. Age stratification revealed that patients >55 years old were likely to have worse biochemical outcomes; however, these were still not significantly different (21.4% vs. 8.6%, p = 0.220). Of the 114 AVS-based patients who achieved complete biochemical success, 37 (32.4%) with bilateral normal or bilateral abnormal CT images changed treatment options according to AVS results, 1 (0.9%) avoided adrenalectomy on the wrong side. Our results indicated that surgery based on CT images might be feasible for highly selected PA patients with visible unilateral adenomas and less limited by age, while for those with normal adrenal or bilateral adrenal lesions, treatment strategy must be decided by AVS.

Corticotropin Stimulation in Adrenal Venous Sampling for Patients With Primary Aldosteronism: The ADOPA Randomized Clinical Trial

Importance

Adrenal venous sampling (AVS) is usually recommended to distinguish between unilateral and bilateral primary aldosteronism (PA) before definitive surgical or medical treatment is offered. Whether a treatment decision based on AVS with or without corticotropin (ACTH) stimulation leads to different biochemical and clinical remission rates in patients with PA remains unclear.

Objective

To evaluate whether treatment decisions based on AVS with or without ACTH stimulation lead to different biochemical and clinical remission rates in patients with PA.

Design, Setting, and Participants

This randomized clinical trial (RCT) was conducted at a tertiary hospital in China from July 8, 2020, to February 20, 2023, among patients with PA aged 18 to 70 years. Patients were followed up for 12 months after the initiation of treatment. An intention-to-diagnose analysis was conducted.

Interventions

Patients were randomly assigned to undergo either ACTH-stimulated or non-ACTH-stimulated AVS.

Main Outcomes and Measures

The primary end point was the proportion of patients with complete biochemical remission after 12 months of follow-up. Secondary outcomes included the proportion of patients who achieved complete clinical remission after 12 months of follow-up, dosages of antihypertensive agents, rate of successful bilateral AVS, and adverse events.

Results

Of 228 patients with PA, 115 were randomized to the non-ACTH-stimulated group (median age, 50.0 years [IQR, 41.0-57.0 years]; 70 males [60.9%]) and 113 to the ACTH-stimulated group (median age, 50.0 years [IQR, 43.5-56.5 years]; 63 males [55.8%]). A total of 68 patients (59.1%) underwent adrenalectomy in the non-ACTH group and 65 (57.5%) in the ACTH group. There was no significant difference in the proportion of patients with complete biochemical remission who were managed on the basis of AVS with vs without ACTH stimulation (with: 56 of 113 [49.6%]; without: 59 of 115 [51.3%]; P = .79). There also was no significant difference in the proportion of patients who achieved complete clinical remission between the non-ACTH and ACTH groups (26 of 115 [22.6%] and 31 of 113 [27.4%], respectively; P = .40). The intensity of therapy with antihypertensives, successful catheterization of bilateral adrenal veins, and incidence of adverse events did not significantly differ between the non-ACTH and ACTH groups.

Conclusions and Relevance

In this RCT, treatment of PA on the basis of non-ACTH-stimulated or ACTH-stimulated AVS did not lead to significant differences in clinical outcomes for the patients. These results suggest that ACTH stimulation during AVS may not have clinical benefit, at least in the Chinese population.

Trial Registration

ClinicalTrials.gov Identifier: NCT04461535.

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.

18-Oxocortisol: A journey

The search for mineralocorticoids to explain some cases of low renin hypertension with suppressed aldosterone levels led to the isolation of the abundant steroid 18-hydroxycortisol in human urine. 18-Hydroxycortisol proved to be inactive, but because of its similarity to precursors for the synthesis of aldosterone, bullfrog adrenals were incubated with cortisol, resulting in the discovery of 18-oxocortisol which is structurally similar to aldosterone, but with a 17α-hydroxy group like cortisol. 18-Oxocortisol is a weak mineralocorticoid. Its synthesis occurs primarily in the zona glomerulosa where co-expression of the CYP11B2 (aldosterone synthase) and the CYP17A1 (17α-hydroxylase) occurs in a variable number of cells. The clinical value of the measurement of 18-oxocortisol is that it serves to distinguish subtypes of primary aldosteronism. It is significantly elevated in patients with aldosterone-producing adenomas in comparison to those with idiopathic bilateral hyperaldosteronism and helps predict the type of somatic mutation in the aldosterone-producing adenomas, as it is higher in those with KCNJ5 mutations compared to other gene mutations.

The performance of left/right adrenal volume ratio and volume difference in predicting unilateral primary aldosteronism

PURPOSE

The role of computed tomography (CT) in the diagnosis of primary aldosteronism (PA) warrants attention, since the success application of adrenal venous sampling (AVS) remains limited. We aimed to investigate the value of CT-based volumetric indicators, including left-versus-right-adrenal-volume ratio (L/Rv) and left-subtract-right-adrenal-volume difference (L - Rv), in the diagnosis of unilateral primary aldosteronism (UPA).

METHODS

A retrospective case-control study included 153 patients with PA and 1272 controls. AVS was used to classify patients into bilateral disease, left-sided disease, and right-sided disease groups.

RESULTS

Adrenal gland volume on both sides of PA patients was significantly larger than controls. The optimal cutoff values of L/Rv and L - Rv were 1.417 [area under the curve (AUC) 0.864] and 1.185 (AUC 0.827), respectively, for the diagnosis of left-sided PA, and 1.030 (AUC 0.767) and 0.220 (AUC 0.769), respectively, for the diagnosis of right-sided PA. The mean AUC for subsequent cross-validation ranged from 0.77 ± 0.03 to 0.86 ± 0.02. Based on the optimal cutoff values, the combination of L/Rv and L - Rv detected 69.6% of patients with left-sided PA and 74.3% of patients with right-sided PA, with a specificity of 93.5% and 89.0%, respectively. For a better clinical application, we reported the sub-optimal cutoffs corresponding to a specificity of 95%. A L/Rv higher than 1.431 and a L - Rv higher than 3.185 as sub-optimal cutoff values was detected in 26.1% of patients with left-sided PA (specificity: 97.2%). A L/Rv smaller than 0.892 and a L - Rv smaller than -0.640 could detect 48.6% of patients with right-sided PA (specificity: 97.5%).

CONCLUSIONS

CT-based L/Rv and L - Rv performed well in predicting UPA. The combination of L/Rv and L - Rv may serve as a potential indicator for guiding surgical decision making in centers without AVS programs.

The adrenal vein sampling outcomes study (AVOS): success rates following adrenalectomy for unilateral primary aldosteronism

The objective was to determine the clinical and biochemical success rates and assess the nature of follow-up after adrenalectomy in patients with unilateral primary aldosteronism (PA), subtyped by adrenal vein sampling (AVS) in West Australia (WA) using the Primary Aldosteronism Surgical Outcome (PASO) criteria. Clinical and biochemical outcomes were retrospectively evaluated in patients with unilateral PA who underwent adrenalectomy according to AVS between September 2017 and September 2020. Pre- and post-surgical data were collected using a standardised questionnaire, review of clinic letters and examination of private and public pathology results and radiological reports. Follow-up data were available for 47 patients post-adrenalectomy; biochemical outcome data were available for 37 patients, clinical outcome data for 40 patients, with 30 patients having both outcomes available. Final assessment was performed between 0 to 3 months in 23/37 (62.2%) patients with biochemical outcomes, 15/40 (37.5%) with clinical outcomes, and 17/30 (56.7%) with both clinical and biochemical outcomes. Complete biochemical success was achieved in 83.8% (31/37) of patients, with 26.7% (8/30) obtaining both complete clinical and biochemical success. Complete clinical success was achieved in 35.0% (14/40) of patients, with 47.5% (19/40) obtaining partial clinical success. Overall, 93.6% (44/47) of patients derived benefit from adrenalectomy. The outcomes of adrenalectomy for unilateral PA in Western Australian using standardised PASO criteria demonstrate highly comparable clinical and biochemical success rates to international data. However, further standardisation of post-operative follow-up care needs to be implemented to ensure the recommended repeat follow-up assessment criteria are collected.

Endovascular image-guided sampling of tumor-draining veins provides an enriched source of oncological biomarkers

Introduction

Circulating tumor-derived biomarkers can potentially impact cancer management throughout the continuum of care. This small exploratory study aimed to assess the relative levels of such biomarkers in the tumor-draining vascular beds in patients with solid tumors compared to levels in their peripheral veins.

Methods

Using an endovascular image-guided approach, we obtained blood samples from peripheral veins and other vascular compartments–including the most proximal venous drainage from solid tumors–from a set of nine oncology patients with various primary and metastatic malignancies. We then interrogated these samples for a panel of oncological biomarkers, including circulating tumor cells (CTCs), exosome-derived microRNAs (miRNAs), circulating tumor DNA (ctDNA) mutations, and certain cancer-related proteins/biochemical markers.

Results

We found substantially higher levels of CTCs, certain miRNAs, and specific ctDNA mutations in samples from vascular beds closer to the tumor compared with those from peripheral veins and also noted that some of these signals were altered by treatment procedures.

Discussion

Our results indicate that tumor-proximal venous samples are highly enriched for some oncological biomarkers and may allow for more robust molecular analysis than peripheral vein samples.

Accuracy of Gallium-68 Pentixafor Positron Emission Tomography-Computed Tomography for Subtyping Diagnosis of Primary Aldosteronism

IMPORTANCE

Adrenal vein sampling (AVS) is the recommended procedure for subtyping primary aldosteronism (PA) as unilateral PA (UPA) or bilateral PA (BPA), with different treatment needed for each: adrenalectomy for UPA and medication for BPA. However, AVS is invasive and technically difficult, and how to subtype PA noninvasively is currently a great challenge.

OBJECTIVE

To evaluate the accuracy of gallium-68 pentixafor positron emission tomography-computed tomography (PET-CT) in subtyping PA using AVS as a reference standard.

DESIGN, SETTING, AND PARTICIPANTS

This diagnostic study was conducted at a tertiary hospital in China among patients diagnosed with PA. Enrollment was started in November 2021, with follow-up ending in May 2022.

EXPOSURES

: Patients were recruited to undergo gallium-68 pentixafor PET-CT and AVS.

MAIN OUTCOMES AND MEASURES

Maximum standardized uptake value (SUVmax) of each adrenal gland during PET-CT was measured to calculate the lateralization index of SUVmax. Area under the receiver operating characteristic curve (AUROC), specificity, and sensitivity were used to analyze the accuracy of the lateralization index based on SUVmax for subtyping PA.

RESULTS

Among 100 patients with PA who completed the study (47 female [47.0%] and 53 male [53.0%]; median [IQR] age, 49 [38-56] years), 43 individuals had UPA and 57 individuals had BPA. Aldosterone-cortisol ratio (Spearman ρ = 0.26; P < .001) in adrenal veins was positively correlated with SUVmax of adrenal glands at 10 minutes during PET-CT. Using lateralization index based on SUVmax at 10 minutes to identify UPA, the AUROC was 0.90 (95% CI, 0.83-0.97). A cutoff value for lateralization index based on SUVmax at 10 minutes set at 1.65 conferred a specificity of 1.00 (95% CI, 0.94-1.00) and sensitivity of 0.77 (95% CI, 0.61-0.88). The diagnostic concordance rate of PET-CT and AVS was 90 patients (90.0%) compared with 54 patients (54.0%) between traditional CT and AVS.

CONCLUSIONS AND RELEVANCE

This study found good diagnostic accuracy of gallium-68 pentixafor PET-CT in differentiating UPA from BPA. These findings suggest that gallium-68 pentixafor PET-CT may be used to avoid invasive AVS in some patients with PA.

First survey on the diagnosis and treatment of primary aldosteronism by Spanish Endocrinology and Nutrition specialists

OBJECTIVE

To evaluate the indication and the resources for the screening/diagnosis of primary aldosteronism (PA) in Endocrinology units in Spain.

MATERIAL AND METHODS

An anonymous 2-phase (2020/2021) online survey was conducted by the AdrenoSEEN group among SEEN members with data about screening, confirmation tests, availability of catheterisation and the treatment of PA.

RESULTS

Eighty-eight (88) specialists completed the survey. Plasma aldosterone concentration and plasma renin activity were available at all centres; urinary aldosterone was available in 55% of them. The most frequent indications for determining the aldosterone/renin ratio (ARR) were adrenal incidentaloma (82.6%), hypertension with hypokalaemia (82.6%), hypertension in patients <40 years (79.1%) and a family history of PA (77.9%). 61% and 18% of the respondents used an ARR cut-off value of PA of ≥30 and 20ng/dl per ng/mL/, respectively. The intravenous saline loading test was the most commonly used confirmatory test (66.3%), followed by the captopril challenge test (24.4%), with the 25mg dose used more than the 50mg dose (65% versus 35%). 67.4% of the participants confirmed the availability of adrenal vein catheterization (AVC). 41% of this subgroup perform it with a continuous infusion versus 30.5% with an ACTH (1-24) bolus, whereas 70.3% employ sequential adrenal vein catheterization. 48% of the participants reported an AVC success <50%. Total laparoscopic adrenalectomy was the treatment of choice (90.6%), performed by specialists in General and Digestive Surgery specialising in endocrinological pathology.

CONCLUSION

PA screening and diagnostic tests are extensively available to Spanish endocrinologists. However, there is a major variability in their use and in the cut-off points of the diagnostic methods. The AVS procedure remains poorly standardised and is far from delivering optimal performance. Greater standardisation in the study and diagnosis of PA is called for.

Subtyping primary aldosteronism by inconclusive adrenal vein sampling: A derivation and validation study in a tertiary centre

OBJECTIVE

Indices based on aldosterone/cortisol (A/C) concentration in the successfully cannulated adrenal vein (AV) and in the inferior vena cava (IVC) (AV/IVC) appear to be possible markers to verify the subtype of primary aldosteronism (PA) in the case of inconclusive results of adrenal vein sampling (AVS). The variability of results in previous studies encouraged us to calculate AV/IVC and adrenal A/C cutoff values that could predict the aetiology of PA.

METHODS

This retrospective study included 96 patients who underwent AVS due to PA between 2015 and 2020. The derivation cohort ultimately consisted of 60 patients with bilaterally successful AVS and a clear diagnosis of unilateral or bilateral disease. Receiver operating characteristic analysis was used to find the optimal A/C and AV/IVC cutoff values predicting the subtype of PA. The validation cohort consisted of 11 patients with either unsuccessful cannulation or a borderline lateralization index (LI), those patients underwent adrenalectomy because their indices were suggestive of unilateral disease based on the derivation cohort data.

RESULTS

The cutoff values of A/C ≤ 0.63 or AV/IVC ≤ 0.37 identified unaffected glands with a sensitivity of 91.2% and 97.1%, respectively, and a specificity of 90.7% and 88.4%, respectively. Unilateral ipsilateral gland involvement was characterized by A/C ≥ 3.5 or AV/IVC ≥ 3.4 with a corresponding specificity of 100%. All patients in the validation cohort achieved biochemical remission postoperatively.

CONCLUSIONS

A/C and AV/IVC cutoff values could be a useful tool to determine the subtype of PA in patients with unilateral successful AVS as well as in patients with a borderline LI.

Primary aldosteronism - a multidimensional syndrome

Primary aldosteronism is a common cause of hypertension and is a risk factor for cardiovascular and renal morbidity and mortality, via mechanisms mediated by both hypertension and direct insults to target organs. Despite its high prevalence and associated complications, primary aldosteronism remains largely under-recognized, with less than 2% of people in at-risk populations ever tested. Fundamental progress made over the past decade has transformed our understanding of the pathogenesis of primary aldosteronism and of its clinical phenotypes. The dichotomous paradigm of primary aldosteronism diagnosis and subtyping is being redefined into a multidimensional spectrum of disease, which spans subclinical stages to florid primary aldosteronism, and from single-focal or multifocal to diffuse aldosterone-producing areas, which can affect one or both adrenal glands. This Review discusses how redefining the primary aldosteronism syndrome as a multidimensional spectrum will affect the approach to the diagnosis and subtyping of primary aldosteronism.

Prevalence and Characteristics of Adrenal Tumors in an Unselected Screening Population : A Cross-Sectional Study

BACKGROUND

With the widespread use of advanced imaging technology, adrenal tumors are increasingly being identified.

OBJECTIVE

To investigate the prevalence and characteristics of adrenal tumors in an unselected screening population in China.

DESIGN

Cross-sectional study. (ClinicalTrials.gov: NCT04682938).

SETTING

A health examination center in China.

PATIENTS

Adults having an annual checkup were invited to be screened for adrenal tumors by adrenal computed tomography.

MEASUREMENTS

The participants with adrenal tumors had further evaluation for malignancy risk and adrenal function.

RESULTS

A total of 25 356 participants were screened, 351 of whom were found to have adrenal tumors, for a prevalence of 1.4%. The prevalence increased with age, from 0.2% in participants aged 18 to 25 years to 3.2% in those older than 65 years. Among 351 participants with adrenal tumors, 337 were diagnosed with an adrenocortical adenoma, 14 with another benign nodule, and none with a malignant mass. In 212 participants with an adenoma who completed endocrine testing, 69.3% were diagnosed with a nonfunctioning adenoma, 18.9% with cortisol autonomy, 11.8% with primary aldosteronism, and none with pheochromocytoma. Proportions of nonfunctioning adenomas were similarly high in various age groups (72.2%, 67.8%, and 72.2% in those aged <46, 46 to 65, and ≥66 years, respectively).

LIMITATION

Only 212 of 337 participants with an adrenocortical adenoma had endocrine testing.

CONCLUSION

The prevalence of adrenal tumors in the general adult screening population is 1.4%, and most of these tumors are nonfunctioning regardless of patient age. Cortisol and aldosterone secretion are the main causes of functional adenomas.

PRIMARY FUNDING SOURCE

National Key Research and Development Program of China and National Natural Science Foundation of China.

Development and validation of model for sparing adrenal venous sampling in diagnosing unilateral primary aldosteronism

CONTEXT

Current guidelines recommend adrenal venous sampling (AVS) to identify unilateral primary aldosteronism (UPA) before offering adrenalectomy. However, AVS is costly and technically challenging, limiting its use to expert centres.

OBJECTIVE

To establish a model to predict UPA, and therefore, bypass the need for AVS prior to surgery.

DESIGN AND SETTING

The model was developed in a Chinese cohort and validated in an Australian cohort. Previously published prediction models of UPA were also tested.

PARTICIPANTS

primary aldosteronism patients with a definite subtyping diagnosis based on AVS and/or surgery.

MAIN OUTCOME MEASURE

Diagnostic value of the model.

RESULTS

In the development cohort (268 UPA and 88 bilateral primary aldosteronism), combinations of different levels of low serum potassium (≤3.0 or 3.5 mmol/l), high PAC (≥15-30 ng/dl), low PRC (≤2.5-10 μIU/ml) and presence of unilateral nodule on adrenal CT (>8-15 mm in diameter) showed specificity of 1.00 and sensitivity of 0.16-0.52. The model of serum potassium 3.5 mmol/l or less, PAC at least 20 ng/dl, PRC 5 μIU/ml or less plus a unilateral nodule at least 10 mm had the highest sensitivity of 0.52 (0.45-0.58) and specificity of 1.00 (0.96-1.00). In the validation cohort (84 UPA and 117 bilateral primary aldosteronism), the sensitivity and specificity of the model were 0.13 (0.07-0.22) and 1.00 (0.97-1.00), respectively. Ten previous models were tested, and only one had a specificity of 1.00 in our cohorts but with a very low sensitivity [0.07 (0.04-0.10) and 0.01 (0.00-0.06) in our development and validation cohorts, respectively].

CONCLUSION

A combination of high PAC, low PRC, low serum potassium and unilateral adrenal nodule could accurately determine primary aldosteronism subtype in 13-52% of patients with UPA and obviate the need for AVS before surgery.

Prevalence and clinical characteristics of primary aldosteronism in a tertiary-care center in Korea

Approximately 29% of Korean adults have hypertension; however, the prevalence of primary aldosteronism among the hypertensive population is largely unknown. The aim of our study was to evaluate the prevalence and clinical characteristics of primary aldosteronism in a tertiary-care center in Korea. We retrospectively analyzed 1173 patients with newly diagnosed or preexisting hypertension who were referred to our tertiary-care hospital between January 2013 and December 2018. Patients were screened for primary aldosteronism with the aldosterone-renin ratio and underwent a saline infusion test for diagnostic confirmation. Adrenal computed tomography and adrenal venous sampling were performed for subtype classification for primary aldosteronism. Among the 1173 patients (mean age, 51.8 years; women, 53.2%), 360 (30.7%) had positive screening-test results, of whom 71 (6.1%) were finally diagnosed with primary aldosteronism. Conclusive subtype differentiation was made in 55 patients, of whom 15 (27%) had an aldosterone-producing adenoma, 4 (7%) had unilateral adrenal hyperplasia, and 36 (66%) had bilateral adrenal hyperplasia. Patients with primary aldosteronism had a higher ambulatory blood pressure, left ventricular mass index, and urinary albumin-to-creatinine ratio than those without. Moreover, the primary aldosteronism group had a higher prevalence of left ventricular hypertrophy and albuminuria than the non-primary aldosteronism group. Primary aldosteronism may be more common (6.1%) among Korean patients with hypertension than generally recognized. Primary aldosteronism was associated with a higher degree and prevalence of target organ damage and a higher blood pressure level. Wide application of screening tests for primary aldosteronism may be beneficial in detecting this potentially curable cause of hypertension.

Usefulness and accuracy of segmental adrenal venous sampling on localisation and functional diagnosis of various adrenal lesions in primary aldosteronism

AIM

To clarify the usefulness and accuracy of segmental adrenal venous sampling (sAVS) on localisation and functional diagnosis of various adrenal lesions in primary aldosteronism.

MATERIALS AND METHODS

Consecutive patients (n=162) who underwent adrenalectomy and 138 patients indicated for medication following sAVS were analysed retrospectively. Based on immunohistopathological diagnosis, the positive predictive value (PPV) of computed tomography (CT)-detectable aldosterone-producing adenoma (APA) was calculated. Moreover, endocrinological and sAVS characteristics were analysed quantitatively and qualitatively among APA, CT-undetectable aldosterone-producing nodules (APNs), multiple aldosterone-producing micronodules (MAPM), and medication groups.

RESULTS

The PPV of APA by sAVS was 137/141 (97.1%; 95% confidence interval, 92.9-99.2%). Compared to the medication cases, the APA group showed stronger disease activity clinically and significant differences in adrenal hormones, such as a higher aldosterone level and aldosterone-to-cortisol ratio, and lower cortisol levels in the adrenal central vein and aldosterone maximum tributaries on the dominant side after cosyntropin stimulation. The APA group shows focal aldosterone hypersecretion, such as mean number of aldosterone elevated segments (1.7 ± 0.7 versus 2 ± 0.9, p=0.003) and presence of aldosterone-not-elevated segments (93% versus 41%, p<0.001). Clinically and in terms of sAVS, APN and MAPM showed similar characteristics to APA and to the medication cases, respectively.

CONCLUSION

sAVS can localise functionally active tissues of CT-detectable and CT-undetectable lesions enabling decisions on surgical or medical treatment.

Case Report: Primary Aldosteronism and Subclinical Cushing Syndrome in a 49-Year-Old Woman With Hypertension Plus Hypokalaemia

Background

Coexisting primary aldosteronism (PA) and subclinical Cushing's syndrome (SCS) caused by bilateral adrenocortical adenomas have occasionally been reported. Precise diagnosis and treatment of the disease pose a challenge to clinicians due to its atypical clinical manifestations and laboratory findings.

Case Summary

A 49-year-old woman was admitted to our hospital due to fatigue, increased nocturia and refractory hypertension. The patient had a history of severe left hydronephrosis 6 months prior. Laboratory examinations showed hypokalaemia (2.58 mmol/L) and high urine potassium (71 mmol/24 h). Adrenal computed tomography (CT) showed bilateral adrenal masses. Undetectable ACTH and unsuppressed plasma cortisol levels by dexamethasone indicated ACTH-independent Cushing's syndrome. Although the upright aldosterone-to-renin ratio (ARR) was 3.06 which did not exceed 3.7, elevated plasma aldosterone concentrations (PAC) with unsuppressed PAC after the captopril test still suggested PA. Adrenal venous sampling (AVS) without adrenocorticotropic hormone further revealed hypersecretion of aldosterone from the right side and no dominant side of cortisol secretion. A laparoscopic right adrenal tumor resection was performed. The pathological diagnosis was adrenocortical adenoma. After the operation, the supine and standing PAC were normalized; while the plasma cortisol levels postoperatively were still high and plasma renin was activated. The patient's postoperative serum potassium and 24-h urine potassium returned to normal without any pharmacological treatment. In addition, the patient's blood pressure was controlled normally with irbesartan alone.

Conclusion

Patients with refractory hypertension should be screened for the cause of secondary hypertension. AVS should be performed in patients in which PA is highly suspected to determine whether there is the option of surgical treatment. Moreover, patients with PA should be screened for hypercortisolism, which can contribute to a proper understanding of the AVS result.

Indices of ACTH-stimulated adrenal venous sampling as predictors of postsurgical outcomes in primary aldosteronism

OBJECTIVE

This study aimed to investigate the impact of indices of adrenal venous sampling (AVS) on postsurgical outcomes in patients with primary aldosteronism (PA).

DESIGN AND PATIENTS

This retrospective study determined biochemical and clinical outcomes based on ACTH-stimulated AVS parameters (lateralisation index [LI], contralateral ratio [CLR], and ipsilateral ratio [ILR]) in 251 patients with PA at 3 months after surgery.

RESULTS

Modified complete biochemical success was achieved in 8 of 12 (66.7%) patients with LI = 3-4, 39 of 47 (83.0%) with LI = 4-10, and 155 of 169 (91.7%) with LI ≥ 10 (p = .004 for trend). Modified complete biochemical success was achieved in 29 of 38 (76.3%) patients with CLR ≥ 1 and ILR ≤ 2, 73 of 86 (84.9%) with CLR = 0.25-1 and ILR > 2, and 100 of 104 (96.2%) with CLR < 0.25 and ILR > 2 (p = .001 for trend). After adjusting for confounders, modified complete biochemical success was associated with an LI ≥ 10 (odds ratio [OR] = 6.32; 95% confidence interval [CI] = 1.33-29.93) using LI = 3-4 as a reference and combined CLR < 0.25 and ILR > 2 (OR = 11.49; 95% confidence interval [CI] = 2.49-53.01) using combined CLR ≥ 1 and ILR ≤ 2 as a reference. Using combined CLR ≥ 1 and ILR ≤ 2 as a reference, complete clinical success was associated with combined CLR < 0.25 and ILR > 2 (OR = 3.10; 95% CI = 1.03-9.28) and combined CLR = 0.25-1 and ILR > 2 (OR = 4.92; 95% CI = 1.64-14.76).

CONCLUSION

LI ≥ 10 may be appropriate for achieving biochemical success. With ILR > 2, CLR < 0.25, and CLR < 1 may be appropriate for achieving biochemical and clinical success, respectively.

Outcome-Based Decision-Making Algorithm for Treating Patients with Primary Aldosteronism

BACKGROUND

Optimal management of primary aldosteronism (PA) is crucial due to the increased risk of cardiovascular and cerebrovascular diseases. Adrenal venous sampling (AVS) is the gold standard method for determining subtype but is technically challenging and invasive. Some PA patients do not benefit clinically from surgery. We sought to develop an algorithm to improve decision- making before engaging in AVS and surgery in clinical practice.

METHODS

We conducted the ongoing Korean Primary Aldosteronism Study at two tertiary centers. Study A involved PA patients with successful catheterization and a unilateral nodule on computed tomography and aimed to predict unilateral aldosterone-producing adenoma (n=367). Study B involved similar patients who underwent adrenalectomy and aimed to predict postoperative outcome (n=330). In study A, we implemented important feature selection using the least absolute shrinkage and selection operator regression.

RESULTS

We developed a unilateral PA prediction model using logistic regression analysis: lowest serum potassium level ≤3.4 mEq/L, aldosterone-to-renin ratio ≥150, plasma aldosterone concentration ≥30 ng/mL, and body mass index <25 kg/m2 (area under the curve, 0.819; 95% confidence interval, 0.774 to 0.865; sensitivity, 97.6%; specificity, 25.5%). In study B, we identified female, hypertension duration <5 years, anti-hypertension medication <2.5 daily defined dose, and the absence of coronary artery disease as predictors of clinical success, using stepwise logistic regression models (sensitivity, 94.2%; specificity, 49.3%). We validated our algorithm in the independent validation dataset (n=53).

CONCLUSION

We propose this new outcome-driven diagnostic algorithm, simultaneously considering unilateral aldosterone excess and clinical surgical benefits in PA patients.

Accurate Location of Catheter Tip With the Free-to-Total Metanephrine Ratio During Adrenal Vein Sampling

BACKGROUND

The selectivity index (SI) of cortisol is used to document correct catheter placement during adrenal vein sampling (AVS) in patients with primary aldosteronism (PA). We aimed to determine the cutoff values of the SIs based on cortisol, free metanephrine, and the free-to-total metanephrine ratio (FTMR) using an adapted AVS protocol in combination with CT.

METHODS

Adults with PA and referred for AVS were recruited in two hypertension centers. The cortisol and free metanephrine-derived SIs were calculated as the concentration of the analyte in adrenal veins divided by the concentration of the analyte in the distal vena cava. The FTMR-derived SI was calculated as the concentration of free metanephrine in the adrenal vein divided by that of total metanephrine in the ipsilateral adrenal vein. The AVS was classified as an unequivocal radiological success (uAVS) if the tip of the catheter was seen in the adrenal vein. The SI cutoffs of each index marker were established using receiver operating characteristic curve analysis.

RESULTS

Out of 125 enrolled patients, 65 patients had an uAVS. The SI cutoffs were 2.6 for cortisol, 10.0 for free metanephrine, 0.31 for the FTMR on the left side, and 2.5, 9.9, and 0.25 on the right side. Compared to free metanephrine and the FTMR, cortisol misclassified AVS as unsuccessful in 36.6% and 39.0% of the cases, respectively.

CONCLUSION

This study is the first to calculate the SIs of cortisol, free metanephrine, and the FTMR indices for the AVS procedure. It confirms that free metanephrine-based SIs are better than those based on cortisol.