Adrenal vein sampling for Primary Aldosteronism: time for a reality check

Treating Primary Aldosteronism-Induced Hypertension: Novel Approaches and Future Outlooks

Primary aldosteronism (PA) is the most common cause of secondary hypertension and is associated with increased morbidity and mortality when compared with blood pressure-matched cases of primary hypertension. Current limitations in patient care stem from delayed recognition of the condition, limited access to key diagnostic procedures, and lack of a definitive therapy option for nonsurgical candidates. However, several recent advances have the potential to address these barriers to optimal care. From a diagnostic perspective, machine-learning algorithms have shown promise in the prediction of PA subtypes, while the development of noninvasive alternatives to adrenal vein sampling (including molecular positron emission tomography imaging) has made accurate localization of functioning adrenal nodules possible. In parallel, more selective approaches to targeting the causative aldosterone-producing adrenal adenoma/nodule (APA/APN) have emerged with the advent of partial adrenalectomy or precision ablation. Additionally, the development of novel pharmacological agents may help to mitigate off-target effects of aldosterone and improve clinical efficacy and outcomes. Here, we consider how each of these innovations might change our approach to the patient with PA, to allow more tailored investigation and treatment plans, with corresponding improvement in clinical outcomes and resource utilization, for this highly prevalent disorder.

Fluorinated aldosterone synthase (CYP11B2)-inhibitors for differential diagnosis between bilateral and unilateral conditions of primary aldosteronism

The enzyme aldosterone synthase (CYP11B2) is specifically expressed in aldosterone-producing tissue of the adrenal cortex and is overexpressed in aldosterone-producing adenomas (APA). It therefore represents an ideal target for molecular imaging, particularly for the differential diagnosis between bilateral hyperplasia and unilateral APA in primary aldosteronism. However, the presence of the cortisol-producing enzyme 11β-hydroxylase (CYP11B1) in the adrenal cortex remains very challenging owing to its high homology to CYP11B2. Within this study, we efficiently synthesized a variety of disubstituted fluorinated pyridines and pyrazines by Suzuki coupling reactions. These compounds were evaluated for their ability to inhibit CYP11B1 and CYP11B2 in transfected Y1 cells and in NCI-h295 cells. Several compounds were found to exhibit excellent affinity (IC50 < 10 nM) to CYP11B2 as well as strong selectivity (up to 125-fold) over CYP11B1. These findings support the further development of an analogous 18F-labelled PET tracer.

Improving the Visualization of the Adrenal Veins Using Virtual Monoenergetic Images from Dual-Energy Computed Tomography before Adrenal Venous Sampling

(1) Background: This study explored the optimal energy level in advanced virtual monoenergetic images (VMI+) from dual-energy computed tomography angiography (DE-CTA) for adrenal veins visualization before adrenal venous sampling (AVS). (2) Methods: Thirty-nine patients were included in this prospective single-center study. The CT value, noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured in both adrenal veins and abdominal solid organs and were then compared between VMI+ within the range of 40-80 kiloelectron volt (keV). The visualization rate of the adrenal veins and the overall image quality of solid organs were subjectively compared among different keV VMI+. The AVS success rate was recorded for 20 patients. (3) Results: For the adrenal veins, 40 keV VMI+ had the peak CT value, noise and CNR (p < 0.05). Subjectively, the visualization rate was the highest at 40 keV (100% for the right adrenal vein, and 97.4% for the left adrenal vein) (p < 0.05). For solid organs, the CT value, noise and CNR at 50 keV were lower than those at 40 keV (p < 0.05), but the SNR was similar between 40 keV and 50 keV. The overall subjective image quality of solid organs at 50 keV was the best (p < 0.05). The AVS success rate was 95%. (4) Conclusions: For VMI+, 40 keV was the preferential energy level to obtain a high visualization rate of the adrenal veins and a high success rate of AVS, while 50 keV was the favorable energy level for the depiction of abdominal organs.

International multicenter survey on screening and confirmatory testing in primary aldosteronism

OBJECTIVE

Primary aldosteronism (PA) is one of the most frequent causes of secondary hypertension. Although clinical practice guidelines recommend a diagnostic process, details of the steps remain incompletely standardized.

DESIGN

In the present SCOT-PA survey, we have investigated the diversity of approaches utilized for each diagnostic step in different expert centers through a survey using Google questionnaires. A total of 33 centers from 3 continents participated.

RESULTS

We demonstrated a prominent diversity in the conditions of blood sampling, assay methods for aldosterone and renin, and the methods and diagnostic cutoff for screening and confirmatory tests. The most standard measures were modification of antihypertensive medication and sitting posture for blood sampling, measurement of plasma aldosterone concentration (PAC) and active renin concentration by chemiluminescence enzyme immunoassay, a combination of aldosterone-to-renin ratio with PAC as an index for screening, and saline infusion test in a seated position for confirmatory testing. The cutoff values for screening and confirmatory testing showed significant variation among centers.

CONCLUSIONS

Diversity of the diagnostic steps may lead to an inconsistent diagnosis of PA among centers and limit comparison of evidence for PA between different centers. We expect the impact of this diversity to be most prominent in patients with mild PA. The survey raises 2 issues: the need for standardization of the diagnostic process and revisiting the concept of mild PA. Further standardization of the diagnostic process/criteria will improve the quality of evidence and management of patients with PA.

Prognosis of adrenalectomy guided by computed tomography versus adrenal vein sampling in patients with primary aldosteronism: A systematic review and meta‐analysis

Adrenal vein sampling (AVS) is recommended to be the gold standard for patients with unilateral subtypes of primary aldosteronism to clinical diagnosis and surgery therapy. However, it is uncertain whether AVS is better for prognosis than computed tomography (CT), which is the most widely used. Pubmed, Embase, and Cochrane Library were searched for articles with no start date restriction. The last search was conducted on Jun 15, 2021. Eligible studies compared the distinct subtypes of primary aldosteronism by AVS with CT (as a control group) and reported the prognosis at follow‐up. Evaluation of cohort studies referred to Newcastle ‐ Ottawa Quality Assessment Scale, and randomized controlled trials referred to Updated Cochrane Collaboration tool. A random‐effect model or fixed‐effect model was chosen according to the heterogeneity test. All processes were performed following the PRISMA 2020 statement. Eleven studies were identified, including 1325 patients based on AVS and 907 patients based on CT. Compared with patients guided by CT, patients who underwent AVS had an increased possibility of complete biochemical success (odds ratio [OR] 2.78, 95% CI 1.88–4.12) and a decreased chance of absent biochemical success (OR 0.23, 95% CI 0.13–0.40) at follow‐up. Nevertheless, the rate of complete clinical success (OR 1.09, 95% CI 0.89–1.35) and absent clinical success (OR 0.96, 95% CI 0.68–1.33) had no significant difference. Therefore, distinguishing subtypes by AVS for early treatment may be crucial since it can promote biochemical improvement.

Reduction of Radiation Exposure in Adrenal Vein Sampling: Impact of the Rapid Cortisol Assay

PURPOSE

 To determine radiation exposure associated with adrenal vein sampling and its reduction by implementing the rapid cortisol assay and modification of the sampling protocol.

MATERIALS AND METHODS

 A single-center retrospective study of adrenal vein sampling performed between August 2009 and March 2020 revealed data from 151 procedures. Three subgroups were determined. In group I, a sampling protocol including sampling from the renal veins without the rapid cortisol assay was applied. In group II, blood was sampled using the same protocol but applying the rapid cortisol assay. In group III, a modified sampling protocol was used, in which the additional sampling from the renal veins was dispensed with, while the rapid cortisol assay was retained. Primary endpoints were radiation exposure parameters with dose area product, fluoroscopy time, and effective dose. As secondary endpoints, procedural data including technical success, lateralization, the correlation between patient BMI and radiation exposure, and concordance of lateralization with cross-sectional imaging were investigated. Furthermore, the correlation of aldosterone-cortisol ratios between the adrenal and ipsilateral renal vein was calculated to assess the benefit of sampling from the renal veins.

RESULTS

 For all procedures performed in the study collective, the median dose area product was 60.01 Gy*cm² (5.71-789.31), the median fluoroscopy time was 14.90 min (3.27-80.90), and the calculated median effective dose was 12.60 mSv (1.20-165.76). Significant differences in radiation exposure parameters between the study subgroups could be revealed. Dose area product resulted in reductions of 57.94 % after implementation of the rapid cortisol assay and a further 40.44 % after revision of the sampling protocol. Fluoroscopy time was reduced by 40.48 % after integration of the rapid cortisol assay and a further 40.47 % after protocol refinement. Radiation doses were increased in cases of resampling (dose area product 51.31 vs. 118.11 Gy*cm², fluoroscopy time of 12.48 vs. 28.70 min). A strong correlation between patient BMI and procedural dose area product could be found. After the introduction of the rapid cortisol assay, successive improvement of the technical success rate could be found (33.33 % in group I, 90.22 % in group II and 92.11 % in group III). The correlation of aldosterone-cortisol ratios between adrenal and renal veins was poor.

CONCLUSION

 The introduction of the rapid cortisol assay significantly decreased the radiation exposure and increased the technical success rate. Renal vein sampling did not provide further benefit in the evaluation of primary aldosteronism subtype and its omission resulted in a further reduction of radiation dose.

KEY POINTS

· The rapid cortisol assay significantly reduces the procedure-related radiation dose in adrenal vein sampling and increases the procedural technical success.. · Since additional sampling from the renal veins offers no further diagnostic benefit, a refinement of the sampling protocol can enable a further reduction of radiation dose.. · Resampling, technical unsuccessful procedures, and higher patients' BMI are associated with higher radiation exposures..

CITATION FORMAT

· Augustin A, Dalla Torre G, Fuss CT et al. Reduction of Radiation Exposure in Adrenal Vein Sampling: Impact of the Rapid Cortisol Assay. Fortschr Röntgenstr 2021; 193: 1392 - 1402.

The importance of adrenal venous sampling in ACTH-independent Cushing syndrome: A case report and literature review

Independent Cushing's adrenocorticotropic hormone (ACTH) syndrome can have several causes, including adrenal carcinoma or simple adrenal hyperplasia. Although the distinction between malignant and benign can be effectively made through imaging investigations, in the situation where there are bilateral formations, their hormonal activity is impossible to appreciate via non-invasive techniques. The present study includes the presentation of a clinical case on the basis of which a literature review was made. The clinical case pertains to a 32-year-old patient with ACTH-independent Cushing's syndrome and bilateral adrenal tumor formations leading to the utility of adrenal venous sampling to avoid bilateral adrenalectomy. A literature review was subsequently conducted focusing on articles pertaining to the PICO criteria in order to describe: The diagnosis of adrenal tumor masses, the decision on the type of surgery and most importantly, the impact of adrenal venous sampling in avoiding surgical resection. These interventions severely limit the patients' quality of life.

Feasibility of Iodine-131 6β-Methyl-Iodo-19 Norcholesterol (NP-59) Scintigraphy to Complement Adrenal Venous Sampling in Management of Primary Aldosteronism: A Case Series

Purpose

Primary aldosteronism (PA) is mainly comprised of aldosterone-producing adenoma and bilateral idiopathic adrenal hyperplasia. Current guidelines recommend adrenal venous sampling (AVS) as a gold standard method to classify the subtypes. However, because of technical challenges in AVS including invasiveness of AVS and a wide range of success rate for cannulation, it is not uncommon that appropriate decisions could not be made depending on AVS. The aim of this study is to elucidate the proper role of I‑131‑6β‑iodomethyl‑norcholesterol (NP-59) scintigraphy in management of PA.

Patients and Methods

Between January 2009 and October 2018, patients with PA were retrospectively reviewed for the study. Five patients were included in the study who had NP-59 scintigraphy with non-conclusive AVS results or without AVS. We described the clinical outcome of patients in whom clinical decisions were made according to NP-59 scintigraphy results.

Results

Patients in the presenting cases were diagnosed for PA. AVS, the most reliable test to identify unilateral APA, were not applicable because of hypersensitivity to contrast dye (patient 1), and use of antiplatelet agents after acute cerebral infarction (patient 2). NP-59 scintigraphy was performed in patients 3 and 4 whose result of AVS and CT scan were inconsistent. In patient 5, who had bilateral adrenal adenomas (two in the left and one in the right adrenal gland), both unsuccessful catheterization and coexistence of cortisol overproduction made AVS results unreliable.

Conclusion

Based on clinical outcomes of these case series, it is noticeable that NP-59 scintigraphy could play a substantial role in management of PA in selected cases.

A clinical prediction score using age at diagnosis and saline infusion test parameters can predict aldosterone-producing adenoma from idiopathic adrenal hyperplasia

PURPOSE

Accurate subtyping of the primary aldosteronism into aldosterone-producing adenoma (APA) and idiopathic adrenal hyperplasia (IAH) is important to direct for specific treatment modalities. The objective of the study was to compare the clinical and biochemical parameters of APA and IAH patients to derive a Clinical Prediction Score reliably predicting APA from IAH.

METHODS

This was a retrospective multi-centre study recruiting 38 APA patients and 42 IAH patients from four major hospitals in Hong Kong using database from Surgical Outcomes Monitoring and Improvement Programme and Clinical Data Analysis and Reporting System. Their clinical and biochemical parameters were evaluated.

RESULTS

Patients in APA group were younger than IAH group (mean age 48.6 ± 9.2 vs. 57.1 ± 7.3 years old, p < 0.001), had more suppressed renin before saline infusion in saline infusion test (SIT) (median 0.19 [IQR 0.15-0.37] vs. 0.39 [IQR 0.19-0.69] ng/mL/h, p = 0.01), and higher aldosterone level after saline infusion in SIT (median 674 [IQR 498-1000] vs. 327 [IQR 242-483] pmol/L, p < 0.001). A clinical prediction score using three parameters was devised, comprising age at diagnosis < 50 years, PRA before saline infusion in SIT ≤ 0.26 ng/mL/h, and aldosterone level after saline infusion in SIT ≥ 424 pmol/L. A score of 2 would predict APA with a sensitivity of 84.2% and specificity of 88.1%, and a score of 3 would predict APA with a sensitivity of 31.6% and specificity of 100%.

CONCLUSIONS

Clinical Prediction Score based on the combination of age at diagnosis, PRA, and aldosterone level in the saline infusion tests could reliably predict APA from IAH.

Radiation exposure of adrenal vein sampling: a German Multicenter Study

OBJECTIVE

Adrenal vein sampling (AVS) represents the current diagnostic standard for subtype differentiation in primary aldosteronism (PA). However, AVS has its drawbacks. It is invasive, expensive, requires an experienced interventional radiologist and comes with radiation exposure. However, exact radiation exposure of patients undergoing AVS has never been examined.

DESIGN AND METHODS

We retrospectively analyzed radiation exposure of 656 AVS performed between 1999 and 2017 at four university hospitals. The primary outcomes were dose area product (DAP) and fluoroscopy time (FT). Consecutively the effective dose (ED) was approximately calculated.

RESULTS

Median DAP was found to be 32.5 Gy*cm2 (0.3–3181) and FT 18 min (0.3–184). The calculated ED was 6.4 mSv (0.1–636). Remarkably, values between participating centers highly varied: Median DAP ranged from 16 to 147 Gy*cm2, FT from 16 to 27 min, and ED from 3.2 to 29 mSv. As main reason for this variation, differences regarding AVS protocols between centers could be identified, such as number of sampling locations, frames per second and the use of digital subtraction angiographies.

CONCLUSIONS

This first systematic assessment of radiation exposure in AVS not only shows fairly high values for patients, but also states notable differences among the centers. Thus, we not only recommend taking into account the risk of radiation exposure, when referring patients to undergo AVS, but also to establish improved standard operating procedures to prevent unnecessary radiation exposure.

Adrenal androgen measurement for assessing the selectivity of adrenal venous sampling in primary aldosteronism

Adrenal venous sampling (AVS) is the reference standard for primary aldosteronism (PA) subtyping. Cortisol is widely used to assess the success of selective AVS, but it is not always reliable. The aim of the present study was to investigate the usefulness of adrenal androgens, compared to cortisol, in assessing the selectivity of AVS. We consecutively recruited 37 patients with PA undergoing AVS. AVS procedures were performed with the bilateral simultaneous technique without cosyntropin stimulation. We collected two baseline blood samples from 10 patients with a 15-min interval between time-15 (t-15) and time 0 (t0) to measure the variability in the levels of the tested hormones over time. Cortisol, androstenedione, dehydroepiandrosterone (DHEA), and DHEA sulfate (DHEAS) concentrations were measured in adrenal and peripheral venous (AV and PV, respectively) samples. The selectivity index (SI) values for androstenedione and DHEA were on average 3.0- and 2.0-fold higher, respectively, than those for cortisol, respectively (P < 0.05). However, the SI for DHEAS was 5.0-fold lower than the SI for cortisol (P < 0.05). Plasma androstenedione and DHEA concentrations positively correlated with cortisol and aldosterone concentrations in AV samples (P < 0.01). Compared to cortisol, the variation ratio of AV androstenedione and DHEA decreased from t-15 to t0 (0.23 and 0.43 vs. 0.52; P = 0.001 and P = 0.061, respectively). Using receiver operating characteristic curves, an SI ≥ 3 for androstenedione or DHEA provided optimal sensitivity and specificity in AVS. Given the much larger AV/PV ratios and reduced variability compared to cortisol, the adrenal androgens androstenedione and DHEA are useful for assessing the selectivity of AVS without cosyntropin stimulation and may be superior analytes in conditions with marked variability of cortisol levels or with adrenocortical tumors cosecreting cortisol and aldosterone.

Targeting CXCR4 (CXC Chemokine Receptor Type 4) for Molecular Imaging of Aldosterone-Producing Adenoma

Primary aldosteronism is the most frequent cause of secondary hypertension and is associated with increased morbidity and mortality compared with hypertensive controls. The central diagnostic challenge is the differentiation between bilateral and unilateral disease, which determines treatment options. Bilateral adrenal venous sampling, currently recommended for differential diagnosis, is an invasive procedure with several drawbacks, making it desirable to develop novel noninvasive diagnostic tools. When investigating the expression pattern of chemokine receptors by quantitative real-time polymerase chain reaction and immunohistochemistry, we observed high expression of CXCR4 (CXC chemokine receptor type 4) in aldosterone-producing tissue in normal adrenals, adjacent adrenal cortex from adrenocortical adenomas, and in aldosterone-producing adenomas (APA), correlating strongly with the expression of CYP11B2 (aldosterone synthase). In contrast, CXCR4 was not detected in the majority of nonfunctioning adenomas that are frequently found coincidently. The specific CXCR4 ligand 68Ga-pentixafor has recently been established as radiotracer for molecular imaging of CXCR4 expression and showed strong and specific binding to cryosections of APAs in our study. We further investigated 9 patients with primary aldosteronism because of APA by 68Ga-pentixafor-positron emission tomography. The tracer uptake was significantly higher on the side of increased adrenocortical aldosterone secretion in patients with APAs compared with patients investigated by 68Ga-pentixafor-positron emission tomography for other causes. Molecular imaging of aldosterone-producing tissue by a CXCR4-specific ligand may, therefore, be a highly promising tool for noninvasive characterization of patients with APAs.

Adrenal vein sampling versus CT scan to determine treatment in primary aldosteronism: an outcome-based randomised diagnostic trial

BACKGROUND

The distinction between unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia as causes of primary aldosteronism is usually made by adrenal CT or by adrenal vein sampling (AVS). Whether CT or AVS represents the best test for diagnosis remains unknown. We aimed to compare the outcome of CT-based management with AVS-based management for patients with primary aldosteronism.

METHODS

In a randomised controlled trial, we randomly assigned patients with aldosteronism to undergo either adrenal CT or AVS to determine the presence of aldosterone-producing adenoma (with subsequent treatment consisting of adrenalectomy) or bilateral adrenal hyperplasia (subsequent treatment with mineralocorticoid receptor antagonists). The primary endpoint was the intensity of drug treatment for obtaining target blood pressure after 1 year of follow-up, in the intention-to-diagnose population. Intensity of drug treatment was expressed as daily defined doses. Key secondary endpoints included biochemical outcome in patients who received adrenalectomy, health-related quality of life, cost-effectiveness, and adverse events. This trial is registered with ClinicalTrials.gov, number NCT01096654.

FINDINGS

We recruited 200 patients between July 6, 2010, and May 30, 2013. Of the 184 patients that completed follow-up, 92 received CT-based treatment (46 adrenalectomy and 46 mineralocorticoid receptor antagonist) and 92 received AVS-based treatment (46 adrenalectomy and 46 mineralocorticoid receptor antagonist). We found no differences in the intensity of antihypertensive medication required to control blood pressure between patients with CT-based treatment and those with AVS-based treatment (median daily defined doses 3·0 [IQR 1·0-5·0] vs 3·0 [1·1-5·9], p=0·52; median number of drugs 2 [IQR 1-3] vs 2 [1-3], p=0·87). Target blood pressure was reached in 39 (42%) patients and 41 (45%) patients, respectively (p=0·82). On secondary endpoints we found no differences in health-related quality of life (median RAND-36 physical scores 52·7 [IQR 43·9-56·8] vs 53·2 [44·0-56·8], p=0·83; RAND-36 mental scores 49·8 [43·1-54·6] vs 52·7 [44·9-55·5], p=0·17) for CT-based and AVS-based treatment. Biochemically, 37 (80%) of patients with CT-based adrenalectomy and 41 (89%) of those with AVS-based adrenalectomy had resolved hyperaldosteronism (p=0·25). A non-significant mean difference of 0·05 (95% CI -0·04 to 0·13) in quality-adjusted life-years (QALYs) was found to the advantage of the AVS group, associated with a significant increase in mean health-care costs of €2285 per patient (95% CI 1323-3248). At a willingness-to-pay value of €30 000 per QALY, the probability that AVS compared with CT constitutes an efficient use of health-care resources in the diagnostic work-up of patients with primary aldosteronism is less than 0·2. There was no difference in adverse events between groups (159 events of which nine were serious vs 187 events of which 12 were serious) for CT-based and AVS-based treatment.

INTERPRETATION

Treatment of primary aldosteronism based on CT or AVS did not show significant differences in intensity of antihypertensive medication or clinical benefits for patients after 1 year of follow-up. This finding challenges the current recommendation to perform AVS in all patients with primary aldosteronism.

FUNDING

Netherlands Organisation for Health Research and Development-Medical Sciences, Institute of Cardiology, Warsaw.

A case of adrenal Cushing's syndrome with bilateral adrenal masses

A functional lesion in corticotrophin (ACTH)-independent Cushing's syndrome is difficult to distinguish from lesions of bilateral adrenal masses. Methods for distinguishing these lesions include adrenal venous sampling and (131)I-6β-iodomethyl-19-norcholesterol ((131)I-NP-59) scintigraphy. We present a case of a 29-year-old Han Chinese female patient with a history of hypercholesterolaemia and polycystic ovary syndrome. She presented with a 6month history of an 8kg body weight gain and gradual rounding of the face. Serial examinations revealed loss of circadian rhythm of cortisol, elevated urinary free-cortisol level and undetectable ACTH level (<5pg/mL). No suppression was observed in both the low- and high-dose dexamethasone suppression tests. Adrenal computed tomography revealed bilateral adrenal masses. Adrenal venous sampling was performed, and the right-to-left lateralisation ratio was 14.29. The finding from adrenal scintigraphy with NP-59 was consistent with right adrenal adenoma. The patient underwent laparoscopic right adrenalectomy, and the pathology report showed adrenocortical adenoma. Her postoperative cortisol level was 3.2μg/dL, and her Cushingoid appearance improved. In sum, both adrenal venous sampling and (131)I-NP-59 scintigraphy are good diagnostic methods for Cushing's syndrome presenting with bilateral adrenal masses.

LEARNING POINTS

The clinical presentation of Cushing' syndrome includes symptoms and signs of fat redistribution and protein-wasting features.The diagnosis of patients with ACTH-independent Cushing's syndrome with bilateral adrenal masses is challenging for localisation of the lesion.Both adrenal venous sampling and (131)I-NP-59 scintigraphy are good methods to use in these patients with Cushing's syndrome presenting with bilateral adrenal masses.

Adrenal Venous Sampling in Patients With Positive Screening but Negative Confirmatory Testing for Primary Aldosteronism

Adrenal venous sampling is considered to be the most reliable diagnostic procedure to lateralize aldosterone excess in primary aldosteronism (PA). However, normative criteria have not been established partially because of a lack of data in non-PA hypertensive patients. The aim of the study was to investigate aldosterone concentration and its gradient in the adrenal vein of non-PA hypertensive patients. We retrospectively studied the results of cosyntropin-stimulated adrenal venous sampling in 40 hypertensive patients who showed positive screening testing but negative results in 2 confirmatory tests/captopril challenge test and saline infusion test. Plasma aldosterone concentration, aldosterone/cortisol ratio, its higher/lower ratio (lateralization index) in the adrenal vein with cosyntropin stimulation were measured. Median plasma aldosterone concentration in the adrenal vein was 25 819 pg/mL (range, 5154-69 920) in the higher side and 12 953 (range, 1866-36 190) pg/mL in the lower side (P<0.001). There was a significant gradient in aldosterone/cortisol ratio between the higher and the lower sides (27.2 [5.4-66.0] versus 17.3 [4.0-59.0] pg/mL per μg/dL;P<0.001) with lateralization index ranging from 1.01 to 3.87. The aldosterone lateralization gradient was between 1 to 2 in 32 patients and 2 to 4 in 8 patients. None of the patients showed lateralization index ≥4. The present study demonstrated that plasma aldosterone concentration in the adrenal veins showed significant variation and lateralization gradient even in non-PA hypertensive patients. Adrenal venous sampling aldosterone lateralization gradients between 2 and 4 should be interpreted with caution in patients with PA because these gradients can be found even in patients with negative confirmatory testing for PA.

Optimum position of left adrenal vein sampling for subtype diagnosis in primary aldosteronism

CONTEXT

Although adrenal vein sampling (AVS) is the standard method for subtype diagnosis in primary aldosteronism (PA), protocol details including the sampling position in the adrenal vein are not standardized.

OBJECTIVE

To establish the optimum sampling position in the left adrenal vein based on postoperative outcome in PA patients.

DESIGN AND SETTING

Retrospective study in nine referral centres.

PARTICIPANTS

Of 496 consecutive PA patients who underwent AVS between 2006 and 2013, 217 with successful AVS under cosyntropin stimulation, and with concomitant data from two positions: proximal (common trunk) and distal (central vein) to the junction with the inferior phrenic vein, were included.

MAIN OUTCOME MEASURES

Discordant rate of subtype diagnosis between common trunk and central vein, and postoperative outcomes in patients with discordant results.

RESULTS

Subtype diagnosis using common trunk and central vein was discordant in 10 (4·6%) of the 217 patients (κ = 0·87, P < 0·05). Of these 10 patients, eight with left unilateral subtype and two with bilateral subtype using common trunk data showed bilateral subtype and unilateral subtype, respectively, using central vein data. Five patients with left unilateral subtype and one with bilateral subtype by common trunk data underwent unilateral adrenalectomy. All six patients were cured of PA after adrenalectomy, resulting in false-negative rates of 17% (1/6) by common trunk data, and 83% (5/6) by central vein data.

CONCLUSION

In view of its better potential diagnostic accuracy, technical ease, lower cost and lower risk of vein rupture, blood sampling from the common trunk of the left adrenal vein may be preferable as the standard method of AVS in patients with PA, although additional studies in a larger number of cases are required.

Cost-Effectiveness of Screening for Primary Aldosteronism and Subtype Diagnosis in the Resistant Hypertensive Patients

BACKGROUND

Primary aldosteronism (PA) is a common and underdiagnosed disease with significant morbidity potentially cured by surgery. We aim to assess if the long-term cardiovascular benefits of identifying and treating surgically correctable PA outweigh the upfront increased costs in patients at the time patients are diagnosed with resistant hypertension (RH).

METHODS AND RESULTS

A decision-analytic model compares aggregate costs and systolic blood pressure changes of 6 recommended or implemented diagnostic strategies for PA in a simulated population of at-risk RH patients. We also evaluate a 7th "treat all" strategy wherein all patients with RH are treated with a mineralocorticoid-receptor antagonist without further testing at RH diagnosis. Changes in systolic blood pressure are subsequently converted into gains in quality-adjusted life years (QALYs) by applying National Health and Nutrition Examination Survey data on concomitant risk factors to an existing cardiovascular disease simulation model. QALYs and lifetime costs were then used to calculate incremental cost-effectiveness ratios for the competing strategies. The incremental cost-effectiveness ratio for the strategy of computerized tomography (CT) followed by adrenal venous sampling (AVS) was $82,000/QALY compared with treat all. Incremental cost-effectiveness ratios for CT alone and AVS alone were $200,000/QALY and $492,000/QALY; the other strategies were more costly and less effective. Integrating differential patient-reported health-related quality of life adjustments for patients with PA, and incremental cost-effectiveness ratios for screening patients with CT followed by AVS, CT alone, and AVS alone were $52,000/QALY, $114,000/QALY, and $269,000/QALY gained.

CONCLUSIONS

CT scanning followed by AVS was a cost-effective strategy to screen for PA among patients with RH.

Mineralocorticoid and apparent mineralocorticoid syndromes of secondary hypertension

The mineralocorticoid aldosterone is a key hormone in the regulation of plasma volume and blood pressure in man. Excessive levels of this mineralocorticoid have been shown to mediate metabolic disorders and end-organ damage more than what can be attributed to its effects on blood pressure alone. Inappropriate excess levels of aldosterone contribute significantly to the cardiorenal metabolic syndrome and target organ injury that include atherosclerosis, myocardial hypertrophy, fibrosis, heart failure, and kidney disease. The importance of understanding the role of excess mineralocorticoid hormones such as aldosterone in resistant hypertension and in those with secondary hypertension should be visited. Primary aldosteronism is one of the commonly identified causes of hypertension and is treatable and/or potentially curable. We intend to review the management of mineralocorticoid-induced hypertension in the adult population along with other disease entities that mimic primary aldosteronism.

Adrenal vein sampling in primary aldosteronism: towards a standardised protocol

Primary aldosteronism comprises subtypes that need different therapeutic strategies. Adrenal vein sampling is recognised by Endocrine Society guidelines as the only reliable way to correctly diagnose the subtype of primary aldosteronism. Unfortunately, despite being the gold-standard procedure, no standardised procedure exists either in terms of performance or interpretation criteria. In this Personal View, we address several questions that clinicians are presented with when considering adrenal vein sampling. For each of these questions we provide responses based on the available evidence, and opinions based on our experience. In particular, we discuss the most appropriate way to prepare the patient, whether adrenal vein sampling can be avoided for some subgroups of patients, the use of ACTH (1-24) during the procedure, the most appropriate criteria for interpretation of adrenal vein cannulation and lateralisation, the use of contralateral suppression, and strategies to improve success rates of adrenal vein sampling in centres with little experience.

Regulation of aldosterone secretion: from physiology to disease

Arterial hypertension is a major cardiovascular risk factor that affects between 10 and 40% of the population in industrialized countries. Primary aldosteronism (PA) is the most common form of secondary hypertension with an estimated prevalence of around 10% in referral centers and 4% in a primary care setting. Despite its high prevalence until recently, the underlying genetic and molecular basis of this common disease had remained largely obscure. Over the past decade, a number of insights have been achieved that have relied on in vitro cellular systems, wild-type and genetically modified in vivo models, as well as clinical studies in well-characterized patient populations. This progress has been made possible by a number of independent technical developments including that of specific hormone assays that allow measurement in small sample volumes as well as genetic techniques that enable high-throughput sequencing of a large number of samples. Furthermore, animal models have provided important insights into the physiology of aldosterone regulation that have served as a starting point for investigation of mechanisms involved in autonomous aldosterone secretion. Finally, national and international networks that have built up registries and biobanks have been instrumental in fostering translational research endeavors in PA. Therefore, it is to be expected that in the near future, further pathophysiological mechanisms that result in autonomous aldosterone secretion will be unraveled.

A clinical prediction score to diagnose unilateral primary aldosteronism

CONTEXT

Adrenal venous sampling is recommended to assess whether aldosterone hypersecretion is lateralized in patients with primary aldosteronism. However, this procedure is invasive, poorly standardized, and not widely available.

OBJECTIVE

Our goal was to identify patients' characteristics that can predict unilateral aldosterone hypersecretion in some patients who could hence bypass adrenal venous sampling before surgery.

DESIGN AND SETTING

A cross-sectional diagnostic study was performed from February 2009 to July 2010 at a single center specialized in hypertension care.

PATIENTS

A total of 101 consecutive patients with primary aldosteronism who underwent adrenal venous sampling participated in the study. The autonomy of aldosterone hypersecretion was assessed with the saline infusion test.

INTERVENTION

Adrenal venous sampling was performed without ACTH infusion but with simultaneous bilateral sampling.

MAIN OUTCOME MEASURES

Variables independently associated with a lateralized adrenal venous sampling in multivariate logistic regression were used to derive a clinical prediction rule.

RESULTS

Adrenal venous sampling was successful in 87 patients and lateralized in 49. All 26 patients with a typical Conn's adenoma plus serum potassium of less than 3.5 mmol/liter or estimated glomerular filtration rate of at least 100 ml/min/1.73 m2 (or both) had unilateral primary aldosteronism; this rule had 100% specificity (95% confidence interval, 91-100) and 53% sensitivity (95% confidence interval, 38-68).

CONCLUSIONS

If our results are validated on an independent sample, adrenal venous sampling could be omitted before surgery in patients with a typical Conn's adenoma if they meet at least one of two supplementary biochemical characteristics (serum potassium<3.5 mmol/liter or estimated glomerular filtration rate ≥100 ml/min/1.73 m2).

Improving adrenal venous sampling in primary aldosteronism

Primary aldosteronism is the most frequent cause of secondary arterial hypertension. As adrenal imaging has been shown to have only limited value for differential diagnosis, adrenal vein sampling (AVS) has been implemented as a gold standard in the guidelines. However, AVS is a not well-standardized technique, and success rates vary in a wide range. Successful AVS procedures presuppose careful preparation and operational efficiency in an interdisciplinary team. Besides ruling out malignancy, multidetector-row helical computed tomography facilitates the localization of the adrenal veins. Rapid cortisol measurement has been shown to increase cannulation rates. The values of cosyntropin stimulation and bilateral simultaneous versus sequential catheterization remain unclear, but consistency is important. AVS should be performed in specialized centers by a limited number of radiologists in order to ensure success rates of at least 70%. Standardization of cutoff values should be accomplished through a consensus statement for consistent decision-making in patient care.

Blood pressure and medication changes following adrenalectomy for unilateral primary aldosteronism: a follow-up study

OBJECTIVE

Adrenalectomy for unilateral primary aldosteronism cures hypertension in less than 50% of patients, but improvement is observed in most of the remaining ones. Our goal was to quantify the blood pressure (BP) decrease adjusted for medication changes following adrenalectomy and to identify preoperative predictors of this outcome.

METHODS

We analyzed simultaneous changes in BP and medication by reviewing the records of 156 consecutive patients who had undergone adrenalectomy for unilateral primary aldosteronism in one center between 2001 and 2009 for whom postoperative follow-up data were available.

RESULTS

Median [interquartile range] baseline SBP was 149 [135-160] mmHg on drugs from two [1-3] different classes. After adrenalectomy, SBP decreased by 21 [5-31] mmHg and the number of drug classes administered, by one [0-2]. The decrease in SBP, adjusted for the change in the number of drug classes, was 26 [14-36] mmHg. Each drug class dropped after surgery was equivalent to a 5 mmHg SBP decrease. Patients with higher preoperative BP or serum sodium levels experienced a greater BP decrease after adrenalectomy. Adrenalectomy cured hypertension in 68 (44%) patients. Hypertension was less likely to be cured in patients with a longer history of hypertension, higher preoperative BP levels, larger number of drug classes, or lower urinary aldosterone levels.

CONCLUSION

Although patients with severe hypertension are likely to derive considerable benefits from adrenalectomy in terms of BP or treatment reduction, they should be warned that hypertension cure is unlikely.

A stress reaction affects assessment of selectivity of adrenal venous sampling and of lateralization of aldosterone excess in primary aldosteronism

BACKGROUND

A stress reaction involving increased cortisol release, which has not been documented thus far, might affect the assessment of selectivity of catheterization during adrenal venous sampling (AVS).

OBJECTIVE

To investigate whether an ACTH-driven cortisol release occurs during AVS and whether it influences the assessment of selectivity by the step-up of cortisol (plasma cortisol concentrations, PCC) between the adrenal vein blood (PCC(SIDE)) and the inferior vena cava (PCC(IVC)), e.g. the selectivity index (SI).

DESIGN AND METHODS

We determined the SI in samples obtained simultaneously at starting AVS (t-15) and again after 15  min (t0) in 34 consecutive patients with proven aldosterone-producing adenoma. We then calculated the SI with PCC(SIDE) obtained at t-15 and at t0, and the PCC(IVC) values obtained at the different time point, thus simulating sequential AVS.

RESULTS

The PCC(SIDE) and the SI fell significantly from t-15 to t0 on both the sides. When PCC(SIDE) obtained at t-15 was combined with PCC(IVC) at t0, the SI values were higher than those obtained with simultaneously drawn samples. This led to label as selective more AVS studies than with bilaterally simultaneous data, especially when using higher cutoffs for the SI.

CONCLUSIONS

A transient increase in cortisol release from both adrenal glands occurs in the majority of the patients who undergo AVS. This stress reaction can influence the assessment of both the selectivity of the catheterization during the sequential AVS technique and the lateralization of aldosterone excess.

Adrenal vein sampling using rapid cortisol assays in primary aldosteronism is useful in centers with low success rates

OBJECTIVE

Adrenal vein sampling (AVS) is considered the gold standard in the differential diagnosis of primary aldosteronism (PA), but success rates vary between centers. We hypothesized that rapid (intraprocedure) cortisol measurement can improve performance in a center with initially low AVS success rate.

DESIGN

We analyzed 46 patients with confirmed PA studied between 2008 and 2010. Forty-seven PA patients studied between 2004 and 2008 identified by retrospective chart review served as controls. All patients were treated at a single tertiary care university hospital.

METHODS

Starting in 2008, rapid cortisol assays (RCA) were performed in all patients during the AVS procedure. A cortisol gradient of ≥2.0 between adrenal vein and a femoral vein sample was used as success criterion. Up to two repeat samples were drawn if adrenal vein cortisol was below this threshold. Results During the control period 26 of 47 AVS were successful (55%). After introduction of RCA, 39 out of 46 AVS (85%) were successful (P=0.003). In 21 of the 46 cases (46%) a resampling was necessary. The increase in overall success was due to an increase in successful right AVS (85 vs 62% before introduction of RCA; P=0.02) and a training effect (P=0.024 for trend).

CONCLUSION

RCA during AVS are useful in centers with an initially low AVS success rate.

Diagnosis and treatment of primary aldosteronism

A few simple rules can allow physicians to successfully identify many patients with arterial hypertension caused by PA among the so-called essential hypertensive patients. The hyperaldosteronism and the hypokalemia can be cured with adrenalectomy in practically all of these patients. Moreover, in a substantial proportion of them, the blood pressure can be normalized or markedly lowered if a unilateral cause of PA is discovered. Hence, the screening for PA can be rewarding both for the patient and for the clinician, particularly in those cases where hypertension is severe and/or resistant to treatment, in which the removal of an APA can allow blood pressure to be brought under control despite withdrawal of, or a prominent reduction in, the number and doses of antihypertensive medications.

Primary aldosteronism: A contrarian view

This paper provides evidence that primary aldosteronism is likely much less common than is believed by the other authors of this collection. The basis for this contrarian view is simple: there is no way to know the true prevalence of PA because of the uncertain validity of all of the diagnostic procedures used to find and characterize this disease. Moreover, even if these uncertainties are overcome, the eventual treatment of most who have PA can be provided without the need for extensive testing and expensive treatment.

Primary aldosteronism and a Texas two-step

Primary aldosteronism is unquestionably the most common secondary cause of hypertension, and effective approaches to diagnosis and targeted treatments exist. Even the most conservative estimates of the prevalence of primary aldosteronism, however, indicate that the condition is grossly underdiagnosed. Part of the reason why diagnosis and treatment lag far behind is the lack of expertise, even among endocrinologists and hypertension specialists, in the approach to the patient with possible primary aldosteronism. We will never make an impression on this important problem unless general internists and primary care physicians actively participate in the screening and referral process. A healthcare delivery team need not fear an overwhelming and fruitless battle with an intractable conundrum if a practical and staged approach to workup and treatment is taken. This review discusses the approach we have taken in Dallas, a strategy of targeted screening, referral for positive screens, and individualized management.

Primary aldosteronism: what consensus for the diagnosis

Primary Aldosteronism (PA) is characterized by inappropriate aldosterone production partially autonomous of the renin-angiotensin system. Since the ARR ratio was introduced a much higher prevalence of this disease is recognized. PA could be the most common identifiable, specifically treatable and potentially curable form of hypertension so the need of a clinical practice guideline on primary aldosteronism becomes mandatory. Recently the Endocrine Society USA published clinical practice guidelines for the diagnosis and treatment of patients with primary hyperaldosteronism. Systematic reviews of available evidence were used to formulate the key treatment and prevention recommendations. Actually the Endocrine Society consensus is the most used guidelines in diagnosis and treatment of hyperaldosteronism. However, there remains a few unresolved issues, which unfortunately require more of a detour guide and cannot be easily addressed by a straight forward guideline.

Current diagnosis and treatment of primary aldosteronism

Primary aldosteronism is more common than previously recognized but much less common than most experts in this arena have recently stated. The recognition of autonomous hyperaldosteronism is not difficult but the identification of the source of excess aldosterone requires a costly and difficult procedure. Most patients with hyperaldosteronism turn out to have bilateral adrenal hyperplasia for which medical therapy with an aldosterone blocker is indicated. Many of these patients are not hypokalemic and can safely be treated without the need for a costly and usually negative work-up.