Comparison of the Captopril and the Saline Infusion Test for Excluding Aldosterone-Producing Adenoma

Cardiovascular Outcomes of KCNJ5 Mutated Aldosterone-Producing Adenoma: A Systematic Review

BACKGROUND

While clinical features of KCNJ5-mutated aldosterone-producing adenoma (APA) have been reported, evidence of its clinical outcomes is lacking. We aimed to synthesize available literature about the associations between KCNJ5 mutation with cardiovascular and metabolic outcomes among patients with APA.

METHODS

In this systematic review of observational studies, MEDLINE and Embase were searched through August 2022. Two independent authors screened the search results and extracted data from eligible observational studies investigating cardiovascular or metabolic outcomes between KCNJ5-mutated APAs and KCNJ5-non-mutated APAs. Risk of Bias In Non-randomized Studies of Interventions was used to assess the quality of the included studies.

RESULTS

A total of 573 titles/abstracts were screened and after the expert opinion of the literature, full text was read in 20 titles/abstracts, of which 12 studies were included. Across 3 studies comparing the baseline or change in the cardiac function between KCNJ5-mutated APAs and KCNJ5-non-mutated APAs, all studies reported the association between impaired cardiac functions and KCNJ5 mutation status. Among 6 studies evaluating the cure of hypertension after surgery, all studies showed that KCNJ5 mutation was significantly associated with the cure of hypertension. In quality assessment, 7 studies were at serious risk of bias, while the remaining studies were at moderate risk of bias.

CONCLUSIONS

This systematic review provided evidence of the significant association between KCNJ5 mutation and unfavorable cardiovascular outcomes in patients with primary aldosteronism. Further research is needed to improve the quality of evidence on this topic and elucidate the underlying mechanisms of the potential burden of KCNJ5 mutation.

Familial hyperaldosteronism: an European Reference Network on Rare Endocrine Conditions clinical practice guideline

We describe herein the European Reference Network on Rare Endocrine Conditions clinical practice guideline on diagnosis and management of familial forms of hyperaldosteronism. The guideline panel consisted of 10 experts in primary aldosteronism, endocrine hypertension, paediatric endocrinology, and cardiology as well as a methodologist. A systematic literature search was conducted, and because of the rarity of the condition, most recommendations were based on expert opinion and small patient series. The guideline includes a brief description of the genetics and molecular pathophysiology associated with each condition, the patients to be screened, and how to screen. Diagnostic and treatment approaches for patients with genetically determined diagnosis are presented. The recommendations apply to patients with genetically proven familial hyperaldosteronism and not to families with more than one case of primary aldosteronism without demonstration of a responsible pathogenic variant.

Diagnosis and management of primary hyperaldosteronism in patients with hypertension: a practical approach endorsed by the British and Irish Hypertension Society

Alongside the lack of homogeneity among international guidelines and consensus documents on primary hyperaldosteronism, the National UK guidelines on hypertension do not provide extensive recommendations regarding the diagnosis and management of this condition. Local guidelines vary from area to area, and this is reflected in the current clinical practice in the UK. In an attempt to provide support to the clinicians involved in the screening of subjects with hypertension and clinical management of suspected cases of primary hyperaldosteronism the following document has been prepared on the behalf of the BIHS Guidelines and Information Service Standing Committee. Through remote video conferences, the authors of this document reviewed an initial draft which was then circulated among the BIHS Executive members for feedback. A survey among members of the BIHS was carried out in 2022 to assess screening strategies and clinical management of primary hyperaldosteronism in the different regions of the UK. Feedback and results of the survey were then discussed and incorporated in the final document which was approved by the panel after consensus was achieved considering critical review of existing literature and expert opinions. Grading of recommendations was not performed in light of the limited available data from properly designed randomized controlled trials.

Do multiple types of confirmatory tests improve performance in predicting subtypes of primary aldosteronism?

OBJECTIVE

The clinical practice guideline for primary aldosteronism (PA) places a high value on confirmatory tests to sparing patients with false-positive results in case detection from undergoing adrenal venous sampling (AVS). However, it is unclear whether multiple types of confirmatory tests are more useful than a single type. To evaluate whether the machine-learned combination of two confirmatory tests is more useful in predicting subtypes of PA than each test alone.

DESIGN

A retrospective cross-sectional study in referral centres.

PATIENTS

This study included 615 patients with PA randomly assigned to the training and test data sets. The participants underwent saline infusion test (SIT) and captopril challenge test (CCT) and were subtyped by AVS (unilateral, n = 99; bilateral, n = 516).

MEASUREMENTS

The area under the curve (AUC) and clinical usefulness using decision curve analysis for the subtype prediction in the test data set.

RESULTS

The AUCs for the combination of SIT and CCT, SIT alone and CCT alone were 0.850, 0.813 and 0.786, respectively, with no significant differences between them. The AUC for the baseline clinical characteristics alone was 0.872, whereas the AUCs for these combined with SIT, combined with CCT and combined with both SIT and CCT were 0.868, 0.854 and 0.855, respectively, with no significant improvement in AUC. The additional clinical usefulness of the second confirmatory test was unremarkable on decision curve analysis.

CONCLUSIONS

Our data suggest that patients with positive case detection undergo one confirmatory test to determine the indication for AVS.

Exclusion Tests in Unilateral Primary Aldosteronism (ExcluPA) Study

CONTEXT

Determining the diagnostic accuracy of "exclusion" tests for primary aldosteronism (PA) compared to the aldosterone to renin ratio (ARR) is fundamental to avoid invasive subtyping in false-positive patients at screening.

OBJECTIVE

To assess the accuracy of exclusion tests for PA using the diagnosis of unilateral PA as reference.

METHODS

PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched for studies published from January 1, 1970, to December 31, 2021, meeting tight quality criteria. Data were extracted following the PRISMA methodology. We performed a two-stage meta-analysis that entailed an exploratory and a validation phase based on a "golden" or "gold" diagnostic standard, respectively. Pooled specificity, negative likelihood ratio, diagnostic odds ratio, and summary area under the ROC curve (sAUROC) were calculated to analyze the accuracy of exclusion tests.

RESULTS

A meta-analysis of 31 datasets comprising a total of 4242 patients fulfilling the predefined inclusion criteria found that pooled accuracy estimates (sAUROC) did not differ between the ARR (0.95; 95% CI, 0.92-0.98), the captopril challenge test (CCT) (0.92; 95% CI, 0.88-0.97), and the saline infusion test (SIT) (0.96; 95% CI, 0.94-0.99). Solid information could not be obtained for the fludrocortisone suppression test and the furosemide upright test, which were assessed in only 1 study each.

CONCLUSION

The apparently high diagnostic accuracy of the CCT and the SIT was due to the selection of patients with an elevated ARR and thus a high pretest probability of unilateral PA; however, neither test furnished a diagnostic gain over the ARR. Therefore, the systematic use of these exclusion tests in clinical practice is not justified by available evidence.

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.

Performance of Confirmatory Tests for Diagnosing Primary Aldosteronism: a Systematic Review and Meta-Analysis

Background:

Confirmatory tests are recommended for diagnosing primary aldosteronism, but the supporting evidence is unclear.

Methods:

We searched Medline, EMBASE, and the Cochrane Central Register of Controlled Trials. Studies evaluating any guideline-recommended confirmatory test (ie, saline infusion test, salt loading test, fludrocortisone suppression test, and captopril challenge test), compared with a reference standard were included. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess the risk of bias. Meta-analyses were conducted using hierarchical summary receiver operating characteristic models.

Results:

Fifty-five studies were included, comprising 26 studies (3654 participants) for the recumbent saline infusion test, 4 studies (633 participants) for the seated saline infusion test, 2 studies (99 participants) for the salt loading test, 7 studies (386 participants) for the fludrocortisone suppression test, and 25 studies (2585 participants) for the captopril challenge test. Risk of bias was high, affecting more than half of studies, and across all domains. Studies with case-control sampling overestimated accuracy by 7-fold (relative diagnostic odds ratio, 7.26 [95% CI, 2.46–21.43]) and partial verification or use of inconsistent reference standards overestimated accuracy by 5-fold (5.12 [95% CI, 1.48–17.77]). There were large variations in how confirmatory tests were conducted, interpreted, and verified. Under most scenarios, confirmatory testing resulted in an excess of missed cases. The certainty of evidence underlying each test (Grading of Recommendations, Assessment, Development, and Evaluations) was very low.

Conclusions:

Recommendations for confirmatory testing in patients with abnormal screening tests and high probability features of primary aldosteronism are based on very low-quality evidence and their routine use should be reconsidered.

Japan Endocrine Society clinical practice guideline for the diagnosis and management of primary aldosteronism 2021

Primary aldosteronism (PA) is associated with higher cardiovascular morbidity and mortality rates than essential hypertension. The Japan Endocrine Society (JES) has developed an updated guideline for PA, based on the evidence, especially from Japan. We should preferentially screen hypertensive patients with a high prevalence of PA with aldosterone to renin ratio ≥200 and plasma aldosterone concentrations (PAC) ≥60 pg/mL as a cut-off of positive results. While we should confirm excess aldosterone secretion by one positive confirmatory test, we could bypass patients with typical PA findings. Since PAC became lower due to a change in assay methods from radioimmunoassay to chemiluminescent enzyme immunoassay, borderline ranges were set for screening and confirmatory tests and provisionally designated as positive. We recommend individualized medicine for those in the borderline range for the next step. We recommend evaluating cortisol co-secretion in patients with adrenal macroadenomas. Although we recommend adrenal venous sampling for lateralization before adrenalectomy, we should carefully select patients rather than all patients, and we suggest bypassing in young patients with typical PA findings. A selectivity index ≥5 and a lateralization index >4 after adrenocorticotropic hormone stimulation defines successful catheterization and unilateral subtype diagnosis. We recommend adrenalectomy for unilateral PA and mineralocorticoid receptor antagonists for bilateral PA. Systematic as well as individualized clinical practice is always warranted. This JES guideline 2021 provides updated rational evidence and recommendations for the clinical practice of PA, leading to improved quality of the clinical practice of hypertension.

Primary Hyperaldosteronism: When to Suspect It and How to Confirm Its Diagnosis

The definition of primary hyperaldosteronism (PA) has shifted, as progress has been made in understanding the disease. PA can be produced by unilateral or bilateral cortical adrenal hyperproduction of aldosterone, due to hyperplasia, aldosterone-secreting cell clusters, aldosterone-producing macro or micro adenoma/s, and combinations of the above, or by an aldosterone-producing carcinoma. PA is a highly prevalent disease, affecting close to 10% of the hypertensive population. However, PA is clearly underdiagnosed. The purpose of this review is to address current knowledge of PA’s clinical manifestations, as well as current methods of diagnosis. PA is associated with a higher cardiovascular morbidity and mortality than essential hypertension with similar blood pressure control. Young hypertensive patients, those with a first-degree relative with PA or ictus, and/or those with apnea/hypopnea syndrome, moderate/severe/resistant hypertension, adrenal incidentaloma, and/or hypokalemia should be screened for PA. PA can induce atrial fibrillation (AF), and those patients should also be screened for PA. We propose the use of the Captopril challenge test (CCT), oral salt loading, or intravenous salt loading for PA diagnosis, given their availability in the majority of hospital centers. CCT could be first-line, since it is safe and easy to perform.

KCNJ5 Somatic Mutation Is Associated With Higher Aortic Wall Thickness and Less Calcification in Patients With Aldosterone-Producing Adenoma

OBJECTIVE

Primary aldosteronism (PA) is the most common type of secondary hypertension, and it is associated with a higher rate of cardiovascular complications. KCNJ5 somatic mutations have recently been identified in aldosterone-producing adenoma (APA), however their influence on vascular remodeling and injury is still unclear. The aim of this study was to investigate the association between KCNJ5 somatic mutation status and vascular status.

METHODS

We enrolled 179 APA patients who had undergone adrenalectomy from a prospectively maintained database, of whom 99 had KCNJ5 somatic mutations. Preoperative clinical, biochemical and imaging data of abdominal CT, including abdominal aortic calcification (AAC) score, aortic diameter and wall thickness at levels of superior (SMA) and inferior (IMA) mesenteric arteries were analyzed.

RESULTS

After propensity score matching for age, sex, body mass index, triglycerides and low-density lipoprotein, there were 48 patients in each KCNJ5 (+) and KCNJ5 (-) group. Mutation carriers had a lower AAC score (217.3 ± 562.2 vs. 605.6 ± 1359.1, P=0.018), higher aortic wall thickness (SMA level: 2.2 ± 0.6 mm vs. 1.8 ± 0.6 mm, P=0.006; IMA level: 2.4 ± 0.6 mm vs. 1.8 ± 0.7 mm, P<0.001) than non-carriers. In multivariate analysis, KCNJ5 mutations were independently associated with AAC score (P=0.014) and aortic wall thickness (SMA level: P<0.001; IMA level: P=0.004). After adrenalectomy, mutation carriers had less aortic wall thickness progression than non-carriers (Δthickness SMA: -0.1 ± 0.8 mm vs. 0.9 ± 0.6 mm, P=0.024; IMA: -0.1 ± 0.6 mm vs. 0.8 ± 0.7 mm, P=0.04).

CONCLUSION

KCNJ5 mutation carriers had less calcification burden of the aorta, thickened aortic wall, and less wall thickness progression than non-carriers.

KCNJ5 Somatic Mutations in Aldosterone-Producing Adenoma Are Associated with a Greater Recovery of Arterial Stiffness

Simple Summary

Primary aldosteronism (PA) is the most common form of secondary hypertension and induces various cardiovascular injuries. Aldosterone-producing adenoma (APA) is one of the major forms of PA. The occurrence of APA is closely correlated with somatic mutations, including KCNJ5. We described here the impact of KCNJ5 somatic mutations on arterial stiffness excluding the influence of age, sex, and blood pressure status. We found KCNJ5 mutation carriers had similar arterial stiffness before surgery, but greater improvement of arterial stiffness after adrenalectomy compared with non-carriers. Hence, APA patients with KCNJ5 mutations had a greater improvement in arterial stiffness after adrenalectomy than those without mutations.

Abstract

Primary aldosteronism is the most common form of secondary hypertension and induces various cardiovascular injuries. In aldosterone-producing adenoma (APA), the impact of KCNJ5 somatic mutations on arterial stiffness excluding the influence of confounding factors is uncertain. We enrolled 213 APA patients who were scheduled to undergo adrenalectomy. KCNJ5 gene sequencing of APA was performed. After propensity score matching (PSM) for age, sex, body mass index, blood pressure, number of hypertensive medications, and hypertension duration, there were 66 patients in each group with and without KCNJ5 mutations. The mutation carriers had a higher aldosterone level and lower log transformed brachial–ankle pulse wave velocity (baPWV) than the non-carriers before PSM, but no difference in log baPWV after PSM. One year after adrenalectomy, the mutation carriers had greater decreases in log plasma aldosterone concentration, log aldosterone–renin activity ratio, and log baPWV than the non-carriers after PSM. Only the mutation carriers had a significant decrease in log baPWV after surgery both before and after PSM. KCNJ5 mutations were not correlated with baseline baPWV after PSM but were significantly correlated with ∆baPWV after surgery both before and after PSM. Conclusively, APA patients with KCNJ5 mutations had a greater regression in arterial stiffness after adrenalectomy than those without mutations.

Aldosterone and cortisol synthesis regulation by angiotensin-(1-7) and angiotensin-converting enzyme 2 in the human adrenal cortex

OBJECTIVE

The branch of the renin--angiotensin system constituting angiotensin-(1-7) [Ang-(1-7)], the Ang II type 2 receptor, the Mas receptors and the Ang-(1-7)-forming enzyme ACE-2, by counteracting the Ang II type 1 receptor (AT1R)-mediated effects, are held to be cardiovascular protective in several conditions. However, whether Ang-(1-7) and ACE-2 are detectable in human adrenocortical tissues and whether they affect aldosterone and cortisol biosynthesis was unknown.

METHODS

We measured angiotensin peptides with liquid chromatography tandem-mass spectrometry and ACE-2 mRNA with digital droplet (dd)PCR in human aldosterone-producing adenoma (APA) and APA-adjacent tissue obtained from patients with primary aldosteronism. We also investigated the effects of Ang-(1-7) and the ACE-2 activator diminazene aceturate (DIZE) on aldosterone synthase (CYP11B2) and 11β-hydroxylase (CYP11B1) gene expression, in the absence or presence of the AT1R antagonist irbesartan, or of the MasR antagonist A779.

RESULTS

APA and APA-adjacent adrenocortical tissues express ACE-2 mRNA and contain detectable amounts of Ang II and Ang-(2-8), but not of Ang I, Ang-(1-5), Ang (3-8) and Ang-(1-7). Under unstimulated and Ang II- stimulated conditions Ang-(1-7) did not blunt CYP11B1 and CYP11B2 mRNA. At supraphysiological concentrations (10-4 mol/l), Ang-(1-7) stimulated both CYP11B1 and CYP11B2 mRNA via the AT1R. The ACE-2 activator DIZE increased by 1.5-fold ACE-2 mRNA but did not blunt Ang II- upregulated CYP11B1 and CYP11B2 expression.

CONCLUSION

These results do not support the hypothesis that the ACE-2/Ang-(1-7)/MasR axis play a protective role by counteracting enhanced aldosterone secretion in humans.

Regression of left ventricular hypertrophy in primary aldosteronism after adrenalectomy: a meta-analysis of echocardiographic studies

AIM

Available evidence on regression of left ventricular (LV) hypertrophy in patients with primary aldosteronism after unilateral adrenalectomy is scanty. We performed a systematic meta-analysis of echocardiographic studies to provide an updated and comprehensive information on this issue.

METHODS

The PubMed, OVID-MEDLINE and Cochrane library databases were analyzed to search English-language articles published from 1 January 1990 up to 30 June 2020. Studies were identified by using MeSH terms and crossing the following search items: 'primary aldosteronism' 'Conn's syndrome' 'adrenalectomy', with 'cardiac damage', 'hypertensive heart disease' 'left ventricular mass', 'left ventricular hypertrophy', 'left ventricular hypertrophy regression', 'echocardiography'.

RESULTS

A total of 629 hypertensive patients with primary aldosteronism (mean age 49 years, 45% men) were included in 14 studies. Baseline and postintervention pooled mean LV mass/BSA values were 134 ± 4 and 108 ± 3 g/m2 [standard means difference (SMD) -0.42 ± 0.05, confidence interval (CI) -0.52/-0.32, P < 0.0001]; corresponding values for LV mass/h2.7 were 56 ± 2 and 49 ± 1 g/h2.7 (SMD -0.45 ± 0.06, CI -0.52/-0.36, P < 0.0001). Adrenalectomy, followed by a marked decrease in blood pressure, was associated with a decrease in relative wall thickness (SMD -0.17 ± 0.06, CI -0.31/-0.03, P < 0.01) as well as in the number of antihypertensive drugs (SMD -0.45 ± 0.04, CI -0.50-0.32, P < 0.0001).

CONCLUSION

The present meta-analysis suggests that adrenalectomy in patients with primary aldosteronism exerts a beneficial effect on LV structure and geometry by reducing the burden of LV hypertrophy and LV concentric geometry.

Seated Saline Suppression Test Is Comparable With Captopril Challenge Test for the Diagnosis of Primary Aldosteronism: A Prospective Study

OBJECTIVE

The saline suppression test (SST) and captopril challenge test (CCT) are commonly used confirmatory tests for primary aldosteronism (PA). Seated SST (SSST) has been reported to be superior to recumbent SST. Whether SSST is better than CCT remains unclear. We aimed to compare the diagnostic accuracy of SSST and CCT in a prospective study.

METHODS

Hypertensive patients at a high risk of PA were consecutively included. Patients with an aldosterone-renin ratio of ≥1.0 ng/dL/μIU/mL were asked to complete SSST, CCT, and the fludrocortisone suppression test (FST). Using FST as a reference standard (plasma aldosterone concentration [PAC] post FST ≥ 6.0 ng/dL), area under the receiver-operating characteristic curve (AUC), sensitivity, and specificity of SSST and CCT were calculated, and multiple regression analyses were performed to identify potential factors leading to false diagnosis.

RESULTS

A total of 196 patients diagnosed with PA and 73 with essential hypertension completed the study. Using PAC post SSST and PAC post CCT to confirm PA, SSST and CCT had comparable AUCs (AUC_SSST 0.87 [95% CI 0.82-0.91] vs AUC_CCT 0.88 [0.83-0.95], P = .646). When PAC post SSST and post CCT were set at 8.5 and 11 ng/dL, respectively, the sensitivity and specificity of SSST (0.72 [0.65, 0.78] and 0.86 [0.76, 0.93]) and CCT (0.73 [0.67, 0.80] and 0.85 [0.75, 0.92]) were not significantly different. In the multiple regression analyses, 1-SD increment of sodium intake resulted in a 40% lower risk of false diagnosis with SSST.

CONCLUSION

SSST and CCT have comparable diagnostic accuracy. Insufficient sodium intake decreases the diagnostic efficiency of SSST but not of CCT. Since CCT is simpler and cheaper, it is preferred over SSST.

Computed tomography combined with confirmatory tests for the diagnosis of aldosterone-producing adenoma

Primary aldosteronism (PA) is the most common cause of secondary hypertension, and a simpler non-invasive method for identification of aldosterone-producing adenoma (APA) is required to improve the standard of medical treatment for PA patients. We retrospectively analyzed the clinical data of hypertensive patients with an aldosterone/renin ratio (ARR) ≥30 (ng/dL)/(ng/mL/h), and surgical and/or adrenal venous sampling (AVS) results served as the gold standard for APA diagnosis. The study aimed to determine whether positive CCT and SIT results plus a unilateral adrenal nodule found by CT allow unambiguous identification of an APA with high diagnostic specificity. Clinical data from 71 APA and 47 non-APA patients were collected, and logistic regression analysis was performed to construct models. Receiver operating characteristic (ROC) curves were used to analyze the efficacy of diagnostic tests. The areas under the ROC curves (AUCs) were similar between the post-SIT plasma aldosterone concentration (PAC) and post-CCT PAC (p > 0.05). The optimal post-SIT and post-CCT PAC cutoff values were 17.2 and 21.2 ng/dL, respectively. Positive CT findings combined with a post-SIT PAC >17.2 ng/dL or post-CCT PAC >21.2 ng/dL provided specificities of 97.8% and 95.7% for predicting APA, respectively. Logistic diagnostic models 1 (M1, CT finding + post-SIT PAC) and 2 (M2, CT finding + post-CCT PAC) were built, which showed equivalent diagnostic value (AUC = 0.959 and 0.932, respectively) (p > 0.05). The models combining CT findings with post-SIT PACs or post-CCT PACs represent an easier method to distinguish APA patients from other hypertensive patients with positive upright ARR results, especially in primary care where AVS may be unavailable.

Prediction of unilateral hyperaldosteronism on adrenal vein sampling using captopril challenge test in patients with primary aldosteronism

Captopril challenge test (CCT) is a simple and safe confirmatory test for primary aldosteronism (PA). We investigated the effectiveness of the indices after captopril administration for prediction of unilateral hyperaldosteronism (UHA) on adrenal vein sampling (AVS). We studied 238 patients with PA who had CCT and successful AVS between July 2007 and December 2019 in Sapporo City General Hospital. Receiver operating characteristic (ROC) curve analysis showed that the diagnostic performance for prediction of UHA on AVS in regard to the reduction rate of plasma aldosterone concentration (PAC) after captopril administration was inferior to aldosterone to renin ratio (ARR) and PAC (area under the ROC curve 0.72 vs. 0.84, 0.72 vs. 0.89, respectively, both p < 0.01). Based on the optimal cut-off values in ARR (897 pg/mL/ng/mL/h, sensitivity 64.6%, specificity 93.0%) and PAC (203 pg/mL, sensitivity 73.9%, specificity 93.0%) after captopril administration, the patients were divided into three groups: (1) both positive, (2) one positive, and (3) both negative. The prevalence of UHA on AVS in the three groups were 90.0%, 52.9%, and 7.3%, respectively. In the first group, 31 of 32 patients with unilateral nodular lesion on CT had an ipsilateral unilateral AVS. In conclusion, the combination of post-captopril ARR and PAC is useful for prediction of laterality diagnosis on AVS. AVS is strongly recommended in patients with both positive or one positive results for the optimal cut-off values of post-captopril ARR and PAC and is weakly recommended in patients with both negative results.

Significance of Discordant Results Between Confirmatory Tests in Diagnosis of Primary Aldosteronism

CONTEXT

Current clinical guidelines recommend confirmation of a positive result in at least one confirmatory test in the diagnosis of primary aldosteronism (PA). Clinical implication of multiple confirmatory tests has not been established, especially when patients show discordant results.

OBJECTIVE

The aim of the present study was to explore the role of 2 confirmatory tests in subtype diagnosis of PA.

DESIGN AND SETTING

A retrospective cross-sectional study was conducted at two referral centers.

PARTICIPANTS AND METHODS

We identified 360 hypertensive patients who underwent both a captopril challenge test (CCT) and a saline infusion test (SIT) and exhibited at least one positive result. Among them, we studied 193 patients with PA whose data were available for subtype diagnosis based on adrenal vein sampling (AVS).

MAIN OUTCOME MEASURE

The prevalence of bilateral subtype on AVS according to the results of the confirmatory tests was measured.

RESULTS

Of patients studied, 127 were positive for both CCT and SIT (double-positive), whereas 66 were positive for either CCT or SIT (single-positive) (n = 34 and n = 32, respectively). Altogether, 135 were diagnosed with bilateral subtype on AVS. The single-positive patients had milder clinical features of PA than the double-positive patients. The prevalence of bilateral subtype on AVS was significantly higher in the single-positive patients than in the double-positive patients. (63/66 [95.5%] vs 72/127 [56.7%], P < .01). Several clinical parameters were different between CCT single-positive and SIT single-positive patients.

CONCLUSION

Patients with discordant results between CCT and SIT have a high probability of bilateral subtype of PA on AVS.

Confirmatory testing of primary aldosteronism with saline infusion test and LC-MS/MS

OBJECTIVE

Saline infusion testing (SIT) for confirmation of primary aldosteronism (PA) is based on impaired aldosterone suppression in PA compared to essential hypertension (EH). In the past, aldosterone was quantified using immunoassays (IA). Liquid chromatography tandem mass spectrometry (LC-MS/MS) is increasingly used in clinical routine. We aimed at a method-specific aldosterone threshold for the diagnosis of PA during SIT and explored the diagnostic utility of steroid panel analysis.

DESIGN

Retrospective cohort study of 187 paired SIT samples (2009-2018). Diagnosis of PA (n = 103) and EH (n = 84) was established based on clinical routine workup without using LC-MS/MS values.

SETTING

Tertiary care center.

METHODS

LC-MS/MS using a commercial steroid panel. Receiver operator characteristics analysis was used to determine method-specific cut-offs using a positive predictive value (PPV) of 90% as criterion.

RESULTS

Aldosterone measured by IA was on average 31 ng/L higher than with LC-MS/MS. The cut-offs for PA confirmation were 54 ng/L for IA (sensitivity: 95%, 95% CI: 89.0-98.4; specificity: 87%, 95% CI: 77.8-93.3; area under the curve (AUC): 0.955, 95% CI: 0.924-0.986; PPV: 90%, 95% CI: 83.7-93.9) and 69 ng/L for LC-MS/MS (79%, 95% CI: 69.5-86.1; 89%, 95% CI: 80.6-95.0; 0.902, 95% CI: 0.857-0.947; 90%, 95% CI: 82.8-94.4). Other steroids did not improve SIT.

CONCLUSIONS

Aldosterone quantification with LC-MS/MS and IA yields comparable SIT-cut-offs. Lower AUC for LC-MS/MS is likely due to the spectrum of disease in PA and previous decision making based on IA results. Until data of a prospective trial with clinical endpoints are available, the suggested cut-off can be used in clinical routine.

The Value of Different Single or Combined Indexes of the Captopril Challenge Test in the Diagnosis of Primary Aldosteronism

OBJECTIVE

The result interpretation of the captopril challenge test (CCT) for the diagnosis of primary aldosteronism (PA) is not standardized. Superiorities of different indexes in the CCT have not been fully investigated. We aimed to comprehensively evaluate the value and influence factors of different CCT-associated indexes in the diagnosis of PA.

METHODS

We enrolled 312, 85, 179 and 97 patients in the groups of PA, essential hypertension (EH), unilateral PA (UPA) and bilateral PA (BPA), respectively. For each single index investigated, we computed diagnostic estimates including the area under the receiver operating characteristic curve (AUC). We performed pre-specified subgroup analyses to explore influence factors. We assessed the diagnostic value of combined indexes in binary logistic regression models.

RESULTS

Post-CCT aldosterone to renin ratio (ARR) (AUC = 0.8771) and plasma aldosterone concentration (PAC) (AUC = 0.8769) showed high value in distinguishing PA from EH, and their combination (AUC = 0.937) was even superior to either alone. The diagnostic efficacy was moderately high for post-CCT aldosterone to angiotensin II ratio (AA2R) (AUC = 0.834) or plasma renin activity (PRA) (AUC = 0.795) but low for the suppression percentage of PAC (AUC = 0.679). Post-CCT PAC had a significantly higher AUC in the UPA than BPA subgroup (AUC = 0.914 vs 0.827, P<0.05).

CONCLUSION

We can take post-CCT ARR and PAC altogether into account to distinguish PA from EH, while caution should be taken to interpret CCT results with the suppression percentage of PAC. Post-CCT PAC may perform better to identify the unilateral than bilateral form of PA.

KCNJ5 Somatic Mutations in Aldosterone-Producing Adenoma Are Associated With a Worse Baseline Status and Better Recovery of Left Ventricular Remodeling and Diastolic Function

Primary aldosteronism is the most common secondary endocrine form of hypertension and causes many cardiovascular injuries. KCNJ5 somatic mutations have recently been identified in aldosterone-producing adenoma. However, their impacts on left ventricular remodeling precluding the interference of age, sex, and blood pressure are still uncertain. We enrolled 184 aldosterone-producing adenoma patients who received adrenalectomy. Clinical, biochemical, and echocardiographic data were analyzed preoperatively and 1 year postoperatively. KCNJ5 gene sequencing of aldosterone-producing adenoma was performed. After propensity score matching for age, sex, body mass index, blood pressure, hypertension duration, and number of hypertensive medications, there were 60 patients in each group with and without KCNJ5 mutations. The mutation carriers had higher left ventricular mass index (LVMI) and inappropriately excessive LVMI (ieLVMI) and lower e' than the noncarriers. After adrenalectomy, the mutation carriers had greater decreases in LVMI and ieLVMI than the noncarriers. In addition, only mutation carriers had a significant decrease in E/e' after surgery. In multivariate analysis, baseline LVMI correlated with KCNJ5 mutations, the number of hypertensive medications, and systolic blood pressure. Baseline ieLVMI correlated with KCNJ5 mutations and the number of hypertensive medications. The regression of both LVMI and ieLVMI after surgery was mainly correlated with KCNJ5 mutations and changes in systolic blood pressure. Aldosterone-producing adenoma patients with KCNJ5 mutations had higher LVMI and ieLVMI and a greater regression of LVMI and ieLVMI after adrenalectomy than those without mutations. The patients with KCNJ5 mutations also benefited from adrenalectomy with regard to left ventricular diastolic function, whereas noncarriers did not.

The value of the post-captopril aldosterone/renin ratio for the diagnosis of primary aldosteronism and the influential factors: A meta-analysis

OBJECTIVE

The procedure for the captopril challenge test (CCT) in diagnosing primary aldosteronism (PA) is not standardized. We performed a meta-analysis to evaluate the controversial diagnostic value and influential factors of the post-captopril aldosterone/renin ratio (ARR).

METHODS

We searched literature in databases for eligible studies (until October 1, 2020). We extracted information regarding study and patient characteristics, CCT methods, outcome data. We pooled studies using the random-effect model. We performed meta-regression and six pre-specified subgroup analyses to explore heterogeneity.

RESULTS

Nineteen studies involving 4568 subjects were included. The pooled sensitivity and specificity were 0.825 (95% CI 0.804-0.844) and 0.919 (95% CI 0.908-0.928). The area under the summary receiver operating characteristic curve was 0.9487 (95% CI 0.9207-0.9767). Meta-regression revealed that heterogeneity might derive from time interval (p = 0.0117) and study population (p = 0.0033). Subgroup analyses showed significant differences between the subgroups stratified by the dose, posture, study region, time interval, cut-off value and study population for sensitivity and/or specificity (p < 0.05).

CONCLUSION

Post-captopril ARR is comparably valuable for diagnosing PA at cut-offs from 12.0 to 50.0. Conducting the CCT in the supine position with 25 mg of captopril may attain greater sensitivity. Conducting the CCT in the seated position with 50 mg of captopril may attain greater specificity. A 90-min time interval may perform best in both the sensitivity and specificity.

Parameters of captopril challenge test can predict results of other confirmatory tests for primary aldosteronism and propose the next test to be done

In Japan, primary aldosteronism (PA) is diagnosed if any one of the captopril challenge test (CCT), saline infusion test (SIT), furosemide-upright test (FUP), and oral salt-loading test (OST) is positive. The present study aimed to investigate if parameters of CCT, the safest confirmatory test, could predict decisions of other tests and propose the next test to diagnose PA in CCT-negative patients. In a cross-sectional design, 142 patients, who were referred to our hospital for the scrutiny of PA and underwent at least two confirmatory tests, were enrolled. While 123 patients underwent all of the CCT, SIT, and FUP, the OST was successfully done in only six patients and excluded from further analyses. CCT parameters showing correlations of higher degrees with SIT and FUP parameters were selected, and their powers to predict SIT and FUP decisions were investigated by receiver operating characteristic analyses. Proposals of the next test based on the CCT parameters were validated with SIT and FUP decisions in subsets of CCT-negative patients divided by cut-offs of the CCT parameters. The plasma aldosterone concentration and plasma renin activity 60 min after the load of CCT (CCT60-PAC and CCT60-PRA) were selected, and CCT60-PAC ≤59.0 pg/mL and CCT60-PRA ≥1.05 ng/mL/h could predict negativities of SIT and FUP, respectively, with >95% specificities. Based on the validation, the present study suggested the SIT as the next test to be done if the CCT-negative patient belonged to the subset with CCT60-PAC >59.0 pg/mL and CCT60-PRA ≥1.05 ng/mL/h, otherwise the FUP should be selected.

Primary Aldosteronism: JACC State-of-the-Art Review

Primary aldosteronism (PA) is a common, but frequently overlooked, cause of arterial hypertension and excess cardiovascular events, particularly atrial fibrillation. As timely diagnosis and treatment can provide a cure of hyperaldosteronism and hypertension, even when the latter is resistant to drug treatment, strategies to screen patients for PA early with a simplified diagnostic algorithm are justified. They can be particularly beneficial in some subgroups of hypertensive patients, as those who are at highest cardiovascular risk. However, identification of the surgically curable cases of PA and achievement of optimal results require subtyping with adrenal vein sampling, which, as it is technically challenging and currently performed only in tertiary referral centers, represents the bottleneck in the work-up of PA. Measures aimed at improving the clinical use of adrenal vein sampling and at developing alternative techniques for subtyping, alongside recommendations for drug treatment, including new development in the field, and for follow-up are discussed.

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

Background and aim

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

Methods

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

Results

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

Conclusions

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

Seated saline infusion test in predicting subtype diagnosis of primary aldosteronism

CONTEXT

Although saline infusion test is widely used as a confirmatory test for primary aldosteronism (PA), it is reportedly less sensitive in patients in whom aldosterone is responsive to the upright position by performing it in recumbent position. Based on a single-centre experience, seated saline infusion test (SSIT) has been reported to be highly sensitive and superior to recumbent testing in identifying both unilateral and bilateral forms of PA. However, due to limited participants number, the utility of SSIT needs to be validated in other series.

OBJECTIVE

This study aimed to evaluate the accuracy of SSIT in determining the PA subtypes compared with adrenocorticotropic hormone stimulation test under dexamethasone suppression (Dex-AT).

PATIENTS AND SETTING

Sixty-four patients with PA who underwent both SSIT and Dex-AT were included. Subtype diagnosis of PA was determined by adrenal venous sampling (AVS) (16 unilateral and 48 bilateral forms).

MAIN OUTCOME MEASURE

Plasma aldosterone concentrations (PACs) were measured after SSIT and Dex-AT.

RESULTS

The area under the receiver operating characteristic (ROC) curve for diagnosing unilateral PA was greater in SSIT than that in Dex-AT (0.907 vs. 0.755; P = .023). ROC curve analysis predicted optimal cut-off PACs of 13.1 ng/dL (sensitivity, 93.8%; specificity, 79.2%) for SSIT and 34.2 ng/dL (sensitivity, 75.0%; specificity, 68.8%) for Dex-AT.

CONCLUSIONS

Seated saline infusion test has superior accuracy in subtype diagnosis of PA compared with Dex-AT. SSIT can be a sensitive test for determining patients who require AVS prior to surgery.

Left Ventricular Dysfunction in Patients With Primary Aldosteronism: A Propensity Score-Matching Follow-Up Study With Tissue Doppler Imaging

Background

Primary aldosteronism is the most common cause of secondary hypertension and is associated with left ventricular hypertrophy. However, whether aldosterone excess is responsible for left ventricular (LV) diastolic dysfunction is unknown.

Methods and Results

We prospectively enrolled 129 patients with aldosterone‐producing adenoma and 120 patients with essential hypertension, and analyzed their clinical, biochemical, and echocardiographic data, including tissue Doppler images. The patients with aldosterone‐producing adenoma were reevaluated 1 year after adrenalectomy. After propensity score matching, there were 105 patients in each group. The patients with aldosterone‐producing adenoma had worse diastolic function than the patients with essential hypertension, as reflected by lower e′ (P<0.001) and higher E/e′ (P=0.003). Multivariate analysis showed that LV diastolic function was significantly correlated with age (P<0.001), sex (P<0.001), body mass index (P=0.002), systolic blood pressure (P=0.004), creatinine (P=0.008), and log‐transformed aldosterone‐renin ratio (P=0.003). After adrenalectomy, the patients with aldosterone‐producing adenoma had significant improvements in LV diastolic function as reflected by an increase in e′ (P=0.003) and decrease in E/e′ (P=0.002). The change in E/e′ was independently correlated with baseline E/e′ (P<0.001) and change in LV mass index (P=0.006).

Conclusions

The patients with primary aldosteronism had worse LV diastolic function than the patients with essential hypertension after propensity score matching, and this could be reversed after adrenalectomy, suggesting that aldosterone excess may induce LV diastolic dysfunction.

Plasma Aldosterone After Seated Saline Infusion Test Outperforms Captopril Test at Predicting Clinical Outcomes After Adrenalectomy for Primary Aldosteronism

OBJECTIVE

The saline infusion test (SIT) and the captopril test (CT) are widely used as confirmatory tests for primary aldosteronism (PA). We hypothesized that post-SIT and post-CT plasma aldosterone concentrations (PAC) indicate the severity of aldosterone-producing adenoma (APA) and might predict clinical outcome.

METHODS

We recruited 216 patients with APA in the Taiwan Primary Aldosteronism Investigation (TAIPAI) registry who received both seated SIT and CT as confirmatory tests. The data of 143 patients who underwent adrenalectomy with complete follow-up after diagnosis were included in the final analysis. We determined the proportion of patients achieving clinical success in accordance with the Primary Aldosteronism Surgical Outcome consensus. Logistic regression analysis was conducted to identify preoperative factors associated with cure of hypertension.

RESULTS

Complete clinical success was achieved in 48 (33.6%) patients and partial clinical success in 59 (41.2%) patients; absent clinical success was seen in 36 (25.2%) of 143 patients. Post-SIT PAC but not post-CT PAC was independently associated with clinical outcome. Higher levels of post-SIT PAC had a higher likelihood of clinical benefit (complete plus partial clinical success; odds ratio = 1.04 per ng/dl increase, 95% confidence interval = 1.01, 1.06; P = 0.004). Patients with post-SIT PAC > 25 ng/dl were more likely to have a favorable clinical outcome after adrenalectomy. This cutoff value translated into a positive predictive value of 86.0%.

CONCLUSIONS

We suggest that post-SIT PAC is a better predictor than post-CT PAC for clinical success in PA post adrenalectomy.

A short review of primary aldosteronism in a question and answer fashion

OBJECTIVES

The aim of this study was to present up to date information concerning the diagnosis and treatment of primary aldosteronism (PA). PA is the most common cause of endocrine hypertension. It has been reported up to 24% of selective referred hypertensive patients.

METHODS

We did a search in Pub-Med and Google Scholar using the terms: PA, hyperaldosteronism, idiopathic adrenal hyperplasia, diagnosis of PA, mineralocorticoid receptor antagonists, adrenalectomy, and surgery. We also did cross-referencing search with the above terms. We had divided our study into five sections: Introduction, Diagnosis, Genetics, Treatment, and Conclusions. We present our results in a question and answer fashion in order to make reading more interesting.

RESULTS

PA should be searched in all high-risk populations. The gold standard for diagnosis PA is the plasma aldosterone/plasma renin ratio (ARR). If this test is positive, then we proceed with one of the four confirmatory tests. If positive, then we proceed with a localizing technique like adrenal vein sampling (AVS) and CT scan. If the lesion is unilateral, after proper preoperative preparation, we proceed, in adrenalectomy. If the lesion is bilateral or the patient refuses or is not fit for surgery, we treat them with mineralocorticoid receptor antagonists, usually spironolactone.

CONCLUSIONS

Primary aldosteronism is the most common and a treatable case of secondary hypertension. Only patients with unilateral adrenal diseases are eligible for surgery, while patients with bilateral and non-surgically correctable PA are usually treated by mineralocorticoid receptor antagonist (MRA). Thus, the distinction between unilateral and bilateral aldosterone hypersecretion is crucial.

Application of strict criteria in adrenal venous sampling increases the proportion of missed patients with unilateral disease who benefit from surgery for primary aldosteronism

OBJECTIVES

Adrenal vein sampling (AVS) is intended to confirm unilateral forms of primary aldosteronism, which are amenable to surgical cure. Excessively strict AVS criteria to define lateralization may result in many patients incorrectly categorized as bilateral primary aldosteronism and opportunity for surgical cure missed.

METHODS

Retrospective review of an AVS-primary aldosteronism database in which surgical cases are verified by standardized outcomes. Having used 'less strict' AVS criteria for lateralization, we examined the distribution of AVS lateralization indices in our confirmed unilateral primary aldosteronism cases both with and without cosyntropin stimulation. The proportion of proven unilateral cases that would have been missed with stricter AVS interpretation criteria was calculated. Particular focus was given to the proportion of missed cases according to use of international guidelines. False-positive lateralization with 'less strict' interpretation was also calculated.

RESULTS

Of 80 surgical primary aldosteronism cases, 10-23% would have been missed with AVS lateralization indices of 3 : 1 to 5 : 1, with or without cosyntropin. If strict selectivity indices (for confirmation of catheterization) were combined with strict lateralization indices, up to 70% of unilateral primary aldosteronism cases could have been missed. Use of Endocrine Society AVS guidelines would have missed 21-43% of proven unilateral cases. 'Less strict' AVS interpretation yielded one case (1.2%) of false lateralization.

CONCLUSION

Excessively strict AVS interpretation criteria will result in a high rate of missed unilateral primary aldosteronism with subsequent loss of opportunity for intervention. Use of more lenient lateralization criteria will improve the detection rate of unilateral primary aldosteronism with very low false-positive rate.

The characteristics of captopril challenge test-positive patients using various criteria

Introduction:

The captopril challenge test (CCT) is the major confirmatory test for primary aldosteronism (PA), and frequently carried out because of its convenience. However, it presents false-negative results with a certain probability, and as there are many criteria for CCT, it is not concluded yet which criteria to use.

Materials and methods:

A total of 71 PA patients were evaluated. We compared CCT-positive and CCT-negative patients in the following three criteria: plasma aldosterone/renin ratio (ARR) >200 after the CCT (criterion 1); plasma aldosterone concentration (PAC) >120 pg/ml after the CCT (criterion 2); and PAC suppression <30% of PAC before CCT (criterion 3).

Results:

The positive rate was 70.4%, 64.8% and 54.9% for criterion 1, criterion 2 and criterion 3, respectively. With criterion 1, the baseline plasma renin activity was lower, thus baseline ARR was higher in CCT-positive patients. With criterion 2, PAC was higher and estimated sodium intake and K were lower in CCT-positive patients. With criterion 3, K and PAC were lower in CCT-positive patients. Although it was not significant, in the patients with high sodium intake, the positive rate of criterion 1 was higher than that of the other criteria.

Conclusions:

ARR>200 is the valuable criterion for the diagnosis of PA.

The captopril challenge test for diagnosing primary Aldosteronism in a Chinese population

BACKGROUND

The Captopril challenge test (CCT) is an easy-conduct confirmatory test for diagnosing primary aldosteronism (PA). Guidelines show that plasma aldosterone is normally suppressed by captopril (> 30%) in primary hypertension (PH) and in healthy people. It is unclear whether this standard is applicable in Chinese subjects. The aim of the present study was to investigate the post-CCT efficacy of plasma aldosterone concentration (PAC) suppression and determine the post-CCT aldosterone renin activity ratio (ARR) and PAC for PA diagnosis.

METHODS

We recruited 110 consecutive patients with PA, 163 with primary hypertension (PH), and 40 healthy volunteers (NC). The CCT was conducted in all patients. Total sodium intake was estimated from 24-h urinary excretions. ROC curves were used to analyze the efficiency of different CCT diagnostic criteria for diagnosing PA.

RESULTS

In NC and PH patients, PRA was increased and PAC was decreased post-CCT (P < 0.05). The mean degree of PAC decline after CCT was approximately 9.3%, and only 11.7% of the patients with PH showed a greater than 30% suppression of PAC after CCT. In patients with PA, the post-CCT change in PRA and PRC was slight. The post-CCT degree of PAC decline was unrelated to dietary salt intake. The areas under the ROC for the post-CCT ARR, PAC and PAC suppression % were 0.994, 0.754 and 0.606, respectively. The optimal post-CCT cutoff value for ARR for diagnosing PA was 20, which yielded a sensitivity and specificity of 94.0 and 99.4%, respectively.

CONCLUSIONS

The PAC suppression percentage after CCT recommended by current clinical guidelines is not applicable when diagnosing Chinese subjects with PA. Compared to post-CCT PAC, post-CCT ARR was a better approach, having an optimal cutoff of 20 when interpreting the results of the CCT in Chinese patients. We found no relationship between high salt intake and low responses of the renin-angiotensin system (RAS) to the CCT.

Confirmatory tests for the diagnosis of primary aldosteronism: A systematic review and meta-analysis

OBJECTIVE

Saline infusion test (SIT), captopril challenge test (CCT), fludrocortisone suppression test (FST) and oral sodium loading test (SLT) are recommended by the Endocrine Society's Clinical Practice Guidelines to diagnose primary aldosteronism, but which one is the best remains controversial. We aimed to summarize the available comparative data and evaluate the diagnostic accuracy of these four tests.

DESIGN

We searched PubMed, Embase and the Cochrane Library for relevant studies published between January 1980 and January 2018.

PATIENTS

Eligible studies reported on the accuracy of one or more of the four confirmatory tests in patients suspected of PA.

MEASUREMENTS

Two reviewers independently conducted the data extraction of all selected studies, which consisted of study characteristics and data to estimate the summary receiver operating characteristic (SROC) curve and the corresponding summary area under the curve (SAUC), pooled sensitivity and specificity, diagnostic odds ratios (DOR) with 95% confidence interval (CI).

RESULTS

We identified 26 articles including 3686 patients. Fifteen articles evaluated the diagnostic accuracy of CCT, 10 of SIT, 1 of FST and none of SLT. For CCT, the SAUC was 0.9207, and the pooled sensitivity and specificity were 0.87 (95% CI: 0.84-0.89) and 0.84 (95% CI: 0.81-0.86), respectively. For SIT, the SAUC was 0.9232, and the pooled sensitivity and specificity were 0.85 (95% CI: 0.82-0.87) and 0.87 (95% CI: 0.85-0.89), respectively. For FST, the pooled sensitivity and specificity were 0.87 (95% CI: 0.66-0.97) and 0.95 (95% CI: 0.82-0.99), respectively. Overall, we found no significant differences in the diagnostic accuracy of CCT and SIT.

CONCLUSIONS

CCT and SIT exhibit high and comparable accuracy for diagnosing PA. CCT may be a more feasible alternative as it is safe and much easier to perform.

[Two case reports on resistant hypertension]

Primary aldosteronism (PA) is a frequent cause of resistant hypertension. The clinical presentation is heterogeneous, but a suppressed or low normal renin (especially with ACE inhibitors or sartans) should raise suspicion for primary aldosteronism, even when aldosterone levels are in the normal range. Diagnosis of unilateral hormone production from an adrenal adenoma (Conn syndrome), which is curable by surgery, requires adrenal vein sampling, which should be performed in experienced centers.

The Biology of Normal Zona Glomerulosa and Aldosterone-Producing Adenoma: Pathological Implications

The identification of several germline and somatic ion channel mutations in aldosterone-producing adenomas (APAs) and detection of cell clusters that can be responsible for excess aldosterone production, as well as the isolation of autoantibodies activating the angiotensin II type 1 receptor, have rapidly advanced the understanding of the biology of primary aldosteronism (PA), particularly that of APA. Hence, the main purpose of this review is to discuss how discoveries of the last decade could affect histopathology analysis and clinical practice. The structural remodeling through development and aging of the human adrenal cortex, particularly of the zona glomerulosa, and the complex regulation of aldosterone, with emphasis on the concepts of zonation and channelopathies, will be addressed. Finally, the diagnostic workup for PA and its subtyping to optimize treatment are reviewed.

Comparison of Seated With Recumbent Saline Suppression Testing for the Diagnosis of Primary Aldosteronism

CONTEXT

Failure of plasma aldosterone suppression during fludrocortisone suppression testing (FST) or saline suppression testing (SST) confirms primary aldosteronism (PA). Aldosterone is often higher upright than recumbent in PA; upright levels are used during FST. In a pilot study (24 patients with PA), seated saline suppression testing (SSST) was more sensitive than recumbent saline suppression testing (RSST).

OBJECTIVE, DESIGN, AND PATIENTS

The current validation study involved 100 patients who underwent FST, RSST, and SSST, eight before and after unilateral adrenalectomy. Of the 108 FSTs, 73 confirmed and 18 excluded PA. Four patients with inconclusive FST lateralized on adrenal venous sampling, making a total of 77 with PA.

RESULTS

The area under the receiver operating characteristic (ROC) curve was greater for SSST than RSST (0.96 vs. 0.80; P < 0.01). ROC analysis predicted optimal cutoff aldosterone levels of 162 pmol/L for SSST and 106 pmol/L for RSST. At these cutoffs, SSST showed high sensitivity for PA (87%) that markedly exceeded that for RSST (38%; P < 0.001) but similar specificity (94 vs. 94%; not significant). SSST was more sensitive than RSST in detecting both unilateral (n = 28, 93% vs. 68%, P < 0.05) and bilateral (n = 40, 85% vs. 20%, P < 0.001) forms of PA. Only three SSST (vs. 9 RSST and 17 FST) results were inconclusive.

CONCLUSIONS

SSST is highly sensitive and superior to RSST in identifying both unilateral and bilateral forms of PA and has a low rate of false positives and inconclusive results. It therefore offers a reliable and much less complicated and expensive alternative to FST for confirming PA.

Evaluation of the Saline Infusion Test and the Captopril Challenge Test in Chinese Patients With Primary Aldosteronism

CONTEXT

The aim of this study was to determine whether the diagnosis cutoff values associated with the saline infusion test (SIT) and captopril challenge test (CCT) in the Endocrine Society guidelines are applicable to Chinese subjects.

OBJECTIVE AND DESIGN

We performed a head-to-head comparison of the SIT and CCT among Chinese subjects with primary aldosteronism (PA) and essential hypertension (EH).

PARTICIPANTS AND SETTING

One hundred sixty-four hypertensive patients were enrolled.

INTERVENTION

All participants underwent both the SIT and CCT.

MAIN OUTCOME MEASURES

The plasma aldosterone concentration (PAC) and plasma renin activity were measured before and after the SIT and CCT. The degree of PAC decline after CCT was calculated.

RESULTS

This study included 115 PA and 49 EH subjects. The prevalence of hypokalemia was 74.8% in the PA group. Supine PACs in the EH and PA groups were 15.1 ± 4.7 mmol/L and 30.4 ± 12.1 mmol/L. Post-SIT PACs were 8.8 ± 1.7 ng/dL and 22.7 ± 10.2 ng/dL in the EH and PA groups. The degree of PAC decline after CCT was 17.7% and 14.2% in the EH and PA groups; post-CCT PACs were 11.7 ± 3.3 ng/dL and 25.9 ± 10.6 ng/dL. PAC values of 11.2 ng/dL and 16.7 ng/dL after the SIT and CCT represented the optimal cutoff values for PA diagnosis. The post-SIT and post-CCT area under the receiver operating characteristic curve values were 0.972 [95% confidence interval (CI) = 0.934 to 0.991] and 0.933 (95% CI = 0.883 to 0.966).

CONCLUSIONS

Post-SIT and post-CCT PACs, but not the degree of PAC suppression, were both reliable for PA diagnosis. However, the optimal cutoffs were slightly higher in Chinese subjects than those recommended by the Endocrine Society.

Quantitative Value of Aldosterone-Renin Ratio for Detection of Aldosterone-Producing Adenoma: The Aldosterone-Renin Ratio for Primary Aldosteronism (AQUARR) Study

Background

Current guidelines recommend use of the aldosterone‐renin ratio (ARR) for the case detection of primary aldosteronism followed by confirmatory tests to exclude false‐positive results from further diagnostic workup. We investigated the hypothesis that this could be unnecessary in patients with a high ARR value if the quantitative information carried by the ARR is taken into due consideration.

Methods and Results

We interrogated 2 large data sets of prospectively collected patients studied with the same predefined protocol, which included the captopril challenge test. We used an unambiguous diagnosis of aldosterone‐producing adenoma as reference index. We also assessed whether the post‐captopril ARR and plasma aldosterone concentration fall furnished a diagnostic gain over baseline ARR values. We found that the false‐positive rate fell exponentially, and, conversely, the specificity increased with rising ARR values. At receiver operating characteristics curves and diagnostic odds ratio analysis, the high baseline ARR values implied very high positive likelihood ratio and diagnostic odds ratio values. The baseline and post‐captopril ARR showed similar diagnostic accuracy (area under the receiver operating characteristics curve) in both the exploratory and validation cohorts, indicating lack of diagnostic gain with this confirmatory test (between‐area under the curve difference, 0.005; 95% CI, −0.031 to 0.040; P=0.7 for comparison, and 0.05; 95% CI, −0.061 to 0.064; P=0.051 for comparison, respectively).

Conclusions

These results indicate that the ARR conveys key quantitative information that, if properly used, can simplify the diagnostic workup, resulting in saving of money and resources. This can offer the chance of diagnosis and ensuing adrenalectomy to a larger number of hypertensive patients, ultimately resulting in better control of blood pressure.

Scoring system for the diagnosis of bilateral primary aldosteronism in the outpatient setting before adrenal venous sampling

OBJECTIVE

The only reliable method for subtyping primary aldosteronism (PA) is adrenal venous sampling (AVS), which is costly and time-consuming. Considering the limited availability of AVS, it would be helpful to obtain information on the diagnosis of bilateral hyperaldosteronism (BHA) from routine tests. We aimed to establish new, simple criteria for outpatients to diagnose BHA from PA before AVS.

DESIGN

We retrospectively analysed 82 patients who were diagnosed with PA and underwent AVS. Thirty-seven patients were diagnosed with unilateral hyperaldosteronism (UHA), and 36 with BHA and nine were undetermined. Among the variables that were significantly different between UHA and BHA in the univariate analysis, we chose three variables to be included in multivariate logistic regression models and constructed a subtype prediction score.

RESULTS

The subtype prediction score was calculated as follows: 3 points for no adrenal nodules on computed tomography imaging, 2 for serum potassium of ≥3·5 mmol/l and 2 for aldosterone-to-renin ratio of <490 after a captopril challenge test. Receiver operating characteristic curve analysis for the ability to discriminate BHA from UHA showed that a score of 7 points had 50% sensitivity and 100% specificity and a score of 5 points had 67% sensitivity and 94% specificity (area under the curve: 0·922; 95% CI: 0·863-0·980).

CONCLUSIONS

Our new, simple criteria specifically distinguished BHA from UHA in the outpatient setting before AVS. Furthermore, not only endocrinologists but also general internists can use this convenient, safe scoring system.

Prospective validation of an automated chemiluminescence-based assay of renin and aldosterone for the work-up of arterial hypertension

BACKGROUND

The availability of simple and accurate assays of plasma active renin (DRC) and aldosterone concentration (PAC) can improve the detection of secondary forms of arterial hypertension. Thus, we investigated the performance of an automated chemiluminescent assay for DRC and PAC in referred hypertensive patients.

METHODS

We prospectively recruited 260 consecutive hypertensive patients referred to an ESH Center for Hypertension. After exclusion of six protocol violations, 254 patients were analyzed: 67.3% had primary hypertension, 17.3% an aldosterone producing adenoma (APA), 11.4% idiopathic hyperaldosteronism (IHA), 2.4% renovascular hypertension (RVH), 0.8% familial hyperaldosteronism type 1 (FH-1), 0.4% apparent mineralocorticoid excess (AME), 0.4% a renin-producing tumor, and 3.9% were adrenalectomized APA patients. Bland-Altman plots and Deming regression were used to analyze results. The diagnostic accuracy (area under the curve, AUC of the ROC) of the DRC-based aldosterone-renin ratio (ARRCL) was compared with that of the PRA-based ARR (ARRRIA) using as reference the conclusive diagnosis of APA.

RESULTS

At Bland-Altman plot, the DRC and PAC assay showed no bias as compared to the PRA and PAC assay. A tight relation was found between the DRC and the PRA values (concordance correlation coefficient=0.92, p<0.0001) and the PAC values measured with radioimmunoassay and chemiluminescence (concordance correlation coefficient=0.93, p<0.001). For APA identification the AUC of the ARRCL was higher than that of the ARRRIA [0.974 (95% CI 0.940-0.991) vs. 0.894 (95% CI 0.841-0.933), p=0.02].

CONCLUSIONS

This rapid automated chemiluminescent DRC/PAC assay performed better than validated PRA/PAC radioimmunoassays for the identification of APA in referred hypertensive patients.

Reassessment of the cosyntropin stimulation test in the confirmatory diagnosis and subtype classification of primary aldosteronism

OBJECTIVE

Although corticotropin is a representative secretagogue of aldosterone, the utility of the cosyntropin stimulation test (C-ST) in diagnosing primary aldosteronism (PA) has not been elucidated. Aim of the study was to evaluate the clinical utility of C-ST for confirmatory testing and subtype classification of PA.

DESIGN, SETTING AND PATIENTS

In this retrospective study, we identified patients with hypertension and positive case-detection results for PA who underwent C-ST and saline infusion testing (SIT) between 2006 and 2013 at eight referral centres in Japan. PA and essential hypertension (EH) were distinguished based on SIT results. PA subtype classification was determined by adrenal venous sampling (AVS). Plasma aldosterone concentration (PAC) was measured before and 30 and 60 min after intravenous cosyntropin administration. The ability of C-ST to distinguish PA from EH and to distinguish unilateral from bilateral disease was assessed by the area under the receiver operating characteristic curve.

RESULTS

Of 205 patients with hypertension and positive case-detection results, 139 (68%) had PA based on SIT results. Eighteen patients in whom AVS was unsuccessful were excluded from analysis. The baseline PAC before C-ST was significantly higher (P < 0·01) in patients with PA than in those with EH. However, the degree of difference in PAC between patients with PA and EH was not enhanced by the administration of cosyntropin. In addition, the administration of cosyntropin did not improve the distinction between bilateral and unilateral PA subtypes.

CONCLUSIONS

C-ST has no utility as a confirmatory and subtype testing of PA when the diagnosis of PA is based on the positive results in SIT.

ACTH stimulation test and computed tomography are useful for differentiating the subtype of primary aldosteronism

The diagnostic steps for primary aldosteronism (PA) include case screening tests, confirmatory tests, and localization. The aim of this study was to identify useful confirmatory tests and their cut-off values for differentiating the subtype of primary aldosteronism, especially in unilateral PA, such as aldosterone-producing adenoma, and bilateral PA, such as idiopathic hyperaldosteronism. Seventy-six patients who underwent all four confirmatory tests, the captopril-challenge test (CCT), furosemide upright test (FUT), saline infusion test (SIT), and ACTH stimulation test (AST), and who were confirmed to have an aldosterone excess by adrenal venous sampling (AVS) were recruited. Subjects were diagnosed as having unilateral aldosterone excess (n=17) or bilateral aldosterone excess (n=59) by AVS. The SIT-positive rate was significantly higher in the unilateral group (94.1%) than in the bilateral group (57.6%). Multivariable logistic regression analysis showed that tumor on computed tomography (CT) and plasma aldosterone concentration (PAC)_max/cortisol on the AST were useful for differentiating the subtype of PA. Receiver operating characteristic (ROC) curve analysis for distinguishing the subtype of PA showed that a cut-off value of 18.3 PAC_max/cortisol on the AST had a sensitivity of 83% and a specificity of 88%. The area under the ROC curve was 0.918 (95% confidence interval 0.7916-0.9708). These data suggest that abdominal CT and AST are useful for differentiating the subtype of PA and the indication for AVS.

Primary Aldosteronism: Diagnosis and Management

Primary aldosteronism (PA) is an important and commonly unrecognized cause of secondary hypertension. Idiopathic hyperaldosteronism and aldosterone-producing adenomas account for more than 95% of PA and are characterized, respectively, by bilateral or unilateral involvement of the adrenal glands. When there is suspicion for the presence of PA, a plasma aldosterone to renin ratio should be obtained initially. Localization to determine adrenal gland involvement is done by imaging, with computerized tomography or magnetic resonance imaging. After imaging, adrenal vein sampling is done to establish treatment options. Patients with unilateral disease, who are good surgical candidates, are most appropriately managed with adrenalectomy. A biochemical cure is almost certain following adrenalectomy; however, only 30-50% of patients would show adequate blood pressure improvement. Patients with bilateral adrenal disease and those believed not to be surgical candidates are managed with mineralocorticoid antagonists.

SFE/SFHTA/AFCE consensus on primary aldosteronism, part 3: Confirmatory testing

Aldosterone/renin ratio (ARR) identifies patients at high or low risk of primary aldosteronism (PA), but sensitivity and especially specificity are suboptimal and confirmatory testing may therefore be necessary, in some but not all patients. In patients with elevated ARR and plasma aldosterone concentration above 550pmol/L (20ng/dL) on two assessments, PA can be diagnosed without confirmatory testing. Conversely, PA can be ruled out without confirmatory testing in patients with normal ARR and plasma aldosterone concentration below 240pmol/L (9ng/dL) on two assessments. In patients not corresponding to either of the previous conditions, dynamic confirmatory testing is mandatory. Several tests are available, based on aldosterone suppression by saline loading, fludrocortisone administration or converting enzyme inhibition by captopril. One test is based on renin stimulation by furosemide administration. Each of these tests has its limitations, and validation is incomplete. We recommend aldosterone suppression by saline infusion test. Renin stimulation by captopril may be used if sodium loading is contraindicated by impaired cardiac function.

Diagnostic Role of Captopril Challenge Test in Korean Subjects with High Aldosterone-to-Renin Ratios

BACKGROUND

Diagnosis of primary aldosteronism (PA) begins with aldosterone-to-renin ratio (ARR) measurement followed by confirmative tests. However, the ARR has high false positive rates which led to unnecessary confirmatory tests. Captopril challenge test (CCT) has been used as one of confirmatory tests, but the accuracy of it in the diagnosis of PA is still controversial. We aimed to examine the clinical efficacy of CCT as a post-screening test in PA.

METHODS

In a prospective study, we enrolled subjects with suspected PA who had hypertension and ARR >20 (ng/dL)/(ng/mL/hr). Sixty-four patients who underwent both the saline infusion test and the CCT were included.

RESULTS

The diagnostic performance of plasma aldosterone concentration (PAC) post-CCT was greater than that of ARR post-CCT and ARR pre-CCT in PA (area under the curve=0.956, 0.797, and 0.748, respectively; P=0.001). A cut-off value of 13 ng/dL showed the highest diagnostic odds ratio considering PAC post-CCT at 60 and 90 minutes. A PAC post-CCT of 19 ng/dL had a specificity of 100%, which can be used as a cut-off value for the confirmative test. Determining the diagnostic performance of PAC post-CCT at 90 minutes was sufficient for PA diagnosis. Subjects with PAC post-CCT at 90 minutes <13 ng/dL are less likely to have PA, and those with PAC post-CCT at 90 minutes ≥13 but <19 ng/dL should undergo secondary confirmatory tests.

CONCLUSION

The CCT test may be a reliable post-screening test to avoid the hospitalization in the setting of falsely elevated ARR screening tests.

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.