Development and Validation of Criteria for Sparing Confirmatory Tests in Diagnosing Primary Aldosteronism

Optimizing the aldosterone-to-renin ratio cut-off for screening primary aldosteronism based on cardiovascular risk: a collaborative study

OBJECTIVES

Aldosterone-to-renin ratio (ARR) based screening is the first step in the diagnosis of primary aldosteronism (PA). However, the guideline-recommended ARR cutoff covers a wide range, from the equivalent of 1.3 to 4.9 ng·dl-1/mIU∙l-1. We aimed to optimize the ARR cutoff for PA screening based on the risk of cardiovascular diseases (CVD).

METHODS

Longitudinally, we included hypertensive participants from the Framingham Offspring Study (FOS) who attended the sixth examination cycle and followed up until 2014. At baseline (1995-1998), we used circulating concentrations of aldosterone and renin to calculate ARR (unit: ng·dl-1/mIU∙l-1) among 1,433 subjects who were free of CVD. We used spline regression to calculate the ARR threshold based on the incident CVD. We used cross-sectional data from the Chongqing Primary Aldosteronism Study (CONPASS) to explore whether the ARR cutoff selected from FOS is applicable to PA screening.

RESULTS

In FOS, CVD risk increased with an increasing ARR until a peak of ARR 1.0, followed by a plateau in CVD risk (hazard ratio 1.49, 95%CI 1.19-1.86). In CONPASS, when compared to essential hypertension with ARR < 1.0, PA with ARR ≥ 1.0 carried a higher CVD risk (odds ratio 2.24, 95%CI 1.41-3.55), while essential hypertension with ARR ≥ 1.0 had an unchanged CVD risk (1.02, 0.62-1.68). Setting ARR cutoff at 2.4 ~ 4.9, 10% ~30% of PA subjects would be unrecognized although they carried a 2.45 ~ 2.58-fold higher CVD risk than essential hypertension.

CONCLUSIONS

The CVD risk-based optimal ARR cutoff is 1.0 ng·dl-1/mIU∙l-1 for PA screening. The current guideline-recommended ARR cutoff may miss patients with PA and high CVD risk.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT03224312).

Sparing confirmatory testing in primary aldosteronism (SCIPA): a multicenter retrospective diagnostic accuracy study

BACKGROUND

The diagnosis of primary aldosteronism (PA) is comprehensive, which includes case-detection testing, case confirmation followed by subtype classification. In certain instances, such as in the setting of spontaneous hypokalemia, suppressed renin activity (PRA) plus plasma aldosterone concentration (PAC) of > 15 ng/dL, one may not proceed with confirmatory tests. However, the quality of evidence behind this approach is very low. This study sought to evaluate the proposed "simplified confirmatory pathway" that can spare confirmatory testing for primary aldosteronism by evaluating the diagnostic performances of the various pre-specified PAC thresholds in combination with findings of suppressed renin and spontaneous hypokalemia.

METHODS

This is a multi-center, retrospective diagnostic accuracy cohort-selected cross-sectional study. A total of 133 participants aged 18 years and above underwent saline infusion test between January 2010 to March 2024. The outcome measures comprise of the diagnostic performances of the different index test combinations (baseline PAC, baseline PRA and presence of spontaneous hypokalemia): sensitivity, specificity, negative predictive value, positive predictive value, positive likelihood ratio, negative likelihood ratio, and diagnostic accuracy. Data analysis was performed using SPSS 29.0.1.0 & MedCalc 20.218.

RESULTS

Of the 133 patients who underwent saline infusion test, 88 (66.17%) were diagnosed with PA. A PAC of > 25 ng/dL plus PRA < 1.0 ng/dL/hr with spontaneous hypokalemia showed the highest specificity at 100% (95% CI 90.51%, 100.00%) and positive predictive value at 100% (85.18 - 100.00%). The minimum acceptable combination criteria were determined to be a PAC of > 20 ng/dL plus PRA < 0.6 ng/dL/hr, and presence of spontaneous hypokalemia. It has high specificity (94.59%; 95% CI 81.81%, 99.34%), positive predictive value (93.55%, 95% CI 78.49%, 98.29%), and moderate positive likelihood ratio (LR+) (6.39, 95% CI 1.61, 25.38) CONCLUSION: A hypertensive patient with spontaneous hypokalemia and screening findings of PAC > 20 ng/dL and suppressed PRA of < 0.6 ng/ml/hr, may be classified as "overt primary aldosteronism confirmed" and may not need to proceed with dynamic confirmatory testing.

PROTOCOL REGISTRATION NUMBER

SRCTN34186253.

Health Care Challenges in the Management of Primary Aldosteronism in Southeast Asia

CONTEXT

While guidelines have been formulated for the management of primary aldosteronism (PA), following these recommendations may be challenging in developing countries with limited health care access.

OBJECTIVE

We aimed to assess the availability and affordability of health care resources for managing PA in the Association of Southeast Asian Nations (ASEAN) region, which includes low-middle-income countries.

METHODS

We instituted a questionnaire-based survey to specialists managing PA, assessing the availability and affordability of investigations and treatment. Population and income status data were taken from the national census and registries.

RESULTS

Nine ASEAN country members (48 respondents) participated. While screening with aldosterone-renin ratio is performed in all countries, confirmatory testing is routinely performed in only 6 countries due to lack of facilities and local assays, and cost constraint. Assays are locally available in only 4 countries, and some centers have a test turnaround time exceeding 3 weeks. In 7 countries (combined population of 442 million), adrenal vein sampling (AVS) is not routinely performed due to insufficient radiological facilities or trained personnel, and cost constraint. Most patients have access to adrenalectomy and medications. In 6 countries, the cost of AVS and adrenalectomy combined is more than 30% of its annual gross domestic product per capita. While most patients had access to spironolactone, it was not universally affordable.

CONCLUSION

Large populations currently do not have access to the health care resources required for the optimal management of PA. Greater efforts are required to improve health care access and affordability. Future guideline revisions for PA may need to consider these limitations.

The effect of different treatment strategies on glycolipid metabolism disorders and cardiovascular events in primary aldosteronism

Recent studies have explored the association between primary aldosteronism and cardiovascular disease incidence. The association between specific primary aldosteronism treatments and differential improvement in cardiovascular event rates is yet to be established. This study was designed to compare the relative effects of spironolactone therapy and surgical intervention on cardiovascular outcomes among primary aldosteronism patients. This retrospective observational study included 853 primary aldosteronism patients from the First Affiliated Hospital of China Medical University between 2014 and 2022. Patients who had completed abdominal computed tomography (CT) examinations with similar metabolic characteristics and 6-month follow-up analyses were included in this study. These patients were separated into a surgical treatment group (n = 33) and a spironolactone treatment group (n = 51). Demographic data, biochemical analysis results, liver/spleen (L/S) X-ray attenuation ratio, hospitalization frequency, and cardiovascular events were compared between the two groups. The spironolactone group demonstrated significantly improved metabolic characteristics compared to the surgical group, shown by lower BMI, blood pressure, total cholesterol (TC), insulin resistance index (IRI), and reduced non-alcoholic fatty liver disease prevalence. Metabolic parameters did not differ significantly within the surgical treatment group when comparing pre- and postoperative values. The incidence of cardiovascular events was lower in the spironolactone group compared to the surgery group (23/33 vs. 20/51, P < 0.001) despite higher hospitalization rates(37/31 vs. 61/53, P < 0.001). In patients with primary aldosteronism, spironolactone treatment is more effective than surgical intervention in remediating abnormal lipid and glucose metabolism while improving cardiovascular outcomes. Chinese clinical trial registry registration number: ChiCTR2300074574.

The role of confirmatory tests in the diagnosis of primary aldosteronism

Confirmatory tests for diagnosis of primary aldosteronism (PA) play an important role in sparing patients with a false-positive aldosterone-to-renin ratio (ARR) screening test from undergoing invasive subtyping procedures. We recommend that patients with a positive ARR test should undergo at least one confirmatory test to confirm or exclude the diagnosis of PA before directly proceeding to subtype studies, except for patients with significant PA phenotypes, including spontaneous hypokalemia, plasma aldosterone concentration >20 ng/dL plus plasma renin activity below a detectable level. Although a gold standard confirmatory test has not been identified, we recommend that saline infusion test and captopril challenge test, which were widely used in Taiwan. Patients with PA have been reported to have a higher prevalence of concurrent autonomous cortisol secretion (ACS). ACS is a biochemical condition of mild cortisol overproduction from adrenal lesions, but without the typical clinical features of overt Cushing's syndrome. Concurrent ACS may result in incorrect interpretation of adrenal venous sampling (AVS) and may lead to adrenal insufficiency after adrenalectomy. We recommend screening for ACS in patients with PA scheduled for AVS examinations as well as for adrenalectomy. We recommend the 1-mg overnight dexamethasone suppression test as screening method to detect ACS.

Cost-effectiveness of screening for primary aldosteronism in hypertensive patients in Australia: a Markov modelling analysis

BACKGROUND

Primary aldosteronism affects 3-14% of hypertensive patients in the primary care setting and up to 30% in the hypertensive referral units. Although primary aldosteronism screening is recommended in patients with treatment-resistant hypertension, diagnosis at an earlier stage of disease may prevent end-organ damage and optimize patient outcomes.

METHODS

A Markov model was used to estimate the cost-effectiveness of screening for primary aldosteronism in treatment and disease (cardiovascular disease and stroke) naive hypertensive patients. Within the model, a 40-year-old patient with hypertension went through either the screened or the unscreened arm of the model. They were followed until age 80 or death. In the screening arm, the patient underwent standard diagnostic testing for primary aldosteronism if the screening test, aldosterone-to-renin ratio, was elevated above 70 pmol/l : mU/l. Diagnostic accuracies, transition probabilities and costs were derived from published literature and expert advice. The main outcome of interest was the incremental cost effectiveness ratio (ICER).

RESULTS

Screening hypertensive patients for primary aldosteronism compared with not screening attained an ICER of AU$35 950.44 per quality-adjusted life year (QALY) gained. The results were robust to different sensitivity analyses. Probabilistic sensitivity analysis demonstrated that in 73% of the cases, it was cost-effective to screen at the commonly adopted willingness-to-pay (WTP) threshold of AU$50 000.

CONCLUSION

The results from this study demonstrated that screening all hypertensive patients for primary aldosteronism from age 40 is cost-effective. The findings argue in favour of screening for primary aldosteronism before the development of severe hypertension in the Australian healthcare setting.

Captopril challenge test in the diagnosis of primary aldosteronism: consistency between 1- and 2- h sampling

Objective

To examine the consistency of plasma aldosterone concentration at 1 and 2 h in the captopril challenge test (CCT) and to explore the possibility of replacing 2-h aldosterone concentration with 1-h aldosterone concentration for diagnosis of primary aldosteronism (PA).

Methods

This retrospective analysis included a total of 204 hypertensive patients suspected of having PA. Subjects received oral captopril challenge at 50 mg (25 mg if the systolic blood pressure was <120 mmHg), and plasma aldosterone concentration and direct renin concentration were measured at 1 and 2 h afterward (chemiluminescence immunoassay Liaison® DiaSorin, Italy). Sensitivity and specificity were used to reflect the diagnostic performance of 1-h aldosterone concentration using 2-h aldosterone concentration (11 ng/dl as the cutoff) as the reference. A receiver operating characteristic curve analysis was also conducted.

Results

Among the 204 included patients [median age of 57.0 (48.0-61.0) years, 54.4% men], a diagnosis of PA was established in 94 patients. Aldosterone concentration in the patients with essential hypertension was 8.40 (interquartile range 7.05-11.00) ng/dl at 1 h and 7.65 (5.98-9.30) ng/dl at 2 h (P < 0.001). In patients with PA, aldosterone concentration was 16.80 (12.58-20.50) ng/dl at 1 h and 15.55 (12.60-20.85) ng/dl at 2 h (P > 0.999). At a cutoff of 11 ng/dl, the sensitivity and specificity of using 1-h aldosterone concentration to diagnose PA were 87.2% and 78.2%, respectively. A higher cutoff of 12.5 ng/ml increased specificity to 90.0% but decreased sensitivity to 75.5%. A lower cutoff of 9.3 ng/ml increased sensitivity to 97.9% but decreased specificity to 65.4%.

Conclusions

When diagnosing PA with CCT, 1-h aldosterone concentration could not be used to replace 2-h aldosterone concentration.

Renin-independent aldosteronism and chronic kidney disease in diabetes: Observational and Mendelian randomization analyses

BACKGROUND

Renin-independent aldosteronism (RIA) describes the spectrum of autonomous aldosterone secretion from mild to overt. We aimed to explore whether RIA is causally associated with chronic kidney disease (CKD) in patients with diabetes.

METHODS

We cross-sectionally included 1027, 402 and 39,709 patients with any type of diabetes from cohorts of EIMDS, CONPASS and UK Biobank, respectively. In EIMDS, we defined RIA and renin-dependent aldosteronism based on plasma aldosterone and renin concentrations. We performed captopril challenge test to confirm renin-dependent or independent aldosteronism in CONPASS. In UK Biobank, we generated genetic instruments for RIA based on the genome-wide association studies (GWAS). We extracted the corresponding single nucleotide polymorphisms (SNPs) information from the GWAS data of CKD in diabetes. We harmonized the SNP-RIA and SNP-CKD data to conduct the two-sample Mendelian randomization analyses.

FINDINGS

In EIMDS and CONPASS, when compared to subjects with normal aldosterone concentration or renin-dependent aldosteronism, participants with RIA had a lower estimated glomerular filtration rate, a higher prevalence of CKD, and a higher multivariate-adjusted odds ratio (OR) of CKD (OR 2.62 [95%CI 1.09-6.32] in EIMDS, and 4.31 [1.39-13.35] in CONPASS). The two-sample Mendelian randomization analysis indicated that RIA was significantly associated with a higher risk of CKD (inverse variance weighted OR 1.10 [95 % CI 1.05-1.14]), with no evidence of significant heterogeneity or substantial directional pleiotropy.

INTERPRETATION

Among patients with diabetes, renin-independent aldosteronism is causally associated with a higher risk of CKD. Targeted treatment of autonomous aldosterone secretion may benefit renal function in diabetes.

Renin, Aldosterone, and Cortisol in Pregnancy-Induced Hypertension

INTRODUCTION

We aimed to assess renin, aldosterone, and cortisol in the early stages of pregnancy-induced hypertension (PIH), i. e., at the time of diagnosis.

METHODS

During the postural test, we measured aldosterone, renin [Liason DiaSorin Inc. (Italy)], as well as cortisol, sodium, potassium, and 24-h urinary sodium and potassium excretion in 62 women with newly diagnosed PIH, 70 healthy women during the 3rd trimester of pregnancy, and in 22 healthy non-pregnant women.

RESULTS

In all groups, there was a significant increase in aldosterone and renin in upright versus supine posture (p<0.01). Both supine and upright aldosterone concentrations were higher in healthy pregnant women than in women with PIH and the lowest in healthy not-pregnant [supine (median±intequartile range): 25.04±18.4 ng/dL, 18.03±12.58 ng/dL, and 7.48±4.78 ng/dL, p<0.001, upright: 31.60±21.32 ng/dL, 25.11±13.15 ng/dL, and 12.4±12.4 ng/dL, p<0.001, for healthy pregnant, pregnant with PIH, and non-pregnant, respectively]. Supine renin concentrations were higher only in healthy pregnant (p<0.001), while in the upright position, there was a difference only between healthy pregnant and women with PIH (p=0.002). Both in supine and upright positions, there was no difference in the aldosterone-to-renin ratio between healthy pregnant women and women with PIH, though, in both groups, the ratio was higher than in non-pregnant women (p<0.001). Morning cortisol concentrations and 24-h urinary sodium excretion were lower in women with PIH than in healthy pregnant (p<0.001, p=0.002, respectively).

CONCLUSION

Hyperaldosteronism is not involved in the etiology of PIH. In PIH, there is also a tendency towards lower sodium excretion and lower morning cortisol concentrations.

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

IMPORTANCE

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

OBJECTIVE

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

DESIGN, SETTING, AND PARTICIPANTS

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

EXPOSURES

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

MAIN OUTCOMES AND MEASURES

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

RESULTS

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

CONCLUSIONS AND RELEVANCE

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

Primary Aldosteronism: State-of-the-Art Review

We are witnessing a revolution in our understanding of primary aldosteronism (PA). In the past 2 decades, we have learned that PA is a highly prevalent syndrome that is largely attributable to pathogenic somatic mutations, that contributes to cardiovascular, metabolic, and kidney disease, and that when recognized, can be adequately treated with widely available mineralocorticoid receptor antagonists and/or surgical adrenalectomy. Unfortunately, PA is rarely diagnosed, or adequately treated, mainly because of a lack of awareness and education. Most clinicians still possess an outdated understanding of PA; from primary care physicians to hypertension specialists, there is an urgent need to redefine and reintroduce PA to clinicians with a modern and practical approach. In this state-of-the-art review, we provide readers with the most updated knowledge on the pathogenesis, prevalence, diagnosis, and treatment of PA. In particular, we underscore the public health importance of promptly recognizing and treating PA and provide pragmatic solutions to modify clinical practices to achieve this.

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.

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

CONTEXT

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

OBJECTIVE

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

DESIGN AND SETTING

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

PARTICIPANTS

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

MAIN OUTCOME MEASURE

Diagnostic value of the model.

RESULTS

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

CONCLUSION

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

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.

Reliability Analysis of a Functional Diagnostic Test for Primary Hyperaldosteronism Based on Data Analysis

Primary aldosteronism (PA) is one of the most common causes of secondary hypertension, with a prevalence of 12-20% in the hypertensive population. To determine the characteristic function of a fuzzy concept based on the epidemiological data, clinical manifestations, and auxiliary examinations of PA, the essence is to select a suitable domain and determine the affiliation of each element in the domain. The aldosterone/renin ratio was proposed to increase the detection rate of PA, which has the shortcoming of a high underdiagnosis rate when relying only on clinical manifestations. However, there is no unified standard for the diagnostic cut point, and there are differences in testing methods and diagnostic cut point values for different populations, which require different laboratories to establish appropriate cut points according to different regional populations to improve the diagnostic accuracy. In this article, we analyzed the reliability of functional diagnostic tests for PA based on data analysis and compared the sensitivity and specificity of different plasma aldosterone cut points for the diagnosis of PA in the 40 mg kibbutz test. The results showed that when post-saline PAC and post-cato PAC were used to confirm the diagnosis of proaldosterone, respectively, there was a similar subject working area under the curve between SSST and CCT, 0.89 and 0.78, respectively, with no significant difference in the area under the curve between the two (p=0.546). Therefore, blood sodium and blood potassium have higher specificity and sensitivity than SUSPUP, but both are lower than ARR, and data analysis can be used as an auxiliary indicator for screening.

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.

Hypertension and Arrhythmias: A Clinical Overview of the Pathophysiology-Driven Management of Cardiac Arrhythmias in Hypertensive Patients

Because of demographic aging, the prevalence of arterial hypertension (HTN) and cardiac arrhythmias, namely atrial fibrillation (AF), is progressively increasing. Not only are these clinical entities strongly connected, but, acting with a synergistic effect, their association may cause a worse clinical outcome in patients already at risk of ischemic and/or haemorrhagic stroke and, consequently, disability and death. Despite the well-known association between HTN and AF, several pathogenetic mechanisms underlying the higher risk of AF in hypertensive patients are still incompletely known. Although several trials reported the overall clinical benefit of renin–angiotensin–aldosterone inhibitors in reducing incident AF in HTN, the role of this class of drugs is greatly reduced when AF diagnosis is already established, thus hinting at the urgent need for primary prevention measures to reduce AF occurrence in these patients. Through a thorough review of the available literature in the field, we investigated the basic mechanisms through which HTN is believed to promote AF, summarising the evidence supporting a pathophysiology-driven approach to prevent this arrhythmia in hypertensive patients, including those suffering from primary aldosteronism, a non-negligible and under-recognised cause of secondary HTN. Finally, in the hazy scenario of AF screening in hypertensive patients, we reviewed which patients should be screened, by which modality, and who should be offered oral anticoagulation for stroke prevention.

Establishing Reference Ranges for Aldosterone, Renin and Aldosterone-to-Renin Ratio for Women in the Third-Trimester of Pregnancy

OBJECTIVE

Diagnosis of primary hyperaldosteronism in pregnancy is complicated due to lack of reference ranges for aldosterone, renin and aldosterone-to-renin ratio. We have endeavoured to establish third-trimester reference ranges for the above-mentioned parameters.

DESIGN & PATIENTS

We performed postural tests for aldosterone and renin (chemiluminescence immunoassay Liason® DiaSorin Inc., Italy) in 70 healthy pregnant women (age 30.53±4.51 years), at 32.38±4.25 weeks of gestation and in 22 non-pregnant healthy women (age 33.08±8.72 years).

RESULTS

Aldosterone reference ranges were 6.51-73.97 ng/dl and 12.33-86.38 ng/dl, for supine and upright positions, respectively and that for renin were 6.25-59.36 µIU/ml and 11.12-82.55 µIU/ml, respectively. Aldosterone and renin concentrations were higher in an upright position (p=0.000459 and p=0.00011, respectively). In contrast, aldosterone-to-renin ratio was not affected by posture (i. e. 0.497-3.084 ng/dl/µIU/ml versus 0.457-3.06 ng/dl/µIU/ml, p=0.12), but was higher (p=0.00081) than in non-pregnant controls. In comparison to manufacturer-provided non-pregnant reference range, supine aldosterone concentrations increased by 556% (lower cut-off) and 313% (upper cut-off), while upright aldosterone concentrations increased by 558% (lower cut-off) and 244% (upper cut-off). The reference range for supine renin concentrations increased by 223% (lower cut-off) and 48.7% (upper cut-off), while upright renin concentrations increased by 253% (lower cut-off) and 79% (upper cut-off).

CONCLUSIONS

There is an upward shift in aldosterone and renin reference ranges in the third-trimester of pregnancy accompanied by an increase in an aldosterone-to-renin ratio, that is not influenced by posture. It remains to be established whether the aldosterone-to-renin ratio may be used as a screening tool for primary hyperaldosteronism in pregnancy.

[Diagnosis and therapy of primary aldosteronism: new aspects]

Primary aldosteronism represents the most frequent cause of endocrine hypertension. It is associated with a higher morbidity and mortality compared to essential hypertension. Early identification of the affected patients is crucial, as the adequate therapy leads to an excellent long-term prognosis, especially after unilateral adrenalectomy. Diagnosis consists of three steps: diagnosis, confirmation test and subtype differentiation. The 2 most frequent causes of primary aldosteronism are aldosterone producing adenoma, which can be cured by surgery, and idiopathic bilateral adrenal hyperplasia, which is treated with mineralocorticoid receptor antagonists.Screening by aldosterone-to-renin ratio is recommended in designed risk populations. As the aldosterone-to-renin ratio displays a limited sensitivity and specificity, confirmatory testing is recommended in most patients with positive screening test. Prediction scores allow to skip confirmatory testing under certain circumstances. Adrenal vein sampling still represents the gold standard in subtype differentiation of primary aldosteronism. Steroid profiling could possibly make dispensable adrenal vein sampling in patients with bilateral hyperplasia. Different studies investigate the potential of functional imaging for differential diagnosis of primary aldosteronism.

Elevated Myoglobin in Patients With Primary Aldosteronism: A Cross-Sectional Study

OBJECTIVES

Primary aldosteronism (PA) is characterized by the autonomous excessive production of aldosterone in the adrenal cortex. Aldosterone is associated with damages to heart muscle and skeletal muscle. The purpose of this study was to evaluate serum levels of muscle injury markers and their associated factors in patients with primary aldosteronism.

METHODS

We retrospectively enrolled subjects with PA and essential hypertension (EH) who had completed testing for serum high sensitivity troponin T (hs-TnT), creatine kinase isoenzyme MB (CK-MB) and myoglobin from the database of the Chongqing Primary Aldosteronism Study (CONPASS). Univariate and multivariate linear regression analyses were performed to analyze the influencing factors of myocardial injury markers.

RESULTS

In total, 278 patients with PA and 445 patients with EH were enrolled in this study. Compared with EH patients, serum concentrations of hs-TnT [7.0 (4.0-12.0) vs. 6.0 (3.0-11.0) ng/L; p=0.005] and myoglobin [24.2 (21.0-38.1) vs. 21.8 (21.0-31.9) μg/L; p=0.023] were significantly higher among PA patients, while no significant difference of CK-MB was found between two groups [1.4 (1.0-2.0) vs. 1.3 (0.9-1.9) μg/L; p=0.154]. Univariate linear regression analysis showed that myoglobin was negatively correlated with serum potassium (β=-0.31; p<0.01) and positively correlated with plasma aldosterone concentration (β=0.40; p<0.01) in the PA group, while no significant correlation was found between hs-TnT and biochemical parameters. After adjusting for multiple confounders, myoglobin was negatively correlated with serum potassium (β=-0.15; p<0.05) and positively correlated with plasma aldosterone concentration (β=0.34; p<0.01) in the PA group.

CONCLUSIONS

The serum level of myoglobin was significantly increased in PA patients, and myoglobin was independently correlated with plasma aldosterone concentration.

Heightened Cardiovascular Risk in Hypertension Associated With Renin-Independent Aldosteronism Versus Renin-Dependent Aldosteronism: A Collaborative Study

Background While both renin-dependent and renin-independent aldosterone secretion contribute to aldosteronism, their relative associations with cardiovascular disease (CVD) risk has not been investigated. Methods and Results A total of 2909 participants from the FOS (Framingham Offspring Study) with baseline, serum aldosterone concentration, and plasma renin concentration who attended the sixth examination cycle and were followed up until 2014 and who were free of CVD were included. We further recruited 2612 hypertensive participants from the CONPASS (Chongqing Primary Aldosteronism Study). Captopril challenge test was performed to confirm renin-dependent or -independent aldosteronism in CONPASS. Among 1433 hypertensive subjects of FOS, when compared with those with serum aldosterone concentration <10 ng dL-1 (normal aldosterone), participants who had serum aldosterone concentration ≥10 ng dL-1 and plasma renin concentration ≤15 mIU L-1 (identified as renin-independent aldosteronism) showed a higher risk of CVD (hazard ratio, 1.40 [95% CI, 1.08-1.82]), while those who had serum aldosterone concentration ≥10 ng dL-1 and plasma renin concentration >15 mIU L-1 (identified as renin-dependent aldosteronism) showed an unchanged CVD risk. In CONPASS, renin-independent aldosteronism carried a significantly higher risk of CVD than normal aldosterone (odds ratio, 2.57 [95% CI, 1.13-5.86]), while the CVD risk remained unchanged in renin-dependent aldosteronism. Elevation of the urinary potassium-to-sodium excretion ratio, reflective of mineralocorticoid receptor activity, was only observed in participants with renin-independent aldosteronism. Conclusions Among patients with hypertension, renin-independent aldosteronism is more closely associated with CVD risk than renin-dependent aldosteronism.

Hypertension Management in Stroke Prevention: Time to Consider Primary Aldosteronism

Primary aldosteronism confers a higher risk of stroke, atrial fibrillation, and cardiovascular disease than blood pressure matched essential hypertension. It is the most common endocrine cause of secondary hypertension with prevalence estimates of up to 13% in primary care and 30% in referral centers around the world. Unlike essential hypertension, primary aldosteronism has targeted medical treatment and potentially curative surgical solutions which can ameliorate the associated cardiovascular risks. This narrative review highlights an evidence gap in the optimal diagnosis and targeted treatment of primary aldosteronism in secondary stroke prevention. Over half of the patients suffering a stroke have blood pressure in the hypertensive range and less than a third achieve optimal blood pressure control. There are no guideline recommendations to test for primary aldosteronism in these patients, although up to 30% of patients with resistant hypertension may have this disease. The accurate diagnosis of primary aldosteronism could significantly improve blood pressure, simplify the medication regimen and reduce the overall cardiovascular risk in these patients. The challenges associated with screening for primary aldosteronism following stroke may be overcome by novel blood tests which are less affected by antihypertensive medications routinely used in stroke care. Approximately one-quarter of all strokes occur in patients who have previously had a stroke. Modifying hypertension, the leading modifiable risk factor, would, therefore, have significant public health implications. As clinicians, we must increase our awareness of primary aldosteronism in patients with stroke, particularly in those with resistant hypertension, to enable targeted therapy and reduce the risk of stroke recurrence.

[Update on treatment resistant hypertension and secondary hypertension]

Resistant hypertension (RH) is defined in patients who do not meet their blood pressure targets despite the daily intake of three antihypertensive drugs in maximally tolerated dosages. This triple treatment should comprise (1) an angiotensin-converting enzyme inhibitor (ACE-I) or angiotensin receptor blocker (ARB), (2) a calcium channel blocker and (3) a diuretic. RH should also be diagnosed in patients on four or more antihypertensive drug classes. Of note, the diagnosis of RH requires the exclusion of non-adherence, "white coat effect", and incorrect BP-measurement.After diagnosing RH, it is important to recommend lifestyle interventions (e. g. low dietary salt intake, regular physical activity), to pause BP-elevating substances, and to consider the presence of secondary hypertension.Such secondary forms of hypertension primarily include endocrine disorders and renal disease (both acute kidney injury and chronic kidney disease). The leading endocrine cause is primary hyperaldosteronism, the management of which was highlighted in a recent guideline. Other endocrine causes - such as phaeochromocytoma or hypercortisolism - are much less frequent. In contrast, sleep apnoea disorders are now mostly considered as a comorbidity rather than as a cause of secondary hypertension.Treatment options for RH include lifestyle optimisation and escalation of antihypertensive medication. In most patients on triple treatment (ACE-I or ARB plus calcium channel blocker plus diuretic), mineralocorticoid receptor antagonists (MRA) should be the next treatment choice. As MRA may be associated with hyperkalemia (particularly in patients with chronic kidney disease), the concurrent use of potassium-lowering agents such as patiromer may allow a safe long-term treatment. In contrast, novel interventional treatment options in RH such as renal denervation are still controversially discussed.

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.

Recent Development toward the Next Clinical Practice of Primary Aldosteronism: A Literature Review

For the last seven decades, primary aldosteronism (PA) has been gradually recognized as a leading cause of secondary hypertension harboring increased risks of cardiovascular incidents compared to essential hypertension. Clinically, PA consists of two major subtypes, surgically curable and uncurable phenotypes, determined as unilateral or bilateral PA by adrenal venous sampling. In order to further optimize the treatment, surgery or medications, diagnostic procedures from screening to subtype differentiation is indispensable, while in the general clinical practice, the work-up rate is extremely low even in the patients with refractory hypertension because of the time-consuming and labor-intensive nature of the procedures. Therefore, a novel tool to simplify the diagnostic flow has been recently in enormous demand. In this review, we focus on recent progress in the following clinically important topics of PA: prevalence of PA and its subtypes, newly revealed histopathological classification of aldosterone-producing lesions, novel diagnostic biomarkers and prediction scores. More effective strategy to diagnose PA based on better understanding of its epidemiology and pathology should lead to early detection of PA and could decrease the cardiovascular and renal complications of the patients.

Surgical Outcomes Among Primary Aldosteronism Patients Without Visible Adrenal Lesions

CONTEXT

Many patients with unilateral primary aldosteronism (PA) have normal adrenal imaging, but little is known about their outcome following adrenalectomy.

OBJECTIVE

To evaluate biochemical and clinical outcomes after adrenalectomy in patients with unilateral PA and normal-appearing adrenal imaging.

DESIGN

Retrospective cohort study of patients seen between January 2006 and May 2018.

SETTING

A Canadian tertiary care PA referral center.

PATIENTS

Consecutive individuals with PA, normal cross-sectional adrenal imaging, and lateralizing adrenal vein sampling (AVS) who underwent adrenalectomy during the study period.

PRIMARY OUTCOME

Biochemical response to adrenalectomy graded according to the Primary Aldosteronism Surgical Outcome criteria.

RESULTS

A total of 40 patients were included. Biochemical outcomes were available for 33 people (mean age, 54.7 years; 91% male; median follow-up, 2.7 months), with 28 (85%) showing a complete or partial response and 5 (15%) with no response. Clinical outcomes were available for 36 people (mean age, 54.6 years; 86% male; median follow-up, 9.8 months), with 31 (86%) demonstrating a complete or partial response and 5 (14%) with no response.

CONCLUSIONS

The prognosis after adrenalectomy is highly favorable for patients with unilateral PA and normal-appearing adrenal imaging. Patients with lateralizing disease should be considered for surgery despite apparently normal adrenal imaging.