Detecting primary aldosteronism in Australian primary care: a prospective study

Screening for primary aldosteronism in primary care: a scoping review

BACKGROUND

Primary aldosteronism (PA) is the most common treatable and potentially curable cause of secondary hypertension. Prompt diagnosis and management by primary care physicians (PCPs) is important given the increased risk of cardiovascular complications however screening rates are low in primary care. Our aim was to identify factors that influence screening behaviour for PA among PCPs.

METHOD

A rigorous scoping review of seven databases between 16/08/22 and 09/08/23 was used to investigate PA screening practices. Articles written in English from peer-reviewed literature within the last 20 years were eligible for inclusion if an aspect of their study was conducted in primary care.

RESULTS

A total of 1380 titles and abstracts, and 61 full texts were screened, with 20 studies selected for data extraction. We identified three broad categories of factors influencing screening by PCPs-the patient, the clinician, and the healthcare system. Some studies targeted these factors to improve screening rates although there is little data on implementation and outcomes.

CONCLUSION

Low awareness, inadequate guidelines, and poor access to testing were identified as key barriers to PA screening. Targeted education sessions for PCPs, clear guidelines, and closer proximity to diagnostic centres may be required to improve PA detection in primary care.

Prevalence of primary aldosteronism in acute stroke or transient ischemic attack: a systematic review and meta-analysis

Background and purpose

Primary aldosteronism (PA) is the most common endocrine cause of secondary hypertension with a prevalence of 14% in patients with newly diagnosed hypertension. Patients with PA experience a higher rate of cardiovascular events including stroke when compared to those with blood pressure matched essential hypertension. This systematic review and meta-analysis summarize current evidence on the prevalence of PA in patients with acute stroke or transient ischemic attack (TIA).

Methods

Two reviewers independently reviewed the literature for observational studies on the prevalence of PA in patients with acute stroke or TIA. MEDLINE and Embase were searched for studies up to December 13, 2023.

Results

Three single center studies conducted in Japan, Singapore and China were found to meet the inclusion criteria. The reported prevalence of PA in two cohort studies of adults with stroke or TIA were 3.1% and 4.0% and a third cross-sectional study in adults under 45 years old revealed a prevalence rate of 12.9%. Following a meta-analysis, the pooled prevalence of PA in adults with stroke or TIA is 5.8% [95% CI 1.6%-12.3%].

Conclusions

A considerable proportion of patients with stroke or TIA may have PA as the underlying cause of their hypertension. Given the increased risk of stroke associated with PA, clinicians should consider screening for PA in hypertensive patients with stroke or TIA. Further research is needed to evaluate the effect of timing and interfering medications on test results, which will inform an evidence-based approach to testing for PA following TIA or stroke.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022328644.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Hypertension in the emergency department: A missed opportunity to screen for primary aldosteronism?

OBJECTIVES

Primary aldosteronism (PA) is a common but underdiagnosed secondary cause of hypertension. Emergency departments (EDs) often assess patients with severe hypertension or its sequelae, some of whom have underlying PA. We aimed to determine the proportion of patients presenting to the ED with hypertension who meet the Endocrine Society criteria for PA testing and the proportion who were screened.

METHODS

We performed a structured retrospective chart review of adults who presented to three EDs in an Australian tertiary health network between August 2019 and February 2020, with a coded presenting complaint of hypertension. Clinical parameters to determine whether the patients met the criteria for PA testing were extracted from electronic medical records.

RESULTS

Of the 418 patients who presented to the EDs with documented elevated blood pressure (BP), 181 patients (43.3%) fulfilled PA screening criteria and nine patients (2.2%) underwent PA testing. Individuals who fulfilled screening criteria were older; had higher prevalence of Type 2 diabetes, coronary artery disease, and congestive heart failure; took more antihypertensive medications; and had lower estimated glomerular filtration rate. Individuals who were tested for PA were younger and had higher BP on presentation. Screening for PA was more frequent in patients who were referred to medical teams.

CONCLUSIONS

As far as we are aware, our study is the first to evaluate PA testing in hypertensive patients who present to ED. More than 40% of adults presenting to the EDs with hypertension met the current criteria for testing for PA but only few were tested. These results emphasize that increased awareness of PA in the ED is needed to encourage opportunistic testing, referral, and treatment, especially in patients who present with hypertensive emergencies. Prospective studies are required to determine the feasibility and effectiveness of this.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Diagnostic Delay and Disease Burden in Primary Aldosteronism: An International Patient Survey

BACKGROUND

Primary aldosteronism (PA) is a common but underdiagnosed cause of hypertension. Many patients experience preventable end-organ injury due to delayed or missed diagnosis but data on the experience of patients are limited.

METHODS

We evaluated the lived experience of PA and determines factors associated with diagnostic delay through an international anonymous online cross-sectional survey, codesigned by researchers and PA consumers. We distributed the survey through academic medical centers, Amazon Mechanical Turk, Twitter, PA patient advocacy groups, and hypertension support groups on Facebook between March 21 and June 5, 2022.

RESULTS

Of 684 eligible respondents, 66.5% were women. Diagnostic delay (defined as ≥5 years between the diagnosis of hypertension and PA) was reported in 35.6%. Delay was more likely in women than in men (odds ratio, 1.55 [95% CI, 1.10-2.20]) and respondents with ≥3 comorbidities versus none (odds ratio, 1.77 [95% CI, 1.05-3.02]), ≥10 symptoms versus none (odds ratio, 2.73 [95% CI, 1.74-4.44]), and on ≥4 antihypertensive medications versus none (odds ratio, 18.23 [95% CI, 6.24-77.72]). Three-quarters of patients (74.4%) experienced reduced symptom burden following targeted PA treatment. Quality of life improved in 62.3% of patients, and greater improvement was associated with being a woman (odds ratio, 1.42, [95% CI, 1.02-1.97]), receiving adrenalectomy (odds ratio, 2.36 [95% CI, 1.67-3.35]), and taking fewer antihypertensive medications following diagnosis (odds ratio, 5.28 [95% CI, 3.55-7.90]).

CONCLUSIONS

One-third of patients with PA experienced prolonged diagnostic delays. Targeted treatment led to reduced symptom burden and improved quality of life. Gender differences in diagnostic delay and symptom burden are prominent. These findings suggest that routine screening for PA at the onset of hypertension may reduce diagnostic delay and facilitate timely diagnosis.

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

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

A cost-analysis of managing secondary and apparent treatment-resistant hypertension in a specialist multidisciplinary hypertension clinic

OBJECTIVES

A knowledge gap exists around the costs and budget impact of specialist hypertension clinics. This study reports on the cost of providing care in a multidisciplinary hypertension clinic staffed by nephrologist, endocrinologist and cardiologist, which manages patients with suspected secondary hypertension and/or apparent treatment-resistant hypertension. The aim of this study is to provide the evidence required to inform policy and planning care pathways for this patient group.

METHODS

A cost analysis from a healthcare provider perspective using micro-costing techniques was conducted to estimate the direct implementation costs of existing standard practice for the care pathway of patients attending the multidisciplinary hypertension clinic. Sixty-five patients originally recruited for a study of medication adherence in hypertension were included in the sample.

RESULTS

The total care-pathway cost per patient, taking into account clinic visits, clinical reviews, investigations and MDT discussion, was estimated to be €3277, on average. For the patient subgroups, the average cost was €5644 for patients diagnosed with primary aldosteronism and €1446 for patients diagnosed with essential hypertension.

CONCLUSION

There is significant cost associated with providing specialized hypertension care for patients with apparent treatment-resistant hypertension. Given the high rates of nonadherence in this population, it is likely that some of this cost could be avoided with better detection and management of medication adherence in this challenging population. Future studies should consider the cost-effectiveness of this or similar models of care by exploring the benefit to patients and the wider healthcare context of providing care of this type.

Prolonged Hypokalemia and Delayed Diagnosis of Primary Aldosteronism: Clinical Course and Risk Factors

INTRODUCTION

Primary Aldosteronism (PA) is a common cause of hypertension. However, diagnosis is often delayed, leading to poorer clinical outcomes. Hypokalemia with hypertension is characteristic of PA, and is an indication for screening. We evaluated if patients with PA had prolonged hypokalemia before diagnosis, the subsequent biochemical/clinical control, and factors associated with delayed diagnosis.

METHODS

Our study included all PA patients with hypokalemia diagnosed between 2001 to 2022. Delayed diagnosis was defined as duration of hypokalemia of >1 year from first occurrence, to first evaluation by a PA specialist. Patients were reassessed post-adrenalectomy using the Primary Aldosteronism Surgery Outcomes criteria. We performed multivariable analysis to assess for factors associated with delayed diagnosis.

RESULTS

Among 240 patients with PA who presented with hypokalemia, 122 (51%) patients had delayed diagnosis, with prolonged hypokalemia of median duration 4.5 (2.4-7.5) years. Patients with delayed diagnosis were older, had longer duration of hypertension, higher pill burden, lower renal function and more prevalent cardiovascular disease. Factors associated with delayed diagnosis included older age, presence of hyperlipidaemia, and less severe hypokalemia (serum potassium >3.0mmol/L). Compared to patients with early diagnosis, a lower proportion of those with delayed diagnosis underwent adrenal vein sampling (73% vs 58%), P<0.05. Sixty of 118 (50.8%) non-delayed, and 39 of 122 (32.0%) patients with delayed diagnosis underwent surgery.

CONCLUSION

Despite manifestation of hypokalemia, many patients with PA fail to be promptly screened. Greater emphasis in hypertension guidelines, and efforts to improve awareness of PA amongst primary care physicians are urgently needed.

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

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

Immunohistochemical staining seems mandatory for individualizing and shortening follow-up in unilateral primary aldosteronism

OBJECTIVE

The clinical significance of immunohistochemistry (IHC) for unilateral primary aldosteronism (PA) has been unclear. Individualized follow-up of PA patients could be in sight. Long-term outcomes of patients, classified based on IHC, need further investigation. We aimed to assess long-term clinical outcomes for unilateral PA, classifying patients based on IHC.

DESIGN

A nationwide observational study, with up to 16 years follow-up, executed in 2007-2016 at Landspitali University Hospital, tertiary referral center. Patients were diagnosed and treated in line with the current guidelines. Haematoxylin and eosin (H&E) tissue slides were stained using CYP11B1 and -B2 antibodies. All cases were re-evaluated and classified according to the HISTALDO consensus. Outcomes were assessed using the PASO criteria.

PATIENTS

All unilateral PA patients diagnosed in 2007-2016 in Iceland, 26 patients aged 28-73 years, who underwent adrenalectomy, were included.

MEASUREMENTS

Aldosterone, renin, and cortisol values, use and dosage of antihypertensives, potassium supplementation, blood pressure and serum potassium pre-intervention and throughout follow-up, and histopathology results post-adrenalectomy.

RESULTS

Following IHC, an aldosterone-producing nodule was seen in 12 adrenals, an aldosterone-producing adenoma in 10 and multiple aldosterone-producing micronodules in four. IHC altered histopathology from previous H&E diagnosis in 23% (6/26) of the patients. In total, 81% (21/26) of the patients had partial clinical success. Eight percent (2/26) of the patients needed potassium supplementation during follow-up. In the classical group, the AVS results were more determinative with significantly higher lateralization index (median 10.1 vs. 5.3, p = .04) and more contralateral suppression (median nondominant ratio 0.4 vs. 1.0, p = .03). One out of five patients with complete clinical success at 12 months post-op had severe relapse later, the other four were normotensive without antihypertensives for up to 10 years.

CONCLUSIONS

We found IHC mandatory for accurate histopathologic diagnosis of PA. Our results support the importance of contralateral suppression when interpreting AVS results. Also, the study highlights the complicated assessment of clinical outcome and importance of aldosterone and renin measurements during follow-up.

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.

Willingness to be tested for a secondary cause of hypertension: a survey of the Australian general community

BACKGROUND

Primary aldosteronism (PA) represents the most common and potentially curable cause of secondary hypertension. However, PA is not commonly screened for, and up to 34% of patients who screen positive do not complete the full diagnostic process. This suggests that the diagnostic process may pose a barrier to patients and may contribute to the under-diagnosis of PA.

AIMS

To evaluate the willingness of the Australian general public to undergo testing for secondary causes of hypertension and identify enablers or barriers to testing from the patients' perspective.

METHODS

An online survey containing questions on knowledge and attitudes towards hypertension, willingness to be tested and enablers/barriers towards testing was distributed to the Australian community.

RESULTS

Of 520 adult respondents (mean age 50.4 years, SD 27.3 years; 28.8% hypertensive; 56.0% female), the majority of non-hypertensive and hypertensive respondents (82.7% vs 70.0%; P = 0.03) were willing to undergo testing for a secondary cause of hypertension that involved blood and urine tests. Greater knowledge of hypertensive risk modification strategies and complications was predictive of willingness to be tested, whereas age, sex, education level, geographic location, socio-economic status and cardiovascular comorbidities were not. The top three barriers to testing included fear of a serious underlying condition, lack of belief in further testing and increased stress associated with further testing.

CONCLUSION

A high proportion of patients are willing to engage in testing for a secondary cause of hypertension. Education about the risks associated with hypertension and the testing process may overcome several barriers to testing.

Aldosterone and renin concentrations and blood pressure in young Indigenous and non-Indigenous adults in the Northern Territory: a cross-sectional study

OBJECTIVES

To evaluate aldosterone and renin levels and aldosterone-to-renin ratios (ARRs) in young Indigenous and non-Indigenous adults in the Northern Territory, and their association with blood pressure levels.

DESIGN

Cross-sectional study; single time point sub-study of two prospective birth cohort studies.

SETTING, PARTICIPANTS

Participants in the Aboriginal Birth Cohort (ABC) - born to Indigenous mothers at the Royal Darwin Hospital during 1987-1990 - and the Top End Cohort (TEC) - people born to non-Indigenous mothers in Darwin, recruited during 2007-2009 - aged 32-35 years at the time of this sub-study.

MAIN OUTCOME MEASURES

Plasma aldosterone and direct renin concentrations; ARRs (positive screening test result for primary aldosteronism defined as > 70 pmol/mU); systolic and diastolic blood pressure.

RESULTS

A total of 255 ABC (205 in remote, 50 in urban locations) and 76 TEC members participated. Median aldosterone concentration was similar for all three groups. The median renin concentration was 7.5 mU/L (interquartile range [IQR], 4.1-12.4 mU/L) in the TEC group, 12.4 mU/L (IQR, 5.1-19 mU/L) in the urban ABC group, and 29.3 mU/L (IQR, 15.0-52.9 mU/L) in the remote ABC group. The median ARR was 10 pmol/mU (IQR, 6-19 pmol/mU) in the remote ABC group, 28 pmol/mU (IQR, 16-70 pmol/mU) in the urban ABC group, and 43 pmol/mU (IQR, 26-74 pmol/mU) in the TEC group. Thirteen urban ABC participants (26%), 21 TEC participants (28%), and six people in the remote ABC group (3%) had ARR values above 70 pmol/mU. Adjusted for age and body mass index (BMI), mean systolic and diastolic blood pressure were lower for women than men in all participant groups; after adjusting for age, sex, and BMI, larger ARR was associated with higher systolic blood pressure in the TEC group but not the two ABC groups.

CONCLUSION

Screening test results for primary aldosteronism were positive for about one-quarter of urban Indigenous and non-Indigenous participants. A prospective study that includes confirmatory testing would more accurately assess the prevalence of primary aldosteronism among Indigenous Australians in the Northern Territory.

Improving Detection Rates for Primary Aldosteronism

Primary aldosteronism (PA), once considered a rare disease, is being increasingly recognized as an important cause of hypertension. It is associated with higher rates of cardiovascular complications compared to blood pressure-matched essential hypertension. Targeted treatments are available which can mitigate the excess cardiovascular risks and, in some cases, cure hypertension. Making a timely diagnosis of PA is, therefore, highly beneficial for patients. Furthermore, numerous studies from different parts of the world have found PA to be a relatively common disease that can affect patients in any stage of hypertension, regardless of their age or potassium levels. Despite this well-established data, the current rate of PA detection is appallingly low, much below its actual prevalence. This review explores the challenges that clinicians often face in diagnosing PA and offers strategies that may improve the detection of this potentially curable form of hypertension.

Effect of Oral Contraception on Screening Tests for Primary Aldosteronism: A 10-Year Longitudinal Study

CONTEXT

Primary aldosteronism (PA) and oral contraception (OC) can both cause hypertension in young women. However, the effect of OC on the screening test for PA, the aldosterone to renin ratio (ARR), is not clear.

OBJECTIVE

We evaluated the impact of OC on the screening test for PA.

METHODS

In this retrospective cohort study, we analyzed data from the female offspring (Gen2) of women enrolled in the Raine Study, a population-based birth cohort, who had blood pressure (BP) measurements, blood samples, and information about OC use at age 17 years (N = 484) and/or age 27 years (N = 486).

RESULTS

Aldosterone concentration was significantly higher in OC users than nonusers at 17 years (median 486 pmol/L vs 347 pmol/L, P < 0.001). Renin concentration was significantly lower in OC users at both 17 years (13.4 mU/L vs 20.6 mU/L) and 27 years (9.2 mU/L vs 11.8 mU/L), hence the ARR was significantly higher in OC users compared to nonusers at both 17 years (31.5 vs 18.3) and 27 years (27.3 vs 21.1). The proportion of participants with ARR > 70 pmol/mU (current threshold for PA detection) was significantly higher in OC users at both 17 years (12.6% vs 2.1%) and 27 years (6.4% vs 0.4%); however, they had comparable BP to those with ARR < 70. OC use at any age abolished the relationship between ARR and BP that is observed in nonusers.

CONCLUSION

OC can increase the ARR and cause a false positive PA screening result. Until more reliable criteria for PA screening in OC users are established, alternative contraception should be considered during screening.

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

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

[11C]metomidate PET-CT versus adrenal vein sampling for diagnosing surgically curable primary aldosteronism: a prospective, within-patient trial

Primary aldosteronism (PA) due to a unilateral aldosterone-producing adenoma is a common cause of hypertension. This can be cured, or greatly improved, by adrenal surgery. However, the invasive nature of the standard pre-surgical investigation contributes to fewer than 1% of patients with PA being offered the chance of a cure. The primary objective of our prospective study of 143 patients with PA ( NCT02945904 ) was to compare the accuracy of a non-invasive test, [11C]metomidate positron emission tomography computed tomography (MTO) scanning, with adrenal vein sampling (AVS) in predicting the biochemical remission of PA and the resolution of hypertension after surgery. A total of 128 patients reached 6- to 9-month follow-up, with 78 (61%) treated surgically and 50 (39%) managed medically. Of the 78 patients receiving surgery, 77 achieved one or more PA surgical outcome criterion for success. The accuracies of MTO at predicting biochemical and clinical success following adrenalectomy were, respectively, 72.7 and 65.4%. For AVS, the accuracies were 63.6 and 61.5%. MTO was not significantly superior, but the differences of 9.1% (95% confidence interval = -6.5 to 24.1%) and 3.8% (95% confidence interval = -11.9 to 9.4) lay within the pre-specified -17% margin for non-inferiority (P = 0.00055 and P = 0.0077, respectively). Of 24 serious adverse events, none was considered related to either investigation and 22 were fully resolved. MTO enables non-invasive diagnosis of unilateral PA.

Aldosterone, Renin, and Aldosterone-to-Renin Ratio Variability in Screening for Primary Aldosteronism

CONTEXT

The plasma aldosterone concentration (PAC), renin, and aldosterone-to-renin ratio (ARR) are used to screen for primary aldosteronism (PA). Substantial intra-individual variability of PAC and ARR using plasma renin activity in the context of usual antihypertensive therapy has been described, but there is no data on ARR variability calculated using direct renin concentration (DRC).

OBJECTIVE

To describe the intra-individual variability of PAC, DRC, and ARR in the absence of interfering medications in patients with and without PA.

DESIGN

Retrospective cohort study.

PATIENTS

Hypertensive patients referred for investigation of PA, with at least 2 ARR measurements while off interfering medications.

SETTING

Endocrine hypertension service of a tertiary center, from May 2017 to July 2021.

MAIN OUTCOME MEASURES

PAC, DRC, and ARR variability was calculated as coefficient of variation (CV) and percent difference (PD).

RESULTS

Analysis of 223 patients (55% female, median age 52 years), including 162 with confirmed PA, demonstrated high variability with a sample CV of 22-25% in the PAC and sample CV of 41% to 42% in the DRC and ARR in both the PA and non-PA groups. The degree of variability was substantially higher than the assays' analytical CV. Sixty-two patients (38%) with PA had at least one ARR below 70 pmol/L:mU/L (2.4 ng/dL:mU/L), a cut-off for first-line screening of PA.

CONCLUSIONS

Significant intra-individual variability in PAC, DRC, and hence ARR occurs in a large proportion of patients being investigated for PA. These findings support the need for at least 2 ARR before PA is excluded or further investigated.

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.

Ambulatory fludrocortisone suppression test in the diagnosis of primary aldosteronism: Safety, accuracy and cost-effectiveness

OBJECTIVE

The aims of this study were to explore if the ambulatory fludrocortisone suppression test (FST) was safe, accurate and cost-effective.

CONTEXT

The diagnosis of primary aldosteronism (PA) remains time-consuming and complex. The FST is used to confirm PA, but it is an in-patient test due to potentially serious complications such as hypokalemia. In Stockholm, FST has been performed since 2005 as an ambulatory procedure.

DESIGN

This is a retrospective study including all patients investigated with FST in four hospitals in Stockholm, Sweden, during 2005-2019.

PATIENTS/MEASUREMENTS

In total, 156 cases of ambulatory FST (FSTamb) and 15 cases of in-patient FST (FSTin) were included. FSTamb and FSTin were compared regarding health costs, clinical characteristics and laboratory results.

RESULTS

No difference was found in the outcomes of FSTamb and FSTin. No severe complications were reported in FSTamb patients. No difference was found in the median value for plasma potassium on Day 5 between the two groups. Only three patients (1.9%) in the FSTamb had to repeat the test due to incomplete intake of medications. FSTamb and FSTin were equally accurate. The cost of performing FSTamb was at least 50% lower compared with FSTin ($2400 vs. $5200 per patient). The time needed for FSTamb was 60 min of physician's time and 150 min of nurse's time which were lower than the 5 days in FSTin.

CONCLUSIONS

Ambulatory FST is safe and accurate and can be performed with significantly less healthcare costs compared to FSTin.

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.

'I can't understand why others don't screen more': a qualitative study exploring why Australian general practitioners screen for primary aldosteronism

OBJECTIVE

We sought to understand the factors that influence a general practitioner's (GP's) experience of screening for primary aldosteronism (PA) in hypertensive patients.

DESIGN

A qualitative study, framed by phenomenology, using semistructured interviews that were audiorecorded, transcribed verbatim, entered into NVivo V.12.0 for coding and analysed for emerging themes.

SETTING

Melbourne, Australia.

PARTICIPANTS

Eligible GPs had received education on PA as part of a previous study. We recruited a purposive sample of 16 GPs (6 females, 10 males) who varied in practice location, clinical experience and the number of patients screened for PA.

RESULTS

Although GPs had been educated about PA, they found it challenging to explain the condition to patients and were uncertain about how to screen patients who were already taking antihypertensive medications. Most viewed the screening process to be practical, inexpensive and, by and large, acceptable to their patients. However, they found it inconvenient to alter antihypertensive medications before screening to allow for easier interpretation of the aldosterone-renin ratio. They were also less enthused about screening patients whom they thought fitted a clinical picture of essential hypertension. Knowledge of the screening process, cost and convenience of performing the aldosterone-renin ratio, conceptualisation of risk related to PA, and a desire to improve clinical care were influencing factors that modified the GPs' screening experience.

CONCLUSION

Our findings suggest that knowledge gaps, practical limitations of the aldosterone-renin ratio, and errors in diagnostic reasoning were challenges of routine PA screening. Most of these practical barriers could be addressed by relatively simple educational and practice modifications to increase PA screening rates and optimise detection for the most common cause of secondary hypertension in primary care.

Performance of the aldosterone-to-renin ratio as a screening test for primary aldosteronism in primary care

Primary aldosteronism (PA) is the most common and potentially curable form of secondary hypertension, affecting 5-10% of primary care patients with hypertension. Primary care physicians have an important role in initiating the screening for PA in patients with hypertension and referring to a specialist service depending on the screening test results. The currently recommended screening test for PA is the plasma aldosterone-to-renin ratio (ARR). Test results are influenced by medications so careful patient preparation is required including adjusting existing antihypertensive medications to avoid diagnostic errors. A range of laboratory method-dependent ARR thresholds are used for the screening of PA around the world. Periodic clinical audits and case reviews by clinicians and the laboratory may help refine the local thresholds. Patients with an abnormally elevated ARR should be referred to a specialist for confirmatory testing while patients with a high pre-test probability but a normal ARR could have a repeat test in view of the within-individual variability. Despite the heterogenous ARR thresholds, measuring the ARR is still more likely to detect PA than not screening at all.