Mineralocorticoid Receptor Antagonists Decrease the Rates of Positive Screening for Primary Aldosteronism

Challenges in Diagnosing and Managing the Spectrum of Primary Aldosteronism

Primary aldosteronism, characterized by the dysregulated production of aldosterone from 1 or both adrenal glands, is the most common endocrine cause of hypertension. It confers a high risk of cardiovascular, renal, and metabolic complications that can be ameliorated with targeted medical therapy or surgery. Diagnosis can be achieved with a positive screening test (elevated aldosterone to renin ratio) followed by confirmatory testing (saline, captopril, fludrocortisone, or oral salt challenges) and subtyping (adrenal imaging and adrenal vein sampling). However, the diagnostic pathway may be complicated by interfering medications, intraindividual variations, and concurrent autonomous cortisol secretion. Furthermore, once diagnosed, careful follow-up is needed to ensure that treatment targets are reached and adverse effects, or even recurrence, are promptly addressed. These challenges will be illustrated in a series of case studies drawn from our endocrine hypertension clinic. We will offer guidance on strategies to facilitate an accurate and timely diagnosis of primary aldosteronism together with a discussion of treatment targets which should be achieved for optimal patient outcomes.

Screening for primary aldosteronism on and off interfering medications

OBJECTIVE

To determine whether antihypertensives will affect diagnostic accuracy of the aldosterone-to-renin ratio (ARR) to an extent that is clinically relevant.

METHODS

Confirmatory tests were used to confirm or exclude PA diagnosis. Area under the receiver operating characteristic curve (AUC), specificity and sensitivity of ARR performance in different conditions were calculated.

RESULTS

208 PA and 78 essential hypertension (EH), and 125 PA and 206 EH patients, were included in the retrospective and prospective cohort, respectively. AUC of ARR on interfering medications was comparable to ARR off interfering medications (retrospective: 0.82 vs. 0.87, p = 0.20; prospective: 0.78 vs. 0.84, p = 0.07). At a threshold of 20 pg/μIU, the sensitivity of ARR on interfering medications was lower (11.1-23.2%) while the specificity was higher (10.2-15.2%) than ARR off interfering medications. However, when the ARR threshold on interfering medications was lowered to 10 pg/μIU, both the sensitivity (retrospective: 0.91 vs. 0.90, p = 0.61; prospective: 0.86 vs. 0.82, p = 0.39) and specificity (retrospective: 0.49 vs. 0.59, p = 0.20; prospective: 0.58 vs. 0.66, p = 0.10) were comparable to the ARR threshold off interfering medications.

CONCLUSION

Using ARR to screen for PA whilst taking interfering antihypertensive drugs is feasible in most cases, but the ARR threshold needs to be reduced.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04991961.

Practical recommendations for antihypertensive therapy during the primary aldosteronism screening test

BACKGROUND

The aldosterone-to-renin activity ratio (ARR) is recommended as a screening test for primary aldosteronism (PA). The use of antihypertensive medication is one of the most important factors to take into account when interpreting the ARR.

OBJECTIVES

The goal of this study was to compare the effect of various antihypertensive drug classes on biochemical testing and provide practical recommendations for antihypertensive medication regimens in patients suspected of having PA.

METHODS

We retrospectively investigated 4218 hypertensive patients who underwent PA detection between January 2020 and February 2023. Finally, 25 patients with essential hypertension (EH) and 39 with PA were involved. The enrolled EH patients were selected from EH patients with at least two screening tests with interfering medication changes for at least 4 weeks.

RESULTS

A total of 2/18 (11.1%) EH patients had opposite screening results after angiotensin II receptor blockers (ARBs), angiotensin-converting enzyme inhibitors (ACEIs), dihydropyridine-calcium channel blockers (DHP-CCBs) and diuretics were withdrawn. A total of 3/3 (100%) of the patients were initially screened as positive but had results that tested negative after β-blockers withdrawal. A total of 3/39 (7.7%) PA patients were misdiagnosed with EH with drug effects. Only plasma renin activity was markedly reduced after antihypertensive medication washout (P = 0.0173).

CONCLUSIONS

Not every patient receiving β-blockers, ACEIs, ARBs and DHP-CCBs with negative reports needed withdrawal or switching antihypertensive drugs. We recommend that patients be left on a regimen that includes β-blockers, ACEIs, ARBs, DHP-CCBs and spironolactone when determining the ARR during the initial test.

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.

Evolution of the cardiometabolic profile of primary hyperaldosteronism patients treated with adrenalectomy and with mineralocorticoid receptor antagonists: results from the SPAIN-ALDO Registry

OBJECTIVE

To analyze the evolution of the cardiometabolic profile of patients with primary hyperaldosteronism (PA) after the treatment with surgery and with mineralocorticoid receptor antagonists (MRA).

DESIGN

Retrospective multicentric study of patients with PA on follow-up in twelve Spanish centers between 2018 and 2020.

RESULTS

268 patients with PA treated by surgery (n = 100) or with MRA (n = 168) were included. At baseline, patients treated with surgery were more commonly women (54.6% vs 41.7%, P = 0.042), had a higher prevalence of hypokalemia (72.2% vs 58%, P = 0.022) and lower prevalence of obesity (37.4% vs 51.3%, P = 0.034) than patients treated with MRA. Adrenalectomy resulted in complete biochemical cure in 94.0% and clinical response in 83.0% (complete response in 41.0% and partial response in 42.0%). After a median follow-up of 23.6 (IQR 9.7-53.8) months, the reduction in blood pressure (BP) after treatment was similar between the group of surgery and MRA, but patients surgically treated reduced the number of antihypertensive pills for BP control more than those medically treated (∆antihypertensives: -1.3 ± 1.3 vs 0.0 ± 1.4, P < 0.0001) and experienced a higher increased in serum potassium levels (∆serum potassium: 0.9 ± 0.7 vs 0.6 ± 0.8mEq/ml, P = 0.003). However, no differences in the risk of the onset of new renal and cardiometabolic comorbidities was observed between the group of surgery and MRA (HR = 0.9 [0.5-1.5], P = 0.659).

CONCLUSION

In patients with PA, MRA and surgery offer a similar short-term cardiovascular protection, but surgery improves biochemical control and reduces pill burden more commonly than MRA, and lead to hypertension cure or improvement in up to 83% of the patients.

High Prevalence of Autonomous Aldosterone Production in Hypertension: How to Identify and Treat It

PURPOSE OF REVIEW

Primary aldosteronism (PA) affects millions of individuals worldwide. When unrecognized, PA leads to cardiovascular and renal complications via mechanisms independent from those mediated by hypertension. In this review, we emphasize the importance of PA screening in at-risk populations, and we provide options for customized PA therapy, with consideration for a variety of clinical care settings.

RECENT FINDINGS

Compelling evidence puts PA at the forefront of secondary hypertension etiologies. Cardiovascular and renal damage likely begins in early stages of renin-independent aldosterone excess. PA must be considered not only in patients with resistant hypertension or hypokalemia, but also when hypertension is associated with obstructive sleep apnea or atrial fibrillation, or in those with early-onset hypertension. Screening with plasma aldosterone and renin is widely accessible, and targeted PA therapy can successfully circumvent the excess cardiorenal risk relative to equivalent primary hypertension. Identifying and treating PA in early stages provide opportunities for personalized hypertension therapy in a large number of patients. Additionally, early targeted therapy of PA is essential for pivoting the care of such patients from reactive to preventive of cardiovascular and renal morbidity and mortality.

In Silico Analysis of the Gene Expression Patterns between Aldosterone-Producing Adenoma and Nonfunctional Adrenocortical Adenoma

Primary aldosteronism is the most common form of secondary hypertension, and aldosteronoma makes up a significant proportion of primary aldosteronism cases. Aldosteronoma is also called aldosterone-producing adenoma (APA). Although there have been many studies about APA, the pathogenesis of this disease is not yet fully understood. In this study, we aimed to find out the difference of gene expression patterns between APA and nonfunctional adrenocortical adenoma (NFAA) using a weighted gene coexpression network (WGCNA) and differentially expressed gene (DEG) analysis; only the genes that meet the corresponding standards of both methods were defined as real hub genes and then used for further analysis. Twenty-nine real hub genes were found out, most of which were enriched in the phospholipid metabolic process. WISP2, S100A10, SSTR5-AS1, SLC29A1, APOC1, and SLITRK4 are six real hub genes with the same gene expression pattern between the combined and validation datasets, three of which indirectly or directly participate in lipid metabolism including WISP2, S100A10, and APOC1. According to the gene expression pattern of DEGs, we speculated five candidate drugs with potential therapeutic value for APA, one of which is cycloheximide, an inhibitor for phospholipid biosynthesis. All the evidence suggests that phospholipid metabolism may be an important pathophysiological mechanism for APA. Our study provides a new perspective regarding the pathophysiological mechanism of APA and offers some small molecules that may possibly be effective drugs against APA.

Mineralocorticoid Receptor Antagonist Effect on Aldosterone to Renin Ratio in Patients With Primary Aldosteronism

CONTEXT

Although current international guidelines recommend to avoid mineralocortcoid receptor antagonists in patients undergoing screening test for primary aldosteronism, a recent report suggested that mineralocorticoid receptor antagonist treatment can be continued without significant influence on screening results.

OBJECTIVE

We aimed to evaluate the effect of mineralocorticoid receptor antagonists on the aldosterone to renin ratio in patients with primary aldosteronism.

METHODS

We prospectively enrolled 121 patients with confirmed primary aldosteronism who started mineralocorticoid receptor antagonist (canrenone) treatment. Eighteen patients (11 with unilateral and 7 with bilateral primary aldosteronism) constituted the short-term study cohort and underwent aldosterone, renin, and potassium measurement after 2 and 8 weeks of canrenone therapy. The long-term cohort comprised 102 patients (16 with unilateral and 67 with bilateral primary aldosteronism, and 19 with undetermined subtype) who underwent hormonal and biochemical re-assessment after 2 to 12 months of canrenone therapy.

RESULTS

Renin and potassium levels showed a significant increase, and the aldosterone to renin ratio displayed a significant reduction compared with baseline after both a short- and long-term treatment. These effects were progressively more evident with higher doses of canrenone and after longer periods of treatment. We demonstrated that canrenone exerted a deep impact on the diagnostic accuracy of the screening test for primary aldosteronism: the rate of false negative tests was raised to 16.7%, 38.9%, 54.5%, and 72.5% after 2 weeks, 8 weeks, 2 to 6 months, and 7 to 12 months of mineralocorticoid receptor antagonist treatment, respectively.

CONCLUSION

Mineralocorticoid receptor antagonists should be avoided in patients with hypertension before measurement of renin and aldosterone for screening of primary aldosteronism.

Primary Aldosteronism: a Continuum from Normotension to Hypertension

PURPOSE OF REVIEW

Primary aldosteronism (PA) is the most common cause of secondary hypertension. Emerging evidence suggests that PA is associated with cardiovascular, metabolic, and renal complications, that likely develop insidiously, due to prolonged inappropriate mineralocorticoid receptor activation. In this review, we discuss the expanding clinical and pathological spectrum of PA.

RECENT FINDINGS

Clinical and molecular studies conducted over the recent years reveal that PA traverses a series of contiguous stages. Pre-clinical, but hormonally overt PA has been identified in patients with normal blood pressure, and such patients harbor an increased risk of developing hypertension. Similarly, genetic and histopathological advancements have exposed a spectrum of PA pathology that corresponds to a continuum that spans from pre-clinical stages to florid PA. PA evolves from pre-hypertensive stages to resistant hypertension, along with serious cardiovascular and renal consequences. Early recognition of PA and targeted therapy will be essential for cardiovascular morbidity and mortality prevention in a large number of patients.

The Effect of Antihypertensive Medications on Testing for Primary Aldosteronism

Primary aldosteronism (PA) is a potentially curable form of secondary hypertension caused by excessive renin-independent aldosterone secretion, leading to increased target organ damage and cardiovascular morbidity and mortality. The diagnosis of PA requires measuring renin and aldosterone to calculate the aldosterone-to-renin ratio, followed by confirmatory tests to demonstrate renin-independent aldosterone secretion and/or PA subtype differentiation. Various antihypertensive drug classes interfere with the renin-angiotensin-aldosterone axis and hence evaluation for PA should ideally be performed off-drugs. This is, however, often precluded by the risks related to suboptimal control of blood pressure and serum potassium level in the evaluation period. In the present review, we summarized the evidence regarding the effect of various antihypertensive drug classes on biochemical testing for PA, and critically appraised the issue whether and which antihypertensive medications should be withdrawn or, conversely, might be continued in patients evaluated for PA. The least interfering drugs are calcium antagonists, alpha-blockers, hydralazine, and possibly moxonidine. If necessary, the testing may also be attempted during treatment with beta-blockers, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers but renin and aldosterone measurements must be interpreted in the context of known effects of these drugs on these parameters. Views are evolving on the feasibility of testing during treatment with mineralocorticoid receptor antagonists, as these drugs are now increasingly considered acceptable in specific patient subsets, particularly in those with severe hypokalemia and/or poor blood pressure control on alternative treatment.

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.

Evolution of the Primary Aldosteronism Syndrome: Updating the Approach

CONTEXT

New approaches are needed to address the evolution of the primary aldosteronism syndrome and to increase its recognition. Herein, we review evidence indicating that primary aldosteronism is a prevalent syndrome that is mostly unrecognized, and present a pragmatic and pathophysiology-based approach to improve diagnosis and treatment.

METHODS

Evidence was gathered from published guidelines and studies identified from PubMed by searching for primary aldosteronism, aldosterone, renin, and hypertension. This evidence was supplemented by the authors' personal knowledge, research experience, and clinical encounters in primary aldosteronism.

INTERPRETATION OF EVIDENCE

Renin-independent aldosterone production is a prevalent phenotype that is diagnosed as primary aldosteronism when severe in magnitude, but is largely unrecognized when milder in severity. Renin-independent aldosterone production can be detected in normotensive and hypertensive individuals, and the magnitude of this biochemical phenotype parallels the magnitude of blood pressure elevation, the risk for incident hypertension and cardiovascular disease, and the likelihood and magnitude of blood pressure reduction with mineralocorticoid receptor antagonist therapy. Expansion of the indications to screen for primary aldosteronism, combined with the use of a pathophysiology-based approach that emphasizes inappropriate aldosterone production in the context of renin suppression, will substantially increase the diagnostic and therapeutic yields for primary aldosteronism.

CONCLUSIONS

The landscape of primary aldosteronism has evolved to recognize that it is a prevalent syndrome of renin-independent aldosterone production that contributes to the pathogenesis of hypertension and cardiovascular disease. Expanding screening indications and simplifying the diagnostic approach will enable implementation of targeted treatment for primary aldosteronism.

MANAGEMENT OF ENDOCRINE DISEASE: The role of surgical adrenalectomy in primary aldosteronism

Primary aldosteronism is common and contributes to adverse cardiovascular, kidney, and metabolic outcomes. When instituted early and effectively, targeted therapies can mitigate these adverse outcomes. Surgical adrenalectomy is among the most effective treatments because it has the potential to cure, or attenuate the severity of, pathologic aldosterone excess, resulting in a host of biochemical and clinical changes that improve health outcomes. Herein, we review the role of surgical adrenalectomy in primary aldosteronism while emphasizing the physiologic ramifications of surgical intervention, and compare these to other targeted medical therapies for primary aldosteronism. We specifically review the role of curative adrenalectomy for unilateral primary aldosteronism, the role of non-curative adrenalectomy for bilateral primary aldosteronism, and how these interventions influence biochemical and clinical outcomes in relation to medical therapies for primary aldosteronism.