A Randomized trial assessing Efficacy and safety of Mineralocorticoid receptor Antagonist therapy compared to Standard antihypertensive Therapy in hypErtension with low Renin (REMASTER): rationale and study design

Low-renin hypertension affects 1 in 4 people with hypertension, but the optimal management of this condition is not known. We hypothesize that a large proportion of people with low-renin hypertension is mediated by excess mineralocorticoid receptor (MR) activation and that targeted treatment with an MR antagonist (MRA) will be beneficial. This randomized, single-blinded, titration-to-effect aims to investigate whether targeted treatment in low-renin hypertension with MRA is better compared to standard antihypertensives in terms of blood pressure control and end-organ protection. Adults with hypertension, who are treatment naïve or are receiving up to two antihypertensive agents and have a low direct renin concentration <10 mU/L will be included. Participants with severe hypertension, a secondary cause of hypertension, pregnant, breastfeeding, with moderate-severe cardiovascular and chronic kidney disease, or on medications that confound interpretation of the plasma direct renin or aldosterone concentrations will be excluded. Eligible participants will be randomized 1:1 to either MRA therapy (spironolactone) or standard anti-hypertensive therapy (perindopril+/- amlodipine) for 48 weeks. Anti-hypertensives will be up-titrated every 12 weeks until target blood pressure is achieved. The primary objective will be to determine the total defined daily dose of antihypertensives required to achieve the target blood pressure and change in mean clinic systolic blood pressure at week 48. Current hypertension guidelines do not have specific recommendations for the choice of anti-hypertensive medications for people with low-renin hypertension. The results of this trial could guide future hypertension guidelines.

Screening and diagnosis of primary aldosteronism. Consensus document of all the Spanish Societies involved in the management of primary aldosteronism

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension (HT), and is associated with a higher cardiometabolic risk than essential HT. However, PA remains underdiagnosed, probably due to several difficulties clinicians usually find in performing its diagnosis and subtype classification. The aim of this consensus is to provide practical recommendations focused on the prevalence and the diagnosis of PA and the clinical implications of aldosterone excess, from a multidisciplinary perspective, in a nominal group consensus approach by experts from the Spanish Society of Endocrinology and Nutrition (SEEN), Spanish Society of Cardiology (SEC), Spanish Society of Nephrology (SEN), Spanish Society of Internal Medicine (SEMI), Spanish Radiology Society (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Society of Laboratory Medicine (SEQC(ML)), Spanish Society of Anatomic-Pathology, Spanish Association of Surgeons (AEC).

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.

Revising the Roles of Aldosterone in Vascular Physiology and Pathophysiology: From Electocortin to Baxdrostat

Aldosterone was initially identified as a hormone primarily related to regulation of fluid and electrolyte homeostasis. However, over the past 20 years there has been an increasing appreciation of its role in regulation of vascular function and pathophysiology in the setting of hypertension, atherosclerosis, and heart failure. This review highlights recent advances in our understanding the biology of aldosterone as it relates to the pathophysiology and the management of vascular disease-especially related to hypertension. The review focuses on 3 key areas: 1) advances in our understanding of the cellular mechanisms by which aldosterone mediates its cellular effects, 2) identification of the hidden epidemic of aldosteronism as a mediator of hypertension, and 3) appreciating new therapeutic advances in the clinical pharmacology of aldosterone inhibition in cardiovascular and renal disease.

Regression of cardiac hypertrophy in health and disease: mechanisms and therapeutic potential

Left ventricular hypertrophy is a leading risk factor for cardiovascular morbidity and mortality. Although reverse ventricular remodelling was long thought to be irreversible, evidence from the past three decades indicates that this process is possible with many existing heart disease therapies. The regression of pathological hypertrophy is associated with improved cardiac function, quality of life and long-term health outcomes. However, less than 50% of patients respond favourably to most therapies, and the reversibility of remodelling is influenced by many factors, including age, sex, BMI and disease aetiology. Cardiac hypertrophy also occurs in physiological settings, including pregnancy and exercise, although in these cases, hypertrophy is associated with normal or improved ventricular function and is completely reversible postpartum or with cessation of training. Studies over the past decade have identified the molecular features of hypertrophy regression in health and disease settings, which include modulation of protein synthesis, microRNAs, metabolism and protein degradation pathways. In this Review, we summarize the evidence for hypertrophy regression in patients with current first-line pharmacological and surgical interventions. We further discuss the molecular features of reverse remodelling identified in cell and animal models, highlighting remaining knowledge gaps and the essential questions for future investigation towards the goal of designing specific therapies to promote regression of pathological hypertrophy.

Low sodium intake ameliorates hypertension and left ventricular hypertrophy in mice with primary aldosteronism

The goal of this paper is to elucidate the effects of sodium restriction on hypertension and left ventricular (LV) hypertrophy in a mouse model with primary aldosteronism (PA). Mice with genetic deletion of TWIK-related acid-sensitive K (TASK)-1 and TASK-3 channels (TASK^-/-) were used as the animal model of PA. Parameters of the LV were assessed using echocardiography and histomorphology analysis. Untargeted metabolomics analysis was conducted to reveal the mechanisms underlying the hypertrophic changes in the TASK^-/- mice. The TASK^-/- adult male mice exhibited the hallmarks of PA, including hypertension, hyperaldosteronism, hypernatremia, hypokalemia, and mild acid-base balance disorders. Two weeks of low sodium intake significantly reduced the 24-h average systolic and diastolic BP in TASK^-/- but not TASK^+/+ mice. In addition, TASK^-/- mice showed increasing LV hypertrophy with age, and 2 weeks of the low-sodium diet significantly reversed the increased BP and LV wall thickness in adult TASK^-/- mice. Furthermore, a low-sodium diet beginning at 4 weeks of age protected TASK^-/- mice from LV hypertrophy at 8-12 weeks of age. Untargeted metabolomics demonstrated that the disturbances in heart metabolism in the TASK^-/- mice (e.g., Glutathione metabolism; biosynthesis of unsaturated fatty acids; amino sugar and nucleotide sugar metabolism; pantothenate and CoA biosynthesis; D-glutamine and D-glutamate metabolism), some of which were reversed after sodium restriction, might be involved in the development of LV hypertrophy. In conclusion, adult male TASK^-/- mice exhibit spontaneous hypertension and LV hypertrophy, which are ameliorated by a low-sodium intake.

Strain Imaging for the Early Detection of Cardiac Remodeling and Dysfunction in Primary Aldosteronism

Speckle tracking echocardiography is a novel technique to quantify cardiac function and deformation. It has been applied in a series of cardiovascular diseases for the evaluation of early cardiac impairment. We recently used this technique to investigate cardiac structure and function in patients with primary aldosteronism. Cardiac damage usually occurs earlier in patients with primary aldosteronism than those with primary hypertension, probably because aldosterone hypersecretion is more commonly observed in the former than the latter patients. In this article, we will review the imaging studies, especially with speckle tracking echocardiography, for the detection of early cardiac dysfunction in primary aldosteronism as a disease model.

New clinical opportunities for mineralocorticoid receptor antagonists: focus on antifibrotic effects

Mineralocorticoid receptor antagonists have been successfully used for many years to treat patients with primary hyperaldosteronism, refractory arterial hypertension and chronic heart failure. The increased interest in this drug in recent years is due to new information about its antifibrotic and antiproliferative effects, both cardiac and extracardiac. The article also discusses the possibility of using spironolactone in patients with the new coronavirus infection SARS-CoV-2 (COVID-19).

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

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

A Prospective Comparative Study on Cardiac Alterations After Surgery and Drug Treatment of Primary Aldosteronism

BACKGROUND

Current guideline recommends both surgery and drug treatment for primary aldosteronism. Treatment effects on the cardiac structure and function remain under investigation.

OBJECTIVE

We performed a prospective study in patients with primary aldosteronism to compare effects of surgery and drug treatment on the cardiac structure and function as assessed by the left ventricular (LV) pressure-strain loop, a novel echocardiographic technique that incorporates myocardial deformation and LV pressure.

METHODS

Our study included 39 and 28 patients treated with surgery and a mineralocorticoid antagonist, respectively. We performed conventional and speckle tracking echocardiography at baseline and 3 and 6 months of follow-up.

RESULTS

During follow-up, both surgery and drug treatment normalized serum potassium concentration and significantly reduced blood pressure. Both treatments significantly and similarly decreased LV mass index and left atrial volume index. However, only in the surgery group did global wasted work significantly decrease (200.8 ± 86.7 at baseline vs. 142.1 ± 58.1 mmHg% at 6 months) and global work efficiency (91.5 ± 3.1 vs. 93.6 ± 2.3%) and global longitudinal strain (-18.3 ± 2.7 vs. -19.2 ± 1.9%) significantly (p < 0.01) increase at 6 months of follow-up. The corresponding differences from the changes in the drug treatment group were 39.5 mmHg% (95% CI, 17.1, 62.0 mmHg%), -1.64% (95% CI, -2.56, -0.71%), and -0.85% (95% CI, -1.51, -0.20%), respectively. In addition, the changes in global wasted work at 6 months of follow-up was significantly correlated with that in 24-h urinary aldosterone excretion in the drug treatment group (r = 0.54) and two groups combined (r = 0.55), but not the surgery group.

CONCLUSION

In spite of similar serum potassium normalization and blood pressure control, surgical removal of an adrenal gland, but not mineralocorticoid receptor antagonism, showed early improvement in cardiac function.

Treatment of primary hyperaldosteronism

Primary aldosteronism is associated with higher cardiovascular and renal morbidity and mortality than essential hypertension in age- and sex-matched patients with the same degree of blood pressure elevation. Therefore, it is essential to establish a specific treatment to avoid the deleterious effects of aldosterone excess. Although adrenalectomy is generally considered the treatment of choice in cases of primary aldosteronism due to unilateral disease, several aspects and circumstances should be taken into account that may make medical treatment more appropriate. Among them, in this review we mention the limited experience and efficacy, and the potential risks of adrenal vein sampling; the risks and low efficacy of adrenalectomy; the high safety and efficacy of medical treatment and some special situations such as primary aldosteronism during pregnancy, in patients of advanced age or hereditary forms of primary aldosteronism, in which medical treatment is considered especially indicated as the first line therapy. The main studies comparing medical and surgical treatment in primary aldosteronism are also discussed.

Salt intake in mineralocorticoid receptor antagonist-treated primary aldosteronism: foe or ally?

Mild hyperkalemia is a common side effect of mineralocorticoid receptor antagonist (MRA) treatment of patients with primary aldosteronism (PA), which can be worsened by instructions to minimize salt intake. Our objective was to evaluate the effect of salt consumption on serum potassium levels and mean, mean minimal, and mean maximal systolic and diastolic blood pressure (BP) in MRA-treated hyperkalemic PA patients under relative salt restriction. Seventeen consecutive mildly hyperkalemic MRA-treated PA patients aged 66.3 ± 8.37 years were recruited. Body mass index (BMI) and BP were assessed, and serum and 24-h urinary sodium and potassium levels, plasma renin, and serum aldosterone were measured, while patients followed a relatively salt-restricted diet, after 1 month of controlled salt supplementation (usual salt-restricted diet plus 4 g salt/day) and after 6 months on instructions for free dietary salt consumption. Baseline salt consumption was additionally evaluated in two more patient groups (normotensive subjects and normokalemic MRA-treated PA patients). One month of controlled salt supplementation (24-h urine sodium (median, min, max): 195.2 (120.30-275.20) vs 110.13 (34.30-139.20) mEq/day, p < 0.001) resulted in increased kaliuresis (62.25 (40.69-97.0) vs 54.0 (23.28-79.60) mEq/day, p = 0.001) and a decrease of serum potassium (5.2 (5-5.70) vs 4.6 (3.8-5.1) mEq/L, p < 0.001), while serum sodium (139 (133-141) vs 1 39 (135-144) mEq/L) and mean systolic (130 (105-141 vs. 130 (106-141) mmHg) and diastolic (76 (53-85) vs75 (53-84) mmHg) BP remained stable. These findings were unchanged after 6 months of free salt consumption. BMI remained constant, while plasma renin and serum aldosterone decreased following salt repletion. Adequate salt consumption attenuates MRA-induced hyperkalemia in relatively salt-restricted PA patients without affecting BP or BMI.

Incidental Congestive Heart Failure in Patients With Aldosterone-Producing Adenomas

Background Previous studies show that patients with primary aldosteronism are associated with higher risk of congestive heart failure (CHF). However, the effect of target treatment to the incidental CHF has not been elucidated. We aimed to investigate the risk of new-onset CHF in patients with aldosterone-producing adenomas (APAs) and explore the effect of adrenalectomy on new onset of CHF. Methods and Results From 1997 to 2009, 688 APA were identified and matched with essential hypertension controls. The risks of developing incidental CHF (hazard ratio, 0.49; 95% CI, 0.31-0.75; P=0.001) and mortality (hazard ratio, 0.29; 95% CI, 0.20-0.44; P<0.001) were significantly lower in the APA group after targeted treatment. A total of 605 patients with APAs who underwent adrenalectomy lowered the risks of CHF (subdistribution hazard ratio, 0.55; 95% CI, 0.34-0.90; P=0.017) and mortality (adjusted hazard ratio, 0.27; 95% CI, 0.16-0.44; P<0.001) compared with essential hypertension controls. Conclusions In conclusion, for patients with APAs, adrenalectomy can be associated with lower risk of incidental CHF and all-cause mortality in a long-term follow-up.

Mild primary aldosteronism (PA) followed by overt PA are possibly the most common forms of low renin hypertension: a single-center retrospective study

Low renin hypertension (LRH) is a common condition in hypertensive patients, and mainly includes primary aldosteronism (PA) and low renin essential hypertension. To investigate the distributions and clinical manifestations of the main LRH forms, we reviewed 1267 hypertensive patients who underwent assessment for plasma renin activity (PRA) and plasma aldosterone concentration (PAC) by standardized protocols in our specialized center. LRH was defined as PRA < 1.0 ng/mL/h. A saline infusion test (SIT) was performed when LRH patients showed positive screening results for PA. The main LRH forms were defined as follows: post-SIT PAC > 10 ng/dL as 'overt PA', post-SIT PAC 5-10 ng/dL as 'mild PA', and post-SIT PAC < 5 ng/dL or negative screening results as 'non-PA'. Overall, 760 patients were defined as LRH, with 160 classified as overt PA, 268 as mild PA, and 332 as non-PA. The total proportion of PA amounted to 56.3% with 21.0% overt PA and 35.3% mild PA. Compared with the mild PA, patients with overt PA had higher systolic and diastolic blood pressures, lower serum potassium, higher urine potassium excretion, more frequent incidence of stage 3 hypertension, hypokalemia, diabetes mellitus, and classical unilateral adenoma on computerized tomography (P < 0.05). PA including overt and mild forms is indeed a major form of LRH. Clinical manifestations in mild PA are less severe than those in overt PA. Nevertheless, mild PA is more prevalent than overt PA in LRH and should be recognized.

U-shaped relationship between left ventricular mass index and estimated glomerular filtration rate in patients with primary aldosteronism

Estimated glomerular filtration rate (eGFR) is an important topic in patients with primary aldosteronism (PA). However, the relationship between left ventricular structure and eGFR is unclear. We conducted a prospective, observational, and cross-sectional study to analyze 168 patients with PA and 168 propensity score-matched patients with essential hypertension (EH) as the control group, matched by age, gender, and systolic blood pressure. In the patients with PA, the eGFR was not correlated with left ventricular mass index (LVMI; r=-0.065, p=0.404), while in the patients with EH, the eGFR was negatively correlated with LVMI (r=-0.309, p<0.001). To test whether eGFR had a non-linear relationship with LVMI among the patients with PA, we stratified the patients with PA according to the tertile of eGFR (low, medium, and high tertile). The medium tertile of patients had a significantly lower LVMI than those in the other two tertiles (LVMI: 143.5±41.6, 120.5±40.5, and 133.1±34.3 g/m², from the lowest to highest tertile of eGFR; analysis of covariance p=0.032). The medium tertile of eGFR is associated with lowest LVMI. Patients with PA with high and low eGFR were associated with higher LVMI. The findings implied that the reasons for an increased LVMI in patients with PA may be different to those in patients with EH.

Mineralocorticoid Receptor Antagonists in Primary Aldosteronism

Background:

Primary aldosteronism is the most common causes of secondary hypertension. Patients suffering from this clinical syndrome have an increased cardiovascular risk and target organ damage. Mineralocorticoid receptor antagonists are the optimal pharmaceutical option for the management of such patients.

Objectives:

The study aimed to assess the effects of mineralocorticoid receptor antagonist in the treatment of patients with primary aldosteronism.

Method:

We conducted an in-depth review of the literature and comprehensive identification of the clinical studies investigating the efficacy of mineralocorticoid receptor antagonists in individuals with primary aldosteronism.

Results:

Mineralocorticoid receptor antagonists result in significant improvement in blood pressure and serum potassium level among patients with primary aldosteronism. Moreover, mineralocorticoid receptor antagonists reverse left ventricular hypertrophy, albuminuria, and carotid intima-media thickness. However, a high risk for atrial fibrillation remains among subject with primary aldosteronism in such agents.

Conclusion:

Mineralocorticoid receptor antagonists are recommended as the first-line treatment in patients with bilateral primary aldosteronism. In patients with unilateral aldosterone-producing adenoma, adrenalectomy should be preferred. However, existing data presents significant limitations and is rather inconclusive. Future randomized control trials are required in order to illustrate the field.

Primary Aldosteronism: Present and Future

Primary aldosteronism (PA), currently recognized to be 5-10% of hypertension, has a cardiovascular risk profile double that in age-, sex-, and blood pressure-matched essential hypertensives. Screening for PA is by determining the plasma aldosterone to renin ratio (ARR), followed by one of half a dozen confirmatory/exclusion tests. Unilateral hyperaldosteronism normally reflects an aldosterone producing adenoma; bilateral disease is the more common form, and termed idiopathic hyperaldosteronism (IHA). Subjects confirmed undergo imaging, followed by adrenal venous sampling (AVS) for lateralization. Unilateral lesions undergo laparoscopic adrenalectomy, to normalize aldosterone levels, and in approximately half reduction of BP/antihypertensive use. Bilateral hyperaldosteronism is treated by low dose mineralocorticoid receptor antagonists MRAs, plus amiloride/conventional antihypertensives, if/as indicated.In the future, what is needed is recognition that inappropriate aldosterone levels for sodium status (i.e., PA) represents up to 50% of "essential" hypertensives; all hypertensive should thus be screened by a modified ARR, using 24-h urinary aldosterone rather than a single plasma aldosterone. The current reluctance to do so reflects the costs of AVS if PA is confirmed-optimally by a standard seated saline suppression test-followed by surgery or life-long MRAs. Increasingly AVS will be replaced by plasma steroid assays capable of discriminating APA from the far more common IAH. Third generation MRAs (as selective as eplerenone, as potent as spironolactone, non-steroidal) are in development; in the interim, to minimize side effects and maximize compliance, spironolactone dosage should be set at 12.5-25 mg/day.

Changes in serum and intracardiac fibroblast growth factor 23 during the progression of left ventricular hypertrophy in hypertensive model rats

BACKGROUND

Recent clinical studies have demonstrated that serum fibroblast growth factor 23 (FGF23) levels have a significant association with left ventricular hypertrophy (LVH). Although LVH is commonly seen in hypertensive patients, the association between FGF23, hypertension, and LVH remains unclear. We aimed to examine the changes in serum and intracardiac FGF23 during the progression of hypertension using spontaneously hypertensive rats (SHR).

METHODS

Male SHR comprised the experimental group (HT group) and Wistar Kyoto rats served as controls. At 10 weeks, urinary and blood biochemical analyses and blood pressure measurements were performed for both the groups. At 18 weeks, the rats were sacrificed: urinary and blood biochemical analyses and real-time PCR were performed.

RESULTS

At 18 weeks, the relative heart weight and serum N-terminal pro-brain natriuretic peptide and aldosterone levels were significantly greater in the HT group. Serum calcium and phosphate levels were significantly lower, while serum FGF23 levels were significantly higher in the HT group compared to the control group. Further analyses showed that the mRNA expression of FGF23 in the heart was significantly increased in the HT group compared to the control group. Both serum FGF23 levels and intracardiac mRNA expression of FGF23 showed significant correlation with the relative heart weight.

CONCLUSIONS

During LVH progression, serum and intracardiac FGF23 increased in hypertension. Although it is unclear whether the change in FGF23 is the cause or result of LVH, the interaction between FGF23 and aldosterone may be associated with the development of LVH in hypertension.

Spironolactone in cardiovascular disease: an expanding universe?

Spironolactone has been marketed for over half a century as a ‘potassium-sparing diuretic’, used primarily in patients with ascites. With the realization that primary aldosteronism is the most common (5-13%) form of secondary hypertension, it has become widely used as a mineralocorticoid receptor antagonist. More recently, in the wake of the RALES trial, spironolactone in addition to standard therapy has been shown to be very beneficial in heart failure with a reduced ejection fraction. Despite the failure of the TOPCAT trial, spironolactone is being increasingly used in diastolic heart failure (i.e. with a preserved ejection fraction). The third currently accepted role for spironolactone is in hypertension resistant to three conventional antihypertensives including a diuretic, where it has been proven to be effective, in contra-distinction to renal artery denervation. Finally, brief consideration will be given to ‘areas in waiting’ – pulmonary hypertension/fibrosis, cancer – where spironolactone may play very useful roles.

Prevalence and Clinical Manifestations of Primary Aldosteronism Encountered in Primary Care Practice

BACKGROUND

Despite being widely recognized as the most common form of secondary hypertension, among the general hypertensive population the true prevalence of primary aldosteronism (PA) and its main subtypes, aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH), remains a matter of debate.

OBJECTIVES

This study sought to determine the prevalence and clinical phenotype of PA in a large cohort of unselected patients with hypertension, consecutively referred to our hypertension unit, by 19 general practitioners from Torino, Italy.

METHODS

Following withdrawal from all interfering medications, patients were screened for PA using the ratio of serum aldosterone to plasma renin activity. PA was diagnosed according to Endocrine Society guidelines. The diagnosis was confirmed or excluded by an intravenous saline infusion test or captopril challenge test and subtype differentiation was performed by adrenal computed tomography scanning and adrenal vein sampling, using strict criteria to define successful cannulation and lateralization of aldosterone production.

RESULTS

A total of 1,672 primary care patients with hypertension (569 newly diagnosed and 1,103 patients already diagnosed with arterial hypertension) were included in the study. A total of 99 patients (5.9%) were diagnosed with PA and conclusive subtype differentiation by adrenal vein sampling was made in 91 patients (27 patients with an APA and 64 patients with BAH). The overall prevalence of PA increased with the severity of hypertension, from 3.9% in stage 1 hypertension to 11.8% in stage 3 hypertension. Patients with PA more frequently displayed target organ damage and cardiovascular events compared with those without PA, independent of confounding variables.

CONCLUSIONS

Our results demonstrated that PA is a frequent cause of secondary hypertension, even in the general population of patients with hypertension, and indicates that most of these patients should be screened for PA.

Novel Approach to Establishing an Aldosterone: Renin Ratio Cutoff for Primary Aldosteronism

Direct renin concentration is replacing plasma renin activity in many laboratories for the investigation of primary aldosteronism, which may have a significant impact on the resulting aldosterone:renin ratios. We sought to develop a population-based approach to establishing an aldosterone:renin ratio cutoff when transitioning between assays. A population-based study was performed in Calgary, Alberta, Canada of 4301 individuals who received testing from January 2012 to November 2015. In 2014, direct renin concentration replaced plasma renin activity in routine testing. We described the prevalence of primary aldosteronism in our population before the change and, using the assumption of disease prevalence stability, determined the corresponding ratio cutoffs after the introduction of the new assay. During the initial portion of the study (using plasma renin activity), 4.9% of those screened were classified as highly probable cases, whereas 10.4% were considered probable and 28.9% possible using locally validated cutoffs. Aldosterone:renin ratio cutoffs were then determined for the direct renin concentration assay. A highly probable case of primary aldosteronism corresponded to a cutoff of >100 pmol L −1 mIU −1 L −1 with hypokalemia. A probable case corresponded to a cutoff of >100 and a possible case to >35 pmol L −1 mIU −1 L −1 . In contrast, cutoffs derived using a conversion factor resulted in significantly higher cutoffs and the potential for missed cases. In conclusion, using large population data, historically consistent aldosterone:renin ratio cutoffs can be established when transitioning between assays. Population-derived cutoffs may be more appropriate for clinical use and less likely to result in false-negative classification than those obtained from conventional direct method comparisons.

Diuretics for Hypertension: A Review and Update

This review and update focuses on the clinical features of hydrochlorothiazide (HCTZ), the thiazide-like agents chlorthalidone (CTDN) and indapamide (INDAP), potassium-sparing ENaC inhibitors and aldosterone receptor antagonists, and loop diuretics. Diuretics are the second most commonly prescribed class of antihypertensive medication, and thiazide-related diuretics have increased at a rate greater than that of antihypertensive medications as a whole. The latest hypertension guidelines have underscored the importance of diuretics for all patients, but particularly for those with salt-sensitive and resistant hypertension. HCTZ is 4.2-6.2 systolic mm Hg less potent than CTDN, angiotensin-converting enzyme inhibitors, beta blockers, and calcium channel blockers by 24-hour measurements and 5.1mm Hg systolic less potent than INDAP by office measurements. For reducing cardiovascular events (CVEs), HCTZ is less effective than enalapril and amlodipine in randomized trials, and, in network analysis of trials, it is less effective than CTDN and HCTZ-amiloride. Combined with thiazide-type diuretics, potassium-sparing agents decrease ventricular ectopy and reduce the risk for sudden cardiac death relative to thiazide-type diuretics used alone. A recent synthesis of 44 trials has shown that the relative potencies in milligrams among spironolactone (SPIR), amiloride, and eplerenone (EPLER) are approximately from 25 to 10 to 100, respectively, which may be important when SPIR is poorly tolerated. SPIR reduces proteinuria beyond that provided by other renin angiotensin aldosterone inhibitors. EPLER also reduces proteinuria and has beneficial effects on endothelial function. While guidelines often do not differentiate among specific diuretics, this review demonstrates that these distinctions are important for managing hypertension.

Long term outcome of Aldosteronism after target treatments

There exists a great knowledge gap in terms of long-term effects of various surgical and pharmacological treatments on outcomes among primary aldosteronism (PA) patients. Using a validated algorithm, we extracted longitudinal data for all PA patients diagnosed in 1997–2010 and treated in the Taiwan National Health Insurance. We identified 3362 PA patients for whom the mean length of follow-up was 5.75 years. PA has higher major cardiovascular events (MACE) than essential hypertension (23.3% vs 19.3%, p = 0.015). Results from the Cox model suggest a strong effect of adrenalectomy on lowering mortality (HR = 0.23 with residual hypertension and 0.21 with resolved hypertension). While need for receptor antagonist (MRA) MRA after diagnosis suggests that a defined daily dose (DDD) of MRA between 12.5 and 50 mg may alleviate risk of death in a U-shape pattern. A specificity test identified patients who has aldosterone producing adenoma (HR = 0.50, p = 0.005) also confirmed adrenalectomy attenuated all-cause mortality. Adrenalectomy decreases long-term all-cause mortality independently from PA cure from hypertension. Prescription corresponding to a DDD between 12.5 and 50 mg may decrease mortality for patients needing MRA. It calls for more attention on early diagnosis, early treatment and prescription of appropriate dosage of MRA for PA patients.

SFE/SFHTA/AFCE consensus on primary aldosteronism, part 7: Medical treatment of primary aldosteronism

Spironolactone, which is a potent mineralocorticoid receptor antagonist, represents the first line medical treatment of primary aldosteronism (PA). As spironolactone is also an antagonist of the androgen and progesterone receptor, it may present side effects, especially in male patients. In case of intolerance to spironolactone, amiloride may be used to control hypokaliemia and we suggest that eplerenone, which is a more selective but less powerful antagonist of the mineralocorticoid receptor, be used in case of intolerance to spironolactone and insufficient control of hypertension by amiloride. Specific calcic inhibitors and thiazide diuretics may be used as second or third line therapy. Medical treatment of bilateral forms of PA seem to be as efficient as surgical treatment of lateralized PA for the control of hypertension and the prevention of cardiovascular and renal morbidities. This allows to propose medical treatment of PA to patients with lateralized forms of PA who refuse surgery or to patients with PA who do not want to be explored by adrenal venous sampling to determine whether they have a bilateral or lateralized form.

The Management of Primary Aldosteronism: Case Detection, Diagnosis, and Treatment: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To develop clinical practice guidelines for the management of patients with primary aldosteronism.

PARTICIPANTS

The Task Force included a chair, selected by the Clinical Guidelines Subcommittee of the Endocrine Society, six additional experts, a methodologist, and a medical writer. The guideline was cosponsored by American Heart Association, American Association of Endocrine Surgeons, European Society of Endocrinology, European Society of Hypertension, International Association of Endocrine Surgeons, International Society of Endocrinology, International Society of Hypertension, Japan Endocrine Society, and The Japanese Society of Hypertension. The Task Force received no corporate funding or remuneration.

EVIDENCE

We searched for systematic reviews and primary studies to formulate the key treatment and prevention recommendations. We used the Grading of Recommendations, Assessment, Development, and Evaluation group criteria to describe both the quality of evidence and the strength of recommendations. We used "recommend" for strong recommendations and "suggest" for weak recommendations.

CONSENSUS PROCESS

We achieved consensus by collecting the best available evidence and conducting one group meeting, several conference calls, and multiple e-mail communications. With the help of a medical writer, the Endocrine Society's Clinical Guidelines Subcommittee, Clinical Affairs Core Committee, and Council successfully reviewed the drafts prepared by the Task Force. We placed the version approved by the Clinical Guidelines Subcommittee and Clinical Affairs Core Committee on the Endocrine Society's website for comments by members. At each stage of review, the Task Force received written comments and incorporated necessary changes.

CONCLUSIONS

For high-risk groups of hypertensive patients and those with hypokalemia, we recommend case detection of primary aldosteronism by determining the aldosterone-renin ratio under standard conditions and recommend that a commonly used confirmatory test should confirm/exclude the condition. We recommend that all patients with primary aldosteronism undergo adrenal computed tomography as the initial study in subtype testing and to exclude adrenocortical carcinoma. We recommend that an experienced radiologist should establish/exclude unilateral primary aldosteronism using bilateral adrenal venous sampling, and if confirmed, this should optimally be treated by laparoscopic adrenalectomy. We recommend that patients with bilateral adrenal hyperplasia or those unsuitable for surgery should be treated primarily with a mineralocorticoid receptor antagonist.

Primary Aldosteronism: New Answers, New Questions

There have been 2, and possibly 3, major questions for primary aldosteronism (PA) answered at least in principle over the past 5 years. The first is that of somatic mutations underlying the majority of aldosterone producing adenomas. The second is the extension of our knowledge of the genetics of familial hypertension, and the third the role of renal intercalated cells in sodium homeostasis. New questions for the next 5 years include a single accepted confirmatory/exclusion test; standardisation of assays and cut-offs; alternatives to universal adrenal venous sampling; reclassification of 'low renin hypertension'; recognition of the extent of 'occult' PA; inclusion of low-dose mineralocorticoid receptor antagonist in first-line therapy for hypertension; and finally, possible resolution of the aldosterone/inappropriate sodium status enigma at the heart of the cardiovascular damage in PA.

Genetics of resistant hypertension: a novel pharmacogenomics phenotype

Resistant hypertension (RHTN), defined as an uncontrolled blood pressure despite the use of multiple antihypertensive medications, is an increasing clinical problem associated with increased cardiovascular (CV) risk, including stroke and target organ damage. Genetic variability in blood pressure (BP)-regulating genes and pathways may, in part, account for the variability in BP response to antihypertensive agents, when taken alone or in combination, and may contribute to the RHTN phenotype. Pharmacogenomics focuses on the identification of genetic factors responsible for inter-individual variability in drug response. Expanding pharmacogenomics research to include patients with RHTN taking multiple BP-lowering medications may identify genetic markers associated with RHTN. To date, the available evidence surrounding pharmacogenomics in RHTN is limited and primarily focused on candidate genes. In this review, we summarize the most current data in RHTN pharmacogenomics and offer some recommendations on how to advance the field.

Pathophysiology and treatment of resistant hypertension: the role of aldosterone and amiloride-sensitive sodium channels

Resistant hypertension is a clinically distinct subgroup of hypertension defined by the failure to achieve blood pressure control on optimal dosing of at least 3 antihypertensive medications of different classes, including a diuretic. The pathophysiology of hypertension can be attributed to aldosterone excess in more than 20% of patients with resistant hypertension. Existing dogma attributes the increase in blood pressure seen with increases in aldosterone to its antinatriuretic effects in the distal nephron. However, emerging research, which has identified and has begun to define the function of amiloride-sensitive sodium channels and mineralocorticoid receptors in the systemic vasculature, challenges impaired natriuresis as the sole cause of aldosterone-mediated resistant hypertension. This review integrates these findings to better define the role of the vasculature and aldosterone in the pathophysiology of resistant hypertension. In addition, a brief guide to the treatment of resistant hypertension is presented.

Outcomes of drug-based and surgical treatments for primary aldosteronism

Treatments for primary aldosteronism (PA) aim to correct or prevent the deleterious consequences of hyperaldosteronism: hypertension, hypokalemia, and direct target organ damage. Patients with unilateral PA considered fit for surgery can undergo laparoscopic adrenalectomy, which significantly decreases blood pressure (BP) and medications in most cases and cures hypertension in about 40%. Mineralocorticoid receptor antagonists (MRA) are used to treat patients with bilateral PA and those with unilateral PA if surgery is not possible or not desired. Spironolactone is more potent than eplerenone, but high doses are poorly tolerated in men. MRA can be replaced or complemented with epithelial sodium channel blockers, such as amiloride. Thiazide diuretics and calcium channel blockers are used when the first-line drugs are insufficient to control BP. Dietary sodium restriction should be implemented in all cases because the deleterious consequences of hyperaldosteronism are dependent on salt loading. Several studies comparing the results of surgery and MRA have reported no differences in terms of BP, serum potassium concentration, or cardiovascular and kidney outcomes, although the benefits of treatment tend to be observed sooner with surgery. Patients with PA display relative glomerular hyperfiltration, which is reversed by specific treatment, revealing CKD in 30% of patients. However, further kidney damage is lessened by the treatment of PA.

Progress in primary aldosteronism. Mineralocorticoid antagonist treatment for aldosterone-producing adenoma

Mineralocorticoid receptor antagonists have been used in patients with aldosterone-producing adenomas (APAs) as a test designed to predict the blood pressure (BP) outcome of surgery. They are commonly used in patients undergoing adrenalectomy to reduce BP and increase plasma potassium levels during the preoperative period. A small number of studies have compared the effects of surgery and mineralocorticoid antagonists either on BP, on serum potassium levels, or on the incidence of cardiovascular and renal outcomes in patients with primary aldosteronism with or without an APA; these studies found no difference between the two therapeutic options. Mineralocorticoid receptor antagonists can be used as a maintenance treatment for patients with APAs, who are judged to be poor operative risks or who do not want to undergo surgery.

Approach to the surgical management of primary aldosteronism

Primary aldosteronism (PA) is the most common cause of endocrine hypertension; it has been reported in more than 11% of referred hypertensive patients. PA may be caused by unilateral adrenal involvement [aldosterone producing adenoma (APA) or unilateral adrenal hyperplasia (UAH)], and bilateral disease (idiopathic adrenal hyperplasia). Only patients with unilateral adrenal hypersecretion may be cured by unilateral adrenalectomy, while patients with bilateral and non-surgically correctable PA are usually treated by mineralocorticoid receptor antagonists; thus the distinction between unilateral and bilateral aldosterone hypersecretion is crucial. Most experts agree that the referral diagnostic test for lateralization of aldosterone hypersecretion should be adrenal venous sampling (AVS) because the interpretation of other imaging techniques [computed tomography (CT), magnetic resonance imaging (MRI) and scintigraphy] may lead to inappropriate treatment. Adrenalectomy represents the elective treatment in unilateral PA variants. Laparoscopic surgery, using transperitoneal or retroperitoneal approaches, is the preferred strategy. Otherwise, the indications to laparoscopic unilateral total or partial adrenalectomy in patients with unilateral PA remain controversial. Adrenalectomy is highly successful in curing the PA, with correction of hypokalemia in virtually all patients, cure of hypertension in about 30-60% of cases, and a marked improvement of blood pressure values in the remaining patients. Interestingly, in several papers the outcomes of surgery focus only on blood pressure changes and the normalization of serum potassium levels is often used as a surrogate of PA recovery. However, the goal of surgery is the normalization of aldosterone, because chronically elevated levels of this hormone can lead to cardiovascular complications, independently from blood pressure levels. Thus, we strongly advocate the need of considering the postoperative normalization of aldosterone-renin ratio (ARR) as the main endpoint for determining outcomes of PA.

Human aldosterone synthase gene polymorphism promotes miRNA binding and regulates gene expression

Hypertension is a serious risk factor for myocardial infarction, heart failure, vascular disease, stroke, and renal failure. Like other complex diseases, hypertension is caused by a combination of genetic and environmental factors. The renin-angiotensin-aldosterone system plays an important role in the regulation of blood pressure. The octapeptide angiotensin II (ANG II) is one of the most active vasopressor agents and is obtained from the precursor molecule, angiotensinogen, by the combined proteolytic action of renin and angiotensin-converting enzyme. ANG II increases the expression of aldosterone synthase (coded by Cyp11B2 gene), which is the rate-limiting enzyme in the biosynthesis of aldosterone. Previous studies have shown that increased expression of aldosterone synthase increases blood pressure and cardiac hypertrophy in transgenic mice. Human Cyp11B2 gene has a T/C polymorphism at -344 positions in its 5'-untranslated region (UTR), and the -344T allele is associated with hypertension. Human Cyp11B2 gene also has an A/G polymorphism at 735 position in its 3'-UTR (rs28491316) that is in linkage disequilibrium with single nucleotide polymorphism at -344. We show here that 1) microRNA (miR)-766 binds to the 735G-allele and not the 735A-allele of the hCyp11B2 gene and 2) transfection of miR-766 reduces the human aldosterone synthase mRNA and protein level in human adrenocortical cells H295R. These studies suggest that miR-766 may downregulate the expression of human aldosterone synthase gene and reduce blood pressure in human subjects containing -344T allele.

Long-term effects of adrenalectomy or spironolactone on blood pressure control and regression of left ventricle hypertrophy in patients with primary aldosteronism

INTRODUCTION

Primary aldosteronism (PA) represents the most common cause of secondary hypertension. Beyond increased blood pressure, additional harmful effects of aldosterone excess including inappropriate left ventricle (LV) hypertrophy were found. We evaluated the effect of adrenalectomy and spironolactone on blood pressure and myocardial remodelling in a long-term follow-up study.

METHODS

Thirty-one patients with PA were recruited. Fifteen patients with confirmed aldosterone-producing adenoma underwent adrenalectomy; in the remaining 16 patients, treatment with spironolactone was initiated. Laboratory data, 24-hour ambulatory blood pressure monitoring (ABPM) and echocardiography parameters were evaluated at baseline and at a median follow-up of 64 months.

RESULTS

Both approaches reduced blood pressure (p = 0.001 vs. baseline). In both groups we observed a decrease in end-diastolic (p = 0.04, p = 0.01) and end-systolic LV cavity diameters (p = 0.03, p = 0.01). Interventricular septum and posterior wall thickness reduction was significant only after adrenalectomy (p = 0.01, p = 0.03) as was reduction of LV mass index (p = 0.004). A trend to lower LV mass on spironolactone was caused predominantly by diminution of the LV cavity, which was reflected in increased relative wall thickness (p = 0.05).

CONCLUSIONS

Although both surgical and conservative treatment can induce a long-term decrease of blood pressure, adrenalectomy seems to be more effective in reduction of LV mass, as it reverses both wall thickening and enlargement of the LV cavity.

Blood pressure and amiloride-sensitive sodium channels in vascular and renal cells

Sodium transport in the distal nephron is mediated by epithelial sodium channel activity. Proteolytic processing of external domains and inhibition with increased sodium concentrations are important regulatory features of epithelial sodium channel complexes expressed in the distal nephron. By contrast, sodium channels expressed in the vascular system are activated by increased external sodium concentrations, which results in changes in the mechanical properties and function of endothelial cells. Mechanosensitivity and shear stress affect both epithelial and vascular sodium channel activity. Guyton's hypothesis stated that blood pressure control is critically dependent on vascular tone and fluid handling by the kidney. The synergistic effects, and complementary regulation, of the epithelial and vascular systems are consistent with the Guytonian model of volume and blood pressure regulation, and probably reflect sequential evolution of the two systems. The integration of vascular tone, renal perfusion and regulation of renal sodium reabsorption is the central underpinning of the Guytonian model. In this Review, we focus on the expression and regulation of sodium channels, and we outline the emerging evidence that describes the central role of amiloride-sensitive sodium channels in the efferent (vascular) and afferent (epithelial) arms of this homeostatic system.

Mineralocorticoid receptor antagonists: emerging roles in cardiovascular medicine

Spironolactone was first developed over 50 years ago as a potent mineralocorticoid receptor (MR) antagonist with undesirable side effects; it was followed a decade ago by eplerenone, which is less potent but much more MR-specific. From a marginal role as a potassium-sparing diuretic, spironolactone was shown to be an extraordinarily effective adjunctive agent in the treatment of progressive heart failure, as was eplerenone in subsequent heart failure trials. Neither acts as an aldosterone antagonist in the heart as the cardiac MR are occupied by cortisol, which becomes an aldosterone mimic in conditions of tissue damage. The accepted term "MR antagonist", (as opposed to "aldosterone antagonist" or, worse, "aldosterone blocker"), should be retained, despite the demonstration that they act not to deny agonist access but as inverse agonists. The prevalence of primary aldosteronism is now recognized as accounting for about 10% of hypertension, with recent evidence suggesting that this figure may be considerably higher: in over two thirds of cases of primary aldosteronism therapy including MR antagonists is standard of care. MR antagonists are safe and vasoprotective in uncomplicated essential hypertension, even in diabetics, and at low doses they also specifically lower blood pressure in patients with so-called resistant hypertension. Nowhere are more than 1% of patients with primary aldosteronism ever diagnosed and specifically treated. Given the higher risk profile in patients with primary aldosteronism than that of age, sex, and blood pressure matched essential hypertension, on public health grounds alone the guidelines for first-line treatment of all hypertension should mandate inclusion of a low-dose MR antagonist.