SFE/SFHTA/AFCE consensus on primary aldosteronism, part 4: Subtype diagnosis

Adrenal Vein Sampling for Primary Aldosteronism: Recommendations From the Australian and New Zealand Working Group

Adrenal vein sampling (AVS) is the current recommended procedure for identifying unilateral subtypes of primary aldosteronism (PA), which are amenable to surgery with the potential for cure. AVS is a technically challenging procedure usually undertaken by interventional radiologists at tertiary centres. However, there are numerous variations in AVS protocols relating to patient preparation, sampling techniques and interpretation which may impact the success of AVS and patient care. To reduce practice variations, improve the success rates of AVS and optimise patient outcomes, we established an Australian and New Zealand AVS Working Group and developed evidence-based expert consensus recommendations for the preparation, performance and interpretation of AVS. These recommendations can be used by all healthcare professionals in a multidisciplinary team who look after the diagnosis and management of PA.

Usefulness of the Upright Posture Test in the Diagnosis of Primary Aldosteronism

Objective

To assess the usefulness of the upright posture stimulation test (UPT) in the confirmation of primary aldosteronism (PA) in patients in whom saline tests (ST) were inconclusive.

Methods

One hundred eighty-seven adult patients with possible PA were retrospectively included and compared to 25 control subjects. Blood samples were obtained after a 1-hour supine posture and during 2 hours of ambulation. An increase in plasma aldosterone concentration (PAC) ≥ 50% with a suppressed renin (≤10.1 ng/L; ≤1 ng/mL/hour) and a cortisol increase ≤50% were considered abnormal.

Results

PA patients had higher basal PAC and lower basal direct renin concentration (DRC) (P < .0001) and a higher maximal PAC (P = .0025) and lower maximal DRC (DRCmax) (P < .0001) during UPT compared to controls. PA was confirmed in 145 patients (77.5%), based on either oral/IV ST or UPT. DRCmax ≤12 ng/L during UPT was a predictor of PA (receiver operating characteristic curve sensitivity 93.8%, specificity 88%), and 95.6% of PA patients increased PAC ≥50% on UPT (median 222.2%), while renin remained suppressed. All 41 PA patients with false-negative IV ST (PAC < 162 pmol/L) and 88.9% with borderline response (162-240 pmol/L) had a DRCmax ≤12, while, respectively, 97.6% and 100% increased aldosterone by ≥50%. Similar responses to UPT were found in lateralized (28/63) and bilateral PA source (35/63). PA diagnosis increased from 23.6% to 88.8% using UPT results instead of IV ST and were confirmed at pathology and clinical outcome after adrenalectomy (n = 22).

Conclusion

UPT can be useful to confirm PA, particularly in patients with suspected false-negative ST.

Selective venous sampling for secondary hypertension

Selective venous sampling (SVS), an invasive radiographic procedure that depends on contrast media, holds a unique role in diagnosing and guiding the treatment of certain types of secondary hypertension, particularly in patients who may be candidates for curative surgery. The adrenal venous sampling (AVS), in particular, is established as the gold standard for localizing and subtyping primary aldosteronism (PA). Throughout decades of clinical practice, AVS could be applied not only to PA but also to other endocrine diseases, such as adrenal Cushing syndrome (ACS) and Pheochromocytomas (PCCs). Notably, the application of AVS in ACS and PCCs remains less recognized compared to PA, with the low success rate of catheterization, the controversy of results interpretation, and the absence of a standardized protocol. Additionally, the AVS procedure necessitates enhancements to boost its success rate, with several helpful but imperfect methods emerging, yet continued exploration remains essential. We also observed renal venous sampling (RVS), an operation akin to AVS in principle, serves as an effective means of diagnosing renin-dependent hypertension, aiding in the identification of precise sources of renin excess and helping the selection of surgical candidates with renin angiotensin aldosterone system (RAAS) abnormal activation. Nonetheless, further basic and clinical research is needed. Selective venous sampling (SVS) can be used in identifying cases of secondary hypertension that are curable by surgical intervention. Adrenal venous sampling (AVS) and aldosterone measurement for classificatory diagnosis of primary aldosteronism (PA) are established worldwide. While its primary application is for PA, AVS also holds the potential for diagnosing other endocrine disorders, including adrenal Cushing's syndrome (ACS) and pheochromocytomas (PCCs) through the measurements of cortisol and catecholamine respectively. In addition, renal venous sampling and renin measurement can help to diagnose renovascular hypertension and reninoma.

Strategies for subtyping primary aldosteronism

Adrenal venous sampling (AVS) is a crucial method for the lateralization of primary aldosteronism (PA). It is advised to halt the use of the patient's antihypertensive medications and correct hypokalemia prior to undergoing AVS. Hospitals equipped to conduct AVS should establish their own diagnostic criteria based on current guidelines. If the patient's antihypertensive medications cannot be discontinued, AVS can be performed as long as the serum renin level is suppressed. The Task Force of Taiwan PA recommends using a combination of adrenocorticotropic hormone stimulation, quick cortisol assay, and C-arm cone-beam computed tomography to maximize the success of AVS and minimize errors by using the simultaneous sampling technique. If AVS is not successful, an NP-59 (131 I-6-β-iodomethyl-19-norcholesterol) scan can be used as an alternative method to lateralize PA. We depicted the details of the lateralization procedures (mainly AVS, and alternatively NP-59) and their tips and tricks for confirmed PA patients who would consider to undergo surgical treatment (unilateral adrenalectomy) if the subtyping shows unilateral disease.

Endocrine causes of hypertension: literature review and practical approach

Hypertension (HTN) affects more than 30% of adults worldwide. It is the most frequent modifiable cardiovascular (CV) risk factor, and is responsible for more than 10 million death every year. Among patients with HTN, we usually distinguish secondary HTN, that is HTN due to an identified cause, and primary HTN, in which no underlying cause has been found. It is estimated that secondary hypertension represents between 5 and 15% of hypertensive patients [1]. Therefore, routine screening of patients for secondary HTN would be too costly and is not recommended. In addition to the presence of signs suggesting a specific secondary cause, screening is based on specific criteria. Identifying secondary HTN can be beneficial for patients in certain situations, because it may lead to specific treatments, and allow better control of blood pressure and sometimes even a cure. Besides, it is now known that secondary HTN are more associated with morbidity and mortality than primary HTN. The main causes of secondary HTN are endocrine and renovascular (mainly due to renal arteries abnormalities). The most frequent endocrine cause is primary aldosteronism, which diagnosis can lead to specific therapies. Pheochromocytoma and Cushing syndrome also are important causes, and can have serious complications. Other causes are less frequent and can be suspected on specific situations. In this article, we will describe the endocrine causes of HTN and discuss their treatments.

A new machine learning-based prediction model for subtype diagnosis in primary aldosteronism

INTRODUCTION

Unilateral primary aldosteronism (UPA) and bilateral primary aldosteronism (BPA) are the two subtypes of PA. Discriminating UPA from BPA is of great significance. Although adrenal venous sampling (AVS) is the gold standard for diagnosis, it has shortcomings. Thus, improved methods are needed.

METHODS

The original data were extracted from the public database "Dryad". Ten parameters were included to develop prediction models for PA subtype diagnosis using machine learning technology. Moreover, the optimal model was chose and validated in an external dataset.

RESULTS

In the modeling dataset, 165 patients (71 UPA, 94 BPA) were included, while in the external dataset, 43 consecutive patients (20 UPA, 23 BPA) were included. The ten parameters utilized in the prediction model include age, sex, systolic and diastolic blood pressure, aldosterone to renin ratio (ARR), serum potassium, ARR after 50 mg captopril challenge test (CCT), primary aldosterone concentration (PAC) after saline infusion test (SIT), PAC reduction rate after SIT, and number of types of antihypertensive agents at diagnosis. The accuracy, sensitivity, specificity, F1 score, and AUC for the optimal model using the random forest classifier were 90.0%, 81.8%, 96.4%, 0.878, and 0.938, respectively, in the testing dataset and 81.4%, 90.0%, 73.9%, 0.818 and 0.887, respectively, in the validating external dataset. The most important variables contributing to the prediction model were PAC after SIT, ARR, and ARR after CCT.

DISCUSSION

We developed a machine learning-based predictive model for PA subtype diagnosis based on ten clinical parameters without CT imaging. In the future, artificial intelligence-based prediction models might become a robust prediction tool for PA subtype diagnosis, thereby, might reducing at least some of the requests for CT or AVS and assisting clinical decision-making.

Diagnosis of primary hyperaldosteronism

Primary aldosteronism (PA) is the most common cause of secondary arterial hypertension. Moreover, it is associated with a higher cardio-metabolic risk than the observed in patients with essential arterial hypertension (EHT). Therefore, a high index of clinical suspicion for PA is mandatory. If an elevated aldosterone/renin ratio is confirmed, confirmatory tests should be performed, with the exception in those patients with florid PA, with, with spontaneous hypokalaemia, plasma aldosterone > 20 ng/dL and suppressed renin, in whom this step would not be strictly necessary. Intravenous saline infusion test or captopril test are the commonly used confirmatory tests. The last step in the diagnosis of PA is the localization study, being the computerized axial tomography (CT) of the adrenal glands the initial test of choice, and adrenal venous sampling (AVS), the definitive localization test in most cases. This review summarizes the available data about the diagnosis of PA, from screening to confirmatory study and localization.

Diagnosis and treatment of primary aldosteronism

Primary aldosteronism is a common cause of secondary hypertension associated with excess cardiovascular morbidities. Primary aldosteronism is underdiagnosed because it does not have a specific, easily identifiable feature and clinicians can be poorly aware of the disease. The diagnostic investigation is a multistep process of screening, confirmatory testing, and subtype differentiation of unilateral from bilateral forms for therapeutic management. Adrenal venous sampling is key for reliable subtype identification, but can be bypassed in patients with specific characteristics. For unilateral disease, surgery offers the possibility of cure, with total laparoscopic unilateral adrenalectomy being the treatment of choice. Bilateral forms are treated mainly with mineralocorticoid receptor antagonists. The goals of treatment are to normalise both blood pressure and excessive aldosterone production, and the primary aims are to reduce associated comorbidities, improve quality of life, and reduce mortality. Prompt diagnosis of primary aldosteronism and the use of targeted treatment strategies mitigate aldosterone-specific target organ damage and with appropriate patient management outcomes can be excellent. Advances in molecular histopathology challenge the traditional concept of primary aldosteronism as a binary disease, caused by either a unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia. Somatic mutations drive autonomous aldosterone production in most adenomas. Many of these same mutations have been identified in nodular lesions adjacent to an aldosterone-producing adenoma and in patients with bilateral disease. In addition, germline mutations cause rare familial forms of aldosteronism (familial hyperaldosteronism types 1-4). Genetic testing for inherited forms in suspected cases of familial hyperaldosteronism avoids the burdensome diagnostic investigation in positive patients. In this Review, we discuss advances and future management approaches in the diagnosis of primary aldosteronism.

Radiofrequency ablation for adenoma in patients with primary aldosteronism and hypertension: ADERADHTA, a pilot study

OBJECTIVE

To evaluate the efficacy and the feasibility of radiofrequency ablation to treat aldosterone-producing adenomas.

METHODS

In an open prospective bicentric pilot study, patients with hypertension on ambulatory blood pressure measurement, a primary aldosteronism, an adenoma measuring less than 4 cm, and confirmation of lateralization by adrenal venous sampling were recruited. The primary endpoint, based on ABPM performed at 6 months after the radiofrequency ablation, was a daytime SBP/DBP less than 135/85 mmHg without any antihypertensive drugs or a reduction of at least 20 mmHg for SBP or 10 mmHg for DBP.

RESULTS

Thirty patients have been included (mean age = 51 ± 11 years; 50% women). Mean baseline daytime SBP and DBP were 144 ± 19 / 95 ± 15 mmHg and 80% received at least two antihypertensive drugs. At 6 months: 47% (95% CI 28-66) of patients reached the primary endpoint, mean daytime SBP and DBP were 131 ± 14 (101-154)/87 ± 10 (71-107) mmHg; 43% of them did not take any antihypertensive drug and 70% of them did not take potassium supplements. Few complications were recorded: four cases of back pain at day 1 postablation; three limited pneumothoraxes, which resolved spontaneously; one lesion of a polar renal artery.

CONCLUSION

Radiofrequency ablation for hypertensive patients with aldosterone-producing adenomas seems to be an emerging promising alternative to surgery. Its efficacy and its feasibility have to be confirmed in a larger sample of patients.

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.

Diagnosis and Management of Endocrine Hypertension in Children and Adolescents

Hypertension in childhood and adolescence has increased in prevalence. Interest in the disease was raised after the 2017 clinical practice guidelines of the American Academy of Paediatrics on the definition and classification of paediatric hypertension. Among the secondary causes of paediatric hypertension, endocrine causes are relatively rare but important due to their unique treatment options. Excess of catecholamine, glucocorticoids and mineralocorticoids, congenital adrenal hyperplasia, hyperaldosteronism, hyperthyroidism and other rare syndromes with specific genetic defects are endocrine disorders leading to paediatric and adolescent hypertension. Adipose tissue is currently considered the major endocrine gland. Obesity-related hypertension constitutes a distinct clinical entity leading to an endocrine disorder. The dramatic increase in the rates of obesity during childhood has resulted in a rise in obesity-related hypertension among children, leading to increased cardiovascular risk and associated increased morbidity and mortality. This review presents an overview of pathophysiology and diagnosis of hypertension resulting from hormonal excess, as well as obesity-related hypertension during childhood and adolescence, with a special focus on management.

The Quality of Clinical Practice Guidelines and Consensuses on the Management of Primary Aldosteronism: A Critical Appraisal

Background: Several guidelines and expert consensuses have been developed for management of primary aldosteronism (PA). It is important to understand the detailed recommendations and quality of these guidelines to help physicians make informed and reliable decision.

Methods: PubMed, EMBASE, and three websites were searched for practice guidelines or consensuses of PA from inception to January 24, 2019. We summarized the major recommendations on the management of PA from these guidelines and consensuses. The Appraisal of Guidelines for Research and Evaluation II was used to assess quality of the included guidelines and consensuses.

Results: We identified three clinical practice guidelines and three consensus statements. Most of the recommendations on the diagnosis and treatment of PA from these guidelines and consensuses were consistent. Some minor conflicts were recorded for patient's screen and confirmation test. All included guideline documents have a good quality (score, >70%) on the scope and purpose (mean score, 81.02%) and clarity of presentation of the recommendations (mean score, 86.88%). However, the reporting for the stakeholder involvement (mean score, 54.32%) and applicability (mean score, 47.92%) were insufficient. There was an insufficient rigorousness in most of the guideline documents (mean score, 45.56%) on the development process. The Endocrine Society practice guideline 2016 ranked highest in quality (score, 81.13%).

Conclusions: Existing guideline documents provided valuable recommendations on the management of PA, but further efforts are needed to improve the methodological quality. The Endocrine Society practice guideline 2016 was recommended for use.

Controversies and advances in adrenal venous sampling in the diagnostic workup of primary aldosteronism

Adrenal venous sampling (AVS) is a key part of the diagnostic workup of primary aldosteronism, distinguishing unilateral from bilateral disease and determining treatment options. Although AVS is a well-established procedure, many aspects remain controversial, including optimal patient selection for the procedure and exactly how AVS is performed and interpreted. Despite the controversies, a growing body of evidence supports the use of AVS in most patients with primary aldosteronism, though some specific patient groups may be able to forego AVS and proceed directly to treatment. Although AVS remains a difficult procedure, success rates may be improved with the use of advanced CT imaging techniques and/or rapid cortisol assays. New advances in nuclear imaging and steroid profiling may also offer alternatives or adjuncts to AVS in the future.

Cosyntropin stimulation in adrenal vein sampling improves the judgment of successful adrenal vein catheterization and outcome prediction for primary aldosteronism

The importance of cosyntropin stimulation during adrenal vein sampling (AVS) is not fully established, partly due to insufficient AVS data relating the presence and absence of cosyntropin stimulation with postoperative outcome. Therefore, we investigated differences in AVS indices before and after cosyntropin stimulation, and determined whether unstimulated or stimulated AVS indices better correlated with treatment outcome. A retrospective study was conducted in two parts: one with 185 patients who underwent AVS and the other with 81 patients who underwent unilateral adrenalectomy for unilateral aldosterone oversecretion. The selectivity index (SI), lateralized ratio (LR), and contralateral ratio (CR) before and after cosyntropin stimulations were determined, along with blood pressure outcome 1 year after surgery. Primary aldosteronism was diagnosed according to the Japanese Endocrine Society 2009 guidelines. The percentage of AVS patients with successful catheterization, defined as unstimulated SI > 2 before and stimulated SI > 5, increased after cosyntropin stimulation from 52% to 93% and from 74% to 98% for the right and left adrenal veins, respectively. LR decreased after cosyntropin stimulation (P < 0.001). In the postoperative patients, complete and partial clinical success was achieved in 49 and 27%, respectively. Low CR (<1) and high LR (≥2.6) after cosyntropin stimulation better correlated with postoperative blood pressure outcome than those before stimulation (CR < 1 and LR ≥ 2). These data suggest that cosyntropin stimulation facilitated the judgment of catheter insertion and postcosyntropin AVS indices may be more useful for predicting treatment outcome after unilateral adrenalectomy. Further study should examine the usefulness of cosyntropin stimulation in AVS performed in other settings.

Familial hyperaldosteronism type III a novel case and review of literature

Less than 15% of hypertension cases in children are secondary to a primary hyperaldosteronism. This is idiopathic in 60% of the cases, secondary to a unilateral adenoma in 30% and 10% remaining by primary adrenal hyperplasia, familial hyperaldosteronism, ectopic aldosterone production or adrenocortical carcinoma.To date, four types of familial hyperaldosteronism (FH I to FH IV) have been reported. FH III is caused by germline mutations in KCNJ5, encoding the potassium channel Kir3.4. The mutations cause the channel to lose its selectivity for potassium, allowing large quantities of sodium to enter the cell. As a consequence, the membrane depolarizes, voltage-gated calcium channels open, calcium enters the cell, initiating the cascade that leads to aldosterone synthesis. Somatic mutations in KCNJ5 has also been described in aldosterone-producing adenomas. The most frequent presentation of FH III is with severe hyperaldosteronism symptoms and resistance to pharmacological therapy which leads to bilateral adrenalectomy. We will review current literature and describe a child with FH III due to a novel de novo deletion in KCNJ5 with wild phenotype as a sign of clinical variability of this disease.

La chirurgie d’épargne surrénalienne : du cortex à la médulla

The 2017 Endocrine Society annual meeting included several communications and debates on the conservative adrenal surgery in bilateral hereditary pheochromocytomas (BHP), bilateral adrenal macronodular hyperplasia (BAMH) and primary hyperaldosteronism (PHA). The general principle is to preserve a part of the adrenal cortex to prevent the occurrence of a definitive adrenal insufficiency. In BHP, cortical sparing surgery allows more than 50% of patients to maintain normal corticotropic function at 10 years with a low recurrence rate (~ 10%). Since the adrenal medulla cannot be removed entirely, recurrence seems inevitable and long-term follow-up is essential. Individual risk of malignancy must be taken into account. In BAMH responsible for Cushing syndrome, unilateral adrenalectomy induces a normalization of urinary free cortisol in 92 to 100% of cases and even corticotropic insufficiency in 40 to 100% of cases. This is most often transient. Late recurrences of Cushing's syndrome may occur in 13 to 60% of cases. Prolonged patient monitoring is therefore essential. In PAH with lateralized aldosterone production, minimally invasive partial adrenal surgery, which consists of removing only the adrenal adenoma visualized at TDM, allows an improvement blood pressure in about 94% of patients. However, failure or recurrence may occur. Its place therefore remains marginal in the treatment of the lateralized PAHs.

Update in diagnosis and management of primary aldosteronism

Primary aldosteronism (PA) is a group of disorders in which aldosterone is excessively produced. These disorders can lead to hypertension, hypokalemia, hypervolemia and metabolic alkalosis. The prevalence of PA ranges from 5% to 12% around the globe, and the most common causes are adrenal adenoma and adrenal hyperplasia. The importance of PA recognition arises from the fact that it can have a remarkably adverse cardiovascular and renal impact, which can even result in death. The aldosterone-to-renin ratio (ARR) is the election test for screening PA, and one of the confirmatory tests, such as oral sodium loading (OSL) or saline infusion test (SIT), is in general necessary to confirm the diagnosis. The distinction between adrenal hyperplasia (AH) or aldosterone-producing adenoma (APA) is essential to select the appropriate treatment. Therefore, in order to identify the subtype of PA, imaging exams such as computed tomography or magnetic ressonance imaging, and/or invasive investigation such as adrenal catheterization must be performed. According to the subtype of PA, optimal treatment – surgical for APA or pharmacological for AH, with drugs like spironolactone and amiloride – must be offered.

Stroke disclosing primary aldosteronism: Report on three cases and review of the literature

OBJECTIVES

There is a growing evidence of increased risk of cerebrovascular events in primary aldosteronism (PA). Nevertheless, acute neurologic ailment as presenting feature of PA is uncommon. Our aim is to highlight the diagnosis challenges in stroke unmasking PA and to discuss the underlying physiopathology and management dilemmas.

MATERIALS AND METHODS

We hereby describe three consecutive rare cases of stroke revealing PA. All patients had brain imaging and thorough biological and morphological assessment to rule out other etiologies of stroke. The diagnosis of primary aldosteronism was established according to the Endocrine Society Clinical Practice Guideline, with a review of the literature on the spectrum of neurologic manifestations in PA.

RESULTS

We report on three cases, two women and a man, presenting with ischemic or hemorrhagic stroke, of early onset in two of them. All of the reported patients had hypertension and hypokaliemia. This association prompted the assessment of renin angiotensin aldosterone system (RAAS) disclosing PA, which was due to bilateral adenomas in the first one or bilateral adrenal hyperplasia in the two others. All patients refused the surgical option and received spironolactone with recurrence of stroke in one of them due to treatment incompliance.

CONCLUSION

Although cerebrovascular events are quite common in PA, their occurrence as initial feature can be misleading. The association of hypokaliemia and refractory hypertension in ischemic or hemorrhagic strokes should prompt an assessment of the RAAS to rule out PA and initiate adequate management as soon as possible in order to avoid further complications.

SFE/SFHTA/AFCE primary aldosteronism consensus: Introduction and handbook

The French Endocrinology Society (SFE) French Hypertension Society (SFHTA) and Francophone Endocrine Surgery Association (AFCE) have drawn up recommendations for the management of primary aldosteronism (PA), based on an analysis of the literature by 27 experts in 7 work-groups. PA is suspected in case of hypertension associated with one of the following characteristics: severity, resistance, associated hypokalemia, disproportionate target organ lesions, or adrenal incidentaloma with hypertension or hypokalemia. Diagnosis is founded on aldosterone/renin ratio (ARR) measured under standardized conditions. Diagnostic thresholds are expressed according to the measurement units employed. Diagnosis is established for suprathreshold ARR associated with aldosterone concentrations >550pmol/L (200pg/mL) on 2 measurements, and rejected for aldosterone concentration<240pmol/L (90pg/mL) and/or subthreshold ARR. The diagnostic threshold applied is different if certain medication cannot be interrupted. In intermediate situations, dynamic testing is performed. Genetic forms of PA are screened for in young subjects and/or in case of familial history. The patient should be informed of the results expected from medical and surgical treatment of PA before exploration for lateralization is proposed. Lateralization is explored by adrenal vein sampling (AVS), except in patients under 35 years of age with unilateral adenoma on imaging. If PA proves to be lateralized, unilateral adrenalectomy may be performed, with adaptation of medical treatment pre- and postoperatively. If PA is non-lateralized or the patient refuses surgery, spironolactone is administered as first-line treatment, replaced by amiloride, eplerenone or calcium-channel blockers if insufficiently effective or poorly tolerated.