Diagnosis and treatment of primary aldosteronism: practical clinical perspectives

Higher prevalence of metabolic disorders in patients with bilateral primary aldosteronism than unilateral primary aldosteronism

OBJECTIVE

Metabolic syndrome (MetS) is a frequent clinical condition in hypertension patients and is more frequently reported in primary aldosteronism (PA). This study is aimed at investigating the prevalence of MetS and its components in the two major types of patients with adrenal venous sampling (AVS)-confirmed unilateral PA and bilateral PA.

DESIGN AND PATIENTS

This was a retrospective cross-section study. We analysed metabolic parameters from 169 PA patients subtyped by AVS, including 85 unilateral PA patients and 84 bilateral PA patients, and we also included 169 non-PA patients matched for age and sex.

RESULTS

Patients with unilateral PA had higher concentrations of aldosterone and lower serum potassium than patients with bilateral PA. However, patients with bilateral PA had higher prevalence of MetS (79.8% vs 64.7%, P = .029), obesity (40.5% vs 24.7%, P = .029), dyslipidemia (72.6% vs 55.3%, P = .019) and hyperglycaemia (29.8% vs 16.5%, P = .040) than those with unilateral PA. Meanwhile, bilateral PA had higher BMI (27.55 ± 4.58 vs 25.57 ± 3.28 kg/m² , P = .001), waist circumference (98.54 ± 11.44 vs 93.32 ± 10.64 cm, P = .003) and fasting plasma glucose (4.98 ± 1.16 vs 4.64 ± 0.93 mmol/L, P = .034). The logistic regression analysis also showed that bilateral PA was associated with the presence of MetS after adjustment for age, sex and duration of hypertension.

CONCLUSIONS

Patients with bilateral PA have a higher prevalence of MetS than those with unilateral PA, despite unilateral PA patients exhibiting higher concentrations of aldosterone and lower serum potassium, suggesting that unilateral PA and bilateral PA may have differing mechanisms of MetS.

Surgical Outcomes of Aldosterone-Producing Adenoma on the Basis of the Histopathological Findings

INTRODUCTION

Previous studies on the surgical outcomes of aldosterone-producing adenoma (APA) patients were mainly based on the histopathological diagnosis of HE staining or adrenal venous sampling (AVS) instead of the functional pathology. The aim of the present study was to evaluate the surgical outcomes of APA patients based on the functional pathological diagnosis of APA according to HISTALDO (histopathology of primary aldosteronism) consensus.

METHODS

Clinical data of 137 patients with suspected APA were analyzed retrospectively. All patients had hypertension and spontaneous hypokalemia. In all patients, CT showed a unilateral solitary hypodense adrenal lesion, and a contralateral adrenal gland of normal morphology. Tumors were removed and immunostained for CYP11B2, and their pathology were identified based on HISTALDO consensus. Patients were followed up 6 to 24 months after operation.

RESULTS

Among 137 cases of presumptive APA diagnosed by CT, 130 (95%) cases were pathologically diagnosed with classical pathology, including 123 APA(90%) and 7 aldosterone-producing nodule (APN) (5%). 7 cases (5%) had non-functioning adenoma (NFA) with aldosterone-producing micronodule (APM) or multiple aldosterone-producing micronodule (MAPM) in the surrounding adrenal tissue. In all 137 patients, hypertension was complete or partial clinical success postoperatively. Complete clinical success was achieved in 73 (53%), and partial clinical success was achieved in 64 (47%) cases. Serum potassium level recovered to normal in all. In 123 patients with APA, complete clinical success was reached in 67 (54%), and partial clinical success was reached in 56 (46%) cases. Gender, duration of hypertension and the highest SBP were significant independent predictors for cure of APA after surgery. A multiple logistic regression model integrating the three predictors was constructed to predict the outcome, which achieved a sensitivity of 72.4% and a specificity of 73.1%.

CONCLUSION

The specificity of CT in the diagnosis of APA and APN patients with hypokalemia was 95%. All patients achieved complete or partial clinical success after surgery. Gender, duration of hypertension and the highest SBP were independent predictors for the postoperative cure of APA.

Primary aldosteronism: Higher volume load, cardiac output and arterial stiffness than in essential hypertension

BACKGROUND

The diagnostics of primary aldosteronism (PA) are usually carried out in patients taking antihypertensive medications. We compared haemodynamics between medicated PA, medicated essential hypertension (EH), never-medicated EH and normotensive controls (n = 130 in all groups).

METHODS

The hypertensive groups were matched for age (53 years), sex (84 male/46 female) and body mass index (BMI) (30 kg m^-2 ); normotensive controls had similar sex distribution (age 48 years, BMI 27 kg m^-2 ). Haemodynamics were recorded using whole-body impedance cardiography and radial pulse wave analysis, and the results were adjusted as appropriate. Radial blood pressure recordings were calibrated by brachial blood pressure measurements from the contralateral arm.

RESULTS

Radial and aortic systolic and diastolic blood pressure was similar in PA and never-medicated EH, and higher than in medicated EH and normotensive controls (P ≤ 0.001 for all comparisons). Extracellular water balance was ~ 4% higher in PA than in all other groups (P < 0.05 for all), whilst cardiac output was ~ 8% higher in PA than in medicated EH (P = 0.012). Systemic vascular resistance and augmentation index were similarly increased in PA and both EH groups when compared with controls. Pulse wave velocity was higher in PA and never-medicated EH than in medicated EH and normotensive controls (P ≤ 0.033 for all comparisons).

CONCLUSIONS

Medicated PA patients presented with corresponding systemic vascular resistance and wave reflection, but higher extracellular water volume, cardiac output and arterial stiffness than medicated EH patients. Whether the systematic evaluation of these features would benefit the clinical diagnostics of PA remains to be studied in future.

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.

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

OBJECTIVE

Mineralocorticoid receptor antagonists (MRAs) are effective in patients with resistant hypertension and/or primary aldosteronism (PA). Screening for PA should ideally be conducted after stopping medications that might interfere with the renin-angiotensin-aldosterone system, but this is challenging in patients with recalcitrant hypertension or hypokalemia. Herein, we aimed to evaluate the impact of MRAs on PA screening in clinical practice.

METHODS

We conducted a retrospective cohort study of patients with hypertension who had plasma aldosterone and renin measurements before and after MRA use in a tertiary referral center, over 19 years.

RESULTS

A total of 146 patients, 91 with PA, were included and followed for up to 18 months. Overall, both plasma renin and aldosterone increased after MRA initiation (from median, interquartile range: 0.5 [0.1, 0.8] to 1.2 [0.6, 4.8] ng/mL/hour and from 19.1 [12.9, 27.7] to 26.4 [17.1, 42.3] ng/dL, respectively; P<.0001 for both), while the aldosterone/renin ratio (ARR) decreased from 40.3 (18.5, 102.7) to 23.1 (8.6, 58.7) ng/dL per ng/mL/hour (P<.0001). Similar changes occurred irrespective of the MRA treatment duration and other antihypertensives used. Positive PA screening abrogation after MRA initiation was found in 45/94 (48%) patients. Conversely, 17% of patients had positive PA screening only after MRA treatment, mostly due to correction of hypokalemia. An initially positive screening test was more likely altered by high MRA doses and more likely persistent in patients with confirmed PA or taking beta-blockers.

CONCLUSION

MRAs commonly reduce ARR and the proportion of positive PA screening results. When PA is suspected, screening should be repeated off MRAs.

ABBREVIATIONS

ACEI = angiotensin-converting enzyme inhibitor; ARB = angiotensin receptor blocker; ARR = aldosterone/renin ratio; DRC = direct renin concentration; MRA = mineralocorticoid receptor antagonist; PA = primary aldosteronism; PAC = plasma aldosterone concentration; PRA = plasma renin activity; RAAS = renin-angiotensin-aldosterone system.

Functional imaging with 11C-metomidate PET for subtype diagnosis in primary aldosteronism

OBJECTIVE

Endocrine Society guidelines recommend adrenal venous sampling (AVS) in primary aldosteronism (PA) if adrenalectomy is considered. We tested whether functional imaging of adrenal cortex with 11C-metomidate (11C-MTO) could offer a noninvasive alternative to AVS in the subtype classification of PA.

DESIGN

We prospectively recruited 58 patients with confirmed PA who were eligible for adrenal surgery.

METHODS

Subjects underwent AVS and 11C-MTO-PET without dexamethasone pretreatment in random order. The lateralization of 11C-MTO-PET and adrenal CT were compared with AVS in all subjects and in a prespecified adrenalectomy subgroup in which the diagnosis was confirmed with immunohistochemical staining for CYP11B2.

RESULTS

In the whole study population, the concordance of AVS and 11C-MTO-PET was 51% and did not differ from that of AVS and adrenal CT (53%). The concordance of AVS and 11C-MTO-PET was 55% in unilateral and 44% in bilateral PA. In receiver operating characteristics analysis, the maximum standardized uptake value ratio of 1.16 in 11C-MTO-PET had an AUC of 0.507 (P = n.s.) to predict allocation to adrenalectomy or medical therapy with sensitivity of 55% and specificity of 44%. In the prespecified adrenalectomy subgroup, AVS and 11C-MTO-PET were concordant in 10 of 19 subjects with CYP11B2-positive adenoma and in 6 of 10 with CYP11B2-positivity without an adenoma.

CONCLUSIONS

The concordance of 11C-MTO-PET with AVS was clinically suboptimal, and did not outperform adrenal CT. In a subgroup with CYP11B2-positive adenoma, 11C-MTO-PET identified 53% of cases. 11C-MTO-PET appeared to be inferior to AVS for subtype classification of PA.

[Primary aldosteronism: The Mayo Clinic approach]

Primary aldosteronism (PA) is the most common reason of secondary hypertension, that can be cured surgically or treated with targeting medical treatment. In many cases PA is not diagnosed on time, leading to aldosterone-specific cardiovascular and nephritic lesions. Effective methods of treatment make it reasonable to perform case detection testing for PA at least once in all patients with hypertension. Mayo Clinic approach is aimed to simplify primary case detection testing. There is no need to use plasma aldosterone concentration/plasma renin activity ratio, all tests can be completed, whilst the patient is taking antihypertensive and other medications. The next step is confirmatory testing. The choice of pharmacological or surgical therapy depends on the results of computed tomography scans of the adrenal glands and adrenal venous sampling. The last one is performed only after discussing with patient the advantages and disadvantages of all therapy methods and positive intention to surgery. Laparoscopic unilateral adrenalectomy is the procedure of choice in patients with unilateral adrenal disease. In patients with bilateral aldosterone hypersecretion, the optimal is a low-sodium diet and lifelong treatment with a mineralocorticoid receptor antagonist administered at a dosage to reach a high-normal serum potassium concentration.

Aldosterone-to-renin ratio is related to arterial stiffness when the screening criteria of primary aldosteronism are not met

Aldosterone-to-renin ratio (ARR) is a screening tool for primary aldosteronism (PA), but the significance of ARR when the PA criteria are not met remains largely unknown. In this cross-sectional study we investigated the association of ARR with haemodynamic variables in 545 normotensive and never-medicated hypertensive subjects (267 men, 278 women, age range 19-72 years) without suspicion of PA. Supine haemodynamic data was recorded using whole-body impedance cardiography and radial tonometric pulse wave analysis. In sex-adjusted quartiles of ARR, determined as serum aldosterone to plasma renin activity ratio, the mean values were 282, 504, 744 and 1467 pmol/µg of angiotensin I/h, respectively. The only difference in haemodynamic variables between the ARR quartiles was higher pulse wave velocity (PWV) in the highest quartile versus other quartiles (p = 0.004), while no differences in blood pressure (BP), heart rate, wave reflections, cardiac output or systemic vascular resistance were observed between the quartiles. In linear regression analysis with stepwise elimination, ARR was an independent explanatory factor for PWV (β = 0.146, p < 0.001, R2 of the model 0.634). In conclusion, ARR was directly and independently associated with large arterial stiffness in individuals without clinical suspicion of PA. Therefore, ARR could serve as a clinical marker of cardiovascular risk.Trial registration: ClinicalTrails.gov: NCT01742702.

Diagnostic value of parameters from a spot urine sample for renal potassium loss in hypokalemia

BACKGROUND

We assessed the value of 1) a spot urine test for diagnosing hypokalemia caused by renal potassium loss, and 2) actual 24-hour urine potassium excretion (24 hUK-actual) for diagnosing hypokalemia caused by renal potassium loss in patients treated with potassium supplementation. The study population was from Southwest China.

METHODS

Patients with hypokalemia were divided into 2 groups: hypokalemia caused by renal potassium loss (n = 67) and hypokalemia caused by extrarenal potassium loss (n = 63). Urine potassium concentration (UK), urine creatinine concentration (UCr), urine potassium-creatinine ratio (UK/UCr), fractional excretion of potassium (FEK), transtubular potassium concentration gradient (TTKG), and 24-h urine potassium excretion (24 hUK-calculated) were derived from spot urine samples collected on admission, before initiation of therapy. Patients received intravenous potassium chloride 0.4 or 0.6 g/h. 24 hUK-actual was detected in patients whose serum potassium did not return to normal after 24 h of therapy.

RESULTS

Patients with hypokalemia caused by renal potassium loss had significantly higher UK, UK/UCr, FEK, TTKG and 24 hUK-calculated compared to patients with hypokalemia caused by extrarenal potassium loss (P < 0.05). FEK predicted renal potassium loss in hypokalemia with high accuracy at a cut-off of 9.29% (sensitivity, 80.6%; specificity, 85.7%). The area under the curve for 24 hUK-actual in predicting renal potassium loss in patients with hypokalemia treated with low or high-dose potassium chloride infusion were 0.939 or 0.956, respectively. On the spot urine test, FEK showed the highest correlation with 24 hUK-actual during low or high dose potassium chloride infusion (r = 0.831, p < 0.001 or r = 0.764, p < 0.001).

CONCLUSIONS

FEK from a spot urine sample represents a convenient and reliable parameter to predict renal potassium loss in patients with hypokalemia.

Endocrine Causes of Hypertension

PURPOSE OF REVIEW

To discuss selected endocrine causes of hypertension and to provide practical clinical recommendations regarding the evaluation and treatment of these disorders.

RECENT FINDINGS

More than 15 endocrine disorders with varying rates of prevalence can cause hypertension. For example, primary aldosteronism may exist in up to 20% of patients with resistant hypertension. Recognition of these important secondary causes of hypertension is essential to provide contemporary targeted therapies in order to improve long-term disease outcomes. Clinicians must have a broad understanding of the prevalence, clinical presentation, and current diagnostic modalities for endocrine causes of hypertension to facilitate prompt referral, identification, and optimal management of these disorders. Endocrine causes of hypertension are multifactorial and, in some cases, widely prevalent. It is important for clinicians considering secondary causes of hypertension to be knowledgeable about the underlying pathophysiology of these disorders and to understand when additional evaluation and treatment may be needed.

Pathogenesis and treatment of primary aldosteronism

Early diagnosis and appropriate treatment of primary aldosteronism, the most frequent cause of secondary hypertension, are crucial to prevent deleterious cardiovascular outcomes. In the past decade, the discovery of genetic abnormalities responsible for sporadic and familial forms of primary aldosteronism has improved the knowledge of the pathogenesis of this disorder. Mutations in genes encoding ion channels and pumps lead to increased cytosolic concentrations of calcium in zona glomerulosa cells, which triggers CYP11B2 expression and autonomous aldosterone production. Improved understanding of the mechanisms underlying the disease is key to improving diagnostics and to developing and implementing targeted treatments. This Review provides an update on the genetic abnormalities associated with sporadic and familial forms of primary aldosteronism, their frequency among different populations and the mechanisms explaining excessive aldosterone production and adrenal nodule development. The possible effects and uses of these findings for improving the diagnostics for primary aldosteronism are discussed. Furthermore, current treatment options of primary aldosteronism are reviewed, with particular attention to the latest studies on blood pressure and cardiovascular outcomes following medical or surgical treatment. The new perspectives regarding the use of targeted drug therapy for aldosterone-producing adenomas with specific somatic mutations are also addressed.

Genetics, prevalence, screening and confirmation of primary aldosteronism: a position statement and consensus of the Working Group on Endocrine Hypertension of The European Society of Hypertension

: Autonomous aldosterone overproduction represents the underlying condition of 5-10% of patients with arterial hypertension and carries a significant burden of mortality and morbidity. The diagnostic algorithm for primary aldosteronism is sequentially based on hormonal tests (screening and confirmation tests), followed by lateralization studies (adrenal CT scanning and adrenal venous sampling) to distinguish between unilateral and bilateral disease. Despite the recommendations of the Endocrine Society guideline, primary aldosteronism is largely underdiagnosed and undertreated with high between-centre heterogeneity. Experts from the European Society of Hypertension have critically reviewed the available literature and prepared a consensus document constituting two articles to summarize current knowledge on the epidemiology, diagnosis, treatment, and complications of primary aldosteronism.

The Concordance Between Imaging and Adrenal Vein Sampling Varies With Aldosterone-Driver Somatic Mutation

BACKGROUND

Correct subtyping of primary aldosteronism (PA) is critical for guiding clinical management. Adrenal imaging is less accurate than adrenal vein sampling (AVS); nonetheless, AVS is invasive, technically challenging, and scarcely available.

OBJECTIVE

To identify predictors of concordance between cross-sectional imaging and lateralized AVS in patients with PA that could help circumvent AVS in a subset of patients.

METHODS

We retrospectively studied all patients with PA who underwent AVS in a tertiary referral center from 2009 to 2019. AVS was performed before and after cosyntropin stimulation. Patients with lateralized AVS in at least one condition were included. Aldosterone synthase-guided next-generation sequencing was performed on available adrenal tissue. Logistic regression was implemented to identify predictors of imaging-AVS lateralization concordance.

RESULTS

A total of 234 patients (62% men), age 20 to 79 years, 73% white, 23% black, and 2% Asian were included. AVS lateralization was found: 1) both pre- and post-cosyntropin (Uni/Uni) in 138 patients; 2) only at baseline (Uni/Bi) in 39 patients; 3) only after cosyntropin stimulation (Bi/Uni) in 29 patients. Catheterization partially failed in 28 patients. AVS-imaging agreement was higher in patients with KCNJ5 versus other aldosterone-driver somatic mutations (90.3% versus 64.6%; P < 0.001); in Asian and white versus black Americans (75%, 70%, and 36%, respectively); in younger patients; and those with left adrenal nodules and contralateral suppression. Conversely, AVS-imaging agreement was lowest in Uni/Bi patients (38% vs. 69% in Uni/Uni, and 62% in Bi/Uni; P = 0.007).

CONCLUSIONS

While AVS-imaging agreement is higher in young white and Asian patients, who have KCNJ5-mutated aldosterone producing adenomas, no predictor confers absolute imaging accuracy.

Subtype diagnosis, treatment, complications and outcomes of primary aldosteronism and future direction of research: a position statement and consensus of the Working Group on Endocrine Hypertension of the European Society of Hypertension

: Primary aldosteronism is a frequent cause of secondary hypertension requiring a specific pharmacological treatment with mineralocorticoid receptor antagonist or with unilateral adrenalectomy. These treatments have shown to reduce the excess of cardiovascular risk characteristically associated with this disease. In part I of this consensus, we discussed the procedures for the diagnosis of primary aldosteronism. In the present part II, we address the strategies for the differential diagnosis of primary aldosteronism subtypes and therapy. We also discuss the evaluation of outcomes and provide suggestions for follow-up as well as cardiovascular and metabolic complications specifically associated with primary aldosteronism. Finally, we analyse the principal gaps of knowledge and future challenges for research in this field.

In the Refractory Hypertension “Labyrinth”. Focus on Primary Hyperaldosteronism

Primary hyperaldosteronism is an existence of a functional autonomous source with increased aldosterone production (full or partial) in relation to the renin-angiotensin system. Increased production of aldosterone by the adrenal cortex is the most common form of a secondary hypertension despite the low attention of internists to the problem. The success of a treatment and a prognosis of these patients depend on correct choice of screening (aldosterone/renin ratio) and clarifying diagnostic methods. There are clear algorithms for conducting these tests in accordance with Russian and International recommendations in the respective groups of patients. The purpose of this case report is to demonstrate the long way to diagnosis of primary hyperaldosteronism in a young patient with refractory hypertension, right adrenal adenoma, and clinical (convulsions, weakness) and laboratory signs of hypokalemia. It should not only have made the diagnosis easy, but it could have also absolutely justified the surgical tactics. Unfortunately, the final verification of the disease by carrying out a saline test was accomplished 13 years after the debut of hypertension and 10 years after the primary visualization of the adrenal adenoma.

Adrenal artery ablation for primary aldosteronism without apparent aldosteronoma: An efficacy and safety, proof-of-principle trial

Primary aldosteronism (PA) is associated with resistant hypertension and cardiovascular events. There are some limitations of current medical and surgical therapies for PA. To determine the efficacy and safety of catheter-based adrenal artery ablation for treatment of PA patients who refused both surgery and medical therapy, we performed this prospective cohort study. Thirty-six PA patients without apparent aldosteronoma were treated by adrenal artery ablation. Primary outcome was postoperative blood pressure and defined daily dose (DDD) of antihypertensive medications after adrenal ablation. Secondary outcome was biochemical success. We assessed outcomes based on Primary Aldosteronism Surgical Outcome (PASO) criteria. Adrenal CT scan, biochemical evaluation, adrenal artery ablation and adrenal venous sampling (AVS) were underwent. After adrenal ablation, complete clinical success (normotension without antihypertensive medication) was achieved in 9/36 (25.0%) patients and partial clinical success (reduction in blood pressure or less antihypertensive medication) in 13/36 (36.1%) patients. Complete biochemical success (correction of hypokalemia and normalization of aldosterone-to-renin ratio) was achieved in 16/36 (44.4%) patients. Office-based and ambulatory blood pressures were reduced by 17/7 and 11/2 mmHg at 6 months after ablation, respectively. The plasma cortisol level in the ablation group decreased slightly, but no patient developed hypoadrenocorticism. Catheter-based adrenal ablation appears to produce substantial and sustained blood pressure reduction and biochemical improvement, with only minor adverse events in PA patients without apparent aldosteronoma. This therapy could be an important supplement for current PA treatments.

Adrenal vein sampling for primary aldosteronism: a 15-year national referral center experience

Background

Adrenal vein sampling (AVS) is essential for diagnostics of primary aldosteronism, distinguishing unilateral from bilateral disease and determining treatment options. We reviewed the performance of AVS for primary aldosteronism at our center during first 15 years, comparing the initial period to the period after the introduction of a dedicated radiologist. Additionally, AVS outcomes were checked against CT findings and the proportion of operated patients with proven unilateral disease was estimated.

Patients and methods

A retrospective cross-sectional study conducted at the national endocrine referral center included all patients with primary aldosteronism who underwent AVS after its introduction in 2004 until the end of 2018. AVS was performed sequentially during Synacthen infusion. When the ratio of cortisol concentrations from adrenal vein and inferior vena cava was at least 5, AVS was considered successful.

Results

Data from 235 patients were examined (168 men; age 32–73, median 56 years; BMI 18–48, median 30.4 kg/ m²). Average number of annual AVS procedures increased from 7 in the 2004–2011 period to 29 in the 2012–2018 period (p < 0.001). AVS had to be repeated in 10% of procedures; it was successful in 77% of procedures and 86% of patients. The proportion of patients with successful AVS (92% in 2012–2018 vs. 66% in 2004–2011, p < 0.001) and of successful AVS procedures (82% vs. 61%, p < 0.001) was statistically significantly higher in the recent period.

Conclusions

Number of AVS procedures and success rate at our center increased over time. Introduction of a dedicated radiologist and technical advance expanded and improved the AVS practice.

A speckle tracking echocardiographic study on right ventricular function in primary aldosteronism

OBJECTIVE

We investigated right ventricular function using speckle tracking echocardiography (STE) in patients with primary aldosteronism.

METHODS

Our study included 51 primary aldosteronism patients and 50 age and sex-matched primary hypertensive patients. We performed two-dimensional echocardiography to measure cardiac structure and function. We performed STE offline analysis on right ventricular four-chamber (RV4CLS) and free wall longitudinal strains (RVFWLS).

RESULTS

Primary aldosteronism patients, compared with primary hypertensive patients, had a significantly (P ≤ 0.045) greater left ventricular mass index (112.0 ± 22.6 vs. 95.8 ± 18.5 g/m) and left atrial volume index (26.9 ± 6.0 vs. 24.7 ± 5.6 ml/m) and higher prevalence of left ventricular concentric hypertrophy (35.3 vs. 12.0%), although they had similarly normal left ventricular ejection fraction (55-77%). Primary aldosteronism patients also had a significantly (P ≤ 0.047) larger right atrium and ventricle, lower tricuspid annular plane systolic excursion, and higher E/E't (the peak early filling velocity of trans-tricuspid flow to the peak early filling velocity of lateral tricuspid annulus ratio), estimated pulmonary arterial systolic pressure and right ventricular index of myocardial performance. On the right ventricular strain analysis, primary aldosteronism patients had a significantly (P < 0.001) lower RV4CLS (-18.1 ± 2.5 vs. -23.3 ± 3.4%) and RVFWLS (-21.7 ± 3.7 vs. -27.9 ± 4.5%) than primary hypertensive patients. Overall, RV4CLS and RVFWLS were significantly (r = -0.58 to -0.41, P < 0.001) correlated with plasma aldosterone concentration and 24-h urinary aldosterone excretion. After adjustment for confounding factors, the associations for RV4CLS and RVFWLS with 24-h urinary aldosterone excretion remained significant (P < 0.001), with a standardized coefficient of -0.48 and -0.55, respectively.

CONCLUSION

In addition to left ventricular abnormalities, primary aldosteronism patients also show impaired right ventricular function, probably because of hyperaldosteronism.

Developments in Primary Aldosteronism Subtyping Using Steroid Profiling

Adrenal venous sampling is the standard of care for identifying patients with unilateral primary aldosteronism, which is often caused by an aldosterone producing adenoma and can be cured with surgery. The numerous limitations of adrenal venous sampling, including its high cost, scarce availability, technical challenges, and lack of standardized protocols, have driven efforts to develop alternative, non-invasive tools for the diagnosis of aldosterone producing adenomas. Seminal discoveries regarding the pathogenesis of aldosterone producing adenomas made over the past decade have leveraged hypotheses-driven research of steroid phenotypes characteristic of various aldosterone producing adenomas. In parallel, the expanding availability of mass spectrometry has enabled the simultaneous quantitation of many steroids in single assays from small volume biosamples. Steroid profiling has contributed to our evolving understanding about the pathophysiology of primary aldosteronism and its subtypes. Herein, we review the current state of knowledge regarding the application of multi-steroid panels in assisting with primary aldosteronism subtyping.

The 2020 Italian Society of Arterial Hypertension (SIIA) practical guidelines for the management of primary aldosteronism

Background and aim

Considering the amount of novel knowledge generated in the last five years, a team of experienced hypertensionlogists was assembled to furnish updated clinical practice guidelines for the management of primary aldosteronism.

Methods

To identify the most relevant studies, the authors utilized a systematic literature review in international databases by applying the PICO strategy, and then they were required to make use of only those meeting predefined quality criteria. For studies of diagnostic tests, only those that fulfilled the Standards for Reporting of Diagnostic Accuracy recommendations were considered.

Results

Each section was jointly prepared by at least two co-authors, who provided Class of Recommendation and Level of Evidence following the American Heart Association methodology. The guidelines were sponsored by the Italian Society of Arterial Hypertension and underwent two rounds of revision, eventually reexamined by an External Committee. They were presented and thoroughly discussed in two face-to-face meetings with all co-authors and then presented on occasion of the 36th Italian Society of Arterial Hypertension meeting in order to gather further feedbacks by all members. The text amended according to these feedbacks was subjected to a further peer review.

Conclusions

After this process, substantial updated information was generated, which could simplify the diagnosis of primary aldosteronism and assist practicing physicians in optimizing treatment and follow-up of patients with one of the most common curable causes of arterial hypertension.

New advances in the diagnosis of primary aldosteronism

Primary aldosteronism (PA) is a common form of endocrine hypertension. The diagnostic process of PA includes a screening test, confirmatory test, and subtype classification. In this review, we have summarized the latest advances in the diagnosis of PA with regard to screening and confirmatory tests and provided some recommendations to improve clinical practice.

Role of Aldosterone and Potassium Levels in Sparing Confirmatory Tests in Primary Aldosteronism

CONTEXT

The current clinical guidelines suggest that confirmatory tests for primary aldosteronism (PA) may be excluded in some of patients who have elevated plasma aldosterone concentration (PAC) under plasma renin suppression. However, this has low-priority evidence and is under debate in use of serum potassium.

OBJECTIVE

This study aimed to investigate an appropriate setting for sparing confirmatory tests in PA.

DESIGN AND SETTING

A retrospective cross-sectional study in a single referral center.

PARTICIPANTS

This study included 327 patients who had hypertension under plasma renin suppression and underwent the captopril challenge test (CCT) between January 2007 and April 2019. CCT results were used to diagnose PA.

MAIN OUTCOME MEASURE

Diagnostic value of PAC and serum potassium in confirmation of PA.

RESULTS

Of the studied patients, 252 of 327 (77%) were diagnosed with PA. All 61 patients with PAC > 30 ng/dL were diagnosed with PA. In patients with PAC between 20 and 30 ng/dL, 44 of 55 (80%) were diagnosed with PA, while all 26 with PAC between 20 to 30 ng/dL who had spontaneous hypokalemia were diagnosed with PA. The proportion of unilateral PA determined by adrenal vein sampling (AVS) was higher in patients who had PAC > 30 ng/dL or those with spontaneous hypokalemia who had PAC between 20 and 30 ng/dL than those who did not meet the criteria (76% vs. 17%, P < .001).

CONCLUSION

Confirmatory tests in PA could be spared in patients who have typical features of PA and these patients had a high probability of unilateral PA on AVS.

Primary aldosteronism: Treatment of the disease, and new therapeutic approaches

Primary aldosteronism is currently considered to represent 5-13% of hypertension, yet fewer than 1% of patients with the disorder are ever diagnosed and treated. Current management of patients screened and confirmed positive for primary aldosteronism involves imaging, and with very few exceptions adrenal venous sampling to lateralize (or not) hyperaldosteronism. Unilateral disease is treated by adrenalectomy: bilateral disease by mineralocorticoid receptor antagonists and conventional antihypertensives as/if required. New therapeutic approaches include (i) routine screening on first presentation for hypertension; (ii) harmonisation of cut-offs for renin and aldosterone, plus use of 24-h urinary rather than spot plasma values for the latter; (iii) adoption of a dexamethasone enhanced seated saline suppression test for confirmation exclusion; (iv) enhanced imaging and steroid profiles as partial replacement for adrenal venous sampling; and finally (v), inclusion of low dose spironolactone in first-line therapy for hypertension.

Prevalence, diagnosis and outcomes of treatment for primary aldosteronism

Primary aldosteronism (PA) is the most common potentially curable form of hypertension. The overproduction of aldosterone leads to an increased risk of cardiovascular and cerebrovascular events as well as adverse effects to the heart and kidney and psychological disorders. PA is mainly caused by unilateral aldosterone excess due to an aldosterone-producing adenoma or bilateral excess due to bilateral adrenocortical hyperplasia. The diagnostic work-up of PA comprises three steps: screening, confirmatory testing and differentiation of unilateral surgically-correctable forms from medically treated bilateral PA. These specific treatments can mitigate or reverse the increased risks associated with PA. Herein we summarise the prevalence, outcomes and current and future clinical approaches for the diagnosis of primary aldosteronism.

Unilateral primary aldosteronism as an independent risk factor for vertebral fracture

CONTEXT

Primary aldosteronism (PA) is known to increase vertebral fracture (VF), although the detailed mechanism remains to be elucidated. We hypothesized that the PA subtype is associated with VF.

OBJECTIVE

To evaluate whether unilateral PA is associated with the prevalence of VF.

DESIGN

This was a retrospective cross-sectional study in a single referral centre.

PATIENTS

We identified 210 hypertensive patients whose clinical data were available for case-detection results. One hundred and fifty-two patients were diagnosed with PA using captopril challenge tests.

MEASUREMENTS

We measured the prevalence of VF, according to PA subtype.

RESULTS

One hundred thirteen patients with PA were subtype classified by adrenal vein sampling. Of these, 37 patients had unilateral PA, 76 patients had bilateral PA, 58 patients had non-PA; 39 patients with PA were not subtype-classified. Patients with PA had a higher prevalence of VF (29%, 44/152) than those with non-PA (12%, 7/58; P = .011). Moreover, unilateral PA had a higher prevalence of VF (46%, 17/37) than bilateral PA (20%, 15/76; P = .021). There was no significant difference in the prevalence of VF between bilateral PA and non-PA. Unilateral PA was an independent risk factor for VF after adjusting for age and sex (OR: 3.16, 95% confidence interval: 1.12-8.92; P = .017). Among patients with unilateral PA, serum cortisol concentrations after 1-mg dexamethasone suppression test were higher in those with VF (1.32 ± 0.67 g/dL) than those without (0.96 ± 0.33 g/dL; P = .048).

CONCLUSIONS

Unilateral PA is an independent risk factor for VF.

Mass Spectrometry Imaging Establishes 2 Distinct Metabolic Phenotypes of Aldosterone-Producing Cell Clusters in Primary Aldosteronism

Aldosterone-producing adenomas (APAs) are one of the main causes of primary aldosteronism and the most prevalent surgically correctable form of hypertension. Aldosterone-producing cell clusters (APCCs) comprise tight nests of zona glomerulosa cells, strongly positive for CYP11B2 (aldosterone synthase) in immunohistochemistry. APCCs have been suggested as possible precursors of APAs because they frequently carry driver mutations for constitutive aldosterone production, and a few adrenal lesions with histopathologic features of both APCCs and APAs have been identified. Our objective was to investigate the metabolic phenotypes of APCCs (n=27) compared with APAs (n=6) using in situ matrix-assisted laser desorption/ionization mass spectrometry imaging of formalin-fixed paraffin-embedded adrenals from patients with unilateral primary aldosteronism. Specific distribution patterns of metabolites were associated with APCCs and classified 2 separate APCC subgroups (subgroups 1 and 2) indistinguishable by CYP11B2 immunohistochemistry. Metabolic profiles of APCCs in subgroup 1 were tightly clustered and distinct from subgroup 2 and APAs. Multiple APCCs from the same adrenal displayed metabolic profiles of the same subgroup. Metabolites of APCC subgroup 2 were highly similar to the APA group and indicated enhanced metabolic pathways favoring cell proliferation compared with APCC subgroup 1. In conclusion, we demonstrate specific subgroups of APCCs with strikingly divergent distribution patterns of metabolites. One subgroup displays a metabolic phenotype convergent with APAs and may represent the progression of APCCs to APAs.

Long-Term Mortality for Patients of Primary Aldosteronism Compared With Essential Hypertension: A Systematic Review and Meta-Analysis

Background: Consistent evidence have demonstrated that patients with primary aldosteronism (PA) have higher risk of cardiovascular events to patients with essential hypertension (EH). Whether the long-term risk of mortality for PA patients is higher than EH patients is unclear. We aim to compare the long-term mortality of patients with PA to patients with EH. Methods: We searched PubMed, Embase, and Cochrane Central Register of Controlled Trials for eligible studies from inception to 14 Nov 2018. We combined the relative risks (RR) of each included study by random-effect model. The amount of between study heterogeneity was measured by the I² statistic. Results: We totally included six studies with cohort design, including 3,039 PA and 45,495 EH patients. The pooled RRs for patients with PA were 1.97 (95%CI: 1.33, 2.91; P = 0.0007) for a follow-up of 3 years, 0.96 (95%CI: 0.75, 1.23; P = 0.76) for 5 years, 0.86 (95%CI: 0.51, 1.46) for 7.5 years, and 0.95 (95%CI: 0.61, 1.48; P = 0.58) for 10 years. For patients with aldosterone-producing adenomas (APA), evidence of lower risk of long-term mortality was observed. Our sensitivity analysis suggested our results were stable. Conclusions: Current evidence supported a higher risk of mortality for patients with primary aldosteronism at 3 years compared to patients with essential hypertension, however this risk no longer sustains as the follow-up time increased to 5 or more years. Patients with aldosterone-producing adenomas may have lower long-term mortality rate than patients with essential hypertension due to the better recovery of adrenalectomy.

Associations between primary aldosteronism and diabetes, poor bone health, and sleep apnea-what do we know so far?

Primary aldosteronism (PA), the most common cause of secondary hypertension, is a well-recognized condition that can lead to cardiovascular and renal complications. PA is frequently left undiagnosed and untreated, leading to aldosterone-specific morbidity and mortality. In this review we highlight the evidence linking PA with other conditions such as (i) diabetes mellitus, (ii) obstructive sleep apnea, and (iii) bone health, along with clinical implications and proposed underlying mechanisms.

Österreichischer Blutdruckkonsens 2019

Erhöhter Blutdruck bleibt eine Hauptursache von kardiovaskulären Erkrankungen, Behinderung und frühzeitiger Sterblichkeit in Österreich, wobei die Raten an Diagnose, Behandlung und Kontrolle auch in rezenten Studien suboptimal sind. Das Management von Bluthochdruck ist eine häufige Herausforderung für Ärztinnen und Ärzte vieler Fachrichtungen. In einem Versuch, diagnostische und therapeutische Strategien zu standardisieren und letztendlich die Rate an gut kontrollierten Hypertoniker/innen zu erhöhen und dadurch kardiovaskuläre Erkrankungen zu verhindern, haben 13 österreichische medizinische Fachgesellschaften die vorhandene Evidenz zur Prävention, Diagnose, Abklärung, Therapie und Konsequenzen erhöhten Blutdrucks gesichtet. Das hier vorgestellte Ergebnis ist der erste Österreichische Blutdruckkonsens. Die Autoren und die beteiligten Fachgesellschaften sind davon überzeugt, daß es einer gemeinsamen nationalen Anstrengung bedarf, die Blutdruck-assoziierte Morbidität und Mortalität in unserem Land zu verringern.

Molecular Mechanisms of Primary Aldosteronism

Primary aldosteronism (PA) results from excess production of mineralocorticoid hormone aldosterone by the adrenal cortex. It is normally caused either by unilateral aldosterone-producing adenoma (APA) or by bilateral aldosterone excess as a result of bilateral adrenal hyperplasia. PA is the most common cause of secondary hypertension and associated morbidity and mortality. While most cases of PA are sporadic, an important insight into this debilitating disease has been derived through investigating the familial forms of the disease that affect only a minor fraction of PA patients. The advent of gene expression profiling has shed light on the genes and intracellular signaling pathways that may play a role in the pathogenesis of these tumors. The genetic basis for several forms of familial PA has been uncovered in recent years although the list is likely to expand. Recently, the work from several laboratories provided evidence for the involvement of mammalian target of rapamycin pathway and inflammatory cytokines in APAs; however, their mechanism of action in tumor development and pathophysiology remains to be understood.

Three Discrete Patterns of Primary Aldosteronism Lateralization in Response to Cosyntropin During Adrenal Vein Sampling

CONTEXT

Cosyntropin [ACTH (1-24)] stimulation during adrenal vein (AV) sampling (AVS) enhances the confidence in the success of AV cannulation and circumvents intraprocedure hormonal fluctuations. Cosyntropin's effect on primary aldosteronism (PA) lateralization, however, is controversial.

OBJECTIVES

To define the major patterns of time-dependent lateralization, and their determinants, after cosyntropin stimulation during AVS.

METHODS

We retrospectively studied patients with PA who underwent AVS before, 10, and 20 minutes after cosyntropin stimulation between 2009 and 2018. Unilateral (U) or bilateral (B) PA was determined on the basis of a lateralization index (LI) value ≥4 or <4, respectively. Available adrenal tissue underwent aldosterone synthase-guided next-generation sequencing.

RESULTS

PA lateralization was concordant between basal and cosyntropin-stimulated AVS in 169 of 222 patients (76%; U/U, n = 110; B/B, n = 59) and discordant in 53 patients (24%; U/B, n = 32; B/U, n = 21). Peripheral and dominant AV aldosterone concentrations and LI were highest in U/U patients and progressively lower across intermediate and B/B groups. LI response to cosyntropin increased in 27% of patients, decreased in 33%, and remained stable in 40%. Baseline aldosterone concentrations predicted the LI pattern across time (P < 0.001). Mutation status was defined in 61 patients. Most patients with KCNJ5 mutations had descending LI, whereas those with ATP1A1 and ATP2B3 mutations had ascending LI after cosyntropin stimulation.

CONCLUSION

Patients with severe PA lateralized robustly regardless of cosyntropin use. Cosyntropin stimulation reveals intermediate PA subtypes; its impact on LI varies with baseline aldosterone concentrations and aldosterone-driver mutations.

Primary Aldosteronism Diagnosis and Management: A Clinical Approach

Primary aldosteronism used to be considered a rare cause of secondary hypertension. However, accruing evidence indicates that primary aldosteronism is more common than previously recognized. The implications of this increased prevalence are important to public health because autonomous aldosterone production contributes to cardiovascular disease and can be treated in a targeted manner. This article focuses on clinical approaches for diagnosing primary aldosteronism more frequently and earlier in its course, as well as practical treatment objectives to reduce the risk for incident cardiovascular disease.

Primary Aldosteronism and Obstructive Sleep Apnea: A Cross-Sectional Multi-Ethnic Study

The association between primary aldosteronism (PA) and obstructive sleep apnea (OSA) has been a matter of debate. 2016 Endocrine Society guideline recommends screening for PA all hypertensive patients with OSA. We designed a multicenter, multiethnic, cross-sectional study to evaluate the prevalence of PA in patients with OSA and the prevalence of OSA in unselected patients with PA. Two hundred and three patients with OSA (102 whites and 101 Chinese) were screened for PA, and 207 patients with PA (104 whites, 100 Chinese, and 3 of African descent) were screened for OSA by cardiorespiratory polygraphy. Eighteen patients with OSA (8.9%) had PA (11.8% of white and 5.9% of Chinese ethnicity). In patients without other indications for PA screening, the prevalence of PA dropped to 1.5%. The prevalence of OSA in patients with PA was 67.6%, consistent in both white and Chinese patients. A correlation between aldosterone levels and apnea/hypopnea index was observed in white patients with PA (R²=0.225, P=0.016) but not in Chinese patients. Multinomial logistic regression confirmed a significant and independent association between plasma aldosterone levels and moderate to severe OSA diagnosis in white patients (odds ratio, 1.002; P=0.002). In conclusion, aldosterone levels may contribute to the severity of OSA in white patients with hyperaldosteronism, but patients with OSA are not at high risk of PA. Results of the present study challenge the current recommendation of the Endocrine Society guideline that all patients with OSA should be screened for PA, irrespective of the grade of hypertension.

Diverse Responses of Autoantibodies to the Angiotensin II Type 1 Receptor in Primary Aldosteronism

Primary aldosteronism is a common form of endocrine hypertension mainly caused by a unilateral aldosterone-producing adenoma (APA) or bilateral adrenal hyperplasia (BAH). AT1R-Abs (autoantibodies to the angiotensin II type 1 receptor) have been reported in patients with disorders associated with hypertension. Our objective was to assess AT1R-Ab levels in patients with primary aldosteronism (APA, n=40 and BAH, n=40) relative to patients with primary hypertension (n=40), preeclampsia (n=23), and normotensive individuals (n=25). AT1R-Abs in whole sera were measured using 2 different ELISAs which gave contrasting results. A functional cell-based assay was used to quantify activation of the AT1R (angiotensin II type 1 receptor) using whole sera or affinity-purified antibodies in the absence or presence of losartan (a specific AT1R antagonist). Serum samples from all groups displayed different levels of AT1R activation with different responses to losartan. Patients with BAH displayed higher losartan-independent affinity-isolated agonistic AT1R-Ab levels compared with patients with APA (P<0.01) and with normotensive individuals (P<0.0001). In patients with APA, BAH, and primary hypertension combined, higher aldosterone-to-renin ratios and lower plasma renin concentrations were associated with higher compared with lower agonistic AT1R-Ab levels. In patients with primary aldosteronism, higher AT1R-Ab activity was associated with an increased likelihood of a diagnosis of BAH compared with APA and with the presence of adrenal hyperplasia detected by computed tomography. Taken together, these data suggest that agonistic AT1R-Abs may have a functional role in a subgroup of patients with primary aldosteronism.

Primary Aldosteronism: KCNJ5 Mutations and Adrenocortical Cell Growth

Aldosterone-producing adenomas with somatic mutations in the KCNJ5 G-protein-coupled inwardly rectifying potassium channel are a cause of primary aldosteronism. These mutations drive aldosterone excess, but their role in cell growth is undefined. Our objective was to determine the role of KCNJ5 mutations in adrenal cell proliferation and apoptosis. The Ki67 proliferative index was positively correlated with adenoma diameter in aldosterone-producing adenomas with a KCNJ5 mutation (r=0.435, P=0.007), a negative correlation was noted in adenomas with no mutation detected (r=-0.548, P=0.023). Human adrenocortical cell lines were established with stable expression of cumate-inducible wild-type or mutated KCNJ5. Increased cell proliferation was induced by low-level induction of KCNJ5-T158A expression compared with control cells (P=0.009), but increased induction ablated this difference. KCNJ5-G151R displayed no apparent proliferative effect, but KCNJ5-G151E and L168R mutations each resulted in decreased cell proliferation (difference P<0.0001 from control cells, both comparisons). Under conditions tested, T158A had no effect on apoptosis, but apoptosis increased with expression of G151R (P<0.0001), G151E (P=0.008), and L168R (P<0.0001). We generated a specific KCNJ5 monoclonal antibody which was used in immunohistochemistry to demonstrate strong KCNJ5 expression in adenomas without a KCNJ5 mutation and in the zona glomerulosa adjacent to adenomas irrespective of genotype as well as in aldosterone-producing cell clusters. Double immunofluorescence staining for KCNJ5 and CYP11B2 (aldosterone synthase) showed markedly decreased KCNJ5 immunostaining in CYP11B2-positive cells compared with CYP11B2-negative cells in aldosterone-producing adenomas with a KCNJ5 mutation. Together, these findings support the concept that cell growth effects of KCNJ5 mutations are determined by the expression level of the mutated channel.

Feasibility of Screening Primary Aldosteronism by Aldosterone-to-Direct Renin Concentration Ratio Derived from Chemiluminescent Immunoassay Measurement: Diagnostic Accuracy and Cutoff Value

Objectives

Aldosterone-to-plasma renin activity ratio (ARR) derived from traditional radioimmunoassay (RIA) is widely used to detect primary aldosteronism (PA). Recently, aldosterone-to-direct renin concentration ratio (ADRR), which is calculated by direct renin concentration (DRC) measured by chemiluminescent immunoassay (CLIA), is proposed to replace ARR as the screening test method for PA. The purpose of the present study was to estimate the diagnostic accuracy and cutoff value of ADRR as screening test for PA.

Methods

450 hypertensive patients with suspected PA referred to hypertension center of our department were enrolled and underwent screening and confirmatory tests of PA. Plasma renin activity (PRA), DRC, and plasma aldosterone concentration (PAC) were measured by both RIA and CLIA simultaneously during screening and confirmatory test.

Results

386 patients were diagnosed as primary hypertension (PH) and 64 patients as PA. Within-patient correlation between PRA and DRC (r=0.88, P<0.001) and correlation between PAC measured by RIA and CLIA were high (r=0.80, P<0.001). The optimal cutoff value of ADRR was 2.93 (ng/dL)/(mU/L), sensitivity 80.33%, and specificity 92.11%. The optimal cutoff value of ARR was 25.28 (ng/dL)/(ng/mL/h), sensitivity 76.92%, and specificity 93.38%.

Conclusion

The optimal cutoff values of ADRR and ARR for screening PA are defined in this patient cohort with high sensitivity and specificity. Our results are of clinical importance for accelerating the extensive use of ADRR as a screening test for PA in daily practice.

Primary Aldosteronism: Cardiovascular Outcomes Pre- and Post-treatment

PURPOSE OF REVIEW

Primary aldosteronism (PA) is a common form of hypertension characterized by autonomous aldosterone secretion from one or both adrenal glands. The purpose of this review is to synthesize recent research findings regarding cardiovascular disease risk in PA both pre- and post-targeted therapy.

RECENT FINDINGS

Previously considered a rare disease, recent prevalence studies demonstrate that PA is actually a very common, yet vastly under-diagnosed, etiology of hypertension. Prior to targeted therapy, PA is associated with substantially higher rates of cardiovascular disease compared with essential hypertension. Surgical adrenalectomy is highly effective in curing or improving hypertension as well as mitigating cardiovascular disease risk in patients with unilateral PA. For the remainder of PA patients, MR antagonists are recommended; however, several recent studies have brought into question their effectiveness in improving cardiovascular outcomes. PA is a common cause of hypertension that leads to disproportionately high rates of cardiovascular disease. Future studies are needed to enhance the clinical approach to both identification and treatment of patients with PA to optimize long-term cardiovascular outcomes.

The aldosterone to renin ratio in the diagnosis of primary aldosteronism: Promises and challenges

The complexity of evaluating patients for secondary treatable causes of hypertension is underappreciated. Primary aldosteronism (PA) is the most prevalent cause of secondary hypertension (3%-32% of hypertensive patients). The recent endocrine society clinical practice guideline (ESCPG), "The Management of Primary Aldosteronism: Case Detection, Diagnosis, and Treatment", differs from the previous version in the explicit recognition of PA as a major public health issue. Despite this, PA is underdiagnosed. The guidelines call on physicians to substantially ramp up the screening of hypertensive patients at risk of PA. Further, it recommends the plasma aldosterone to renin ratio (ARR), as the test of choice for screening for PA. However, the ARR is a highly variable test with reported diagnostic sensitivities and specificities ranging from 66% to 100% and 61% to 100%, respectively. Variability of the ARR can be attributed to the high degree of within-subject variation, differences in sampling protocols, laboratory assays, reporting units, the effect of medications and the population characteristics used to establish the decision thresholds. These factors render the possibility of false positive and false negative results-which have the potential to adversely impact patients. The limitations and caveats to the use of the ARR necessitate an effective clinic-laboratory interface, with specialist physician and clinical scientist collaboration for ARR result interpretation. Improvement in the diagnostic sensitivity and specificity of the ARR is predicated on harmonisation of pretesting patient preparation criteria, knowledge of the analytical methods used to derive the ratio and the method-specific threshold for PA.

Influence of Adrenal Venous Sampling on Management in Patients with Primary Aldosteronism Independent of Lateralization on Cross-Sectional Imaging

BACKGROUND

Patients with primary aldosteronism undergo imaging of the adrenal glands after confirmation of the disease. Adrenal venous sampling (AVS) is a useful adjunct to imaging, and advocates believe that AVS should be performed before surgical management. Others argue that patients with unilateral lesions on imaging do not require AVS. Although AVS accuracy has been established, few studies have evaluated how AVS alters management. Our study aimed to determine how AVS affected management of these patients.

STUDY DESIGN

Patient data were collected retrospectively from the electronic medical records at a single institution. Patients aged 18 years or older who underwent AVS with successful adrenal vein cannulation from 2007 to 2016 were included. The laterality of AVS was compared with laterality of preprocedural imaging for each patient. The management plan before AVS was determined by laterality on preprocedural imaging. The primary outcomes were management of primary aldosteronism, change in management compared with the plan before AVS, and antihypertensive medication use after therapy.

RESULTS

Seventy-four patients had successful adrenal venous cannulation. Thirty-three (44.6%) patients had AVS lateralization that was concordant with preprocedural imaging. Forty-one (55.4%) patients had AVS lateralization that was non-concordant with preprocedural imaging. There was a change in management in 29 (39.2%) patients.

CONCLUSIONS

Adrenal venous sampling can delineate the source of aldosterone hypersecretion, and often this is not concordant with cross-sectional imaging. We found that many patients avoided a potentially non-curative operation due to AVS. Adrenal venous sampling frequently alters the management of aldosteronomas and should be highly considered in patients before surgical intervention.

Timeline of Advances in Genetics of Primary Aldosteronism

The overwhelming majority of cases of primary aldosteronism (PA) occur sporadically due to a unilateral aldosterone-producing adenoma (APA) or bilateral idiopathic adrenal hyperplasia. Familial forms of PA are rare with four subtypes defined to date (familial hyperaldosteronism types I-IV). The molecular basis of familial hyperaldosteronism type I (FH type I or glucocorticoid-remediable aldosteronism) was established in 1992; two decades later the genetic variant causing FH type III was identified and germline mutations causing FH type IV and FH type II were determined soon after. Effective diagnostic protocols and methods to detect the overactive gland in unilateral PA by adrenal venous sampling followed by laparoscopic adrenalectomy have made available APAs for scientific studies. In rapid succession, following the widespread use of next-generation sequencing, recurrent somatic driver mutations in APAs were identified in genes encoding ion channels and transporters. The development of highly specific monoclonal antibodies against key enzymes in adrenal steroidogenesis has unveiled the heterogeneous features of the diseased adrenal in PA and helped reveal the high proportion of APAs with driver mutations. We discuss what is known about the genetics of PA that has led to a clearer understanding of the disease pathophysiology.