Adrenal Venous Sampling-Guided Adrenalectomy Rates in Primary Aldosteronism: Results of an International Cohort (AVSTAT)

Establishment of a scoring model for predicting clinical outcomes in patients with unilateral primary aldosteronism after superselective adrenal artery embolization

OBJECTIVE

Superselective adrenal arterial embolization (SAAE) is a potential alternative treatment for patients with unilateral primary aldosteronism (PA) who refuse unilateral adrenalectomy. Therefore, we aimed to establish a scoring model to differentiate between hypertensive remission after SAAE.

METHODS

This prospective cohort study involved 240 patients who underwent SAAE for unilateral PA. Patients were randomly divided into a model training set and a validation set at a ratio of 7:3. The clinical outcome was a response to hypertension remission, defined as complete, partial, or absent success at 6 months after SAAE. Multivariate logistic regression was performed to identify independent parameters and develop a nomogram to predict clinical outcomes after SAAE. The discrimination, calibration efficacy, and clinical utility of the predictive model were assessed.

RESULTS

Five independent predictors were identified: female sex, duration of hypertension, defined daily dose of antihypertensive medication, diabetes, and target organ damage. The above five independent predictors were put into a predictive model that was presented as a nomogram. Using bootstrapping for internal validation, the C-statistic for the predictive model was 0.866 (95% confidence interval [CI]: 0.834 to 0.898). In the validation cohort, the area under the curve (AUC) of the nomogram for predicting hypertension remission after SAAE was 0.809.

CONCLUSION

The present model is the first nomogram-based score that specifically predicts hypertension remission after SAAE in patients with unilateral PA using conventional parameters. This is an effective risk stratification tool that can be used by clinicians for timely and tailored preoperative risk discussions.

Practical consensus for the treatment and follow-up of primary aldosteronism: a multidisciplinary consensus document

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension and is associated with a higher cardiometabolic risk than essential hypertension. The aim of this consensus is to provide practical clinical recommendations for its surgical and medical treatment, pathology study and biochemical and clinical follow-up, as well as for the approach in special situations like advanced age, pregnancy and chronic kidney disease, from a multidisciplinary perspective, in a nominal group consensus approach of experts from the Spanish Society of Endocrinology and Nutrition (SEEN), Spanish Society of Cardiology (SEC), Spanish Society of Nephrology (SEN), Spanish Society of Internal Medicine (SEMI), Spanish Radiology Society (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Society of Laboratory Medicine (SEQC(ML)), Spanish Society of Anatomic-Pathology and Spanish Association of Surgeons (AEC).

Urine steroid metabolomics as a diagnostic tool in primary aldosteronism

Primary aldosteronism (PA) causes 5-10% of hypertension cases, but only a minority of patients are currently diagnosed and treated because of a complex, stepwise, and partly invasive workup. We tested the performance of urine steroid metabolomics, the computational analysis of 24-hour urine steroid metabolome data by machine learning, for the identification and subtyping of PA. Mass spectrometry-based multi-steroid profiling was used to quantify the excretion of 34 steroid metabolites in 24-hour urine samples from 158 adults with PA (88 with unilateral PA [UPA] due to aldosterone-producing adenomas [APAs]; 70 with bilateral PA [BPA]) and 65 sex- and age-matched healthy controls. All APAs were resected and underwent targeted gene sequencing to detect somatic mutations associated with UPA. Patients with PA had increased urinary metabolite excretion of mineralocorticoids, glucocorticoids, and glucocorticoid precursors. Urine steroid metabolomics identified patients with PA with high accuracy, both when applied to all 34 or only the three most discriminative steroid metabolites (average areas under the receiver-operating characteristics curve [AUCs-ROC] 0.95-0.97). Whilst machine learning was suboptimal in differentiating UPA from BPA (average AUCs-ROC 0.65-0.73), it readily identified APA cases harbouring somatic KCNJ5 mutations (average AUCs-ROC 0.79-85). These patients showed a distinctly increased urine excretion of the hybrid steroid 18-hydroxycortisol and its metabolite 18-oxo-tetrahydrocortisol, the latter identified by machine learning as by far the most discriminative steroid. In conclusion, urine steroid metabolomics is a non-invasive candidate test for the accurate identification of PA cases and KCNJ5-mutated APAs.

Adrenal Venous Sampling Via an Antecubital Approach in Primary Aldosteronism: A Multicenter Study

CONTEXT

Adrenal venous sampling (AVS) is considered the gold standard for differentiating unilateral and bilateral forms of primary aldosteronism. Currently, almost all AVS procedures are performed via femoral vein access.

OBJECTIVE

The aim of this study was to evaluate the success rate and safety of AVS via an antecubital approach.

METHODS

In a retrospective multicenter study involving 7 Chinese medical centers, patients with primary aldosteronism who underwent AVS via an antecubital approach between January 2012 and December 2018 were analyzed. Successful sampling was determined by a selectivity index (cortisol in the adrenal vein/cortisol in inferior vena cava) greater than 2.

RESULTS

A total of 1226 participants (mean age, 47.1 years; 57.9% male) were included. The puncture site was right and left antecubital vein in 1211 (98.8%), and 15 (1.2%) patients. The access of 6 patients (0.5%) was changed to right femoral vein due to the failure of antecubital vein cannulation or anatomic variation of adrenal vein. The success rate of bilateral, right, and left sampling was 91.5%, 94.9%, and 95.1%, respectively. The success rate of bilateral, right, and left sampling increased from 82.9%, 87.1%, and 88.6% during the initial 70 cases (total of initial 10 cases at each center) to 92.0% (P = .012), 95.3% (P = .008), and 95.5% (P = .018) with subsequent cases. Adrenal vein rupture occurred in 5 patients (0.41%), with no sequelae.

CONCLUSION

This multicenter study demonstrates that AVS via an antecubital approach is safe and feasible, with a high rate of successful sampling, which may be an alternative to the femoral vein access method.

Utility of right adrenal signature veins in venous sampling for primary aldosteronism

BACKGROUND

This study aimed to identify the appropriate signature veins for the right adrenal gland using a 3D model fused with adrenal venography images and to verify their accuracy through the selectivity index (SI) >2.

METHODS

We analyzed the right adrenal venography images of 41 patients who underwent adrenal venous sampling (AVS). These images were merged with a 3D structure of the adrenal gland to identify the signature veins of the right adrenal gland. We then used the signature veins observed during adrenal venography to determine the optimal position of the catheter tip during AVS for 53 other patients. Finally, we verified the accuracy of this method according to the SI.

RESULTS

We successfully fused the 3D models of 41 cases with adrenal venography images. We identified the trunk branch type as the major venous morphology in the right anterior oblique at degrees of 30 (38 cases, 92.7%). In addition, the central vein, brush vein, uvula vein, and capsular vein were identified as signature veins for the right AVS. The accuracy of AVS was 100% in the other 53 patients, as verified by an SI >2.

CONCLUSIONS

Our study identified the right adrenal signature veins, including the previously overlooked uvula vein, which can be used to determine the position of the catheter tip and improve the success rate of AVS.

Discordant imaging: adrenal vein sampling in almost half of patients with primary aldosteronism and a unilateral adrenal adenoma

BACKGROUND

Primary hyperaldosteronism (PHA) is an underdiagnosed cause of secondary hypertension, with an increased risk of cardiovascular and renal complications compared with those with essential hypertension alone. Distinguishing between unilateral and bilateral aldosterone secretion is important as management differs. Adrenal vein sampling (AVS) is the gold standard for determining lateralisation. Current international guidelines suggest AVS may be omitted in those aged <35 years with PHA and a unilateral adrenal adenoma on imaging.

AIM

To characterise all patients referred for AVS at Waitematā District Health Board (WDHB), review the success rate of AVS and compare concordance of AVS with imaging.

METHODS

All patients who underwent AVS in WDHB from January 2015 to September 2020 were retrospectively assessed. Clinical records, laboratory data and radiological findings were reviewed.

RESULTS

Ninety-six patients underwent AVS, with four excluded as private records were unable to be obtained. Of the 92 patients included, age ranged from 22 to 79 years. AVS was successful on first attempt in 89 (96.7%) patients. AVS and imaging findings were concordant in 62.2% of patients. One (14.3%) of seven aged <35 years had discordant results, and 16 (47%) of 34 patients with a unilateral adenoma on imaging had discordant results to AVS.

CONCLUSIONS

AVS at WDHB is successful on first attempt in most patients. AVS is essential in the management of PHA for those deemed to be surgical candidates, regardless of age.

Diagnostic Accuracy of Adrenal Iodine-131 6-Beta-Iodomethyl-19-Norcholesterol Scintigraphy for the Subtyping of Primary Aldosteronism

PURPOSE

To evaluate the diagnostic accuracy of the 131I-6β-iodomethyl-19-norcholesterol (NP-59) adrenal scintigraphy for the subtyping diagnosis of primary aldosteronism (PA), considering as gold standard for the diagnosis of unilateral PA (UPA), either the results of the adrenal venous sampling (AVS) or the outcome after adrenalectomy.

METHODS

A retrospective multicenter study was performed on PA patients from 14 Spanish tertiary hospitals who underwent NP-59 scintigraphy with an available subtyping diagnosis. Patients were classified as UPA if biochemical cure was achieved after adrenalectomy or/and if an AVS lateralization index > 4 with ACTH stimulation or >2 without ACTH stimulation was observed. Patients were classified as having bilateral PA (BPA) if the AVS lateralization index was ≤4 with ACTH or ≤2 without ACTH stimulation or if there was evidence of bilateral adrenal nodules >1 cm in each adrenal gland detected by CT/MRI.

RESULTS

A total of 86 patients with PA were included (70.9% (n = 61) with UPA and 29.1% (n = 25) with BPA). Based on the NP-59 scintigraphy results, 16 patients showed normal suppressed adrenal gland uptake, and in the other 70 cases, PA was considered unilateral in 49 patients (70%) and bilateral in 21 (30%). Based on 59-scintigraphy results, 10.4% of the patients with unilateral uptake had BPA, and 27.3% of the cases with bilateral uptake had UPA. The AUC of the ROC curve of the NP-59 scintigraphy for PA subtyping was 0.812 [0.707-0.916]. Based on the results of the CT/MRI and NP-59 scintigraphy, only 6.7% of the patients with unilateral uptake had BPA, and 24% of the cases with bilateral uptake had UPA. The AUC of the ROC curve of the model combining CT/MRI and 59-scintigraphy results for subtyping PA was 0.869 [0.782-0.957].

CONCLUSION

The results of NP-59 scintigraphy in association with the information provided by the CT/MRI may be useful for PA subtyping. However, their diagnostic accuracy is only moderate. Therefore, it should be considered a second-line diagnostic tool when AVS is not an option.

International multicenter survey on screening and confirmatory testing in primary aldosteronism

OBJECTIVE

Primary aldosteronism (PA) is one of the most frequent causes of secondary hypertension. Although clinical practice guidelines recommend a diagnostic process, details of the steps remain incompletely standardized.

DESIGN

In the present SCOT-PA survey, we have investigated the diversity of approaches utilized for each diagnostic step in different expert centers through a survey using Google questionnaires. A total of 33 centers from 3 continents participated.

RESULTS

We demonstrated a prominent diversity in the conditions of blood sampling, assay methods for aldosterone and renin, and the methods and diagnostic cutoff for screening and confirmatory tests. The most standard measures were modification of antihypertensive medication and sitting posture for blood sampling, measurement of plasma aldosterone concentration (PAC) and active renin concentration by chemiluminescence enzyme immunoassay, a combination of aldosterone-to-renin ratio with PAC as an index for screening, and saline infusion test in a seated position for confirmatory testing. The cutoff values for screening and confirmatory testing showed significant variation among centers.

CONCLUSIONS

Diversity of the diagnostic steps may lead to an inconsistent diagnosis of PA among centers and limit comparison of evidence for PA between different centers. We expect the impact of this diversity to be most prominent in patients with mild PA. The survey raises 2 issues: the need for standardization of the diagnostic process and revisiting the concept of mild PA. Further standardization of the diagnostic process/criteria will improve the quality of evidence and management of patients with PA.

Catheter-based adrenal ablation: an alternative therapy for patients with aldosterone-producing adenoma

Unilateral adrenalectomy is the standard treatment for patients with aldosterone-producing adenoma (APA), but it lacks an option for patients with APA who refuse or are not suitable for surgery. In this study, we studied whether catheter-based adrenal ablation for APA is comparable to adrenalectomy. A total of 2185 hypertensive patients were screened, and 112 patients with APA were recruited and counselled on the treatment options. Fifty-two patients opted for catheter-based adrenal ablation, and 60 opted for adrenalectomy. Clinical and biochemical outcomes were assessed at 6 months after treatment. Factors associated with hypertension remission and the advantages and limitations of this approach were evaluated. According to the primary aldosteronism surgical outcome (PASO) criteria, complete and partial clinical success was achieved in 21 (40.4%) and 23 (44.2%) patients in the ablation group vs. 33 (55.0%) and 23 (38.3%) patients in the adrenalectomy group, respectively. Complete and partial biochemical success was achieved in 30 (57.7%) and 17 (32.7%) patients in the ablation group vs. 51 (85.0%) and 5 (8.3%) patients in the adrenalectomy group, respectively. The complete clinical success rate was not (P > 0.05), but the complete biochemical success rate was significantly different between the two groups (P < 0.01). Factors associated with adrenal ablation-mediated hypertension remission were hypertension duration and serum potassium level at baseline. Compared with surgery, adrenal ablation requires a shorter operating time and time to resume physical activity. Catheter-based adrenal ablation may be an alternative and feasible option for APA patients unwilling to receive surgical treatment.

Adrenal Ablation Versus Mineralocorticoid Receptor Antagonism for the Treatment of Primary Aldosteronism: A Single-Center Prospective Cohort Study

BACKGROUND

Superselective adrenal arterial embolization (SAAE) is an alternative treatment for patients with primary aldosteronism (PA). This single-center prospective cohort study aimed to compare the efficacy of SAAE with mineralocorticoid receptor antagonists (MRA) in treating patients with PA who refused unilateral adrenalectomy.

METHODS

Of the 140 PA patients who were enrolled in the study and completed 12-month follow-up, 74 patients underwent SAAE and 66 received MRA treatment. The clinical and biochemical outcome was compared at 1, 6, and 12 months after the procedure.

RESULTS

Baseline clinical and biochemical characteristics of the patients were similar between groups. Office, home, and ambulatory blood pressure reduction at 1 month after discharge was more pronounced in the SAAE group than MRA group (all P < 0.05) while the blood pressure reduction was comparable between the 2 groups at 6 and 12 months. Patients who underwent SAAE took less antihypertensive medications than the MRA group during 12-month follow-up (P < 0.01). Both SAAE and MRA treatment improved renin suppression, aldosterone-to-renin ratio elevation, and hypokalemia at 6 and 12 months, whereas only SAAE but not MRA reduced plasma aldosterone levels. Moreover, SAAE achieved higher rates of complete clinical and biochemical success than MRA (both P < 0.01). Logistic regression found that complete clinical and biochemical success was only directly associated with diagnosis of unilateral PA in contrast to bilateral PA (P < 0.01).

CONCLUSIONS

The present study provides evidence that SAAE is a reasonable choice of treatment in patients with either unilateral or bilateral PA in terms of clinical and biochemical outcomes. This study was registered at Chictr.org.cn (ChiCTR2100045896).

Cardiovascular outcomes and all-cause mortality in primary aldosteronism after adrenalectomy or mineralocorticoid receptor antagonist treatment: a meta-analysis

BACKGROUND

In patients with primary aldosteronism (PA), long-term cardiovascular and mortality outcomes after adrenalectomy vs mineralocorticoid receptor antagonist (MRA) have not been compared yet. We aim to compare the clinical outcomes of these patients after treatment.

DESIGN AND METHODS

A systematic review and meta-analysis was conducted by searching PubMed, Cochrane library, and Embase from no start date restriction to 18 December 2021. Our composite primary outcomes were long-term all-cause mortality and/or major adverse cardiovascular events (MACE), including coronary artery disease (CAD), stroke, arrhythmia, and congestive heart failure. We adopted the random-effects model and performed subgroup analyses, meta-regression, and trial sequential analysis (TSA).

RESULTS

A total of 9 studies with 8473 adult patients with PA (≥18 years) were enrolled. A lower incidence of composite primary outcomes was observed in the adrenalectomy group (odds ratio (OR): 0.46 (95% CI: 0.38-0.56), P < 0.001). We found a lower incidence of all-cause mortality (OR: 0.33 (95% CI: 0.15-0.73), P = 0.006) and MACE (OR: 0.55, (95% CI: 0.40-0.74), P = 0.0001) in the adrenalectomy group. The incidence of CAD (OR: 0.33 (95% CI: 0.15-0.75), P = 0.008), arrhythmias (OR: 0.46 (95% CI: 0.27-0.81), P = 0.007), and congestive heart failure (OR: 0.52 (95% CI: 0.33-0.81), P = 0.004) was also lower in adrenalectomy group. The metaregression showed patient's age may attenuate the benefits of adrenalectomy on composite primary outcomes (coefficient: 1.084 (95% CI: 1.005-1.169), P = 0.036). TSA demonstrated that the accrued sample size and effect size were sufficiently large to draw a solid conclusion, and the advantage of adrenalectomy over MRA was constant with the chronological sequence.

CONCLUSIONS

In conclusion, adrenalectomy could be preferred over MRA for patients with PA in reducing the risk of all-cause mortality and/or MACE and should be considered as the treatment of choice. That patients with PA could get less benefit from adrenalectomy as they age warrants further investigation.

Case report: Percutaneous adrenal arterial embolization cures resistant hypertension

Background

Primary aldosteronism is a common cause of resistant hypertension. Patients with primary aldosteronism due to aldosterone-producing adenoma are generally treated with unilateral adrenalectomy or medical therapy. Superselective adrenal arterial embolization is an alternative treatment for patients with unilateral primary aldosteronism.

Case summary

We present a 39-year-old male patient with a 5-year history of primary aldosteronism and secondary hypertension. The patient refused adrenalectomy while accepted pharmacotherapy. Despite taking adequate dose of spironolactone, the patient experienced repeatedly muscle weakness due to hypokalemia and had poor blood pressure control with left ventricular hypertrophy and renal dysfunction. Aldosterone-producing adenoma in the left adrenal gland was confirmed by computerized tomography and adrenal venous sampling. The left middle adrenal artery, which was confirmed to provide the main arterial supply to the aldosterone-producing adenoma, was embolized by injecting 2 ml ethanol. The embolization normalized his blood pressure for up to 3 months and reversed left ventricular hypertrophy.

Conclusion

Superselective adrenal arterial embolization could be an alternative treatment for patients with aldosterone-producing adenoma who refuse adrenalectomy.

Japan Endocrine Society clinical practice guideline for the diagnosis and management of primary aldosteronism 2021

Primary aldosteronism (PA) is associated with higher cardiovascular morbidity and mortality rates than essential hypertension. The Japan Endocrine Society (JES) has developed an updated guideline for PA, based on the evidence, especially from Japan. We should preferentially screen hypertensive patients with a high prevalence of PA with aldosterone to renin ratio ≥200 and plasma aldosterone concentrations (PAC) ≥60 pg/mL as a cut-off of positive results. While we should confirm excess aldosterone secretion by one positive confirmatory test, we could bypass patients with typical PA findings. Since PAC became lower due to a change in assay methods from radioimmunoassay to chemiluminescent enzyme immunoassay, borderline ranges were set for screening and confirmatory tests and provisionally designated as positive. We recommend individualized medicine for those in the borderline range for the next step. We recommend evaluating cortisol co-secretion in patients with adrenal macroadenomas. Although we recommend adrenal venous sampling for lateralization before adrenalectomy, we should carefully select patients rather than all patients, and we suggest bypassing in young patients with typical PA findings. A selectivity index ≥5 and a lateralization index >4 after adrenocorticotropic hormone stimulation defines successful catheterization and unilateral subtype diagnosis. We recommend adrenalectomy for unilateral PA and mineralocorticoid receptor antagonists for bilateral PA. Systematic as well as individualized clinical practice is always warranted. This JES guideline 2021 provides updated rational evidence and recommendations for the clinical practice of PA, leading to improved quality of the clinical practice of hypertension.

Machine learning-based models for predicting clinical outcomes after surgery in unilateral primary aldosteronism

Unilateral subtype of primary aldosteronism (PA) is a common surgically curable form of endocrine hypertension. However, more than half of the patients with PA who undergo unilateral adrenalectomy suffer from persistent hypertension, which may discourage those with PA from undergoing adrenalectomy even when appropriate. The aim of this retrospective cross-sectional study was to develop machine learning-based models for predicting postoperative hypertensive remission using preoperative predictors that are readily available in routine clinical practice. A total of 107 patients with PA who achieved complete biochemical success after adrenalectomy were included and randomly assigned to the training and test datasets. Predictive models of complete clinical success were developed using supervised machine learning algorithms. Of 107 patients, 40 achieved complete clinical success after adrenalectomy in both datasets. Six clinical features associated with complete clinical success (duration of hypertension, defined daily dose (DDD) of antihypertensive medication, plasma aldosterone concentration (PAC), sex, body mass index (BMI), and age) were selected based on predictive performance in the machine learning-based model. The predictive accuracy and area under the curve (AUC) for the developed model in the test dataset were 77.3% and 0.884 (95% confidence interval: 0.737–1.000), respectively. In an independent external cohort, the performance of the predictive model was found to be comparable with an accuracy of 80.4% and AUC of 0.867 (95% confidence interval: 0.763–0.971). The duration of hypertension, DDD of antihypertensive medication, PAC, and BMI were non-linearly related to the prediction of complete clinical success. The developed predictive model may be useful in assessing the benefit of unilateral adrenalectomy and in selecting surgical treatment and antihypertensive medication for patients with PA in clinical practice.

The Accuracy of Simple and Adjusted Aldosterone Indices for Assessing Selectivity and Lateralization of Adrenal Vein Sampling in the Diagnosis of Primary Aldosteronism Subtypes

OBJECTIVE

This study aimed to evaluate the reliability of simple and corrected aldosterone indices for assessing the selectivity and lateralization of adrenal vein sampling (AVS) in patients with primary aldosteronism.

METHODS

Data of all consecutive patients with primary aldosteronism who underwent AVS for subtype diagnosis, followed at two Italian referral centers, were analyzed retrospectively.

RESULTS

AVS achieved bilateral selectivity in 112/144 patients. Unilateral disease was diagnosed in 60 cases (53.6%) and idiopathic hyperaldosteronism in 52 individuals (46.4%). The aldosterone index (aldosterone ratio between an adrenal vein and the inferior vena cava) showed a high accuracy in predicting selectivity, compared to a cortisol selectivity index of 1.1, and a moderate accuracy, compared to cortisol cut-offs of 2 and 3. The simple aldosterone index showed a moderate accuracy in predicting ipsi/contralateral aldosterone hypersecretion, while lesion side- and hypokalemia-corrected aldosterone index revealed a significant improvement in predicting ipsi/contralateral disease. Moreover, the comparative aldosterone index (aldosterone ratio in the dominant vs the non-dominant adrenal vein) revealed a high accuracy in predicting unilateral primary aldosteronism. For an immediate clinical application of our results, the adjusted cut-offs were calculated, according to the Youden's criterion and to a pre-established specificity of 90%, for all possible combinations of lesion side at imaging and presence/absence of hypokalemia.

CONCLUSIONS

This study demonstrated the diagnostic accuracy of simple and clinical-/imaging-corrected aldosterone indices for adrenal vein sampling in subtype diagnosis of primary aldosteronism and suggests the potential application of these tools to select patients for adrenalectomy when standard indices cannot be performed.

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.

Morphologically Normal-Appearing Adrenal Glands as a Prevalent Source of Aldosterone Production in Primary Aldosteronism

BACKGROUND

Normal-appearing adrenal glands on cross-sectional imaging may still be the source of aldosterone production in primary aldosteronism (PA).

METHODS

We evaluated the prevalence of aldosterone production among morphologically normal-appearing adrenal glands and the impact of this phenomenon on interpretations of localization studies and treatment decisions. We performed a retrospective cohort study of PA patients with at least 1 normal adrenal gland and reanalyzed contemporary studies to assess interpretations of imaging and adrenal venous sampling (AVS) at the individual patient and adrenal levels.

RESULTS

Among 243 patients, 43 (18%) had bilateral normal-appearing adrenals and 200 (82%) had a unilateral normal-appearing adrenal, for a total of 286 normal-appearing adrenal glands. 38% of these normal-appearing adrenal glands were a source of aldosteronism on AVS, resulting in discordance between imaging and AVS findings in 31% of patients. Most patients with lateralizing PA underwent curative unilateral treatment (80%); however, curative treatment was pursued in 92% of patients who had concordant imaging-AVS results but in only 38% who had discordant results (P < 0.05). In young patients, imaging-AVS discordance was detected in 32% of those under 45 years and 21% of those under 35 years. Among 20 contemporary studies (including 4,904 patients and 6,934 normal-appearing adrenal glands), up to 64% of normal-appearing adrenals were a source of aldosteronism resulting in 31% of patients having discordant results.

CONCLUSIONS

Morphologically normal-appearing adrenal glands are commonly the source of aldosterone production in PA, even among young patients. The lack of awareness of this issue may result in inappropriate treatment recommendations.

Primary Hyperaldosteronism: Approach to Diagnosis and Management

Hyperaldosteronism is a relatively more common disorder than previously recognized. Patients with hyperaldosteronism are at high risk for cardiovascular events. Patients suspected of having hyperaldosteronism should undergo initial screening and subsequent confirmatory testing to establish a biochemical diagnosis. Although adrenal computed tomography/magnetic resonance imaging scans often define a disease's subtype, adrenal vein sampling, in order to determine lateralization, may be necessary in some patients who are surgical candidates. Medical therapy using optimal doses of mineralocorticoid receptor antagonists can control symptoms and normalize plasma renin activity. The long-term outcome of patients treated with either surgical or optimal medical therapy appears similar.

Adrenal Venous Sampling for Subtype Diagnosis of Primary Hyperaldosteronism

Adrenal venous sampling (AVS) is the key procedure for lateralization of primary hyperaldosteronism (PA) before surgery. Identification of the adrenal veins using computed tomography (CT) and intraoperative cortisol assay facilitates the success of catheterization. Although administration of adrenocorticotropic hormone (ACTH) has benefits such as improving the success rate, some unilateral cases could be falsely diagnosed as bilateral. Selectivity index of 5 with ACTH stimulation to assess the selectivity of catheterization and lateralization index (LI) >4 with ACTH stimulation for unilateral diagnosis is used in many centers. Co-secretion of cortisol from the tumor potentially affects the lateralization by the LI. Patients aged <35 years with hypokalemia, marked aldosterone excess, and unilateral adrenal nodule on CT have a higher probability of unilateral disease. Patients with normokalemia, mild aldosterone excess, and no adrenal tumor on CT have a higher probability of bilateral disease. Although no methods have 100% specificity for subtype diagnosis that would allow bypassing AVS, prediction of the subtype should be considered when recommending AVS to patients. Methodological standardization and strict indication improve diagnostic quality of AVS. Development of non-invasive imaging and biochemical markers will drive a paradigm shift in the clinical practice of PA.

Adrenal vein sampling: technique and protocol, a systematic review

Primary aldosteronism is the leading cause of secondary hypertension worldwide. Its deleterious effects outstrip those due to blood pressure elevation alone. An essential part of the work-up of a patient with primary aldosteronism is determining if aldosterone production is unilateral or bilateral. With the former, surgery offers a potential cure and better overall outcomes. Adrenal vein sampling is considered the most reliable method to determine whether production is unilateral or bilateral. Sampling may be non-diagnostic when the vein cannot be properly cannulated. But with proper knowledge and experience as well as the utilization of certain techniques, procedure success can be high. Multiple protocols exist; their rationale and drawbacks are reviewed here. This article will give the reader an overview of techniques for improving procedural success as well as background, rationale and evidence to guide one in choosing the appropriate procedural and interpretation protocol.

Age-stratified comparison of clinical outcomes between medical and surgical treatments in patients with unilateral primary aldosteronism

Although adrenalectomy (ADX) is an established treatment for unilateral primary aldosteronism (uPA), the influence of age on the surgical outcomes is poorly understood. Therefore, we aimed to elucidate how age affects the clinical outcomes after treatments. We analyzed 153 older (≥ 65 years) and 702 younger patients (< 65 years) with uPA, treated either with ADX or mineralocorticoid receptor antagonist (MRA) in the Japan PA Study, and compared the estimated glomerular filtration rate (eGFR) or blood pressure over a 36-month period after treatments. ADX-treated patients showed severer biochemical indicators than MRA-treated patients. During 6 and 36 months, the eGFR decreased more prominently in older but not in younger patients with ADX than in those with MRA, which remained significant after adjustment with the inverse probability of treatment weighting (IPTW). There was a significant interaction between the age-groups and the treatment choices in the change of the eGFR with IPTW-adjusted analysis. The post-treatment dose of antihypertensive medication was lower in younger and higher in older patients with ADX than those with MRA. The clinical benefit of ADX differed between younger and older patients with uPA. These findings indicate the need for further validation on whether ADX can benefit older patients with uPA.

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.

Should Adrenal Venous Sampling Be Performed in PA Patients Without Apparent Adrenal Tumors?

INTRODUCTION

Some aldosterone-producing micro-adenomas cannot be detected through image inspection. Therefore, adrenal venous sampling (AVS) is often performed, even in primary aldosteronism (PA) patients who have no apparent adrenal tumors (ATs) on imaging. In most of these cases, however, the PA is bilateral.

OBJECTIVE

To clarify the clinical need for AVS in PA patients without apparent ATs, taking into consideration the rates of adrenalectomy.

METHODS

This is a retrospective cross-sectional study assessing 1586 PA patients without apparent ATs in the multicenter Japan PA study (JPAS). We analyzed which parameters could be used to distinguish unilateral PA patients without apparent ATs from bilateral patients. We also analyzed the prevalences of adrenalectomy in unilateral PA patients.

RESULTS

The unilateral subtype without an apparent AT was diagnosed in 200 (12.6%) of 1586 PA patients. Being young and female with a short hypertension duration, normokalemia, low creatinine level, low plasma aldosterone concentration, and low aldosterone-to-renin ratio (ARR) was significantly more common in bilateral than unilateral PA patients. If PA patients without apparent ATs were female and normokalemic with a low ARR (<560 pg/ml per ng/ml/h), the rate of unilateral PA was only 5 (1.1%) out of 444. Moreover, 77 (38.5%) of the 200 did not receive adrenalectomy, despite being diagnosed with the unilateral subtype based on AVS.

CONCLUSION

The low prevalence of the unilateral subtype in PA patients without apparent ATs suggests AVS is not indicated for all of these patients. AVS could be skipped in female normokalemic PA patients without apparent ATs if their ARRs are not high. However, AVS should be considered for male hypokalemic PA patients with high ARRs because the rates of the unilateral subtype are high in these patients.