Diagnostic utility of data from adrenal venous sampling for primary aldosteronism despite failed cannulation of the right adrenal vein

Calculated Right Adrenal Vein Aldosterone Levels in Patients Undergoing Adrenal Vein Sampling: The Potential to Lateralize Despite Unsuccessful Selection of the Right Adrenal Vein

PURPOSE

The aim of this study was to use calculated aldosterone level in the right adrenal vein (RAV) (cAldoRAV) rather than measured level for identifying the dominant side of aldosterone secretion in patients with primary aldosteronism undergoing adrenocorticotropic hormone-stimulated adrenal venous sampling (AVS).

MATERIALS AND METHODS

Patients with primary aldosteronism who had successful AVS (selectivity index, >3) were studied. Based on the assumption that cortisol production from both adrenal glands is equal, aldosterone level in the RAV was calculated using the data from the left adrenal vein and inferior vena cava. The aldosterone level in the left adrenal vein (AldoLAV) compared with the cAldoRAV (AldoLAV:cAldoRAV ratio) was then used to determine the dominant side of aldosterone secretion compared with standard AVS interpretation using lateralization index (LI). LI ≥4 indicated unilateral disease, and LI ≤3 indicated bilateral disease. The LI between 3 and 4 was diagnosed as indeterminate.

RESULTS

Sixty-eight patients with concordant results between AVS and adrenal imaging study (32 were left-sided, 22 were right-sided, and 14 were bilateral) were selected for studying diagnostic performance. The AldoLAV:cAldoRAV ratio with the cutoff values of ≥3 and ≤0.33 could identify unilateral diseases (left-sided and right-sided disease, respectively) with 92.6% sensitivity and 100% specificity.

CONCLUSIONS

The calculated AldoLAV:cAldoRAV ratio can determine the dominant side of aldosterone secretion with high sensitivity and specificity when compared with standard AVS interpretation of measured levels. It provides an option for identification of unilateral and bilateral disease in select patients in whom right adrenal vein selection is unsuccessful.

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

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

Correlation of Histopathologic Subtypes of Primary Aldosteronism with Clinical Phenotypes and Postsurgical Outcomes

CONTEXT

Clinical implications of unilateral primary aldosteronism (PA) histopathology remain to be determined in various ethnic populations.

OBJECTIVE

We examined the histopathology of unilateral PA using CYP11B2 immunostaining in relation to clinical phenotypes and postsurgical outcomes.

METHODS

Patients consecutively operated for unilateral PA from 2010 to 2020 at 3 tertiary hospitals in South Korea were retrospectively enrolled. Adrenals with solitary aldosterone-producing adenomas and/or dominant aldosterone-producing nodules were classified as the classical and the others as the nonclassical groups. The classical group was subdivided into mixed or solitary group according to whether other aldosterone-producing lesions coexist or not.

RESULTS

Of the 240 cases, 124 were solitary, 86 mixed, and 30 nonclassical. Baseline serum potassium concentration was lower in the solitary group than the mixed or nonclassical group. Plasma aldosterone concentration after saline loading was the highest in the solitary group (median 31.65 ng/dL), followed by the mixed group (median 25.40 ng/dL), and the lowest in the nonclassical group (median 14.20 ng/dL). Solitary and mixed groups showed higher lateralization indices and lower contralateral indices than the nonclassical group. The contralateral index was lower in the solitary group than the mixed group. At 6 to 12 months after adrenalectomy, fewer antihypertensive medications were required for the solitary and mixed groups than the nonclassical group.

CONCLUSION

The solitary group, followed by the mixed group, was associated with more severe hyperaldosteronism and more suppressed aldosterone production from the contralateral side than the nonclassical group. Histopathologic phenotypes were related to the clinical manifestations and may suggest postoperative prognosis.

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

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

Adrenal Vein Sampling: Tips and Tricks

Adrenal vein sampling (AVS) is the standard method for distinguishing unilateral from bilateral sources of autonomous aldosterone production in patients with primary aldosteronism. This procedure has been performed at limited specialized centers due to its technical complexity. With recent advances in imaging technology and knowledge of adrenal vein anatomy in parallel with the development of adjunctive techniques, AVS has become easier to perform, even at nonspecialized centers. Although rare, anatomic variants of the adrenal veins can cause sampling failure or misinterpretation of the sampling results. The inferior accessory hepatic vein and the inferior emissary vein are useful anatomic landmarks for right adrenal vein cannulation, which is the most difficult and crucial step in AVS. Meticulous assessment of adrenal vein anatomy on multidetector CT images and the use of a catheter suitable for the anatomy are crucial for adrenal vein cannulation. Adjunctive techniques such as intraprocedural cortisol assay, cone-beam CT, and coaxial guidewire-catheter techniques are useful tools to confirm right adrenal vein cannulation or to troubleshoot difficult blood sampling. Interventional radiologists should be involved in interpreting the sampling results because technical factors may affect the results. In rare instances, bilateral adrenal suppression, in which aldosterone-to-cortisol ratios of both adrenal glands are lower than that of the inferior vena cava, can be encountered. Repeat sampling may be necessary in this situation. Collaboration with endocrinology and laboratory medicine services is of great importance to optimize the quality of the samples and for smooth and successful operation. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Treatment decision based on unilateral index from nonadrenocorticotropic hormone-stimulated and adrenocorticotropic hormone-stimulated adrenal vein sampling in primary aldosteronism

OBJECTIVE

Adrenal venous sampling (AVS) is recommended for identifying the subtype of primary aldosteronism before making a surgical treatment decision, but failed cannulation of one adrenal vein is common. To evaluate whether using results of one adrenal vein during AVS could accurately predict unilateral primary aldosteronism.

METHODS

A retrospective study was conducted in primary aldosteronism patients receiving bilaterally or unilaterally successful AVS. The aldosterone-cortisol ratio from the adrenal vein divided by the aldosterone-cortisol ratio from the inferior vena cava (IVC) was calculated as the AV/IVC index.

RESULTS

The study examined 455 patients with primary aldosteronism, including 347 patients with unilateral primary aldosteronism. Among them, 250 and 125 patients received non- adrenocorticotropic hormone (ACTH) and ACTH-stimulated AVS, respectively, and 80 patients received both forms of AVS. Under non-ACTH-stimulated AVS, AUC of the AV/IVC index to diagnose ipsilateral and contralateral primary aldosteronism were 0.778 and 0.924, respectively. The specificity was 100% for both, with sensitivities of 5 and 26%, respectively, when using cutoffs of 17.05 to diagnose ipsilateral primary aldosteronism and 0.15 to diagnose contralateral primary aldosteronism. When using cutoffs of 3.60 and 0.70, the specificity decreased, but if combined with CT results (ipsilateral or contralateral adrenal nodules larger than 10 mm), the specificity could be maintained at 99%, with sensitivities of 33 and 45%, respectively. Under ACTH-stimulated AVS, the AV/IVC index showed similar accuracy to diagnose ipsilateral and contralateral primary aldosteronism.

CONCLUSION

The unilateral AV/IVC index can be used to diagnose unilateral primary aldosteronism during AVS. Combining CT results can increase the accuracy further.

Diagnostic performance of the adrenal vein to inferior vena cava aldosterone ratio in classifying the subtype of primary aldosteronism

Adrenal vein sampling (AVS) is the standard procedure for distinguishing unilateral primary aldosteronism (PA) from bilateral PA. In cases where only one adrenal vein is successfully cannulated, it has been suggested that subtype classification can be determined based on the ratio of the concentration of aldosterone between the adrenal vein and the inferior vena cava (AV/IVC index). However, diagnostic performance of the ipsilateral versus contralateral AV/IVC index in predicting lateralization has not been directly compared. In a retrospective cohort of 133 patients with confirmed PA who underwent successful AVS, the performance of the AV/IVC index to predict laterality was evaluated and the area under the receiver operating characteristic (AUROC) curves was calculated. In detecting left unilateral PA (n = 47), the AUROC of the right AV/IVC index (RAV/IVC) was significantly higher than the AUROC of the left AV/IVC (LAV/IVC) index (0.967 vs. 0.871, p = 0.008). In detecting right unilateral PA (n = 30), the AUROC of the LAV/IVC index tended to be higher than that of the RAV/IVC index, but the difference did not reach statistical significance (0.966 vs. 0.906, p = 0.08). In detecting left unilateral PA, the sensitivities of the RAV/IVC and LAV/IVC indices were 83% and 46%, respectively, while the specificities of both were above 90%. In detecting right unilateral PA, the sensitivities of the LAV/IVC and RAV/IVC indices were 80% and 43%, respectively, while the specificities of both were above 90%. The AV/IVC index has superior diagnostic performance in detecting contralateral unilateral PA compared to ipsilateral unilateral PA.

Corticotropin Stimulation in Adrenal Venous Sampling for Patients With Primary Aldosteronism: The ADOPA Randomized Clinical Trial

Importance

Adrenal venous sampling (AVS) is usually recommended to distinguish between unilateral and bilateral primary aldosteronism (PA) before definitive surgical or medical treatment is offered. Whether a treatment decision based on AVS with or without corticotropin (ACTH) stimulation leads to different biochemical and clinical remission rates in patients with PA remains unclear.

Objective

To evaluate whether treatment decisions based on AVS with or without ACTH stimulation lead to different biochemical and clinical remission rates in patients with PA.

Design, Setting, and Participants

This randomized clinical trial (RCT) was conducted at a tertiary hospital in China from July 8, 2020, to February 20, 2023, among patients with PA aged 18 to 70 years. Patients were followed up for 12 months after the initiation of treatment. An intention-to-diagnose analysis was conducted.

Interventions

Patients were randomly assigned to undergo either ACTH-stimulated or non-ACTH-stimulated AVS.

Main Outcomes and Measures

The primary end point was the proportion of patients with complete biochemical remission after 12 months of follow-up. Secondary outcomes included the proportion of patients who achieved complete clinical remission after 12 months of follow-up, dosages of antihypertensive agents, rate of successful bilateral AVS, and adverse events.

Results

Of 228 patients with PA, 115 were randomized to the non-ACTH-stimulated group (median age, 50.0 years [IQR, 41.0-57.0 years]; 70 males [60.9%]) and 113 to the ACTH-stimulated group (median age, 50.0 years [IQR, 43.5-56.5 years]; 63 males [55.8%]). A total of 68 patients (59.1%) underwent adrenalectomy in the non-ACTH group and 65 (57.5%) in the ACTH group. There was no significant difference in the proportion of patients with complete biochemical remission who were managed on the basis of AVS with vs without ACTH stimulation (with: 56 of 113 [49.6%]; without: 59 of 115 [51.3%]; P = .79). There also was no significant difference in the proportion of patients who achieved complete clinical remission between the non-ACTH and ACTH groups (26 of 115 [22.6%] and 31 of 113 [27.4%], respectively; P = .40). The intensity of therapy with antihypertensives, successful catheterization of bilateral adrenal veins, and incidence of adverse events did not significantly differ between the non-ACTH and ACTH groups.

Conclusions and Relevance

In this RCT, treatment of PA on the basis of non-ACTH-stimulated or ACTH-stimulated AVS did not lead to significant differences in clinical outcomes for the patients. These results suggest that ACTH stimulation during AVS may not have clinical benefit, at least in the Chinese population.

Trial Registration

ClinicalTrials.gov Identifier: NCT04461535.

Role of Adrenal Vein Sampling in Guiding Surgical Decision in Primary Aldosteronism

Adrenal vein sampling (AVS) is recommended for subtyping primary aldosteronism (PA) to identify lateralized or bilateral sources of aldosterone excess, allowing for better decision-making in regard to medical or surgical management on a case-by-case basis. To date, no consensus exists on protocols to be used during AVS, especially concerning sampling techniques, the timing of sampling, and whether or not to use adrenocorticotropic hormone (ACTH) stimulation. Interpretation criteria for selectivity, lateralization, and contralateral suppression vary from one expert center to another, with some favoring strict cut-offs to others being more permissive. Clinical and biochemical post-operative outcomes can also be influenced by AVS criteria utilized to indicate surgical therapy.In this review, we reanalyze studies on AVS highlighting the recent pathological findings of frequent micronodular hyperplasia adjacent to a dominant aldosteronoma (APA) overlapping with bilateral idiopathic hyperaldosteronism (IHA) etiologies, as opposed to the less frequent unilateral single aldosteronoma. The variable expression of melanocortin type 2 receptors in the nodules and hyperplasia may explain the frequent discordance in lateralization ratios between unstimulated and ACTH- stimulated samples. We conclude that aldosterone values collected during simultaneous bilateral sampling, both at baseline and post-ACTH stimulation, are required to adequately evaluate selectivity, lateralization, and contralateral suppression during AVS, to better identify all patients with PA that can benefit from a surgical indication. Recommended cut-offs for each ratio are also presented.

The performance of left/right adrenal volume ratio and volume difference in predicting unilateral primary aldosteronism

PURPOSE

The role of computed tomography (CT) in the diagnosis of primary aldosteronism (PA) warrants attention, since the success application of adrenal venous sampling (AVS) remains limited. We aimed to investigate the value of CT-based volumetric indicators, including left-versus-right-adrenal-volume ratio (L/Rv) and left-subtract-right-adrenal-volume difference (L - Rv), in the diagnosis of unilateral primary aldosteronism (UPA).

METHODS

A retrospective case-control study included 153 patients with PA and 1272 controls. AVS was used to classify patients into bilateral disease, left-sided disease, and right-sided disease groups.

RESULTS

Adrenal gland volume on both sides of PA patients was significantly larger than controls. The optimal cutoff values of L/Rv and L - Rv were 1.417 [area under the curve (AUC) 0.864] and 1.185 (AUC 0.827), respectively, for the diagnosis of left-sided PA, and 1.030 (AUC 0.767) and 0.220 (AUC 0.769), respectively, for the diagnosis of right-sided PA. The mean AUC for subsequent cross-validation ranged from 0.77 ± 0.03 to 0.86 ± 0.02. Based on the optimal cutoff values, the combination of L/Rv and L - Rv detected 69.6% of patients with left-sided PA and 74.3% of patients with right-sided PA, with a specificity of 93.5% and 89.0%, respectively. For a better clinical application, we reported the sub-optimal cutoffs corresponding to a specificity of 95%. A L/Rv higher than 1.431 and a L - Rv higher than 3.185 as sub-optimal cutoff values was detected in 26.1% of patients with left-sided PA (specificity: 97.2%). A L/Rv smaller than 0.892 and a L - Rv smaller than -0.640 could detect 48.6% of patients with right-sided PA (specificity: 97.5%).

CONCLUSIONS

CT-based L/Rv and L - Rv performed well in predicting UPA. The combination of L/Rv and L - Rv may serve as a potential indicator for guiding surgical decision making in centers without AVS programs.

An Ancillary Method for Adrenal Venous Sampling in Cases in Which Right Adrenal Vein Sampling Is Difficult

Catheterization of the right adrenal vein (rt.AdV) to obtain blood samples can often be difficult. The aim of the present study was to investigate whether blood sampling from the inferior vena cava (IVC) at its juncture with the rt.AdV can be an ancillary to sampling of blood directly from the rt.AdV. This study included 44 patients diagnosed with primary aldosteronism (PA) in whom AVS with adrenocorticotropic hormone (ACTH) was performed, resulting in a diagnosis of idiopathic hyperaldosteronism (IHA) (n = 24), and patients diagnosed with unilateral aldosterone-producing adenoma (APA) (n = 20; rt.APA = 8, lt.APA = 12). In addition to regular blood sampling, blood was also sampled from the IVC, as the substitute rt.AdV [S-rt.AdV]. Diagnostic performance with the conventional lateralized index (LI) and the modified LI using the S-rt.AdV were compared to examine the utility of the modified LI. The modified LI of the rt.APA (0.4 ± 0.4) was significantly lower than those of the IHA (1.4 ± 0.7) (p < 0.001) and the lt.APA (3.5 ± 2.0) (p < 0.001). The modified LI of the lt.APA was significantly higher than those of the IHA (p < 0.001) and rt.APA (p < 0.001). Likelihood ratios to diagnose rt.APA and lt.APA using the modified LI with threshold values of 0.3 and 3.1 were 27.0, and 18.6, respectively. The modified LI has the potential to be an ancillary method for rt.AdV sampling in cases in which rt.AdV sampling is difficult. Obtaining the modified LI is extremely simple, which might complement conventional AVS.

Subtyping primary aldosteronism by inconclusive adrenal vein sampling: A derivation and validation study in a tertiary centre

OBJECTIVE

Indices based on aldosterone/cortisol (A/C) concentration in the successfully cannulated adrenal vein (AV) and in the inferior vena cava (IVC) (AV/IVC) appear to be possible markers to verify the subtype of primary aldosteronism (PA) in the case of inconclusive results of adrenal vein sampling (AVS). The variability of results in previous studies encouraged us to calculate AV/IVC and adrenal A/C cutoff values that could predict the aetiology of PA.

METHODS

This retrospective study included 96 patients who underwent AVS due to PA between 2015 and 2020. The derivation cohort ultimately consisted of 60 patients with bilaterally successful AVS and a clear diagnosis of unilateral or bilateral disease. Receiver operating characteristic analysis was used to find the optimal A/C and AV/IVC cutoff values predicting the subtype of PA. The validation cohort consisted of 11 patients with either unsuccessful cannulation or a borderline lateralization index (LI), those patients underwent adrenalectomy because their indices were suggestive of unilateral disease based on the derivation cohort data.

RESULTS

The cutoff values of A/C ≤ 0.63 or AV/IVC ≤ 0.37 identified unaffected glands with a sensitivity of 91.2% and 97.1%, respectively, and a specificity of 90.7% and 88.4%, respectively. Unilateral ipsilateral gland involvement was characterized by A/C ≥ 3.5 or AV/IVC ≥ 3.4 with a corresponding specificity of 100%. All patients in the validation cohort achieved biochemical remission postoperatively.

CONCLUSIONS

A/C and AV/IVC cutoff values could be a useful tool to determine the subtype of PA in patients with unilateral successful AVS as well as in patients with a borderline LI.

Validation of three novel clinical prediction tools for primary aldosteronism subtyping

The 20-point clinical prediction SPACE score, the aldosterone-to-lowest potassium ratio (APR), aldosterone concentration (AC) and the AC relative reduction rate after saline infusion test (SIT) have recently been proposed for primary aldosteronism (PA) subtyping prior to adrenal vein sampling (AVS). To validate those claims, we performed a retrospective cross-sectional study that included all patients at our center who had positive SIT to confirm PA and were diagnosed with either bilateral disease (BPA) according to AVS or with lateralized disease (LPA) if biochemically cured after adrenalectomy from November 2004 to the end of 2019. Final diagnoses were used to evaluate the diagnostic performance of proposed clinical prediction tools. Our cohort included 144 patients (40 females), aged 32-72 years (mean 54 years); 59 with LPA and 85 with BPA. The originally suggested SPACE score ≤8 and SPACE score >16 rules yielded about 80% positive predictive value (PPV) for BPA and LPA, respectively. Multivariate analyses with the predictors constituting the SPACE score highlighted post-SIT AC as the most important predictor of PA subtype for our cohort. APR-based tool of <5 for BPA and >15 for LPA yielded about 75% PPV for LPA and BPA. The proposed post-SIT AC <8.79 ng/dL criterion yielded 41% sensitivity and 90% specificity, while the relative post-SIT AC reduction rate of >33.8% criterion yielded 80% sensitivity and 51% specificity for BPA prediction. The application of any of the validated clinical prediction tools to our cohort did not predict the PA subtype with the high diagnostic performance originally reported.

Early Renin Recovery After Adrenalectomy in Aldosterone-Producing Adenomas: A Prospective Study

The aim of the study was to clarify the relationship and the time of aldosterone and renin recoveries at immediate and long-term follow-up in aldosterone-producing adenoma (APA) patients who underwent adrenalectomy. Prospective and longitudinal protocol in a cohort of APA patients was followed in a single center. Among 43 patients with primary aldosteronism (PA), thirteen APA patients were enrolled in this study. Blood was collected for aldosterone, renin, potassium, creatinine, cortisol, and ACTH before and 1, 3, 5, 7, 15, 30, 60, 90, 120, 180, 270, 360 days after adrenalectomy. At diagnosis, most patients (84%) had hypokalemia and high median aldosterone levels (54.8; 24.0-103 ng/dl) that decreased to undetectable (<2.2) or very low (<3.0) levels between fifth to seventh days after surgery; then, between 3-12 months, its levels gradually increased to the lower normal range. The suppressed renin (2.3; 2.3-2.3 mU/l) became detectable between the fifteen and thirty days after surgery, remaining normal throughout the study. The aldosterone took longer than renin to recover (60 vs.15 days; p<0.002) and patients with higher aldosterone had later recovery (p=0.03). The cortisol/ACTH levels remained normal despite the presence of a post-operative hypoaldosteronism. Blood pressure and antihypertensive requirement decreased after adrenalectomy. In conclusion, our prospective study shows the borderline persistent post-operative hypoaldosteronism in the presence of early renin recovery indicating incapability of the zona glomerulosa of the remaining adrenal gland to produce aldosterone. These findings contribute to the comprehension of differences in renin and aldosterone regulation in APA patients, although both are part of the same interconnected system.

Primary Aldosteronism Presenting with Hypertension Five Days after Delivery: A Case Report and Literature Review

A 35-year-old Japanese woman with no history of hypertension developed hypertension 5 days after normal delivery. Endocrinological and radiological examinations indicated primary aldosteronism (PA) and a 1.4-cm left adrenal tumor. The patient underwent laparoscopic adrenalectomy, and a diagnosis of aldosterone-producing adenoma was confirmed immunohistochemically. Her plasma aldosterone concentration and blood pressure normalized. Cases of PA presenting with hypertension in the postpartum period have been reported. This case suggests that PA should be considered in women with postpartum hypertension, especially in those with blood pressure that suddenly increases shortly after delivery, even if they were normotensive before and throughout pregnancy.

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.

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.

Asian Conference on Tumor Ablation Guidelines for Adrenal Tumor Ablation

Thermal ablation is a good alternative treatment in patients who are unable to undergo adrenalectomy. Even though the Asian Conference on Tumor Ablation (ACTA) has been held for many years, adrenal ablation guidelines have not been established. No guidelines for adrenal ablation are established in American and European countries, either. The aim of this review was to introduce the first version of ACTA guidelines for adrenal tumor ablation.

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.

Approach to the Patient with Primary Aldosteronism: Utility and Limitations of Adrenal Vein Sampling

Several studies over the past 3 decades document a higher prevalence of primary aldosteronism (PA) among hypertensive patients than generally presumed. PA exists as a spectrum from mild to severe aldosterone excess. Although a variety of PA subtypes exist, the 2 most common are aldosterone-producing adenomas (APAs) and bilateral hyperaldosteronism (BHA). The distinction is important, because APA-and other subtypes, with aldosterone production mostly from 1 adrenal-can be cured surgically, and BHA should be treated medically with mineralocorticoid-receptor antagonists (MRAs). The major shortcomings in the tailored management of patients with possible PA are the low rates of screening for case identification and the expensive and technically challenging imaging and interventional procedures required to distinguish APA from BHA, especially adrenal vein sampling (AVS). When AVS identifies an APA and allows the patient to be cured surgically, the procedure is of great value. In contrast, the patient with BHA is treated with MRA whether AVS is performed or not. Consequently, it is prudent to gauge how likely it is to benefit from imaging and AVS in each case prior to embarking on these studies. The explosion of information about PA in the past decade, including predictors of APA and of surgical benefit, are useful in limiting the evaluation for some patients with a positive PA screening test. This article will review our suggestions for approaching these patients in a pragmatic style, recognizing the limitations to even the best resources and facilities.

Primary aldosteronism subtyping in the setting of partially successful adrenal vein sampling

BACKGROUND AND AIMS

Frequent failure of adrenal vein (AV) cannulation is a major obstacle to the universal use of adrenal vein sampling (AVS) for subtyping primary aldosteronism (PA). This study aimed to confirm and modify the value of a previously reported AVS parameter for PA subtyping in the case of cannulation failure on one side.

METHODS

Successfully catheterized AVS studies in 157 patients (121 patients as a derivation cohort and 36 patients as a validation cohort) from two tertiary hospitals were retrospectively reviewed. The AV/inferior vena cava (IVC) index was defined by dividing the aldosterone/cortisol ratio (ACR) of AV by the ACR of the IVC. Cutoff values for lateralized PA were obtained from two methods: scatterplots and the values corresponding to Youden's index in receiver operating characteristic (ROC) curves, on the assumption of catheterization failure on one side.

RESULTS

Due to multiple samplings in a single AVS procedure, 252 left AV/IVC ratios (LIRs) and 272 right AV/IVC ratios (RIRs) were calculated. Scatterplot cutoffs of LIR >5.4 or <0.5 predicted unilateral PA with a sensitivity of 42.1% and a specificity of 98.6%. Scatterplot cutoffs of RIR <0.5 or >7.0 showed a sensitivity of 55.1% and a specificity of 98.6%. ROC curve cutoffs of LIR ⩽0.8 or >3.1 predicted unilateral PA with a sensitivity of 82.5% and a specificity of 69.6%. ROC curve cutoffs of RIR ⩽0.8 or >3.9 resulted in 87.4% sensitivity and 80.7% specificity.

CONCLUSION

In the case of unilateral AVS failure, the AV/IVC index may help in diagnosing PA subtype.

Adrenal vein sampling: External validation of multinomial regression modelling and left adrenal vein-to-peripheral vein ratio to predict lateralization index without right adrenal vein sampling

BACKGROUND

Adrenal vein sampling (AVS) failure is mainly due to right adrenal vein unavailability. Multinomial regression modelling (MRM) and left adrenal vein-to-peripheral vein ratio (LAV/PV) were proposed to predict the lateralization index without the right AVS.

OBJECTIVE

To assess external validity of MRM and LAV/PV to predict lateralization index when right adrenal vein sampling is missing.

DESIGN

Diagnostic retrospective study.

PATIENTS

Development and validation cohorts included AVS of 174 and 122 patients, respectively, from 2 different centres.

MEASUREMENTS

Development and validation cohort data were used, respectively, for calibration and for validation of MRM and LAV/PV to predict the lateralization index without the right adrenal vein sampling. Sensitivity and specificity of MRM and LAV/PV were compared between both centres at different pre-established specificity thresholds based on receiver operating characteristic curves generated from the development cohort data.

RESULTS

At a specificity threshold of 95% set in the development cohort, specificity values exceeded 90% (range, 90.6%-98.8%) for all verified MRM and LAV/PV models in the validation cohort. Corresponding sensitivities for MRM and LAV/PV, respectively, range from 54.1% to 83.7% and 32.8% to 88.4% for the development cohort compared to 33.3%-87.5% and 2.8%-79.2% for the validation cohort. Overall, diagnostic accuracy of both methods was higher to detect right (82.8%-93.5%) than left (70.2%-80.6%) lateralization index status in both centres.

CONCLUSIONS

Minimal changes in specificity from development to validation cohorts validate the use of MRM and LAV/PV to predict the lateralization index when the right AVS is missing. Both methods had better accuracy for right than left lateralization detection.

The diagnostic accuracy of adjusted unconventional indices for adrenal vein sampling in the diagnosis of primary aldosteronism subtypes

OBJECTIVE

Simple unconventional indices did not demonstrate a satisfactory accuracy for diagnosing unilateral primary aldosteronism when adrenal vein sampling is not bilaterally selective. This study aimed to evaluate the reliability of clinical/imaging-corrected unconventional indices for adrenal vein sampling in predicting unilateral primary aldosteronism.

METHODS

Data of all consecutive patients with primary aldosteronism subtyped with adrenal vein sampling, referred to two Italian centers, were analyzed retrospectively. All patients with proved unilateral aldosterone hypersecretion underwent adrenalectomy.

RESULTS

Unilateral disease was diagnosed in 58 cases (54.2%) and idiopathic hyperaldosteronism in 49 individuals (45.8%). The monoadrenal index (aldosterone-to-cortisol ratio in the adrenal vein) showed high accuracy in predicting ipsilateral disease and moderate accuracy in predicting contralateral aldosterone hypersecretion. The monolateral index (aldosterone-to-cortisol ratio in the adrenal vein vs. peripheral blood) revealed moderate accuracy in predicting ipsilateral disease and high accuracy in predicting contralateral aldosterone hypersecretion. Lesion side- and hypokalemia-corrected ROC curves for these unconventional indices revealed a significant improvement in the reliability of predicting ipsilateral/contralateral disease, reaching high accuracy in all models. 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 95%, for all possible combinations of lesion side at imaging and presence/absence of hypokalemia.

CONCLUSION

This study demonstrated the high diagnostic accuracy of clinical-/imaging-corrected unconventional indices for adrenal vein sampling in the diagnosis of primary aldosteronism subtypes and suggests the use of these adjusted indices to select patients for adrenalectomy when adrenal vein sampling is not bilaterally selective.

The role of adrenal venous sampling and computed tomography in the management of primary aldosteronism

BACKGROUND

The role of adrenal venous sampling (AVS) has been challenged by some recent evidence. This study aimed to compare the role of AVS and computed tomography (CT) in the management of primary aldosteronism.

METHODS

Patients who underwent unilateral adrenalectomy for primary aldosteronism at a single center between January 2015 and December 2018 were included, and postoperative outcomes of the patients who underwent surgery based on CT (n = 195) or AVS (n = 40) were compared. The data of all the patients who underwent AVS successfully (n = 75) during this period were also collected and analyzed.

RESULTS

There were no significant differences between the CT-guided and AVS-guided adrenalectomies in most of the postoperative outcomes, and the proportion of patients achieving cure of hypokalemia (CT vs. AVS, 98.3 vs. 96.4%) and alleviation of hypertension (89.2 vs. 92.9%) were similar between the two groups. However, since the baseline characteristics of the two groups were not identical, the AVS-guided group showed greater improvement in postoperative hypokalemia and greater reduction in the number of antihypertensive medications than the CT-guided group. In addition, for the 75 patients who underwent AVS successfully, the concordance rate between CT abnormalities and AVS lateralization was 60.0% in total, and 22.7% patients changed treatment plans according to the AVS results.

CONCLUSION

Although the clinical outcomes were not significantly different between the CT-guided and AVS-guided group, the AVS-guided group seemed to benefit more from the surgery, and a considerable number of patients with primary aldosteronism would have received inappropriate treatment if they did not undergo AVS.

Performance of the unilateral AV/IVC index in primary hyperaldosteronism subtype prediction: A validation study in a single tertiary centre

BACKGROUND

Failure of cannulation of the right adrenal vein is frequent during AVS for investigation of primary aldosteronism (PA). The aldosterone:cortisol ratio of either adrenal vein compared with the inferior vena cava (AV/IVC index) has been proposed to differentiate between unilateral and bilateral disease, and aid in lateralization of unilateral disease.

METHODS

Sixty-two patients with unilateral or bilateral PA identified by either successful bilateral (45 patients) or unilateral (17 patients) adrenal vein cannulation, and with biochemical remission following surgery were enrolled into the analysis. The diagnostic performances of the previously identified AV/IVC index cut-offs of ≥5.5 to predict ipsilateral disease and ≤0.5 to predict contralateral disease were validated using data from the entire cohort.

RESULTS

Fifty-three patients had unilateral PA and 9 patients bilateral PA. The area under ROC curve (AUROC) of the AV/IVC cut-off ≤0.5 for identifying unilateral aldosterone secretion from the contralateral adrenal was 0.95 (95% CI; 0.88-0.99), whereas the AUROC of the AV/IVC cut-off ≥5.5 for identifying unilateral aldosterone secretion from ipsilateral adrenal was 0.96 (95% CI; 0.92-0.99). The AV/IVC index cut-off value of 0.5 had 93% sensitivity and 91% specificity, and the AV/IVC index cut-off value of 5.5 had 21% sensitivity and 100% specificity. The optimal AV/IVC cut-offs to achieve 100% specificity for our cohort were >2.4 and <0.1 to predict ipsilateral and contralateral disease.

CONCLUSION

Our data confirm that the AV/IVC index is a potential tool for subtype classification and lateralization in patients with PA in the setting of failed bilateral, but successful unilateral, adrenal vein cannulation during AVS.

Clinical outcomes of primary aldosteronism based on lateralization index and contralateral suppression index after adrenal venous sampling in real-world practice: a retrospective cohort study

BACKGROUND

We investigated whether the contralateral suppression index in aldosterone-producing adrenal adenoma could be used as a diagnostic criterion when catheterization in either right or left adrenal vein fails or when a discrepancy in the adrenal vein sampling (AVS) results and imaging findings occurs in the real-world practice.

METHODS

We retrospectively reviewed 48 patients who had resistant hypertension (HTN) or hypokalemia with a biochemical diagnosis of primary aldosteronism and who underwent AVS from January 2009 to June 2017 at a tertiary referral hospital. Selection index (SI), lateralization index (LI), and contralateral suppression index (CSI) were calculated based on AVS results and the final clinical outcomes were evaluated.

RESULTS

The catheterization of both adrenal veins was successful in 43 of 48 (89.6%) patients. The lateralization based only on LI was performed in 23 out of 43 (53.5%) patients. When CSI and LI were combined in decision making, the concordance between adrenal computed tomography scan and AVS for unilateral lesion improved from 59.3% (19/32) to 75.0% (24/32). CSI also correlated well with unilateral adrenal disease in the catheterization failure group. The final outcomes of HTN were better in the contralateral suppression group.

CONCLUSION

CSI combined with LI could be a supplementary diagnostic tool in patients with non-lateralization or catheterization failure and predict the clinical outcomes of HTN in patients with primary aldosteronism.

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

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

Can incomplete adrenal venous sampling data be used in predicting the subtype of primary aldosteronism?

BACKGROUND

Adrenal venous sampling (AVS) is the gold standard for preoperative differentiation between unilateral and bilateral primary aldosteronism (PA). However, results are sometimes vitiated by failing to access the right adrenal vein.

MATERIALS AND METHODS

The present study assumed that clinical decisions can be made with incomplete AVS data, by comparing aldosterone/cortisol (A/C) ratio in both left and right adrenal veins with that in the inferior vena cava (LAV/IVC and RAV/IVC). Receiver operation characteristic (ROC) curve and scatterplot were used to certify the upper and lower cutoffs and to analyze the significance of discrimination. One hundred and sixty patients diagnosed with PA from April 2017 to June 2018 underwent AVS in the Urology Department of West China Hospital, Chengdu, China. One hundred and eleven with complete AVS data were divided into 3 groups: left-sided (N=40), right-sided (N=29) and bilateral (N=42). We also collected patients from September 2018 to April 2019 in our department as validation cohort to test our hypothesis.

RESULTS

On the basis of LAV/IVC, RAV/IVC and diagnostic category, upper cutoff was 1.14 (50% sensitivity and 100% specificity) and lower cutoff 0.07 (27.5% sensitivity and 100% specificity) for LAV/IVC, and 1.04 (55% sensitivity and 100% specificity) and 0.08 (40% sensitivity and 100% specificity), respectively, for RAV/IVC.

CONCLUSION

The diagnostic model in this study contributes to clinical decision-making in patients with only partial PA with incomplete AVS data.

Improved technical success and radiation safety of adrenal vein sampling using rapid, semi-quantitative point-of-care cortisol measurement

Objective

Primary aldosteronism is a curable cause of hypertension which can be treated surgically or medically depending on the findings of adrenal vein sampling studies. Adrenal vein sampling studies are technically demanding with a high failure rate in many centres. The use of intraprocedural cortisol measurement could improve the success rates of adrenal vein sampling but may be impracticable due to cost and effects on procedural duration.

Design

Retrospective review of the results of adrenal vein sampling procedures since commencement of point-of-care cortisol measurement using a novel single-use semi-quantitative measuring device for cortisol, the adrenal vein sampling Accuracy Kit. Measurements: Success rate and complications of adrenal vein sampling procedures before and after use of the adrenal vein sampling Accuracy Kit. Routine use of the adrenal vein sampling Accuracy Kit device for intraprocedural measurement of cortisol commenced in 2016.

Results

Technical success rate of adrenal vein sampling increased from 63% of 99 procedures to 90% of 48 procedures ( P = 0.0007) after implementation of the adrenal vein sampling Accuracy Kit. Failure of right adrenal vein cannulation was the main reason for an unsuccessful study. Radiation dose decreased from 34.2 Gy.cm2 (interquartile range, 15.8–85.9) to 15.7 Gy.cm2 (6.9–47.3) ( P = 0.009). No complications were noted, and implementation costs were minimal.

Conclusions

Point-of-care cortisol measurement during adrenal vein sampling improved cannulation success rates and reduced radiation exposure. The use of the adrenal vein sampling Accuracy Kit is now standard practice at our centre.

Scoring system for the diagnosis of bilateral primary aldosteronism in the outpatient setting before adrenal venous sampling

OBJECTIVE

The only reliable method for subtyping primary aldosteronism (PA) is adrenal venous sampling (AVS), which is costly and time-consuming. Considering the limited availability of AVS, it would be helpful to obtain information on the diagnosis of bilateral hyperaldosteronism (BHA) from routine tests. We aimed to establish new, simple criteria for outpatients to diagnose BHA from PA before AVS.

DESIGN

We retrospectively analysed 82 patients who were diagnosed with PA and underwent AVS. Thirty-seven patients were diagnosed with unilateral hyperaldosteronism (UHA), and 36 with BHA and nine were undetermined. Among the variables that were significantly different between UHA and BHA in the univariate analysis, we chose three variables to be included in multivariate logistic regression models and constructed a subtype prediction score.

RESULTS

The subtype prediction score was calculated as follows: 3 points for no adrenal nodules on computed tomography imaging, 2 for serum potassium of ≥3·5 mmol/l and 2 for aldosterone-to-renin ratio of <490 after a captopril challenge test. Receiver operating characteristic curve analysis for the ability to discriminate BHA from UHA showed that a score of 7 points had 50% sensitivity and 100% specificity and a score of 5 points had 67% sensitivity and 94% specificity (area under the curve: 0·922; 95% CI: 0·863-0·980).

CONCLUSIONS

Our new, simple criteria specifically distinguished BHA from UHA in the outpatient setting before AVS. Furthermore, not only endocrinologists but also general internists can use this convenient, safe scoring system.

New Advances in the Diagnostic Workup of Primary Aldosteronism

Primary aldosteronism is an important and common cause of hypertension that carries a high burden of morbidity. Outcomes, however, are excellent if diagnosed and treated appropriately. The diagnostic workup for primary aldosteronism is complex and comprises three steps: (1) screening, (2) confirmatory testing, and (3) subtype differentiation. In this review, we discuss recent advances in the diagnostic workup for primary aldosteronism. The development of accurate mass spectroscopy-based assays for measuring aldosterone will lead to improved confidence in all diagnostic aspects involving measurement of aldosterone, and accurate measurement of angiotensin II may soon advance us beyond the measurement of renin. We now have a greater understanding of hormonal influences on the aldosterone/renin ratio, which are particularly important when screening premenopausal women or those taking estrogen-containing preparations. Confirmatory testing is important, but there are limitations to the commonly used methods that have recently become more apparent, with new approaches offering a way forward. Adrenal venous sampling (AVS) is a challenging procedure but is important for deciding on treatment options. Success rates may be improved by the use of Synacthen stimulation and of rapid intraprocedural measurement of cortisol. Better understanding of AVS interpretation criteria allows improved prognostication and aids treatment decisions. The use of labeled metomidate positron emission tomography computed tomography scanning may also offer an alternative to AVS in some units. Although the diagnostic approach to patients with primary aldosteronism remains a complex multistep process in which attention to detail is important, recent advances will improve patient care and outcomes.

Diagnostic criteria for adrenal venous sampling

PURPOSE OF REVIEW

Primary aldosteronism accounts for 3 to 5% of all hypertension cases. Unilateral aldosterone hypersecretion can be treated with adrenalectomy. Guidelines for primary aldosteronism management recommend adrenal vein sampling (AVS) to ascertain unilateral primary aldosteronism before surgery. Many different protocols are used to perform AVS and for the interpretation of its results, but without hard evidence of why one should be given preference. Experts have proposed recommendations to guide clinical practice and the grounds for future research to address this situation.

RECENT FINDINGS

Proper patient preparation is a prerequisite for interpretable results. New trends are emerging to improve adequate cannulation of adrenal veins including: training of a limited number of dedicated radiologists, contrast computed tomography of adrenal veins before or during AVS, and rapid assays to measure cortisol concentrations during AVS. Cosyntropin stimulation is performed in several centers to avoid the variability of cortisol secretion during AVS, but whether this improves diagnostic performance is unknown.

SUMMARY

Better markers of adequate catheter placement are currently under investigation, including other adrenal steroids and metanephrines. Innovative strategies for interpreting partially failed AVS are also being developed. Other approaches to ascertain primary aldosteronism subtype will be necessary because of limited patient access to AVS.