Right adrenal venography findings correlated with C-arm CT for selection during C-arm CT-assisted adrenal vein sampling in primary aldosteronism

Validating Machine Learning Models Against the Saline Test Gold Standard for Primary Aldosteronism Diagnosis

Background

In this study, we developed and validated machine learning models to predict primary aldosteronism (PA) in hypertensive East-Asian patients, comparing their performance against the traditional saline infusion test. The motivation for this development arises from the need to provide a more efficient and standardized diagnostic approach, because the saline infusion test, although considered a gold standard, is often cumbersome, is time-consuming, and lacks uniform protocols. By offering an alternative diagnostic method, this study seeks to enhance patient care through quicker and potentially more reliable PA detection.

Objectives

This study sought to both develop and evaluate the performance of machine learning models in detecting PA among hypertensive participants, in comparison to the standard saline loading test.

Methods

We used patient data from 3 distinct cohorts: TAIPAI (Taiwan Primary Aldosteronism Investigation), CONPASS (Chongqing Primary Aldosteronism Study), and a South Korean cohort. Random Forest's importance scores, XGBoost, and deep learning techniques are adopted to identify the most predictive features of primary aldosteronism.

Results

We present detailed results of the model's performance, including accuracy, sensitivity, and specificity. The Random Forest model achieved an accuracy of 0.673 (95% CI: 0.640-0.707), significantly outperforming the baseline models.

Conclusions

In our discussion, we address both the strengths and limitations of our study. Although the machine learning models demonstrated superior performance in predicting primary aldosteronism, the generalizability of these findings may be limited to East-Asian hypertensive populations. Future studies are needed to validate these models in diverse demographic settings to enhance their applicability.

Cone-beam computed tomography is not a mandatory procedure in adrenal venous sampling for primary hyperaldosteronism

Objectives

To investigate the necessity of cone-beam computed tomography (CBCT) in adrenal venous sampling (AVS).

Methods

This retrospective study included 120 consecutive patients with primary hyperaldosteronism who underwent AVS. Based on the learning curve of the interventional radiologists, the patients were divided into the learning (n = 36) and proficiency (n = 84) groups chronologically. Based on the imaging pattern of the right adrenal vein (RAV), the patients were divided into the typical (n = 36) and atypical (n = 84) groups. The success rate, radiation dose, and sampling time were compared among the entire study population and each subgroup.

Results

A total of 69 patients underwent CBCT, whereas 51 patients did not. The overall success rate was 85.8%, and no difference was noted between patients with and without CBCT (P = 0.347). However, radiation dose (P = 0.018) and sampling time (P = 0.001) were significantly higher in patients who underwent CBCT than in patients who did not. In learning group, CBCT improved success rate from 62.5 to 96.4% (P = 0.028), whereas it was not found in the proficiency group (P = 0.693). Additionally, success rate in patients with an atypical RAV imaging pattern was significantly higher when CBCT was used than when it was not used (P = 0.041), whereas no difference was noted in patients with typical RAV imaging pattern (P = 0.511).

Conclusion

For physicians not very experienced doing AVS, there is a clear significant improvement in success rate when CBCT is used. However, CBCT only has minimal benefit for experienced operators, meanwhile CBCT may take an extra time and increase the radiation dose during AVS.

Prevalence and clinical characteristics of primary aldosteronism in a tertiary-care center in Korea

Approximately 29% of Korean adults have hypertension; however, the prevalence of primary aldosteronism among the hypertensive population is largely unknown. The aim of our study was to evaluate the prevalence and clinical characteristics of primary aldosteronism in a tertiary-care center in Korea. We retrospectively analyzed 1173 patients with newly diagnosed or preexisting hypertension who were referred to our tertiary-care hospital between January 2013 and December 2018. Patients were screened for primary aldosteronism with the aldosterone-renin ratio and underwent a saline infusion test for diagnostic confirmation. Adrenal computed tomography and adrenal venous sampling were performed for subtype classification for primary aldosteronism. Among the 1173 patients (mean age, 51.8 years; women, 53.2%), 360 (30.7%) had positive screening-test results, of whom 71 (6.1%) were finally diagnosed with primary aldosteronism. Conclusive subtype differentiation was made in 55 patients, of whom 15 (27%) had an aldosterone-producing adenoma, 4 (7%) had unilateral adrenal hyperplasia, and 36 (66%) had bilateral adrenal hyperplasia. Patients with primary aldosteronism had a higher ambulatory blood pressure, left ventricular mass index, and urinary albumin-to-creatinine ratio than those without. Moreover, the primary aldosteronism group had a higher prevalence of left ventricular hypertrophy and albuminuria than the non-primary aldosteronism group. Primary aldosteronism may be more common (6.1%) among Korean patients with hypertension than generally recognized. Primary aldosteronism was associated with a higher degree and prevalence of target organ damage and a higher blood pressure level. Wide application of screening tests for primary aldosteronism may be beneficial in detecting this potentially curable cause of hypertension.

Adrenal venous sampling in primary hyperaldosteronism: correlation of hormone indices and collimated C-arm CT findings

PURPOSE

To evaluate the feasibility and effect of an approach to adrenal venous sampling (AVS) analysis by combining established selective cortisol and aldosterone indices with the acquisition of a collimated C-arm CT(CACT_Coll).

METHODS

Overall, 107 consecutive patients (45f,62 m; 54 ± 10 years) undergoing 111 AVS procedures without hormonal stimulation from 7/13 to 2/20 in a single institution were retrospectively analysed. Hormone levels were measured in sequential samples of the suspected adrenal veins and right iliac vein, and selectivity indices (SI) computed. Stand-alone SI_Cortisol and/or SI_Aldosterone ≥ 2.0 as well as SI_Cortisol and/or SI_Aldosterone ≥ 1.1 combined with positive right-sided CACT_Coll of the adrenals (n = 80; opacified right adrenal vein) were defined as a successful AVS procedure. Radiation exposure of CACT was measured via dose area product (DAP) and weighed against an age-/weight-matched cohort (n = 66).

RESULTS

Preliminary success rates (SI_Cortisol and/or SI_Aldosterone ≥ 2.0) were 99.1% (left) and 72.1% (right). These could be significantly increased to a 90.1% success rate on the right, by combining an adjusted SI of 1.1 with a positive CACT_Coll proving the correct sampling position. Sensitivity for stand-alone collimated CACT (CACT_Coll) was 0.93, with 74/80 acquired CACT_Coll confirming selective cannulation by adrenal vein enhancement. Mean DAP_{Coll_CACT} measured 2414 ± 958 μGyxm², while mean DAP_{Full-FOV_CACT} in the matched cohort measured 8766 ± 1956 μGyxm² (p < 0.001).

CONCLUSION

Collimated CACT in AVS procedures is feasible and leads to a significant increase in success rates of (right-sided) selective cannulation and may in combination with adapted hormone indices, offer a successful alternative to previously published AVS analysis algorithms with lower radiation exposure compared to a full-FOV CACT.

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.

Advanced monoenergetic reconstruction technique in dual-energy computed tomography for evaluation of vascular anatomy before adrenal vein sampling

Background

In adrenal vein sampling, selecting the right adrenal vein is technically difficult and it is important to evaluate the right adrenal vein anatomy before adrenal vein sampling. The advanced monoenergetic reconstruction technique has recently become available and we hypothesized that this technique may be useful.

Purpose

To evaluate the usefulness of the advanced monoenergetic reconstruction technique in dual-energy computed tomography (CT; advanced monoenergetic images) for evaluation of vascular anatomy before adrenal vein sampling.

Material and Methods

Twenty-one patients underwent three-phase (20, 30, and 70 s) contrast-enhanced CT before adrenal vein sampling. Advanced monoenergetic images were reconstructed at 40 keV and analyzed objectively and subjectively in comparison with the standard 120-kVp images. As objective evaluation, the signal-to-noise ratio and contrast-to-noise ratio of the right adrenal vein were assessed. As subjective evaluation, two radiologists assessed the delineation of the right adrenal vein using a 5-point Likert scale (1 = poor, 5 = excellent). Furthermore, the technical success rate of adrenal vein sampling and procedure time were also evaluated.

Results

There was no difference in the signal-to-noise ratio between the two groups. The contrast-to-noise ratios of the right adrenal vein of advanced monoenergetic images were higher than those of the standard images ( P < 0.05). The Likert scores of advanced monoenergetic images were higher than those of the standard images ( P < 0.05). The technical success rate of adrenal vein sampling was 95% (20/21) and the median of procedure time was 103 min (range = 59–197 min).

Conclusion

Advanced monoenergetic imaging appears to be useful in the delineation of the right adrenal vein before adrenal vein sampling.

Surgical outcomes of laparoscopic adrenalectomy for primary hyperaldosteronism: 20 years of experience in a single institution

Purpose

Recently, posterior retroperitoneoscopic adrenalectomy (PRA) has been reported to have some advantages over laparoscopic transperitoneal adrenalectomy (LTA). The objectives of this study were to report our experience over 12 years with laparoscopic adrenalectomy for primary hyperaldosteronism (PHA) and to examine surgical outcomes of PRA compared with LTA in patients with PHA.

Methods

The medical records of 527 patients who underwent minimally invasive adrenalectomy, including LTA or PRA, from January 2006 until May 2017 were reviewed at Severance Hospital (Seoul, Korea). Clinicopathologic characteristics and surgical outcomes of 146 patients with PHA who underwent LTA (19 patients) or PRA (127 patients) were analyzed retrospectively by complete chart review.

Results

The overall rates of biochemical and clinical cure were 91.1% and 93.1%, respectively. The mean operation time of the PRA group was significantly shorter than that of the LTA group (72.3 ± 24.1 minutes vs. 115.7 ± 69.7 minutes, P = 0.015). The length of hospital stay in the PRA group was significantly shorter than in the LTA group (3.5 ± 1.3 days vs. 4.2 ± 1.6 days, P = 0.029), and the first meal after surgery came earlier in the PRA group (0.3 ± 0.5 days vs. 0.6 ± 0.5 days, P = 0.049). The number of pain-killers used was also significantly smaller in the PRA group (2.3 ± 2.1 vs. 4.3 ± 2.3, P < 0.001).

Conclusion

PRA offers an alternative or likely superior method for treatment of small adrenal diseases such as PHA, with improved surgical outcomes.

Effects of Altered Calcium Metabolism on Cardiac Parameters in Primary Aldosteronism

BACKGROUND

Increasing evidence supports interplay between aldosterone and parathyroid hormone (PTH), which may aggravate cardiovascular complications in various heart diseases. Negative structural cardiovascular remodeling by primary aldosteronism (PA) is also suspected to be associated with changes in calcium levels. However, to date, few clinical studies have examined how changes in calcium and PTH levels influence cardiovascular outcomes in PA patients. Therefore, we investigated the impact of altered calcium homeostasis caused by excessive aldosterone on cardiovascular parameters in patients with PA.

METHODS

Forty-two patients (mean age 48.8±10.9 years; 1:1, male:female) whose plasma aldosterone concentration/plasma renin activity ratio was more than 30 were selected among those who had visited Severance Hospital from 2010 to 2014. All patients underwent adrenal venous sampling with complete access to both adrenal veins.

RESULTS

The prevalence of unilateral adrenal adenoma (54.8%) was similar to that of bilateral adrenal hyperplasia. Mean serum corrected calcium level was 8.9±0.3 mg/dL (range, 8.3 to 9.9). The corrected calcium level had a negative linear correlation with left ventricular end-diastolic diameter (LVEDD, ρ=-0.424, P=0.031). Moreover, multivariable regression analysis showed that the corrected calcium level was marginally associated with the LVEDD and corrected QT (QTc) interval (β=-0.366, P=0.068 and β=-0.252, P=0.070, respectively).

CONCLUSION

Aldosterone-mediated hypercalciuria and subsequent hypocalcemia may be partly involved in the development of cardiac remodeling as well as a prolonged QTc interval, in subjects with PA, thereby triggering deleterious effects on target organs additively.

C-Arm Computed Tomography-Assisted Adrenal Venous Sampling Improved Right Adrenal Vein Cannulation and Sampling Quality in Primary Aldosteronism

BACKGROUND

Adrenal venous sampling (AVS) is a gold standard for subtype classification of primary aldosteronism (PA). However, this procedure has a high failure rate because of the anatomical difficulties in accessing the right adrenal vein. We investigated whether C-arm computed tomography-assisted AVS (C-AVS) could improve the success rate of adrenal sampling.

METHODS

A total of 156 patients, diagnosed with PA who underwent AVS from May 2004 through April 2017, were included. Based on the medical records, we retrospectively compared the overall, left, and right catheterization success rates of adrenal veins during the periods without C-AVS (2004 to 2010, n=32) and with C-AVS (2011 to 2016, n=124). The primary outcome was adequate bilateral sampling defined as a selectivity index (SI) >5.

RESULTS

With C-AVS, the rates of adequate bilateral AVS increased from 40.6% to 88.7% (P<0.001), with substantial decreases in failure rates (43.7% to 0.8%, P<0.001). There were significant increases in adequate sampling rates from right (43.7% to 91.9%, P<0.001) and left adrenal veins (53.1% to 95.9%, P<0.001) as well as decreases in catheterization failure from right adrenal vein (9.3% to 0.0%, P<0.001). Net improvement of SI on right side remained significant after adjustment for left side (adjusted SI, 1.1 to 9.0; P=0.038). C-AVS was an independent predictor of adequate bilateral sampling in the multivariate model (odds ratio, 9.01; P<0.001).

CONCLUSION

C-AVS improved the overall success rate of AVS, possibly as a result of better catheterization of right adrenal vein.

Progress in the Management of Primary Aldosteronism

Primary aldosteronism (PA) is now considered as one of leading causes of secondary hypertension, accounting for 5-10% of all hypertensive patients and more strikingly 20% of those with resistant hypertension. Importantly, those with the unilateral disease could be surgically cured when diagnosed appropriately. On the other hand, only a very limited portion of those suspected to have PA has been screened, diagnosed, or treated to date. With current advancement in medical technologies and genetic research, expanding knowledge of PA has been accumulated and recent achievements have also been documented in the care of those with PA. This review is aimed to have focused description on updated topics of the following; importance of PA screening both in the general and specialized settings and careful interpretation of screening data, recent achievements in hormone assays and sampling methods and their clinical relevance, and expanding knowledge on PA genetics. Improvement in workup processes and novel treatment options, as well as better understanding of the PA pathogenesis based on genetic research, might be expected to result in increased cure and better care of the patients.

Cone-beam computed tomography with automated bone subtraction in preoperative embolization for pelvic bone tumors

PURPOSE

To evaluate the usefulness of cone-beam computed tomography with automated bone subtraction (CBCT-ABS) in the preoperative embolization of hypervascular tumors located in the pelvic bone.

MATERIALS AND METHODS

This retrospective study included 26 patients with pelvic bone tumors who underwent preoperative embolization between January 2014 and October 2016. A CBCT-ABS scan was taken in a total of 17 patients (CBCT-ABS group), and only a series of digital subtraction angiographies (DSAs) was taken in the remaining 9 patients (DSA group). The percent devascularization, number of angiographic runs, total dose-area product (DAP), fluoroscopy time, interventional procedure time, operative time, and estimated blood loss were compared between the two groups using Mann-Whitney test.

RESULTS

The percent devascularization, interventional procedure time, fluoroscopy time, operative time, and estimated blood loss were not statistically different between the two groups (p > 0.05). On the other hand, the number of angiographic runs in the CBCT-ABS group was significantly lower than that in the DSA group (p = 0.029). The total DAP of the CBCT-ABS group (mean, 17700.7 μGym2) was higher than that of the DSA group (mean, 8939.4 μGym2) (p = 0.002).

CONCLUSIONS

The use of CBCT-ABS during the preoperative embolization of pelvic bone tumors significantly reduces the number of angiographic runs at the cost of an increased radiation dose.

Adrenal hormones before and after venography during adrenal venous sampling: a self-controlled study

OBJECTIVE

A stress reaction involving increased adrenal hormone release occurs when starting adrenal venous sampling (AVS). The purpose of the present study was to investigate the effect of single shot venography on adrenal hormone production during AVS.

SUBJECTS AND METHODS

This was a prospective self-controlled study. We enrolled 54 consecutive patients (21 men, 33 women; mean age 52 ± 11 years) with primary aldosteronism who underwent AVS from May 2014 to February 2015. Under non-stimulated conditions, blood samples were obtained from a common trunk of the left adrenal vein before and after single shot venography. The initial plasma aldosterone and cortisol concentration (PAC and PCC) were compared with those measured after venography for each patient.

RESULTS

PAC and PCC were slightly but significantly decreased between before and after venography (after log transformation 2.12 ± 0.73 vs 2.07 ± 0.72, P = 0.00066, 1.89 ± 0.52 vs 1.83 ± 0.53, P = 0.00031, respectively).

CONCLUSIONS

During non-stimulated left AVS, adrenal hormone secretion was slightly but significantly decreased after venography, similar to the normal time-related stress reaction. Venography did not increase the adrenal hormone secretion.

Cardiac Dysfunction in Association with Increased Inflammatory Markers in Primary Aldosteronism

BACKGROUND

Oxidative stress in primary aldosteronism (PA) is thought to worsen aldosterone-induced damage by activating proinflammatory processes. Therefore, we investigated whether inflammatory markers associated with oxidative stress is increased with negative impacts on heart function as evaluated by echocardiography in patients with PA.

METHODS

Thirty-two subjects (mean age, 50.3±11.0 years; 14 males, 18 females) whose aldosterone-renin ratio was more than 30 among patients who visited Severance Hospital since 2010 were enrolled. Interleukin-1β (IL-1β), IL-6, IL-8, monocyte chemoattractant protein 1, tumor necrosis factor α (TNF-α), and matrix metalloproteinase 2 (MMP-2), and MMP-9 were measured. All patients underwent adrenal venous sampling with complete access to both adrenal veins.

RESULTS

Only MMP-2 level was significantly higher in the aldosterone-producing adenoma (APA) group than in the bilateral adrenal hyperplasia (BAH). Patients with APA had significantly higher left ventricular (LV) mass and A velocity, compared to those with BAH. IL-1β was positively correlated with left atrial volume index. Both TNF-α and MMP-2 also had positive linear correlation with A velocity. Furthermore, MMP-9 showed a positive correlation with LV mass, whereas it was negatively correlated with LV end-systolic diameter.

CONCLUSION

These results suggest the possibility that some of inflammatory markers related to oxidative stress may be involved in developing diastolic dysfunction accompanied by LV hypertrophy in PA. Further investigations are needed to clarify the role of oxidative stress in the course of cardiac remodeling.

Non-stimulated adrenal venous sampling using Dyna computed tomography in patients with primary aldosteronism

In this retrospective study, we aimed to examine the effect of applying Dyna computed tomography (CT) on the success rate of adrenal venous sampling (AVS) without adrenocorticotropic hormone stimulation. A total of 100 consecutive patients with primary aldosteronism who underwent AVS between May 2012 and July 2015 were enrolled. In all the cases, Dyna CT was used in AVS to validate catheter position in the right adrenal vein. A selectivity index (cortisol_{adrenal vein} /cortisol_{inferior vena cava}) of ≥2.0 of both adrenal veins were required for successful AVS. Dyna CT indicated misplaced catheters in 16 patients; of these patients, 75% (12/16) eventually had successful right AVS after catheter repositioning. The success rate of initial sampling at the right adrenal vein was 76% (76/100), which increased to 88% (88/100) after Dyna CT was applied (p < 0.001). The most common inadvertently catheterised vessels detected using Dyna CT were the accessory hepatic veins (56.3%, 9/16), followed by the renal capsular veins (37.5%, 6/16). The overall success rate of non-stimulated AVS using Dyna CT was 87% (87/100). Thus, the application of Dyna CT further increased the success rate of non-stimulated AVS.

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.