Unilateral Disease Is Common in Patients With Primary Aldosteronism Without Adrenal Nodules

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).

The impact of superselective adrenal artery embolization on renal function in patients with primary aldosteronism: a prospective cohort study

Superselective adrenal artery embolization (SAAE) is an effective treatment for patients with primary aldosteronism (PA). However, the impact of SAAE on renal function in the PA population remains uncertain. We investigated the estimated glomerular filtration rate (eGFR) and age, sex, body mass index, and diabetes-specific percentiles of eGFR residuals in 182 PA patients treated with SAAE in a prospective cohort from Nanchang SAAE in treating PA registry study. Data suggest that SAAE caused a significant decrease in eGFR from 91.9 ± 26.1 to 88.7 ± 24.1 ml/min/1.73 m2 (p < 0.05) after a median follow-up of 8 months in PA patients. Patients experienced a significant decrease in eGFR from 110.6 ± 18.9 to 103.8 ± 18.2 ml/min/1.73 m2 (p < 0.001) and a very slight increase from 71.1 ± 14.8 to 71.8 ± 17.8 ml/min/1.73 m2 (p = 0.770) with baseline eGFR ≥90 and <90 ml/min/1.73 m2, respectively. Patients with high eGFR residuals (glomerular hyperfiltration) experienced a significant decrease in their eGFR levels from 123.1 ± 22.6 to 105.0 ± 18.6 ml/min/1.73 m2 (p < 0.001). In contrast, there was no significant impact of SAAE on the eGFR of patients with normal or low eGFR residuals. The very early eGFR changes (24 h after SAAE) best predicted the effect of SAAE on eGFR changes after median of eight months in PA patients. On the whole, SAAE seems to have a beneficial impact on renal function in patients with PA, the results of which vary depending on the patient's baseline eGFR and glomerular hyperfiltration status.

Multiple radiologist review of adrenal CT still frequently misses lateralized surgical primary aldosteronism

Patients with primary aldosteronism (PA) have increased morbidity and mortality compared to those with essential hypertension. Accurate detection of lateralized PA is important so that affected patients can receive potentially curative adrenalectomy. However, around 40% of patients with lateralized PA have "normal" adrenal glands on computed tomography (CT). Additional independent review of imaging has been shown to improve diagnostic accuracy in many areas of imaging. Therefore, the authors sought to establish if multi-reader re-assessment of previously reported normal CT scans would result in increased detection of surgically remediable disease. The authors found that re-assessment of CT imaging by one, two, or three additional radiologists (or a combination thereof) slightly increased the detection of lateralized disease, but these differences were not statistically significant (p > .05). Readers had low inter-observer agreement (kappa = 0.17). If detection of a discrete nodule on CT was made a prerequisite for adrenal vein sampling (AVS), a second read by another reviewer would still result in an excess of missed cases (84.2%, 36.8%, and 65.8%, respectively, for each of the three independent reviewers). Therefore, a "normal" CT does not preclude the possibility of lateralized PA. Adrenal vein sampling should still be strongly considered wherever available and whenever surgery is considered for treatment of PA, irrespective of CT findings.

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.

External Validation of Clinical Prediction Models in Unilateral Primary Aldosteronism

BACKGROUND

Targeted treatment of primary aldosteronism (PA) is informed by adrenal vein sampling (AVS), which remains limited to specialized centers. Clinical prediction models have been developed to help select patients who would most likely benefit from AVS. Our aim was to assess the performance of these models for PA subtyping.

METHODS

This external validation study evaluated consecutive patients referred for PA who underwent AVS at a tertiary care referral center in Alberta, Canada during 2006–2018. In alignment with the original study designs and intended uses of the clinical prediction models, the primary outcome was the presence of lateralization on AVS. Model discrimination was evaluated using the C-statistic. Model calibration was assessed by comparing the observed vs. predicted probability of lateralization in the external validation cohort.

RESULTS

The validation cohort included 342 PA patients who underwent AVS (mean age, 52.1 years [SD, 11.5]; 201 [58.8%] male; 186 [54.4%] with lateralization). Six published models were assessed. All models demonstrated low-to-moderate discrimination in the validation set (C-statistics; range, 0.60–0.72), representing a marked decrease compared with the derivation sets (range, 0.80–0.87). Comparison of observed and predicted probabilities of unilateral PA revealed significant miscalibration. Calibration-in-the-large for every model was >0 (range, 0.35–1.67), signifying systematic underprediction of lateralizing disease. Calibration slopes were consistently <1 (range, 0.35–0.87), indicating poor performance at the extremes of risk.

CONCLUSIONS

Overall, clinical prediction models did not accurately predict AVS lateralization in this large cohort. These models cannot be reliably used to inform the decision to pursue AVS for most patients.

Apparent failed and discordant adrenal vein sampling: A potential confounding role of cortisol cosecretion?

OBJECTIVE

Adrenal vein sampling (AVS) and computed tomography (CT) often show confusingly discordant lateralisation results in primary aldosteronism (PA). We tested a biochemical algorithm using AVS data to detect cortisol cosecretion as a potential explanation for discordant cases.

DESIGN

Retrospective analysis from a large PA + AVS database.

PATIENTS

All patients with PA and AVS, 2005-2020.

MEASUREMENTS

An algorithm using biochemical data from paired AVS + CT images was devised from physiological first principles and informed by data from unilateral, AVS-CT concordant patients. The algorithm involved calculations based upon the expectation that low cortisol levels exist in adrenal vein effluent opposite an aldosterone-and-cortisol-producing adrenal mass and may reverse lateralisation due to inflated aldosterone/cortisol ratios.

MAIN OUTCOMES

The algorithm was applied to cases with discordant CT-AVS lateralisation to determine whether this might be a common or explanatory finding. Clinical and biochemical characteristics of identified cases were collected via chart review and compared to CT-AVS concordant cases to detect evidence of biological plausibility for cortisol cosecretion.

RESULTS

From a total of 588 AVS cases, 141 AVS + CT pairs were clear unilateral PA cases, used to develop the three-step algorithm for AVS interpretation. Applied to 88 AVS + CT discordant pairs, the algorithm suggested possible cortisol cosecretion in 40%. Case review showed that the proposed cortisol cosecretors, as identified by the algorithm, had low/suppressed adrenocorticotropic hormone levels, larger average nodule size and lower plasma aldosterone.

CONCLUSIONS

Pending external validation and outcome verification by surgery and tissue immunohistochemistry, cortisol cosecretion from aldosteronomas may be a common explanation for discordant CT-AVS results in PA.

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.

Surgical Outcomes Among Primary Aldosteronism Patients Without Visible Adrenal Lesions

CONTEXT

Many patients with unilateral primary aldosteronism (PA) have normal adrenal imaging, but little is known about their outcome following adrenalectomy.

OBJECTIVE

To evaluate biochemical and clinical outcomes after adrenalectomy in patients with unilateral PA and normal-appearing adrenal imaging.

DESIGN

Retrospective cohort study of patients seen between January 2006 and May 2018.

SETTING

A Canadian tertiary care PA referral center.

PATIENTS

Consecutive individuals with PA, normal cross-sectional adrenal imaging, and lateralizing adrenal vein sampling (AVS) who underwent adrenalectomy during the study period.

PRIMARY OUTCOME

Biochemical response to adrenalectomy graded according to the Primary Aldosteronism Surgical Outcome criteria.

RESULTS

A total of 40 patients were included. Biochemical outcomes were available for 33 people (mean age, 54.7 years; 91% male; median follow-up, 2.7 months), with 28 (85%) showing a complete or partial response and 5 (15%) with no response. Clinical outcomes were available for 36 people (mean age, 54.6 years; 86% male; median follow-up, 9.8 months), with 31 (86%) demonstrating a complete or partial response and 5 (14%) with no response.

CONCLUSIONS

The prognosis after adrenalectomy is highly favorable for patients with unilateral PA and normal-appearing adrenal imaging. Patients with lateralizing disease should be considered for surgery despite apparently normal adrenal imaging.