Primary Aldosteronism: Does Underlying Pathology Impact Clinical Presentation and Outcomes Following Unilateral Adrenalectomy?

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.

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

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

Novel chemiluminescent immunoassay to measure plasma aldosterone and plasma active renin concentrations for the diagnosis of primary aldosteronism

Determination of plasma aldosterone concentrations (PAC) and plasma active renin concentrations (ARC) is essential for the diagnosis of primary aldosteronism (PA). In Japan, although PAC and ARC are measured by radioimmunoassay and immunoradiometric assay, respectively, non-radioisotopic methods with better detection sensitivity, measurement accuracy, and technical simplicity are needed. We developed two-site sandwich chemiluminescent enzyme immunoassays (CLEIAs) to measure both PAC and ARC using monoclonal antibodies immobilized onto ferrite particles. The results of both assays are obtained simultaneously from a single plasma sample within 30 min using a fully automated system. The novel CLEIAs were validated using plasma samples from patients with PA (n = 52) and essential hypertension (n = 23). The PAC determined by the CLEIA was significantly correlated with that measured by liquid chromatography/mass spectrometry or conventional radioimmunoassay. The ARC determined by the CLEIA was significantly correlated with that measured by immunoradiometric assay. The limits of detection of the CLEIAs for PAC and ARC were 0.1 ng/dl and 0.04 pg/ml, respectively, which were better than those of conventional methods (PAC: 2.5 ng/dl; ARC: 5 pg/ml). The PAC and PAC/ARC ratio (ARR) were significantly higher, and the ARC significantly lower, in patients with PA than in those with essential hypertension. An ARR cut-off of 1.31 ng/dl per pg/ml showed a sensitivity of 96.2% and specificity of 78.3% for PA screening. The newly developed CLEIAs for measuring PAC and ARC could provide a clinically powerful alternative to conventional methods used for hypertension screening in clinical practice.

Single-Center Prospective Cohort Study on the Histopathology, Genotype, and Postsurgical Outcomes of Patients With Primary Aldosteronism

[Figure: see text].

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

OBJECTIVE

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Minimally Invasive Partial Versus Total Adrenalectomy for the Treatment of Primary Aldosteronism: Results of a Multicenter Series According to the PASO Criteria

BACKGROUND

Determination of success after adrenal-sparing surgery for primary aldosteronism (PA) is limited by the lack of standardized definitions of outcomes.

OBJECTIVE

To evaluate the safety and effectiveness of minimally invasive partial adrenalectomy (MIPA) for PA by comparing perioperative and functional outcomes with minimally invasive total adrenalectomy (MITA) according to the Primary Aldosteronism Surgical Outcome (PASO) criteria.

DESIGN, SETTING, AND PARTICIPANTS

Between March 2011 and April 2020, a multicenter adrenalectomy dataset was queried for "unilateral adrenal mass, PA, MIPA (n = 29), or MITA (n = 61)"at four participating Institutions.

INTERVENTION

MITA and MIPA for PA.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Differences between continuous variables were assessed with the Wilcoxon rank sum test, while Pearson's χ² test was used for categorical data. Complete, partial, and absent clinical success rates were assessed for the overall cohort and compared between groups.

RESULTS AND LIMITATIONS

The median tumor size was significantly higher in the MITA group (4.2 vs 2.7 cm; p = 0.001), while preoperative hypertension rate was significantly higher in the MIPA series (82.8% vs 57.4%, p = 0.01). The median length of hospital stay was increased in the MITA cohort (4 vs 3 d; p = 0.038). Overall, at a median follow-up of 42 mo (interquartile range 27-54 mo), complete, partial, and absent clinical success was observed in 60%, 17.7%, and 22.3% of cases, respectively. The complete clinical success rate was higher in the MIPA group (72.4% vs 54.1%), while a partial clinical success was higher in the MITA series (23% vs 6.8%). The absence of clinical success was comparable between groups (MITA 23% vs MIPA 20.7%).

CONCLUSIONS

MIPA showed excellent perioperative results with a complete clinical success rate of 72.4%. Owing to the heterogeneity of the PASO criteria in the assessment of partial or absent success, the quest for a univocal definition of satisfactory clinical outcomes in the treatment of PA remains open.

PATIENT SUMMARY

We compared minimally invasive partial adrenalectomy (MIPA) and minimally invasive total adrenalectomy for the treatment of unilateral primary aldosteronism, assessing the outcomes with the Primary Aldosteronism Surgical Outcome (PASO) criteria. MIPA seems to provide comparable perioperative outcomes and midterm clinical success rates.