Our evolving understanding of primary aldosteronism

Screening for Primary Aldosteronism by Mass Spectrometry Versus Immunoassay Measurements of Aldosterone: A Prospective Within-Patient Study

BACKGROUND

Measurements of aldosterone by mass spectrometry are more accurate and less prone to interferences than immunoassay measurements, and may produce a more accurate aldosterone:renin ratio (ARR) when screening for primary aldosteronism (PA).

METHODS

Differences in diagnostic performance of the ARR using mass spectrometry vs immunoassay measurements of aldosterone were examined in 710 patients screened for PA. PA was confirmed in 153 patients and excluded in 451 others. Disease classifications were not achieved in 106 patients. Areas under receiver-operating characteristic curves (AUROC) and other measures were used to compare diagnostic performance.

RESULTS

Mass spectrometry-based measurements yielded lower plasma aldosterone concentrations than immunoassay measurements. For the ARR based on immunoassay measurements of aldosterone, AUROCs were slightly lower (P = 0.018) than those using mass spectrometry measurements (0.895 vs 0.906). The cutoff for the ARR to reach a sensitivity of 95% was 30 and 21.5 pmol/mU by respective immunoassay and mass spectrometry-based measurements, which corresponded to specificities of 57% for both. With data restricted to patients with unilateral PA, diagnostic sensitivities of 94% with specificities >81% could be achieved at cutoffs of 61 and 52 pmol/mU for respective immunoassay and mass spectrometry measurements.

CONCLUSIONS

Mass spectrometry-based measurements of aldosterone for the ARR provide no clear diagnostic advantage over immunoassay-based measurements. Both approaches offer limited diagnostic accuracy for the ARR as a screening test. One solution is to employ the higher cutoffs to triage patients likely to have unilateral PA for further tests and possible adrenalectomy, while using the lower cutoffs to identify others for targeted medical therapy.German Clinical Trials Register ID: DRKS00017084.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

'I can't understand why others don't screen more': a qualitative study exploring why Australian general practitioners screen for primary aldosteronism

OBJECTIVE

We sought to understand the factors that influence a general practitioner's (GP's) experience of screening for primary aldosteronism (PA) in hypertensive patients.

DESIGN

A qualitative study, framed by phenomenology, using semistructured interviews that were audiorecorded, transcribed verbatim, entered into NVivo V.12.0 for coding and analysed for emerging themes.

SETTING

Melbourne, Australia.

PARTICIPANTS

Eligible GPs had received education on PA as part of a previous study. We recruited a purposive sample of 16 GPs (6 females, 10 males) who varied in practice location, clinical experience and the number of patients screened for PA.

RESULTS

Although GPs had been educated about PA, they found it challenging to explain the condition to patients and were uncertain about how to screen patients who were already taking antihypertensive medications. Most viewed the screening process to be practical, inexpensive and, by and large, acceptable to their patients. However, they found it inconvenient to alter antihypertensive medications before screening to allow for easier interpretation of the aldosterone-renin ratio. They were also less enthused about screening patients whom they thought fitted a clinical picture of essential hypertension. Knowledge of the screening process, cost and convenience of performing the aldosterone-renin ratio, conceptualisation of risk related to PA, and a desire to improve clinical care were influencing factors that modified the GPs' screening experience.

CONCLUSION

Our findings suggest that knowledge gaps, practical limitations of the aldosterone-renin ratio, and errors in diagnostic reasoning were challenges of routine PA screening. Most of these practical barriers could be addressed by relatively simple educational and practice modifications to increase PA screening rates and optimise detection for the most common cause of secondary hypertension in primary care.

Current challenges in laboratory diagnostics of autonomous cortisol secretion in adrenal incidentalomas

Adrenal incidentalomas are unexpectedly identified adrenal masses without prior suspicion of the existence of adrenal disease. The majority of adrenal incidentalomas are benign adrenal adenomas (80-90%), and they are non-functioning adrenocortical adenomas in more than 70% of cases. Mild hypercortisolemia is the most common finding in hormonally active adrenal incidentalomas. It is defined as autonomous cortisol secretion in up to 15% of patients. Despite a lot of research that anticipated higher cardiometabolic risk in patients with autonomous cortisol secretion, there is still no clear consensus on biochemical criteria for an autonomous cortisol secretion diagnosis in patients with adrenal incidentalomas. This review delineates the advantages and limitations of different laboratory tests recommended for the diagnosis of autonomous cortisol secretion in adrenal incidentalomas.

[Expert opinion. Spironolactone: a new twist on an old story]

The article presents recent data on possibilities of a broader use of mineralocorticoid receptor antagonists for existing indications and of expanding indications for the use of this pharmaceutical group in the context of the novel coronavirus infection COVID-19. The authors discussed prospects for expanded detection of aldosteronism using a new diagnostic approach, including an additional evaluation of blood pressure response to spironolactone.