Cost-effectiveness analysis of screening for primary aldosteronism in China

Optimizing the aldosterone-to-renin ratio cut-off for screening primary aldosteronism based on cardiovascular risk: a collaborative study

OBJECTIVES

Aldosterone-to-renin ratio (ARR) based screening is the first step in the diagnosis of primary aldosteronism (PA). However, the guideline-recommended ARR cutoff covers a wide range, from the equivalent of 1.3 to 4.9 ng·dl-1/mIU∙l-1. We aimed to optimize the ARR cutoff for PA screening based on the risk of cardiovascular diseases (CVD).

METHODS

Longitudinally, we included hypertensive participants from the Framingham Offspring Study (FOS) who attended the sixth examination cycle and followed up until 2014. At baseline (1995-1998), we used circulating concentrations of aldosterone and renin to calculate ARR (unit: ng·dl-1/mIU∙l-1) among 1,433 subjects who were free of CVD. We used spline regression to calculate the ARR threshold based on the incident CVD. We used cross-sectional data from the Chongqing Primary Aldosteronism Study (CONPASS) to explore whether the ARR cutoff selected from FOS is applicable to PA screening.

RESULTS

In FOS, CVD risk increased with an increasing ARR until a peak of ARR 1.0, followed by a plateau in CVD risk (hazard ratio 1.49, 95%CI 1.19-1.86). In CONPASS, when compared to essential hypertension with ARR < 1.0, PA with ARR ≥ 1.0 carried a higher CVD risk (odds ratio 2.24, 95%CI 1.41-3.55), while essential hypertension with ARR ≥ 1.0 had an unchanged CVD risk (1.02, 0.62-1.68). Setting ARR cutoff at 2.4 ~ 4.9, 10% ~30% of PA subjects would be unrecognized although they carried a 2.45 ~ 2.58-fold higher CVD risk than essential hypertension.

CONCLUSIONS

The CVD risk-based optimal ARR cutoff is 1.0 ng·dl-1/mIU∙l-1 for PA screening. The current guideline-recommended ARR cutoff may miss patients with PA and high CVD risk.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT03224312).

Health Care Challenges in the Management of Primary Aldosteronism in Southeast Asia

CONTEXT

While guidelines have been formulated for the management of primary aldosteronism (PA), following these recommendations may be challenging in developing countries with limited health care access.

OBJECTIVE

We aimed to assess the availability and affordability of health care resources for managing PA in the Association of Southeast Asian Nations (ASEAN) region, which includes low-middle-income countries.

METHODS

We instituted a questionnaire-based survey to specialists managing PA, assessing the availability and affordability of investigations and treatment. Population and income status data were taken from the national census and registries.

RESULTS

Nine ASEAN country members (48 respondents) participated. While screening with aldosterone-renin ratio is performed in all countries, confirmatory testing is routinely performed in only 6 countries due to lack of facilities and local assays, and cost constraint. Assays are locally available in only 4 countries, and some centers have a test turnaround time exceeding 3 weeks. In 7 countries (combined population of 442 million), adrenal vein sampling (AVS) is not routinely performed due to insufficient radiological facilities or trained personnel, and cost constraint. Most patients have access to adrenalectomy and medications. In 6 countries, the cost of AVS and adrenalectomy combined is more than 30% of its annual gross domestic product per capita. While most patients had access to spironolactone, it was not universally affordable.

CONCLUSION

Large populations currently do not have access to the health care resources required for the optimal management of PA. Greater efforts are required to improve health care access and affordability. Future guideline revisions for PA may need to consider these limitations.

Diagnostic Delay and Disease Burden in Primary Aldosteronism: An International Patient Survey

BACKGROUND

Primary aldosteronism (PA) is a common but underdiagnosed cause of hypertension. Many patients experience preventable end-organ injury due to delayed or missed diagnosis but data on the experience of patients are limited.

METHODS

We evaluated the lived experience of PA and determines factors associated with diagnostic delay through an international anonymous online cross-sectional survey, codesigned by researchers and PA consumers. We distributed the survey through academic medical centers, Amazon Mechanical Turk, Twitter, PA patient advocacy groups, and hypertension support groups on Facebook between March 21 and June 5, 2022.

RESULTS

Of 684 eligible respondents, 66.5% were women. Diagnostic delay (defined as ≥5 years between the diagnosis of hypertension and PA) was reported in 35.6%. Delay was more likely in women than in men (odds ratio, 1.55 [95% CI, 1.10-2.20]) and respondents with ≥3 comorbidities versus none (odds ratio, 1.77 [95% CI, 1.05-3.02]), ≥10 symptoms versus none (odds ratio, 2.73 [95% CI, 1.74-4.44]), and on ≥4 antihypertensive medications versus none (odds ratio, 18.23 [95% CI, 6.24-77.72]). Three-quarters of patients (74.4%) experienced reduced symptom burden following targeted PA treatment. Quality of life improved in 62.3% of patients, and greater improvement was associated with being a woman (odds ratio, 1.42, [95% CI, 1.02-1.97]), receiving adrenalectomy (odds ratio, 2.36 [95% CI, 1.67-3.35]), and taking fewer antihypertensive medications following diagnosis (odds ratio, 5.28 [95% CI, 3.55-7.90]).

CONCLUSIONS

One-third of patients with PA experienced prolonged diagnostic delays. Targeted treatment led to reduced symptom burden and improved quality of life. Gender differences in diagnostic delay and symptom burden are prominent. These findings suggest that routine screening for PA at the onset of hypertension may reduce diagnostic delay and facilitate timely diagnosis.

Cost-effectiveness of screening for primary aldosteronism in hypertensive patients in Australia: a Markov modelling analysis

BACKGROUND

Primary aldosteronism affects 3-14% of hypertensive patients in the primary care setting and up to 30% in the hypertensive referral units. Although primary aldosteronism screening is recommended in patients with treatment-resistant hypertension, diagnosis at an earlier stage of disease may prevent end-organ damage and optimize patient outcomes.

METHODS

A Markov model was used to estimate the cost-effectiveness of screening for primary aldosteronism in treatment and disease (cardiovascular disease and stroke) naive hypertensive patients. Within the model, a 40-year-old patient with hypertension went through either the screened or the unscreened arm of the model. They were followed until age 80 or death. In the screening arm, the patient underwent standard diagnostic testing for primary aldosteronism if the screening test, aldosterone-to-renin ratio, was elevated above 70 pmol/l : mU/l. Diagnostic accuracies, transition probabilities and costs were derived from published literature and expert advice. The main outcome of interest was the incremental cost effectiveness ratio (ICER).

RESULTS

Screening hypertensive patients for primary aldosteronism compared with not screening attained an ICER of AU$35 950.44 per quality-adjusted life year (QALY) gained. The results were robust to different sensitivity analyses. Probabilistic sensitivity analysis demonstrated that in 73% of the cases, it was cost-effective to screen at the commonly adopted willingness-to-pay (WTP) threshold of AU$50 000.

CONCLUSION

The results from this study demonstrated that screening all hypertensive patients for primary aldosteronism from age 40 is cost-effective. The findings argue in favour of screening for primary aldosteronism before the development of severe hypertension in the Australian healthcare setting.

Improving Detection Rates for Primary Aldosteronism

Primary aldosteronism (PA), once considered a rare disease, is being increasingly recognized as an important cause of hypertension. It is associated with higher rates of cardiovascular complications compared to blood pressure-matched essential hypertension. Targeted treatments are available which can mitigate the excess cardiovascular risks and, in some cases, cure hypertension. Making a timely diagnosis of PA is, therefore, highly beneficial for patients. Furthermore, numerous studies from different parts of the world have found PA to be a relatively common disease that can affect patients in any stage of hypertension, regardless of their age or potassium levels. Despite this well-established data, the current rate of PA detection is appallingly low, much below its actual prevalence. This review explores the challenges that clinicians often face in diagnosing PA and offers strategies that may improve the detection of this potentially curable form of hypertension.

Primary aldosteronism - a multidimensional syndrome

Primary aldosteronism is a common cause of hypertension and is a risk factor for cardiovascular and renal morbidity and mortality, via mechanisms mediated by both hypertension and direct insults to target organs. Despite its high prevalence and associated complications, primary aldosteronism remains largely under-recognized, with less than 2% of people in at-risk populations ever tested. Fundamental progress made over the past decade has transformed our understanding of the pathogenesis of primary aldosteronism and of its clinical phenotypes. The dichotomous paradigm of primary aldosteronism diagnosis and subtyping is being redefined into a multidimensional spectrum of disease, which spans subclinical stages to florid primary aldosteronism, and from single-focal or multifocal to diffuse aldosterone-producing areas, which can affect one or both adrenal glands. This Review discusses how redefining the primary aldosteronism syndrome as a multidimensional spectrum will affect the approach to the diagnosis and subtyping of primary aldosteronism.

Diagnosis and treatment of primary aldosteronism

Primary aldosteronism is a common cause of secondary hypertension associated with excess cardiovascular morbidities. Primary aldosteronism is underdiagnosed because it does not have a specific, easily identifiable feature and clinicians can be poorly aware of the disease. The diagnostic investigation is a multistep process of screening, confirmatory testing, and subtype differentiation of unilateral from bilateral forms for therapeutic management. Adrenal venous sampling is key for reliable subtype identification, but can be bypassed in patients with specific characteristics. For unilateral disease, surgery offers the possibility of cure, with total laparoscopic unilateral adrenalectomy being the treatment of choice. Bilateral forms are treated mainly with mineralocorticoid receptor antagonists. The goals of treatment are to normalise both blood pressure and excessive aldosterone production, and the primary aims are to reduce associated comorbidities, improve quality of life, and reduce mortality. Prompt diagnosis of primary aldosteronism and the use of targeted treatment strategies mitigate aldosterone-specific target organ damage and with appropriate patient management outcomes can be excellent. Advances in molecular histopathology challenge the traditional concept of primary aldosteronism as a binary disease, caused by either a unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia. Somatic mutations drive autonomous aldosterone production in most adenomas. Many of these same mutations have been identified in nodular lesions adjacent to an aldosterone-producing adenoma and in patients with bilateral disease. In addition, germline mutations cause rare familial forms of aldosteronism (familial hyperaldosteronism types 1-4). Genetic testing for inherited forms in suspected cases of familial hyperaldosteronism avoids the burdensome diagnostic investigation in positive patients. In this Review, we discuss advances and future management approaches in the diagnosis of primary aldosteronism.

[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.