How Common is Primary Aldosteronism as a Cause of Hypertension?

A revised guideline from The Endocrine Society acknowledges that primary aldosteronism is going undiagnosed and untreated more often than previously thought.

Management of Primary Aldosteronism: Guideline Update
​Alexander M Castellino, PhD
​Medscape Internal Medicine
May 03, 2016

The Endocrine Society has issued a clinical practice guideline that calls for expanded screening for primary aldosteronism (PA). The recommendations are published in the May issue of the Journal of Clinical Endocrinology & Metabolism.

"In the past 8 years we noted that primary aldosteronism, despite being quite common, frequently goes undiagnosed and untreated," John W Funder, MD, PhD, of the Hudson Institute of Medical Research in Clayton, Australia, and chair of the task force that authored the guideline, told Medscape Medical News.

Patients with primary aldosteronism are at a 12-fold higher risk for atrial fibrillation, fourfold higher risk for nonfatal heart attack, and sixfold higher risk for stroke compared with age-, sex-, and blood-pressure–matched subjects with essential hypertension.

Properly targeted treatment is very important for these patients, Dr Funder explained. "These guidelines differ from those issued in 2008 in their explicit recognition of primary aldosteronism as a public-health issue and recommend that all patients suspected of primary aldosteronism be screened," he said.

Primary aldosteronism occurs when one or more adrenal glands secrete excess aldosterone (a steroid hormone) into the bloodstream, which leads to hypertension due to sodium retention. Unilateral aldosterone-producing aldosteromas or bilateral adrenal hyperplasias are together responsible for ~95% of primary aldosteronism cases, Dr Funder pointed out.

Who Should Be Screened?
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The Endocrine Society recommends primary aldosteronism screening for patients who meet the following criteria:

• Patients with hypertension (>140/90 mm Hg) with hypokalemia.
• Patients with hypertension and sleep apnea.
• Patients with sustained blood pressure above 150/100 mm Hg in three separate measurements taken on different days.
• Patients with resistant hypertension (uncontrolled with three conventional antihypertensive drugs).
• Patients with hypertension controlled with four or more medications.
• Patients with hypertension and an adrenal incidentaloma (mass in the adrenal gland).
• Patients with an early onset of hypertension (<40 years of age) and those with a family history of early-onset hypertension or stroke.
• Patients with first-degree relatives with hypertension and a diagnosis of primary aldosteronism.

​"With 70 million patients in the United States living with hypertension, primary aldosteronism may well account for seven million of these cases," Dr Funder said.  "Many people with primary aldosteronism never get screened due to the associated costs," he added.

Endocrinologists, PCPs, and GPs Targeted

Endocrinologists are the key target physicians for these guidelines. But Dr Funder explained that primary-care physicians (PCPs) or general practitioners who see patients on a regular basis will also be included with the co-release of a laminated sheet that explains the guideline. This will ensure that PCPs are aware of primary aldosteronism and will also encourage them to refer patients to an endocrinologist or hypertension center if they suspect primary aldosteronism in any of their patients.

Cardiologists are not the main focus of these guidelines, he added — this is an endocrine disease and is best managed by an endocrinologist or a center established for managing patients across the hypertension spectrum.

The Screening Test and Treatment

The recommended test for screening primary aldosteronism is the plasma aldosterone-to-renin ratio (ARR) test. "Although the test is accepted as a screening test worldwide, differences exist in how these findings should be interpreted," Dr Funder told Medscape Medical News. It is not uncommon to repeat the test, he added.

If patients test positive for primary aldosteronism, they should undergo a confirmatory or exclusion test, he explained. One of six globally available tests should be used, but there is no agreement on which of these is the "gold standard," he explained. But he remains hopeful that when these guidelines next get updated, there will be agreement on one confirmatory test for universal use.

And according to the guideline, all patients diagnosed with primary aldosteronism should undergo a computed tomography scan of the adrenal glands to screen for adrenocortical carcinoma, a rare disease associated with early mortality.

Patients with primary aldosteronism also need to undergo "lateralization" by an interventional radiologist. In the process, an experienced radiologist samples blood drained from each adrenal vein to determine whether primary aldosteronism is associated with one or both adrenals producing excess aldosterone, Dr Funder explained.

"Laparoscopic adrenalectomy to remove the adrenal in question is the treatment of choice for patients with unilateral primary aldosteronism [overactivity in one adrenal]," he said. However, some patients are contraindicated for surgery and not all patients choose to undergo this treatment due to the high cost of lateralization.

"In all these cases, treatment with a mineralocorticoid receptor antagonist [MRA], a drug that antagonizes the action of aldosterone, is strongly recommended and is the preferred treatment option," Dr Funder noted. Bilateral primary aldosteronism is managed by treating patients with an MRA in combination with other medications as required, he added.

"This ensures that patients with primary aldosteronism resulting in uncontrolled high blood pressure do not go untreated," he said.
The Clinical Practice Guideline was cosponsored by the American Heart Association, the American Association of Endocrine Surgeons, the European Society of Endocrinology, the European Society of Hypertension, the International Association of Endocrine Surgeons, the International Society of Hypertension, the Japan Endocrine Society and the Japanese Society of Hypertension.

​The authors of the clinical practice guideline have no relevant financial relationships.