What is hyperaldosteronism (primary aldosteronism)?

From the Guidelines

Hyperaldosteronism should be treated with either surgical removal of the affected adrenal gland for unilateral primary aldosteronism or with mineralocorticoid receptor antagonists (MRAs) such as spironolactone or eplerenone for bilateral primary aldosteronism, as these approaches can significantly improve blood pressure control and reduce the risk of cardiovascular complications and kidney damage. The diagnosis of primary aldosteronism typically involves blood tests to measure aldosterone and renin levels, followed by confirmatory tests such as salt loading tests or captopril challenge tests 1.

Diagnosis and Screening

The aldosterone:renin activity ratio is currently the most accurate and reliable means of screening for primary aldosteronism, with a cutoff value of 30 when plasma aldosterone concentration is reported in nanograms per deciliter (ng/dL) and plasma renin activity in nanograms per milliliter per hour (ng/mL/h) 1. Patients with hypertension and a history of early onset hypertension and/or cerebrovascular accident at a young age may have primary aldosteronism due to glucocorticoid-remediable aldosteronism (familial hyperaldosteronism type-1) and therefore warrant screening 1.

Treatment Options

For unilateral primary aldosteronism, surgical removal of the offending adrenal gland is typically considered, unless the patient is older or has co-morbidities of concern 1. Medical treatment is currently based on MRAs, with spironolactone being the most widely available, and eplerenone being an alternative option with less gynaecomastia and erectile dysfunction in men 1. The effective dose of spironolactone can be titrated up to 300–400 mg once daily, if necessary.

Importance of Treatment

The condition is important to identify because it represents a potentially curable form of hypertension, and untreated hyperaldosteronism can lead to cardiovascular complications and kidney damage 1. Regular monitoring of blood pressure, electrolytes, and kidney function is essential during treatment. Newer agents, such as the non-steroidal MRAs finerenone and exarenone, and the aldosterone synthase inhibitor baxdrostat, are also being tested for treating primary aldosteronism 1.

Key Considerations

• Primary aldosteronism is one of the most frequent disorders that causes secondary hypertension, occurring in 5% to 10% of patients with hypertension and 20% of patients with resistant hypertension 1.
• Patients with primary aldosteronism have a higher risk of cardiovascular complications and kidney damage compared to patients with primary hypertension 1.
• The diagnosis and treatment of primary aldosteronism can significantly improve blood pressure control and reduce the risk of cardiovascular complications and kidney damage 1.

From the Research

Definition and Prevalence of Hyperaldosteronism

• Hyperaldosteronism, also known as primary aldosteronism, is a condition characterized by the excessive production of aldosterone, a hormone that regulates sodium and potassium levels in the body 2, 3.
• The prevalence of primary hyperaldosteronism is estimated to be around 10% of all hypertensive patients, making it a significant contributor to secondary hypertension 2, 3.

Diagnosis and Confirmation of Hyperaldosteronism

• The aldosterone-to-renin ratio is the most sensitive screening test for primary aldosteronism 3.
• Confirmatory tests, such as the furosemide test, are used to confirm the diagnosis of primary aldosteronism 3.
• Adrenal CT scans and bilateral adrenal vein sampling are used to determine the subtype of primary aldosteronism and guide treatment decisions 3, 4.

Treatment Options for Hyperaldosteronism

• Unilateral laparoscopic adrenalectomy is the preferred treatment for patients with aldosterone-producing adenomas 3, 4.
• Mineralocorticoid receptor antagonists, such as spironolactone and eplerenone, are used to treat patients with bilateral adrenal hyperplasia or those who are not candidates for surgery 2, 3, 5.
• Additional treatment with potassium-sparing diuretics or calcium channel antagonists may be necessary in some cases 2.

Pharmacological Treatment of Aldosterone Excess

• Spironolactone is a highly effective treatment for primary aldosteronism, but can cause significant side effects due to its limited selectivity for the mineralocorticoid receptor 5.
• Eplerenone is a more selective mineralocorticoid receptor antagonist with fewer side effects, but may be less potent than spironolactone 5.
• New agents, such as non-steroidal mineralocorticoid receptor antagonists and aldosterone synthase inhibitors, are being developed to treat primary aldosteronism 5.

Use of Aldosterone Antagonists in Resistant Hypertension

• Aldosterone antagonists, such as spironolactone, have been shown to be effective in treating resistant hypertension, even in patients without evidence of hyperaldosteronism 6.
• The use of aldosterone antagonists in patients with resistant hypertension may provide additional benefits beyond blood pressure control, such as reducing cardiovascular morbidity and mortality 6.