Unilateral Primary Aldosteronism, Mineralocorticoid Antagonists Versus Surgical Treatment - A Randomized Controlled Trial

Background

Primary aldosteronism (PA) is caused by hypersecretion of the adrenal hormone aldosterone and is the most common cause of secondary hypertension . The estimated prevalence of PA is 5-13% in the hypertensive population.

In half of the cases, PA is caused by unilateral hypersecretion of aldosterone, most commonly from an aldosterone producing adenoma. Overproduction from both adrenals is seen in the other half, usually caused by bilateral idiopathic hyperplasia. Unilateral adrenalectomy is considered to be the treatment of choice for unilateral PA and mineralocorticoid receptor antagonists (MRAs, i.e. spironolactone or eplerenone) for bilateral PA . Untreated PA is associated with a greatly increased risk for several comorbidities, especially cardiovascular diseases and renal failure, as well as death.

Studies comparing surgical and medical treatment for PA are scarce. Nevertheless, a recent meta-analysis indicated that cardiovascular outcome is better in surgically than medically treated patients . In addition, quality of life seems to improve more after surgery, and the need for antihypertensive medications, and overall health care consumption,seems to be lower following surgery . However, suboptimal dosing of MRA is common in medically treated patients with PA, which makes a fair comparison between surgically treated patients difficult.

To identify candidates for surgical treatment, adrenal venous sampling (AVS) is necessary to confirm unilateral disease . However, AVS is a technically demanding procedure, with a mean success rate in non-specialized centres of only 32% . This, and the fact that AVS is not widely available, suggests that a substantial number of patients with unilateral PA are never identified and thereby not considered for surgical treatment .