Primary Aldosteronism: Are We Missing the Wood for the Trees?

Abstract

The prevalence of primary aldosteronism (PA) is around 10% of hypertensives, with markedly increased risk of cardiovascular damage compared with age-, sex- and BP-matched essential hypertension (EH). Currently, if hypertension is present in 20% of the population, PA will account for 2%; of these PA patients only 1% are ever screened, let alone diagnosed and treated, and the remaining 99% suboptimally treated, if at all. Mineralocorticoid receptor (MR) antagonists are effective in lowering BP, uniquely vasoprotective and safe when titrated to effect in EH. In resistant hypertension (BP elevated despite 3 or more conventional agents, including a diuretic), which constitutes 20-30% of EH, addition of a low dose MR antagonist reproducibly produces BP lowering of 20-30 mm Hg. Two thirds of PA is unilateral, and normally treated by MR antagonists; in unilateral PA surgery is recommended, but there are also studies reporting MR antagonist therapy to be noninferior over the longer term. There thus seems to be a very strong case for including a low dose MR antagonist in first-line therapy for new hypertension, given its utility and safety across EH, its particular efficacy in resistant hypertension, and its specific benefits for the 99% of subjects with occult PA. We do not have the resources to diagnose PA, but we do have the wherewithal to treat it.