Confirmatory tests in the diagnosis of primary aldosteronism

Primary aldosteronism is the most common form of secondary hypertension and patients with hyperaldosteronism are more prone to premature cardiovascular complications compared to essential hypertensives. The diagnostic flow-chart for the diagnosis of PA is performed in three steps: a) screening; b) confirmation; and c) subtype differentiation. Instead of proceeding directly to subtype classification, the recently published Endocrine Society Guidelines recommend that patients with a positive ARR should undergo a confirmatory test, in order to definitively confirm or exclude the diagnosis of PA. The Guidelines recognize four testing procedures: oral sodium loading, saline infusion, fludrocortisone suppression, and captopril challenge. Herein we discuss the diagnostic protocols for these confirmatory tests and highlight both the advantages and contraindications and we discuss studies in which these confirmatory tests have been compared.