Primary aldosteronism: the role of confirmatory tests.

The high prevalence of primary aldosteronism among hypertensives justifies large scale screening by the aldosterone-renin ratio; however, this test is subject to several variables responsible for false-positive results. Functional tests to confirm autonomous aldosterone secretion are commonly used, with the fludrocortisone suppression test considered the gold standard, and saline infusion or captopril challenge, the most practical. However, each of these tests has sub-optimal sensitivity and specificity and none has been so far prospectively validated by comparing the results with the lateralization by adrenal vein sampling and the results of surgery. Their role in confirming the diagnosis of primary aldosteronism due to unilateral adenoma remains incompletely resolved.