SFE/SFHTA/AFCE consensus on primary aldosteronism, part 3: Confirmatory testing

Aldosterone/renin ratio (ARR) identifies patients at high or low risk of primary aldosteronism (PA), but sensitivity and especially specificity are suboptimal and confirmatory testing may therefore be necessary, in some but not all patients. In patients with elevated ARR and plasma aldosterone concentration above 550pmol/L (20ng/dL) on two assessments, PA can be diagnosed without confirmatory testing. Conversely, PA can be ruled out without confirmatory testing in patients with normal ARR and plasma aldosterone concentration below 240pmol/L (9ng/dL) on two assessments. In patients not corresponding to either of the previous conditions, dynamic confirmatory testing is mandatory. Several tests are available, based on aldosterone suppression by saline loading, fludrocortisone administration or converting enzyme inhibition by captopril. One test is based on renin stimulation by furosemide administration. Each of these tests has its limitations, and validation is incomplete. We recommend aldosterone suppression by saline infusion test. Renin stimulation by captopril may be used if sodium loading is contraindicated by impaired cardiac function.