Fuss CT, Brohm K, Fassnacht M, et al. - According to this cohort study, postural stimulation testing (PST) is a simple, non-invasive contribution to subtype differentiation in primary aldosteronism (PA) due to its high specificity of 100% for the detection of unilateral PA in patients with decreased aldosterone by at least 28% after 4 hours.

• There were 106 patients with confirmed PA (unilateral PA: n = 55, bilateral PA: n = 29, AVS unsuccessful/declined by patients: n = 22).

• Based on a ≥ 28% decrease in aldosterone plasma concentration after 4 hours in the upright position, the PST had a sensitivity of 36.4% and a specificity of 100% for identifying unilateral disease.

• PST sensitivity increased to 51.4% with a specificity of 100% in patients with valid testing (drop of cortisol ≥ 10% after 4 hours, n = 53).