Background: The most common pharmacologic test for diagnosis of primary aldosteronism (PA) is administration of captopril to examine whether abnormal aldosterone to plasma rennin activity(PRA)(ARR) persists, although active rennin concentration (ARC) in contrast to PRA may offers advantages with regard to processing and standardization.Objective: To assess whether post captopril ARC offer any additional advantage in screening primary aldosteronism (PA) than PRA and establish thresholds for the diagnosis using ARC.
