The role of confirmatory tests in the diagnosis of primary aldosteronism

The strategy for diagnosis of primary aldosteronism (PA) in the hypertensive population includes firstly a screening step, based on the measurement of plasma aldosterone-to-renin ratio (ARR), a test which must have high sensitivity, and secondly a confirmatory step based on the demonstration of excessive aldosterone production independent of the renin-angiotensin-aldosterone system (RAAS) activity. The high proportion of false-positive ARR results and conversely of actual PA without a persistent elevation in baseline plasma aldosterone concentration necessitates the addition of a confirmatory step in the work-up of PA diagnosis. The present review focuses on the description of the different dynamic tests available for demonstrating autonomy of aldosterone secretion, on the performance and limitations of confirmatory tests and on possible strategies for PA diagnosis which may either include or avoid the confirmatory step for PA diagnosis. Large prospective studies comparing different strategies with and without dynamic testing are mandatory to delineate clearly the role and limits of confirmatory tests in the work-up of PA.