Who and How Should We Screen for Primary Aldosteronism?

There are mounting data that at least 30% of hypertensives who are appropriately screened have primary aldosteronism (PA), rather than the commonly reported figure of 5% to 10%. Second, there are similar data that undertreated patients with PA have a 3-fold higher risk profile than essential hypertensives with the same blood pressure levels. Third, clinicians managing hypertension measure success as sustainable lowering of blood pressure; untreated hypertensive patients with PA are thus in double jeopardy. Finally, and crucially, fewer than 1% of patients with hypertension are ever screened-let alone investigated-for PA. Accordingly, for "Who should we screen?" the answer is simple-all patients with hypertension. For "How they should be screened?" the answer is also simple-add spironolactone 25 mg/day for 4 weeks and measure the blood pressure response. In established hypertension, a fall of <10 mm Hg means PA is unlikely; above 12 mm Hg PA, it is probable. Newly presenting hypertension is much the same-hold off on first-order antihypertensive(s) and prescribe spironolactone 25 mg/day for 4 weeks. If blood pressure falls into the normal range, continue; if it does not, prescribe a standard antihypertensive. It is likely that the above protocols-a first start, amenable to refinement-will find additional hypertensives with unilateral PA; it is probable that the overwhelming majority will have bilateral disease. What this means is that we have a major public health issue on our hands: how can this be the case?