A 42-year-old woman is seen in the clinic because of hypertension (HTN). She was diagnosed with HTN at 34 years of age and is currently managed on chlorthalidone 25 mg daily, telmisartan 80 mg daily, and amlodipine 5 mg daily. Her mean blood pressure (BP) after three readings performed in the clinic is 142/84 mm Hg, similar to values obtained on a recent ambulatory BP monitor. A pill count demonstrates adequate medication adherence.
A screening for primary aldosteronism shows plasma renin activity (PRA) 0.5 ng/mL/hour, aldosterone level (by immunoassay) 22 ng/dL, and potassium level 4.4 mEq/L.
The correct answer is: B. Primary aldosteronism is likely.
This patient's results are consistent with primary aldosteronism. First, screening is appropriate because she met the criteria for apparent resistant HTN, presenting with persistently uncontrolled BP despite three antihypertensive therapies (including a thiazide-like diuretic) and no evidence of a white coat effect or medication nonadherence. Biochemically, her suppressed PRA (≤1 ng/mL/hour) and elevated aldosterone level (≥10 ng/dL) resulted in aldosterone-to-renin ratio >20, supporting a positive screening result.
Given this positive result, there was low concern for a false-negative result. If the result had been negative, factors that would have raised concern for a false-negative result include hypokalemia, medications that raise renin levels (i.e., mineralocorticoid-receptor antagonists [MRAs]), or low renin levels with nonelevated aldosterone levels.
Management options should be discussed via shared decision-making; namely, adrenal vein sampling for patients interested in potential surgical intervention versus empirical medical treatment with an MRA.
This patient case quiz is part of the larger Overcoming Challenges in Hypertension Management initiative, supported by AstraZeneca. To visit the Overcoming Challenges in Hypertension Management grant page and access educational activities on this topic, click here.
References
- Adler GK, Stowasser M, Correa RR, et al. Primary aldosteronism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2025;110(9):2453-2495. doi:10.1210/clinem/dgaf284
