Primary hyperaldosteronism vs Renovascular hypertension
How to tell Primary hyperaldosteronism and Renovascular hypertension apart when a board question makes them look alike.
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Suppressed renin with elevated aldosterone is the key discriminator for primary aldosteronism.
Side by side
Resistant hypertension with suppressed renin and spontaneous or diuretic-provoked hypokalemia suggests primary aldosteronism.
Severe hypertension with elevated renin and aldosterone, abdominal bruit, or sudden creatinine rise after ACE inhibitor suggests renovascular disease.
Autonomous aldosterone secretion from adrenal adenoma or bilateral hyperplasia causes sodium retention and potassium wasting.
Renal artery stenosis lowers renal perfusion and drives renin-mediated secondary hyperaldosteronism.
Screening pattern is plasma aldosterone above 15 ng/dL with aldosterone renin ratio above 20 to 30 and suppressed plasma renin activity; confirm with saline suppression test failure.
Renovascular pattern shows high plasma renin activity with secondary aldosterone elevation, asymmetric kidney size on imaging, and stenosis on CT angiography, MR angiography, or duplex ultrasound.
The trap
A common pitfall is diagnosing primary aldosteronism from hypokalemia alone. The resolving clue is renin behavior: suppressed renin supports primary aldosteronism, while elevated renin supports renovascular hypertension.
The repair move
Next best step: measure morning aldosterone and renin ratio after correcting potassium and adjusting interfering medications when possible. If ratio is elevated with suppressed renin, perform confirmatory suppression testing and then adrenal CT plus adrenal venous sampling to direct surgery versus mineralocorticoid receptor blockade; if renin is high, evaluate renal arteries and treat renovascular disease plus blood pressure control.
Try a free question
CoreA 50-year-old woman with hypertension on three medications has potassium 3.0 mEq/L, aldosterone 22 ng/dL, and plasma renin activity 0.1 ng/mL/h. What is the next best step in management?
Show answer and explanation
Answer: A. Confirm primary aldosteronism with suppression testing. A positive screening profile for primary aldosteronism requires confirmatory suppression testing before subtype-directed treatment.
Why the other choices are tempting
- B. Stenting is not first step without evidence of renovascular anatomy and high renin pattern.
- C. Potassium alone does not treat the endocrine cause.
- D. Thiazides usually worsen hypokalemia.
- E. This biochemical profile is not typical essential hypertension.
Flashcards
Tap a card to flip it.
What renin pattern points to primary hyperaldosteronism in resistant hypertension?
Renin suppression despite elevated aldosterone is the classic biochemical pattern.
What lab profile supports renovascular hypertension instead?
Both renin and aldosterone are elevated because reduced renal perfusion drives the RAAS axis.
Quick answers
What is the fastest way to tell Primary hyperaldosteronism from Renovascular hypertension?
Suppressed renin with elevated aldosterone is the key discriminator for primary aldosteronism.
What is the key clue for Primary hyperaldosteronism?
Resistant hypertension with suppressed renin and spontaneous or diuretic-provoked hypokalemia suggests primary aldosteronism.
What is the key clue for Renovascular hypertension?
Severe hypertension with elevated renin and aldosterone, abdominal bruit, or sudden creatinine rise after ACE inhibitor suggests renovascular disease.
What is the common trap with Primary hyperaldosteronism vs Renovascular hypertension?
A common pitfall is diagnosing primary aldosteronism from hypokalemia alone. The resolving clue is renin behavior: suppressed renin supports primary aldosteronism, while elevated renin supports renovascular hypertension.