Secondary hypertension — structured written assessment

SAQ 1 (10 marks)

Practice scenario. A 45-year-old woman has hypertension (office BP 150/95 mmHg) confirmed by home BP monitoring. She takes amlodipine and hydrochlorothiazide, and her serum potassium is 3.2 mmol/L. She is not obese and has no symptoms of sleep apnoea.^[1][2]

1. Give one ESC 2024 row and one AHA/ACC 2025 row that make her eligible for primary aldosteronism screening, with class and COR. (2)^[1][2]
2. How should she be prepared for the aldosterone-to-renin ratio, and what values does AHA/ACC 2025 give for interpreting it? (2)^[2]
3. From ESC 2024 Table 12, name two drug classes that cause a false-positive ratio and two that cause a false-negative ratio. (2)^[1]
4. Her ratio is positive. Outline the AHA/ACC 2025 sequence that follows. (2)^[2]
5. Give the ESC 2024 spironolactone dose for primary aldosteronism and one advantage and one disadvantage of eplerenone. (2)^[1]

Model answers — SAQ 1

1. ESC 2024: either screening for primary aldosteronism by renin and aldosterone measurements should be considered in all adults with confirmed hypertension (BP ≥140/90 mmHg) (Class IIa, Level B), or patients with hypertension presenting with suggestive signs, symptoms or medical history of secondary hypertension should be appropriately screened (Class I, Level B), since ESC 2024 calls spontaneous or diuretic-induced hypokalaemia strongly suggestive of primary aldosteronism (1 mark).^[1] AHA/ACC 2025: screening is recommended in adults with hypertension and any listed condition, which includes hypokalaemia, spontaneous or diuretic induced (COR 1, LOE C-EO) (1 mark).^[2]
2. AHA/ACC 2025: unrestricted salt intake, serum potassium in the normal range (to avoid false-negative testing), and ideally any MRA withdrawn for at least 4 weeks; her hypokalaemia should be corrected first (1 mark).^[2] Renin activity typically suppressed (<1 ng/mL/h); most data support aldosterone of at least 10 ng/dL to call the test positive, but additional evaluation may be indicated if renin activity is suppressed; most commonly used ratio cut-off 30 (aldosterone in ng/dL, renin activity in ng/mL/h), although some data support alternative thresholds of 20 or 40 (1 mark).^[2]
3. False positive: any two of beta-adrenergic blockers, alpha-2 agonists (clonidine, methyldopa), NSAIDs, steroids, or contraceptive agents containing drospirenone (1 mark).^[1] False negative: any two of ACE inhibitors, ARBs, potassium-sparing diuretics, potassium-wasting diuretics, or short-acting dihydropyridine CCBs (1 mark).^[1]
4. Referral to a hypertension specialist or endocrinologist after a positive screen (COR 1, LOE C-EO); the diagnosis may require an aldosterone suppression test such as an IV saline suppression test or oral salt-loading test (1 mark).^[2] If confirmed and she agrees surgery would be desirable, adrenal venous sampling; unilateral excess leads to laparoscopic adrenalectomy, and bilateral excess, unsuitability for or no interest in surgery leads to an MRA (1 mark).^[2]
5. Spironolactone: usually 50–100 mg once daily, titrated up to 300–400 mg once daily if necessary (1 mark).^[1] Eplerenone: causes less gynaecomastia and erectile dysfunction in men, but is less potent than spironolactone and needs twice-daily administration (1 mark).^[1]

SAQ 2 (10 marks)

Practice scenario. A 29-year-old woman has hypertension that has become difficult to control on three drugs, including a diuretic. An abdominal bruit is heard. Her eGFR is 88 mL/min/1.73 m².^[3]

1. List four clinical signs suggestive of renal artery disease from Table 13 of the 2024 ESC peripheral arterial and aortic diseases guideline. (2)^[3]
2. Which imaging rows does that guideline give, with class and level? (2)^[3]
3. Imaging shows a haemodynamically significant stenosis due to fibromuscular dysplasia. What does the 2024 ESC hypertension guideline say about intervention and about further imaging? (2)^[1]
4. Give the AHA/ACC 2025 rows for atherosclerotic and non-atherosclerotic renal artery stenosis that address revascularisation. (2)^[2]
5. Why does ESC 2024 urge caution with RAS blockers in renovascular disease, and what is bystander renal artery stenosis? (2)^[1]

Model answers — SAQ 2

1. Any four of: hypertension onset before 30 years of age; severe hypertension after 55 years with CKD or heart failure; hypertension and abdominal bruit; rapid and persistent worsening of previously controlled hypertension; resistant hypertension (other secondary forms unlikely); hypertensive crisis; new azotaemia or worsening renal function after RAAS blockers; unexplained atrophic kidney, kidney size discrepancy or unexplained renal failure; flash pulmonary oedema (half a mark each).^[3]
2. Duplex ultrasound is recommended as the first-line imaging modality in patients with suspicion of renal artery stenosis (Class I, Level B) (1 mark).^[3] With DUS-based suspicion of stenosis or inconclusive DUS, MRA or CTA are recommended (Class I, Level B) (1 mark).^[3]
3. Renal artery angioplasty without stenting should be considered for hypertension with haemodynamically significant renal artery stenosis due to fibromuscular dysplasia (Class IIa, Level C) (1 mark).^[1] Because fibromuscular dysplasia is a systemic disease, CT or MRI angiography from head to pelvis is recommended in FMD-related renovascular hypertension (1 mark).^[1]
4. Atherosclerotic, with failed medical management (eg, resistant hypertension, worsening kidney function and/or acute heart failure): referral for percutaneous angioplasty and/or stent placement is reasonable (COR 2a, LOE C-EO) (1 mark).^[2] Non-atherosclerotic, including fibromuscular dysplasia: referral for revascularisation by percutaneous angioplasty may be reasonable (COR 2b, LOE C-LD) (1 mark).^[2]
5. RAS blockers need careful monitoring of renal function because they can cause acute renal failure in tight bilateral stenoses or a stenosed solitary functioning kidney (1 mark).^[1] Bystander renal artery stenosis may be present in essential hypertension without causing secondary hypertension due to renovascular disease (1 mark).^[1]