Resistant hypertension and renal denervation — structured written assessment

SAQ 1 (10 marks)

Practice scenario. A 54-year-old man is referred because his office BP is 158/96 mmHg despite taking perindopril, amlodipine and hydrochlorothiazide, each at the maximum dose he tolerates. He says he takes every tablet.^[1]

1. Give the 2024 ESC definition of resistant hypertension, including how it must be confirmed. (2)^[1]
2. List four causes of pseudo-resistant hypertension from ESC 2024 Table 11. (2)^[1]
3. How would you assess his adherence, with the ESC 2024 class and level? (1)^[1]
4. Give the AHA/ACC 2025 adherence row on single-pill combinations, with COR and LOE. (1)^[2]
5. Which AHA/ACC 2025 row applies to screening him for primary aldosteronism, and what are the ESC 2024 Table 13 screening tests for primary aldosteronism and obstructive sleep apnoea? (2)^[2][1]
6. What do ESC 2024 and AHA/ACC 2025 say about his thiazide diuretic? (2)^[1][2]

Model answers — SAQ 1

1. Hypertension is resistant when a treatment strategy including appropriate lifestyle measures and maximum or maximally tolerated doses of a thiazide or thiazide-like diuretic, a RAS blocker and a CCB fails to lower office systolic and diastolic BP to <140 mmHg and/or <90 mmHg, respectively (1 mark).^[1] These uncontrolled values must be confirmed by out-of-office BP measurement, HBPM or ABPM (1 mark).^[1]
2. Any four of: poor adherence to and persistence with treatment; white-coat phenomenon; poor BP measurement method; marked brachial artery calcification (Osler phenomenon); clinician inertia (inadequate doses, inappropriate combinations); Munchausen syndrome (rare) (half a mark each).^[1]
3. Careful questioning first; objective evaluation of adherence (directly observed treatment or detecting prescribed drugs in blood or urine samples) should be considered in the work-up of apparent resistant hypertension, if resources allow (Class IIa, Level B) (1 mark).^[1]
4. In adults with hypertension, a single-pill combination to reduce pill burden rather than separate pills is effective to improve medication adherence (COR 1, LOE B-R) (1 mark).^[2]
5. AHA/ACC 2025: in adults with resistant hypertension, screening for primary aldosteronism is recommended regardless of whether hypokalaemia is present (COR 1, LOE B-NR) (1 mark).^[2] ESC 2024 Table 13: aldosterone-to-renin ratio for primary aldosteronism, and overnight ambulatory polysomnography for obstructive sleep apnoea syndrome (1 mark).^[1]
6. ESC 2024: BP control may be improved by switching hydrochlorothiazide to a long-acting thiazide-like diuretic such as chlorthalidone (1 mark).^[1] AHA/ACC 2025: replacing thiazide-type diuretics (eg, HCTZ) with thiazide-like diuretics (eg, chlorthalidone and indapamide) may offer additional BP reduction and cardiovascular protection among patients with previous MI or stroke (1 mark).^[2]

SAQ 2 (10 marks)

Practice scenario. A 63-year-old woman has resistant hypertension confirmed by ABPM. Adherence is confirmed by drug detection in urine, and secondary causes have been screened for and excluded. She takes maximally tolerated telmisartan, amlodipine and chlorthalidone. Her eGFR is 52 mL/min/1.73 m² and her plasma potassium is 4.2 mmol/L.^[1][2]

1. What fourth drug do ESC 2024 and AHA/ACC 2025 advise, with class and level? (2)^[1][2]
2. Give the ESC 2024 dose of spironolactone, the eGFR and potassium limits for its use, and the monitoring advised. (2)^[1]
3. She develops breast tenderness on spironolactone. What alternatives do ESC 2024 and AHA/ACC 2025 give? (2)^[1][2]
4. BP remains uncontrolled and she asks about renal denervation. Give the ESC 2024 and AHA/ACC 2025 rows that apply. (2)^[1][2]
5. Name four contraindications from AHA/ACC 2025 Table 25, and two of the ESC 2024 concerns about renal denervation. (2)^[2][1]

Model answers — SAQ 2

1. ESC 2024: in resistant hypertension with uncontrolled BP despite first-line BP-lowering therapies, the addition of spironolactone to existing treatment should be considered (Class IIa, Level B) (1 mark).^[1] AHA/ACC 2025: with uncontrolled resistant hypertension despite optimal first-line therapy (ACEi or ARB plus CCB and a thiazide-like diuretic) and an eGFR of ≥45 mL/min/1.73 m², addition of an MRA is recommended to control BP (COR 1, LOE B-R) (1 mark).^[2]
2. Low-dose spironolactone, 25–50 mg daily, restricted to an eGFR of ≥30 mL/min/1.73 m² and a plasma potassium of ≤4.5 mmol/L (1 mark).^[1] Serum electrolytes and kidney function monitored soon after initiation and frequently thereafter (1 mark).^[1]
3. ESC 2024: if spironolactone is not tolerated because of anti-androgen side effects, eplerenone may be used, and higher doses (50–200 mg daily) and twice-daily dosing may be necessary to achieve a BP-lowering effect; in resistant hypertension when spironolactone is not effective or tolerated, eplerenone instead of spironolactone, or the addition of a beta-blocker if not already indicated and, next, a centrally acting BP-lowering medication, an alpha-blocker, hydralazine or a potassium-sparing diuretic should be considered (Class IIa, Level B) (1 mark).^[1] AHA/ACC 2025: in uncontrolled resistant hypertension when an MRA cannot be tolerated or is contraindicated, adding amiloride, a beta-blocker, an alpha-blocker, a central sympatholytic, a dual endothelin receptor antagonist or a direct vasodilator is reasonable to control BP (COR 2a, LOE B-NR); when spironolactone or eplerenone are not tolerated because of side effects or cost, amiloride (10-20 mg) has been shown to be as effective as spironolactone in adults with resistant hypertension (1 mark).^[2]
4. ESC 2024: to reduce BP, and if performed at a medium-to-high volume centre, catheter-based RDN may be considered for resistant hypertension uncontrolled despite a three-drug combination including a thiazide or thiazide-like diuretic, if she expresses a preference after a shared risk-benefit discussion and multidisciplinary assessment (Class IIb, Level B) (1 mark).^[1] AHA/ACC 2025: in carefully selected patients with systolic and diastolic hypertension (office SBP 140-180 mm Hg and DBP ≥90 mm Hg) and an eGFR of ≥40 mL/min/1.73 m² who have resistant hypertension despite optimal treatment, or intolerable side effects to additional antihypertensive drug therapy, RDN may be reasonable as an adjunct to BP medications and lifestyle modification to reduce BP (COR 2b, LOE B-R); all patients with hypertension who are being considered for RDN should be evaluated by a multidisciplinary team with expertise in resistant hypertension and RDN (COR 1, LOE B-NR) (1 mark).^[2]
5. Any four of: neurogenic orthostatic hypotension; pregnancy; fibromuscular dysplasia; stented renal artery; renal artery aneurysm; significant renal artery stenosis; known kidney or secreting adrenal tumours (1 mark).^[2] Any two of: a relatively modest BP-lowering effect for an invasive procedure; cost-effectiveness not fully established; no adequately powered outcomes trials; possible late complications of an "always on" effect; effects on catheterisation laboratory workflow; no direct evidence that the kidneys are denervated and do not reinnervate (1 mark).^[1]