What is the treatment approach for secondary hypertension?

Treatment Approach for Secondary Hypertension

The treatment of secondary hypertension should primarily focus on identifying and addressing the underlying cause while simultaneously controlling blood pressure with appropriate medications. 1

Diagnostic Evaluation

Before initiating treatment, proper identification of the underlying cause is essential:

• Clinical indicators requiring screening:

  • Resistant hypertension (BP >140/90 mmHg despite three optimal-dose medications including a diuretic)
  • Early-onset hypertension (<30 years of age)
  • Sudden onset or worsening of previously controlled hypertension
  • Severe hypertension
  • Target organ damage disproportionate to hypertension duration/severity 2

• Basic screening tests:

  • Blood tests: serum sodium, potassium, creatinine, eGFR, TSH
  • Urine analysis: dipstick, albumin-to-creatinine ratio
  • 12-lead ECG 1, 2

Treatment Approach by Underlying Cause

1. Primary Aldosteronism (8-20% of resistant hypertension)

• Medical treatment: Mineralocorticoid receptor antagonists

  • Spironolactone (50-100 mg daily, can be titrated up to 300-400 mg)
  • Eplerenone (less potent but fewer side effects like gynaecomastia) 1

• Surgical treatment: Unilateral adrenalectomy for unilateral disease

  • Not an option for bilateral disease 1

2. Renovascular Hypertension

• Fibromuscular dysplasia:

  • Percutaneous transluminal renal angioplasty without stenting is the treatment of choice 1

• Atherosclerotic renal artery stenosis:

  • Medical therapy is the preferred option when renal function is preserved
  • Treatment includes lifestyle modifications, low-dose aspirin, statin, and antihypertensive medications
  • Consider thiazide diuretic, calcium antagonist, and RAS blockers (except in bilateral stenosis) 1

• Indications for revascularization:

  • Refractory hypertension despite three-drug regimen including diuretic
  • Progressive decline in renal function 1

3. Obstructive Sleep Apnea (25-50% of resistant hypertension)

• Treatment options:
  • Weight loss
  • Continuous positive airway pressure (CPAP)
  • Mandibular advancement devices 1

4. Phaeochromocytoma/Paraganglioma

• Screening: Plasma or 24-hour urinary metanephrine and normetanephrine 1
• Treatment: Surgical removal after appropriate preoperative preparation

5. Resistant Hypertension Management

When secondary causes have been ruled out or treated but BP remains uncontrolled:

• Optimize current regimen:

  • Maximize diuretic therapy (consider thiazide-like rather than thiazide diuretics)
  • Use loop diuretics for eGFR <30 ml/min/1.73m² 1

• Add fourth-line agent:

  • Spironolactone (if serum potassium <4.5 mmol/L and eGFR >45 ml/min/1.73m²)
  • If spironolactone is contraindicated: amiloride, doxazosin, eplerenone, clonidine, or beta-blockers 1

• Consider renal denervation:

  • May be considered for patients with uncontrolled BP despite three-drug combination
  • Should be performed at medium-to-high volume centers after multidisciplinary assessment 1

Important Considerations

• Residual hypertension: Despite appropriate treatment of secondary causes, BP rarely returns to completely normal with long-term follow-up, indicating either concomitant essential hypertension or irreversible vascular remodeling 3

• Specialist referral: Complex cases of secondary hypertension should be managed in specialized centers with appropriate expertise and resources 1

• Medication-induced hypertension: Always review current medications that may contribute to hypertension (NSAIDs, oral contraceptives, sympathomimetics, corticosteroids, erythropoietin, cyclosporine, tacrolimus) 2

• Early detection importance: Early identification and treatment of secondary hypertension are crucial to minimize irreversible changes in the vasculature and target organs 3

By systematically identifying and addressing the underlying cause of secondary hypertension while maintaining appropriate blood pressure control, clinicians can significantly improve morbidity, mortality, and quality of life outcomes for these patients.