What is the appropriate management for a patient with secondary hypertension?

Management of Secondary Hypertension

The appropriate management of secondary hypertension requires identifying the underlying cause through targeted screening and implementing cause-specific treatment alongside lifestyle modifications to reduce morbidity and mortality. 1

Identification and Evaluation

When to Suspect Secondary Hypertension

• Young patients (<35 years) with significant hypertension (diastolic >110 mmHg)
• New onset hypertension after age 50
• Sudden development or worsening of previously controlled hypertension
• Refractory hypertension requiring multiple medications
• Deterioration of renal function with ACE inhibitors
• Malignant hypertension with end-organ damage (BP ≥180/110 mmHg)
• Abdominal bruits or generalized arteriosclerotic occlusive disease 1

Diagnostic Approach

1. Initial Screening Tests based on suspected cause:

Suspected Cause	Recommended Screening Test
Primary aldosteronism	Aldosterone-to-renin ratio
Renovascular hypertension	Renal Doppler ultrasound, CT/MR angiography
Pheochromocytoma	24h urinary/plasma metanephrines and normetanephrines
Obstructive sleep apnea	Overnight polysomnography
Renal parenchymal disease	Renal ultrasound, urinalysis, eGFR
Cushing's syndrome	24h urinary free cortisol, dexamethasone suppression
Thyroid disease	TSH
Hyperparathyroidism	PTH, calcium, phosphate
Coarctation of aorta	Echocardiogram, CT angiogram [1]

1. Ambulatory BP monitoring to confirm true resistant hypertension and rule out white-coat hypertension 1

Cause-Specific Management

Primary Aldosteronism (20% of resistant hypertension)

• Unilateral disease: Surgical adrenalectomy
• Bilateral disease: Mineralocorticoid receptor antagonists (spironolactone, eplerenone) 1

Renovascular Hypertension

• Fibromuscular dysplasia: Renal angioplasty without stenting
• Atherosclerotic disease: Optimal cardiovascular risk management with consideration of stenting 1

Pheochromocytoma

• Surgical removal after adequate alpha-blockade
• Critical: Alpha-blockers must be initiated before beta-blockers to prevent hypertensive crisis 1

Obstructive Sleep Apnea (most prevalent secondary cause, up to 83% in resistant hypertension)

• Weight loss
• CPAP therapy
• Mandibular advancement devices 1

Medication-Induced Hypertension

• Identify and discontinue or modify offending agents:
  • NSAIDs
  • Oral contraceptives
  • Corticosteroids
  • Decongestants
  • Anticancer drugs
  • Recreational drugs (cocaine, amphetamines) 1

General Management Principles

Pharmacological Therapy

1. First-line agents:

   • RAS blockers (ACE inhibitors or ARBs)
   • Dihydropyridine calcium channel blockers
   • Thiazide/thiazide-like diuretics (preferably chlorthalidone) 1

2. For resistant hypertension:

   • Optimize current regimen by maximizing diuretic therapy
   • Ensure medication adherence
   • Add fourth-line agents: spironolactone, amiloride, doxazosin, eplerenone, clonidine, or beta-blockers 1

Essential Lifestyle Modifications

• Weight loss for overweight/obese patients
• Sodium restriction (<2g/day)
• Regular physical activity (150 minutes/week)
• DASH diet pattern
• Alcohol moderation (<3 drinks/day) 1

Monitoring and Follow-up

• Regular BP monitoring (home and office)
• Periodic assessment of target organ damage
• Monitor for medication side effects (hyperkalemia, renal function)
• Target BP: 120-129 mmHg systolic if tolerated
• Consider single-pill combinations to improve adherence 1

Common Pitfalls and Caveats

1. Underdiagnosis: Secondary hypertension is often underrecognized despite affecting 5-10% of all hypertensive adults 1, 2, 3

2. Delayed evaluation: Failing to consider secondary causes in resistant hypertension leads to missed opportunities for potential cure 4

3. Medication sequencing errors: When treating pheochromocytoma, initiating beta-blockers before alpha-blockers can precipitate a hypertensive crisis 1

4. Incomplete evaluation: Not performing ambulatory BP monitoring may lead to treating white-coat hypertension unnecessarily 1

5. Overlooking common causes: Obstructive sleep apnea is the most prevalent secondary cause but often missed in evaluation 1

6. Specialist referral timing: Complex cases should be referred early to specialists (endocrinology, nephrology, vascular surgery) rather than after multiple failed treatment attempts 1