What is the initial workup for secondary hypertension?

From the Guidelines

The initial workup for secondary hypertension should include a thorough assessment of history, physical examination, basic blood biochemistry, and dipstick urine analysis, as recommended by the 2020 international society of hypertension global hypertension practice guidelines 1. When evaluating patients with suspected secondary hypertension, it is essential to consider the patient's age, medical history, and clinical presentation.

• Patients with early onset hypertension (<30 years of age), resistant hypertension, sudden deterioration in BP control, hypertensive urgency and emergency, or those presenting with high probability of secondary hypertension based on strong clinical clues should be screened for secondary hypertension 1.
• The basic screening should include a comprehensive history, physical examination, basic blood biochemistry (including serum sodium, potassium, eGFR, TSH), and dipstick urine analysis 1.
• Further investigations for secondary hypertension (additional biochemistry/imaging/others) should be carefully chosen based on information from history, physical examination, and basic clinical investigations 1.
• It is also crucial to exclude pseudoresistant hypertension and drug/substance-induced hypertension before proceeding with further investigations for secondary hypertension, particularly in patients with resistant hypertension 1.
• Referral to a specialist center with access to appropriate expertise and resources should be considered for further investigation and management of suspected secondary hypertension 1.

From the Research

Initial Workup for Secondary Hypertension

The initial workup for secondary hypertension involves a combination of clinical evaluation, laboratory tests, and imaging studies. The following are some of the key components of the initial workup:

• Clinical history and physical examination to identify potential causes of secondary hypertension, such as symptoms suggestive of pheochromocytoma or renal artery stenosis 2, 3
• Laboratory tests, including:
  • Electrolytes, urea, and creatinine to evaluate renal function 4, 3
  • Aldosterone:renin ratio to screen for primary aldosteronism 2, 3
  • Urinalysis and urine albumin:creatinine ratio to evaluate renal function and detect proteinuria 3
• Imaging studies, such as:
  • Abdominal magnetic resonance imaging or computed tomography to detect renal artery stenosis or fibromuscular dysplasia 2
  • Renal ultrasonography to evaluate renal parenchymal disease, particularly in children 2
• 24-hour ambulatory blood pressure monitoring to evaluate blood pressure patterns and detect potential causes of secondary hypertension, such as obstructive sleep apnea 5

Patient Selection for Screening

Not all patients with hypertension require screening for secondary hypertension. The following patients should be considered for screening:

• Those with early-onset or severe hypertension 3
• Those with resistant hypertension 2, 3
• Those with a suggestive family history or clinical clues pointing to a specific secondary cause 3
• Those with symptoms or signs suggestive of a specific secondary cause, such as pheochromocytoma or renal artery stenosis 2, 3

Additional Considerations

The initial workup for secondary hypertension should be tailored to the individual patient's clinical presentation and risk factors. Specialist advice may be sought if needed, and further investigation should be prompted by abnormal laboratory or imaging results 3.