What is the recommended work-up for a patient with suspected secondary hypertension (HTN)?

From the Guidelines

The recommended work-up for suspected secondary hypertension begins with a thorough clinical evaluation to identify specific causes, as outlined in the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1. Initial assessment should include a detailed medical history focusing on medication use (including OTC drugs, supplements, and illicit substances), family history, and symptoms suggesting specific etiologies. Physical examination should assess for signs like abdominal bruits, cushingoid features, or differences in blood pressure between limbs. Laboratory testing should include basic metabolic panel, urinalysis, thyroid function tests, and plasma aldosterone-to-renin ratio if primary aldosteronism is suspected. Some key points to consider in the work-up include:

• Screening for primary aldosteronism with aldosterone-to-renin ratio, as suggested by the 2024 ESC guidelines 1
• Evaluating for renovascular hypertension with renal doppler ultrasound or abdominal CT angiogram or MRI, as recommended in the 2024 ESC guidelines 1
• Assessing for phaeochromocytoma/paraganglioma with 24 h urinary and/or plasma metanephrine and normetanephrine, as outlined in the 2024 ESC guidelines 1
• Considering referral to a specialist center with access to appropriate expertise and resources for further investigation and management of suspected secondary hypertension, as suggested by the 2020 International Society of Hypertension global hypertension practice guidelines 1 Imaging studies are selected based on clinical suspicion: renal ultrasound or CT angiography for renovascular causes, CT or MRI of adrenal glands for pheochromocytoma or primary aldosteronism, and polysomnography for obstructive sleep apnea. 24-hour ambulatory blood pressure monitoring helps confirm true hypertension and identify white coat or masked hypertension. Additional specialized tests may include 24-hour urinary metanephrines for pheochromocytoma, dexamethasone suppression test for Cushing's syndrome, or renal artery duplex ultrasound for renal artery stenosis. This systematic approach is essential because identifying a secondary cause can lead to targeted treatment that may potentially cure the hypertension, rather than simply managing it with antihypertensive medications. It is also important to consider the patient's overall clinical presentation and medical history when selecting tests, as some tests may be more relevant than others in certain cases, as noted in the 2020 International Society of Hypertension global hypertension practice guidelines 1.

From the Research

Secondary HTN Work-up

The recommended work-up for a patient with suspected secondary hypertension (HTN) involves a thorough evaluation to identify the underlying cause of the condition. Some key points to consider include:

• Secondary hypertension affects ∼5-10% of the general hypertensive population 2, 3
• Only patients with clinical suspicion should be screened, as the work-up can be time-consuming and expensive 2, 3
• 24 h ambulatory blood pressure (BP) monitoring plays a central role in the work-up of patients with suspected secondary hypertension 2

Clinical Clues and Evaluation

Clinical clues and evaluation are crucial in identifying the underlying cause of secondary hypertension. Some key points to consider include:

• Obstructive sleep apnoea has been identified as one of the most frequent causes of secondary hypertension 2, 4, 5
• Renal artery stenosis is another potential cause, and catheter-based renal denervation may be considered for treatment 2
• Other causes of secondary hypertension include primary aldosteronism, pheochromocytoma, Cushing's syndrome, and chronic kidney disease 4, 3, 5
• Treatment is specific to the underlying cause and includes medications, procedures, surgery, and device therapies 3, 5

Importance of Early Detection and Treatment

Early detection and treatment of secondary hypertension are essential to minimize or prevent irreversible changes in the vasculature and target organs. Some key points to consider include:

• Early detection of a secondary form of hypertension can lead to cure or better control of high blood pressure, and prevention of hypertension-mediated organ damage and related cardiovascular complications 4
• Even when cure cannot be achieved, diagnosis of a secondary form of hypertension provides a better control of high blood pressure and allows prevention of hypertension-mediated organ damage and related cardiovascular complications 4