From the Guidelines
A secondary antihypertensive workup is indicated for patients with uncontrolled hypertension despite adherence to an appropriate medication regimen, and the approach should begin with a thorough history and physical examination, focusing on symptoms suggesting secondary causes. The most recent and highest quality study, 1, recommends considering screening for secondary hypertension in patients with early onset hypertension, resistant hypertension, sudden deterioration in BP control, hypertensive urgency and emergency, and those presenting with high probability of secondary hypertension based on strong clinical clues. Key aspects of the workup include:
- Basic screening for secondary hypertension should include a thorough assessment of history, physical examination, basic blood biochemistry, and dipstick urine analysis, as suggested by 1.
- Further investigations for secondary hypertension, such as additional biochemistry, imaging, or others, should be carefully chosen based on information from history, physical examination, and basic clinical investigations, as recommended by 1.
- Laboratory testing should include basic metabolic panel to assess kidney function and electrolytes, particularly potassium levels which may indicate primary aldosteronism if low, as mentioned in 1.
- A 24-hour urine collection for metanephrines and catecholamines can help identify pheochromocytoma, while plasma aldosterone-to-renin ratio screening is useful for primary aldosteronism, as noted in 1.
- Imaging studies should include renal ultrasound or CT to evaluate for renal artery stenosis or adrenal masses, and for suspected renovascular hypertension, magnetic resonance angiography or CT angiography may be warranted, as suggested by 1.
- Sleep studies should be considered if obstructive sleep apnea is suspected, as recommended by 1. This systematic approach is important because identifying a secondary cause can lead to targeted therapy that may cure or significantly improve blood pressure control, potentially reducing the need for multiple antihypertensive medications and their associated side effects, as highlighted by 1.
From the Research
Approach to Secondary Antihypertensive Workup
The approach to secondary antihypertensive workup in patients with uncontrolled hypertension involves several key considerations:
- Identifying the underlying causes of uncontrolled hypertension, such as non-adherence to medication, lifestyle factors, or underlying medical conditions 2
- Evaluating the patient's current medication regimen and considering adjustments, such as adding or switching medications, to achieve better blood pressure control 3, 4
- Assessing the patient's cardiovascular risk factors and considering the use of combination therapy, including fixed-dose formulations, to improve medication persistence and reduce adverse effects 5, 4
- Ensuring that antihypertensive medications are administered at the correct dosage and with consideration of the patient's individual clinical characteristics 6
Considerations for Combination Therapy
When considering combination therapy for patients with uncontrolled hypertension:
- Four main classes of medications are used in combination therapy: thiazide diuretics, calcium channel blockers, angiotensin-converting enzyme inhibitors (ACEIs), and angiotensin receptor blockers (ARBs) 3
- ACEIs and ARBs should not be used simultaneously 3
- In black patients, at least one agent should be a thiazide diuretic or a calcium channel blocker 3
- Patients with heart failure with reduced ejection fraction should be treated initially with a beta blocker and an ACEI or ARB, followed by add-on therapy with a mineralocorticoid receptor antagonist and a diuretic based on volume status 3
Lifestyle Modifications
Lifestyle modifications, such as: