Indications and Contraindications of Renal Denervation for Resistant Hypertension
Renal Denervation (RDN) is a promising interventional approach for managing resistant hypertension, a condition where blood pressure remains uncontrolled despite the use of multiple antihypertensive medications. This procedure is typically considered under specific clinical scenarios and after thorough evaluation by specialists.
Who Can Benefit from RDN?
Transcatheter renal denervation may be considered for patients who meet the following criteria:
1. Inadequate Blood Pressure Control Despite Optimal Medical Therapy
Patients should be on a maximally tolerated regimen of at least three different antihypertensive drug classes, including a diuretic. Aldosterone antagonists should be included unless contraindicated. Despite this regimen for several months, office systolic blood pressure should remain ≥160 mmHg. For patients with type 2 diabetes, the threshold is slightly lower at ≥150 mmHg. Diagnosis must be confirmed using 24-hour ambulatory blood pressure monitoring or home blood pressure measurements to rule out white-coat hypertension.
2. Confirmed Diagnosis by Hypertension Specialists
The diagnosis of resistant hypertension should be made by a certified hypertension specialist or at a hypertension center with expertise in managing complex blood pressure cases. This ensures that all contributing factors are appropriately assessed.
3. Exclusion of Secondary and Pseudo-Resistant Hypertension
A comprehensive clinical evaluation is essential to exclude secondary causes of hypertension such as renal artery stenosis, endocrine disorders, or sleep apnea. Additionally, pseudo-resistant hypertension—often due to improper blood pressure measurement techniques, poor medication adherence, or the use of pressor medications—must be ruled out through detailed history and examination.
4. Suitable Renal Anatomy and Function
Patients must have an estimated glomerular filtration rate (eGFR) of at least 45 ml/(min·1.73m²). Imaging studies such as computed tomographic angiography (CTA) or magnetic resonance angiography (MRA) should confirm that the main renal arteries have a diameter of ≥4 mm and a length of ≥20 mm, which is necessary for successful catheter-based intervention.
Additional Considerations for RDN Eligibility
In some cases, RDN may be considered even if the standard criteria are not fully met, provided a multidisciplinary team evaluates the patient:
1. True Drug Intolerance
If a patient has documented intolerance to multiple antihypertensive medications, and this intolerance is confirmed by a hypertension specialist—not due to psychological factors or poor patient-physician communication—RDN may be a viable option.
2. Presence of Reversible Risk Factors
Before considering RDN, reversible contributors to hypertension such as obesity, excessive alcohol consumption, obstructive sleep apnea, and high dietary sodium intake should be addressed. If blood pressure remains uncontrolled after optimizing these factors, or if these factors cannot be modified, RDN may be appropriate.
When Is RDN Not Recommended?
RDN is contraindicated in the following clinical situations:
- Presence of Significant Renal Artery Stenosis: Defined as stenosis greater than 50%, which may require alternative interventions such as angioplasty or stenting.
- Prior Renal Artery Intervention: Patients who have previously undergone renal artery stenting or other interventions are generally not suitable candidates.
- Severe Renal Impairment: An eGFR below 45 ml/(min·1.73m²) is considered a contraindication due to the potential risks associated with further renal denervation.
- Unfavorable Renal Arterial Anatomy: Including multiple renal arteries or a main renal artery with a diameter less than 4 mm or length less than 20 mm, which may hinder safe and effective catheter placement.
RDN offers a novel, minimally invasive treatment option for patients with resistant hypertension, but careful patient selection is crucial to ensure safety and maximize therapeutic benefit.