From the Guidelines
A kidney ultrasound is indicated in younger adults with hypertension when there is suspicion of secondary hypertension, particularly renal causes, or in patients with chronic kidney disease (CKD), as recommended by the 2024 European Society of Cardiology guidelines 1. When evaluating younger adults with hypertension, it is essential to consider the potential for secondary causes, which can be more common in this age group compared to older adults.
- Specific indications for a kidney ultrasound in this population include:
- Resistant hypertension
- Abrupt onset of severe hypertension
- Accelerated hypertension
- Presence of abdominal bruits
- Abnormal renal function tests
- Hematuria
- Proteinuria
- Family history of polycystic kidney disease The 2024 ESC guidelines advise that renal ultrasound should be considered for hypertensive patients with CKD (Class IIa) 1.
- The ultrasound helps identify structural abnormalities such as:
- Renal artery stenosis
- Polycystic kidney disease
- Renal parenchymal disease
- Adrenal masses that could be causing the elevated blood pressure. Early identification of secondary causes can lead to targeted treatment approaches rather than lifelong antihypertensive therapy, ultimately improving morbidity, mortality, and quality of life outcomes. According to the 2024 ESC guidelines, screening for hypertensive organ damage (HMOD) should be considered for young individuals with elevated BP who do not have high-risk CVD conditions (Class IIb) 1.
From the Research
Indications for Kidney Ultrasound in Younger Adults with Hypertension
- Kidney ultrasound is a valuable diagnostic tool that can provide information on possible underlying causes and consequences of hypertension 2
- It can detect abnormalities in renal parenchyma, morphology, or vascularization of the kidneys, influencing further diagnostic work-up and treatment 2
- Renal ultrasound can be used to diagnose and grade renal stenosis in both fibromuscular dysplastic and atherosclerotic diseases 3
- In younger adults with hypertension, kidney ultrasound can be indicated when there are suggestive symptoms and signs of secondary hypertension, such as:
- Severe or resistant hypertension
- Age of onset younger than 30 years
- Malignant or accelerated hypertension
- An acute rise in blood pressure from previously stable readings 4
- Kidney ultrasound can also be used to evaluate renal function and structure in patients with a strong suggestion of renovascular hypertension, although angiography may be necessary for definitive diagnosis 5
Role of Renal Resistive Index (RRI) in Hypertension
- RRI is a marker of renal disease onset and progression, and can be used as an independent predictor of cardiovascular risk 3
- In hypertensives with normal renal function and no albuminuria, especially in younger people, RRI is an early marker of renal damage 3
- RRI can be used to improve current clinical scores used to stratify early renal damage in younger adults with hypertension 3
- However, the clinical relevance of RRI measurement as a surrogate endpoint of specific renal damage or atherosclerotic diffuse vascular damage is still debated 3
Limitations and Considerations
- Morphological changes detected by kidney ultrasound are often non-specific and may be detected late 3
- Non-invasive imaging methods, including kidney ultrasound, may not be sensitive enough to exclude stenoses of small branch vessels in children with suspected renovascular hypertension 5
- The rapid technical evolution of non-invasive methods requires periodic re-consideration of the actual standpoints on the use of kidney ultrasound in hypertension diagnosis and management 5