From the Guidelines
A renal artery ultrasound is reasonable for hypertension evaluation in patients with resistant hypertension, sudden onset or worsening of previously controlled hypertension, or other clinical scenarios suggesting renovascular hypertension, as recommended by the 2024 ESC guidelines 1.
Clinical Scenarios for Renal Artery Ultrasound
The following clinical scenarios suggest renovascular hypertension and may warrant a renal artery ultrasound:
- Resistant hypertension (blood pressure remaining above goal despite three or more antihypertensive medications including a diuretic)
- Sudden onset or worsening of previously controlled hypertension
- Onset of hypertension before age 30 or severe hypertension after age 55
- Accelerated or malignant hypertension
- Abdominal bruit on physical examination
- Unexplained renal dysfunction, especially after starting ACE inhibitors or ARBs
- Asymmetric kidney sizes on imaging
- Flash pulmonary edema without clear cardiac cause
- Hypertension with other evidence of atherosclerotic disease
Rationale for Renal Artery Ultrasound
Renal artery ultrasound uses Doppler imaging to detect stenosis by measuring blood flow velocities and waveform patterns in the renal arteries. The rationale for this imaging is to identify potentially treatable causes of hypertension, as renal artery stenosis leads to reduced kidney perfusion, activating the renin-angiotensin-aldosterone system which causes vasoconstriction and sodium retention, ultimately resulting in hypertension 1.
Diagnostic Strategies for Renal Artery Disease
According to the 2024 ESC guidelines for the management of peripheral arterial and aortic diseases, duplex ultrasound (DUS) is recommended as the first-line imaging modality in patients with suspicion of renal artery stenosis (RAS) 1. In cases of DUS-based suspicion of RAS or inconclusive DUS, magnetic resonance angiography (MRA) or computed tomography angiography (CTA) are recommended.
From the Research
Indications for Renal Artery Ultrasound in Hypertension
- Renal artery ultrasound is a valuable diagnostic tool for evaluating patients with hypertension, particularly those with suspected renal artery stenosis 2, 3, 4.
- It is reasonable to perform a renal artery ultrasound in patients with:
- Uncontrolled renovascular hypertension despite optimal medical therapy 2.
- Ischemic nephropathy and cardiac destabilization syndromes with severe renal artery stenosis 2.
- Resistant hypertension, defined as blood pressure that remains above target despite the use of three or more antihypertensive medications, including a diuretic, at adequate doses 5.
- Symptoms such as severe hypertension, deterioration of renal function, and flash pulmonary edema 3.
- Renal artery ultrasound can detect abnormalities in renal parenchyma, morphology, or vascularization, which can influence further diagnostic work-up and treatment 4.
Diagnostic Modalities
- Duplex ultrasonography is a commonly used screening modality for renal artery stenosis, but it may give false-negative results in some cases 3.
- Other diagnostic modalities, such as computed tomography angiography and magnetic resonance angiography, may be used to confirm the diagnosis of renal artery stenosis 2, 3.
- The choice of diagnostic modality depends on the individual patient's characteristics and the clinical suspicion of renal artery stenosis.
Clinical Context
- Renal artery ultrasound is a non-invasive and relatively low-cost procedure that can provide valuable information on renal artery stenosis and other renal abnormalities 4.
- The results of renal artery ultrasound can guide further management, including medical therapy, renal artery revascularization, or other interventions 2, 3.
- The use of renal artery ultrasound in the evaluation of hypertension is supported by international guidelines and clinical practice recommendations 4, 5.