AHA = American Heart Association; ARAS = atherosclerotic renal artery stenosis; CORAL = Cardiovascular Outcomes in Renal Atherosclerotic Lesions; CTA = computed tomographic angiography; FMD = fibromuscular dysplasia; MRA = magnetic resonance angiography; PTRA = percutaneous transluminal renal angioplasty; RAAS = renin-angiotensin-aldosterone system; RAS = renal artery stenosis; RRI = renal resistive index
enal artery stenosis (RAS), narrowing of the renal arteries, is caused by a heterogeneous group of conditions, including atherosclerosis, fibromuscular dysplasia (FMD), vasculitis, neurofibromatosis, congenital bands, and extrinsic compression, and radiation.1
Atherosclerosis accounts for approximately 90% of the lesions that obstruct blood flow to the renal arteries. Atherosclerotic renal artery stenosis (ARAS) typically involves the ostium and/or proximal one-third of the renal artery and often the adjacent aorta.2
However, segmental and diffuse intrarenal atherosclerosis may also be observed, especially in advanced cases.3
We reviewed the literature using PubMed to search for relevant recent publications with the terms renal artery stenosis, atherosclerotic renal artery stenosis, and renal artery stenosis AND hypertension. This review highlights salient points of the pathophysiology, diagnosis, and treatment of ARAS.
The prevalence of ARAS increases with advancing age and with the presence of traditional cardiovascular risk factors. Among patients with hypertension, ARAS is observed in only 1% to 6%,4-6
whereas the incidence of ARAS is more than 30% in patients undergoing cardiac catheterization7,8
and more than 50% in elderly patients with known atherosclerotic disease.9,10
In a study of 170 patients with ARAS who were followed up with serial duplex scans, the cumulative incidence of disease progression was 51% 5 years after diagnosis.11
In a pooled review of 5 trials using serial arteriography, 49% of all renal arteries examined demonstrated progression of stenosis during follow-up ranging from 6 to 180 months.12
Atherosclerotic renal artery stenosis results in a progressive loss of renal mass and function over time. In a subgroup of patients with renovascular hypertension and 60% obstruction, renal atrophy occurred in 21%.13,14
Historical data suggest that up to 27% of patients with ARAS will develop chronic renal failure within 6 years.15
A prospective angiographic study revealed that ARAS was the cause of end-stage renal disease in 14% of patients in whom dialysis was newly initiated7
; thus, early detection and appropriate treatment of ARAS could have important economic consequences.
The presence of ARAS is known to predict adverse coronary events. In the Cardiovascular Health Study, patients diagnosed as having ARAS had a higher incidence of hospitalization for angina, myocardial infarction, and coronary revascularization.16
In a cohort of patients with ARAS detected at the time of coronary angiography, the 4-year survival rate was 65% for those with vs 86% for those without ARAS.17