Atherosclerotic Renal Artery Stenosis

Abstract

Occlusive disease of the renal arteries poses a major problem. Most cases result from atherosclerotic disease, and the prevalence of incidental renal artery disease detected during imaging studies for symptomatic coronary, aortic, and peripheral vascular disease ranges from 14% to >35%, increasing with age.1 Although many (perhaps most) of these lesions produce only minor hemodynamic effects, it has long been recognized that when some “critical” level of occlusion is breached, poststenotic renal blood flow and glomerular filtration rate (GFR) fall, especially after lowering systemic arterial pressure. In some cases, kidney function can recover after restoring blood flow with either endovascular or surgical revascularization. Several prospective, randomized trials have examined whether the loss of renal function due to atherosclerotic renal artery stenosis can be managed best by medical therapy alone or would further benefit from renal revascularization.2,3 The study reported by Madder and colleagues4 in this issue of Circulation: Cardiovascular Interventions directly challenges whether conventional criteria for estimating GFR and directional trends in such trials are valid. This matter is important for physicians serious about considering renovascular disease. Article see p 219 Atherosclerotic renal artery stenosis (ARAS) is primarily a disease of older persons, with mean ages for most series >70 years.1 Patient series subjected to renal artery procedures routinely have reduced kidney function, usually expressed as reduced GFR. Despite remarkable improvements for many hypertensive and cardiovascular end points, such as stroke and myocardial infarction, attributable in part to effective medical intervention, the prevalence of end-stage renal disease has continued to increase over the past several decades. These observations raise the possibility that occlusive ARAS may be partly responsible for progressive renal injury. How best to evaluate and characterize kidney function in these trials has been controversial. Previous observational reports of renal revascularization used a …