Is Incidental Renal Arteriography Justified in a Population of Patients with Symptomatic Peripheral Arterial Disease?

Abstract

Renal artery stenosis is a consequence of generalized atherosclerosis and many specialists perform routine selective renal angiography to detect and treat renal artery stenosis. The incidence of clinically important renal artery stenosis is not well defined in patients with symptomatic peripheral arterial disease. The purpose of this study was to better delineate the incidence of and the risk factors associated with renal artery stenosis, renovascular hypertension, and ischemic nephropathy incidentally discovered during angiography for symptomatic peripheral arterial disease. Two hundred consecutive patients undergoing angiographic evaluation of symptomatic lower extremity peripheral arterial disease were studied retrospectively. Angiograms were reviewed for the presence of renal artery stenosis (defined as ≥ 25% diameter reduction in either renal artery) and findings were then correlated to the clinical diagnosis of renovascular hypertension (> 50% renal artery stenosis and ≥ 3-drug resistive hypertension) and ischemic nephropathy (defined as > 50% bilateral renal artery stenosis, 3-drug hypertension, and creatinine ≥ 1.5). Angiographic findings were also correlated with risk factors to determine if a relationship correlated to the presence of and degree of renal artery stenosis. Data were analyzed using the Student's t test, Chi-square model, and multiple logistic regression analysis. The overall incidence of any degree of renal artery stenosis in this study population was 26% (52 patients). Only 24 (12%) patients had an incidental finding of ≥ 50% stenosis in either renal artery. Six (3%) of these patients were found to have associated renovascular hypertension. Additionally, 9 (4.5%) patients had coexistent renal insufficiency and significant renal artery stenosis; five with end-stage renal disease on chronic hemodialysis. Only one patient with end-stage renal disease had poorly controlled 3-drug hypertension. Thus definitive ischemic nephropathy was present in only one (0.5%) patient. Statistically significant risk factors associated with the presence of renal artery stenosis include hypertension ( P < .001), coronary disease ( P = .024), female gender ( P = .010), diabetes ( P = .039), aorto-iliac disease ( P = .031), multiple levels of peripheral arterial disease ( P < .001), and age over 60 ( P < .001). While the incidence of renal artery stenosis in patients being evaluated for symptomatic peripheral arterial disease is similar to that reported in the cardiology literature, the incidence of renovascular hypertension and ischemic nephropathy is exceedingly low (3% and 0.5%, respectively)—findings similar to data reported in the general hypertensive population. These data suggest that incidental selective renal angiography is not justified in patients with symptomatic peripheral arterial disease.