The natural history of incidental renal artery stenosis in patients with aortoiliac vascular disease

PURPOSE: To examine the association between incidentally discovered renal artery stenosis and deterioration of renal function as determined by the change in serum creatinine concentration over time. SUBJECTS AND METHODS: We performed a retrospective review of consecutive patients who underwent aortography for aortoiliac vascular disease. Angiograms were reviewed for renal artery stenosis, defined as a narrowing of at least 20% compared with adjacent normal renal artery. For patients with at least 180 days of subsequent follow-up, the change in serum creatinine concentration per year was compared in patients who had or did not have renal artery stenosis. RESULTS: Of the 201 patients, 96 (48%) had some degree of renal artery stenosis in one or both renal arteries, including 53 (26%) who had at least one stenosis ≥50% and 40 (20%) who had bilateral stenoses. The only clinical predictor of renal artery stenosis was a history of coronary artery disease (odds RATIO = 2.0, 95% confidence interval: 1.2 to 3.8, P = 0.001). Among the 174 patients with ≥180 days of follow-up, there was no statistically significant difference (P = 0.88) in the mean change in serum creatinine concentration per year in the 78 patients with renal artery stenosis (0.06 ± 0.33 mg/dL per year) as compared with the 96 patients without renal artery stenosis (0.06 ± 0.22 mg/dL per year). Grouping the patients by the maximal percentage of stenosis did not reveal any difference in the mean changes in serum creatinine concentration per year. CONCLUSIONS: Although renal artery stenosis is a common incidental finding in patients with atherosclerotic vascular disease, it is an uncommon cause of progressive renal disease.