Predictors of renal artery stenosis in patients with normal renal function undergoing coronary angiography

AIM: A number of patients with normal renal function undergoing coronary angiography have shown a renal artery stenosis (RAS). Detection of unknown RAS may influence therapeutic strategy in patients with coronary artery disease (CAD) candidate to coronary revascularization. Prevalence of RAS in patients with normal renal function has not been yet fully investigated. We retrospectively evaluated the prevalence of RAS in patients with normal renal function undergoing coronary angiography and candidate to coronary revascularization. METHODS: Medical records of consecutive patients underwent coronary angiography at a single public institutions over a twelve-month period were evaluated. Patients with normal renal function undergoing coincident diagnostic renal angiography to evaluate renal vessels on the basis of clinical criteria and at least one-vessel CAD were analyzed. Moderate to severe arterial stenosis (>50% stenosis), vessel occlusion were noted as significant angiographic findings. RESULTS: Angiographically significant RAS were reported in 35 (17%) of 205 consecutive patients (mean age 67.1+/-12.8 years, mean serum creatinine 0.8+/-0.5 mg/dL, mean glomerular filtration rate 112+/-13 mL/min). Twenty patients (9.8% of total) underwent renal angioplasty and stenting before successful coronary revascularization. Multivariate logistic regression analyses revealed three-vessel CAD (odds ratio[OR] 8.71; 95% confidence interval [CI] 2.24-40.8; P=0.002), hypertension (OR 2.34 CI 95% 0.96-6.9; P=0.048), and hypercholesterolemia (OR 2.851; CI 95% 1.03 to 7.9; P=0.044) as independent predictors of RAS. CONCLUSIONS: The association of significant RAS with CAD is relatively high in patients with normal renal function. Renal semi-selective or selective angiography may contribute to detect unknown significant RAS in patients undergoing coronary angiography: our small series suggests that this strategy may be useful also in patients with normal renal function in presence of three- or four-vessel CAD and multiple risk factors.