Renal artery stenosis in patients with coronary artery disease

Background: Renal dysfunction is an important factor of cardiovascular risk. Renal artery stenosis (RAS) is a potential cause of secondary hypertension and by renal ischemia may lead to progressive renal insuficiency. in RAS patients a significant increase in prevalence of coronary artery disease (CAD) as well as revascularisation rate and mortality rate was observed. Aim: To determine the prevalence of RAS in patients with suspected CAD. Methods: The study group consisted of 1036 consecutive patients (700 men; 67.6%) in the mean age of 62.1 +/- 9.7 (25-85) years admitted to coronary angiography. Simultaneously renal angiography was performed in all patients. Results: Stenosis >= 50% in at least one main branch of coronary artery was found in 633 (66.1%) patients. The proportion of patients with one, two or three vessel CAD was respectively 291 (46%), 169 (26%) and 173 (27.3%). Non-significant coronary lesions <50% were found in 108 (10.4%) patients, whereas in 295 (28.5%) patients no angiographic evidence of CAD was documented. In the whole group of patients RAS was found in 339 (32.7%) of patients - 124 (12%) had bilateral lesions. RAS prevalence in patients with CAD was 38.3% (284/741) and its frequency increased with severity of CAD: from 25% (27/108) in patients with insignificant coronary lesions up to 36.4% (106/291), 40.2% (68/169) and 48% (83/173) in 1, 2, and 3-vessel disease, respectively (p <0.001). RAS prevalence in patients with normal coronary arteries was 18.6% (55/295). RAS <30% was detected in 194 (18,7%) patients; RAS between 30-49% in 81 patients (8.7%); RAS 50-69% in 38 patients (3.7%) and RAS >= 70% in the remaining 26 patients (2.5%). RAS >= 50% was noted in 8 (2.7%) patients without coronary lesions; in 5 (4.6%) with insignificant coronary artery atherosclerosis and 51 (8%) with coronary artery stenosis >50% (p=0.0008). Stepwise regression analysis identified 4 independent predictors of RAS >50%: CAD severity (p=0.014), serum creatinine concentration (p <0.001), cigarette smoking (p=0.02) and stenosis of aortic arch branches (p <0.001). Conclusions: RAS is a frequent finding in patients with suspected CAD. CAD severity, number of involved aortic arch arteries, cigarette smoking and serum creatinine are independent RAS predictors.