Objective: The aim of our study was to examine the association between the presence of atherosclerotic renal artery stenosis (RAS) and coexisting cardiovascular risk factors in hypertensive patients with coronary artery disease (CAD).
Methods: A total of 333 consecutive hypertensive patients (239 men, 94 women) with CAD underwent clinically indicated non-emergency coronary angiography, followed by renal angiography. Before catheterization clinical examination was performed to determine demographics, cardiac history, known duration of hypertension, cardiovascular risk factors, features of extracoronary vascular disease and related comorbidities. Blood samples for all biochemical evaluations--including highly sensitive C-reactive protein (hsCRP), fibrinogen and homocysteine--were taken. Ambulatory blood pressure monitoring (ABPM), echocardiography and carotid and femoral ultrasound followed by a duplex colour Doppler examination were performed.
Results: Significant RAS (> 50% lumen narrowing) was identified in 40 patients (12%) and non-significant RAS (< 50%) was found in 45 (13.5%) subjects. Patients with significant RAS were older (59.8 versus 56.6 years, P < 0.05) and were characterized by higher systolic ambulatory blood pressure level. Patients with RAS had significantly higher levels of creatinine, hsCRP, fibrinogen and homocysteine and lower creatinine clearance than patients without RAS. Multivessel coronary artery disease (MVD) was more frequent in patients with significant RAS. Patients with significant RAS had significantly higher left ventricular mass index (LVMI) and lower ejection fraction (EF) as compared with those without RAS. Patients with RAS were more often characterized by the presence of carotid and femoral artery atherosclerosis and significantly more pronounced increase in carotid intima-media thickness (IMT) as compared with non-RAS subjects. In a multivariate stepwise logistic regression model carotid IMT [odds ratio (OR) 1.15; 95% confidence interval (CI) 1.03-1.29, P < 0.05], number of coronary arteries stenosed (OR 1.61; 95% CI 1.01-2.56, P < 0.05), creatinine concentration (for 10 micromol/l increase, OR 1.15; 95% CI 1.04-1.28, P < 0.01), body mass index (BMI) (OR 0.86; 95% CI 0.75-0.97, P < 0.05) and number of antihypertensive drugs (OR 1.76; 95% CI 1.18-2.62, P < 0.05) were independently associated with RAS. The areas under receiver operating characteristic curves for carotid IMT, number of coronary arteries stenosed, creatinine concentration, BMI and number of antihypertensive drugs were 0.749, 0.633, 0.703, 0.350 and 0.677, respectively (P < 0.01 for all values).
Conclusions: In conclusion, renal artery stenosis is prevalent in a significant proportion of patients undergoing cardiac catheterization. Renal angiography should be considered particularly in hypertensive patients with multivessel coronary disease coexisting with cardiovascular risk factors, even moderately impaired renal function and increased carotid IMT or vascular disease elsewhere.