Relationship between renal resistive index and early target organ damage in patients with never-treated essential hypertension.

The aim of our study was to evaluate renal resistive index (RI) value in never treated hypertensive patients in relation to ambulatory blood pressure measurement (ABPM) values and early target organ damage. The study included 318 subjects: 223 patients with never treated essential hypertension (mean age 37.1 years) and 95 normotensive healthy subjects (mean age 37.9 years). ABPM, echocardiography and carotid and renal arteries duplex color Doppler examinations were performed. RI values in patients with never treated essential hypertension were no different from the normotensive control group (0.59 +/- 0.05 vs 0.59 +/- 0.05; NS). In the untreated patients RI correlated significantly with 24-h pulse pressure (r=0.234; p<0.01) and ambulatory arterial stiffness index (AASI) values (r=0.274; p<0.001), intima-media thickness (IMT) (r=0.249; p<0.001), E'/A' (rho= -0.279; p<0.001) and relative wall thickness (RWT; r=0.185; p<0.01). In the multivariate stepwise analysis, RI values correlated independently with carotid IMT (beta=0.272; p=0.020) and 24-h AASI values (beta=0.305; p=0.009). In normotensive healthy controls, significant independent correlation between RI and carotid IMT and 24-h AASI values were also found. Our study may indicate limited value of RI in differentiating patients with uncomplicated hypertension with healthy controls. Renal resistive values were independently correlated with carotid IMT and AASI. These may suggest that renal vascular resistance is related to two markers for cardiovascular events both in the hypertensive and normotensive subjects.