Clinical usefulness of duplex ultrasonography for the assessment of renal arteriosclerosis in essential hypertensive patients.

The present study was carried out to investigate whether the renal resistive index (RRI), obtained by ultrasonic duplex scanning, is useful for the evaluation of renal arteriosclerosis in essential hypertensive patients. We also studied the relationships between RRI and other kinds of hypertensive target-organ damage, including carotid atherosclerosis. One hundred and two patients (56.4+/-9.4 years) with untreated mild or moderate essential hypertension were examined. The normal range of RRI was determined for 12 normal age-matched volunteers (55.0+/-6.6 years). Hypertensive organ damage was evaluated by funduscopy, electrocardiograms, and carotid B-mode imaging. Based on the mean and distribution of RRI in normal volunteers (0.60+/-0.05), the normal upper limit of RRI was found to be 0.7. RRI was correlated with creatinine clearance (CCr) (r=-0.61, p<0.05), and blood urea nitrogen (r=0.46, p<0.05), but not with serum creatinine. In addition, the incidence of abnormal RRI (>0.7) was higher in patients with left ventricular hypertrophy and in those with advanced carotid atherosclerosis (p<0.01, respectively). Thus, RRI appears to be more strongly associated with CCr than with serum creatinine, and it increases in patients with hypertensive end-organ damage. The assessment of RRI may be useful for the evaluation of early renal damage in essential hypertension.