ASSOCIATION BETWEEN RENAL RESISTIVE INDEX AND CAROTID INTIMA-MEDIA THICKNESS IN HYPERTENSIVE PATIENTS.

Abstract

Introduction: The assessment of renal hemodynamic parameters by duplex Doppler sonography has been used for many years as a diagnostic tool in the daily work-up of kidney diseases. Recent data suggest that these parameters, especially the intrarenal resistive index (RI) may be also associated with changes of the systemic vascular tree and with an enhanced cardiovascular risk. However, conflicting data exist in literature about the independent association of carotid intima-media thickness (IMT) with RI. Aim: To evaluate the relationship between RI and carotid IMT in the hypertensive subjects consecutively attending our hypertension centre. Methods: We enrolled 264 subjects, aged between 30 and 70 years. They were stratified into two groups, either with normal renal function (n = 140) or with chronic kidney disease (CKD), ranging from stage 1 to stage 4 of the KDIGO classification (n = 124). The GFR was estimated by CKD-EPI equation. All the subjects underwent duplex Doppler assessment of the renal and carotid arteries by the GE Logiq P5 PRO instrument. Results: Patients with carotid IMT > 0.9 mm showed higher values of RI, both in the overall population (p < 0.001) and in the subgroups with (p< 0.01) and without CKD (p< 0.01). In addition, a statistically significant correlation was observed between carotid IMT and RI in the whole population (r = 0.43, p<0.001) and in the subgroups with (r = 0.42, p<0.001) and without CKD (r = 0:39, p<0.001). These correlations held even after adjustment for several confounding factors. Conclusions: Our results, showing a strong independent association between renal RI and carotid IMT, seem to corroborate the concept that the RI, beyond its prognostic renal value, may be considered as a marker of systemic vascular changes and therefore a predictor of cardiovascular risk.