Renal resistive index and cardiovascular organ damage in a large population of hypertensive patients

We evaluated the relationship between renal resistive index (RRI) of the intrarenal vasculature and cardiovascular (CV) organ damage such as left ventricular hypertrophy (LVH), diastolic dysfunction and carotid atherosclerosis in a large sample of hypertensive patients. 566 hypertensive patients underwent echocardiography with conventional Doppler and Doppler tissue imaging (DTI), carotid and renal ultrasonography. In addition, lipids profile, creatinine in serum, and urinary albumin concentrations were determined. The patients were divided according to their RRI values in 2 groups: < 70 and <= 70. Subjects with high RRI were older, had higher systolic and pulse pressure (PP) and more years of hypertension, compared to those with low RRI (P < 0.0001). Patients with the higher RRI showed an increased left ventricular mass index (LVMI) and carotid intima-media thickness (IMT) with a higher prevalence of LVH, carotid plaques and microalbuminuria ( P < 0.001). There were differences in overall diastolic parameters, in particular when evaluated by DTI ( P < 0.001). A positive correlation was found between RRI and age, PP, carotid IMT, LVMI, SBP and a negative correlation was found with DTI diastolic parameters ( P < 0.001). Age, PP, carotid IMT and LVMI were independently related to RRI. While, RRI was independently related to IMT and IVRT. RRI, especially the higher values, are positively correlated with target organ damage in hypertensive patients, indicating that renal vascular resistance is related to morphologic and hemodynamic alteration of the CV system. The evaluation of RRI could predict the presence of early CV damage and provide an accurate estimate of overall risk.