Renal resistive index: Beyond the hemodynamics

We read with great interest the original article entitled “Prognostic significance of the renal resistive index in the primary prevention of type II diabetes” by Delsart et al1 In this issue of The Journal, the authors interestingly underlined the prognostic value of renal resistive index (RRI) in diabetic subjects and its role as an independent predictor of a first cardiovascular or renal event. Similar conclusions were previously obtained by others in different subsets of patients (hypertension, chronic kidney disease, or heart failure), in which intrarenal hemodynamic alterations showed to be independent predictors of cardiovascular events. It is likely that the mechanisms underlying renal hemodynamic alterations in diabetics are similar to those involved in hypertensive subjects and that “renal resistance indices reflect systemic rather than renal vascular damage,” as previously postulated by Heine et al.