Response to Renal Resistive Index and Cardiovascular and Renal Outcomes in Essential Hypertension

We thank Dr Heine et al1 for their interest in our recent findings2,3 and for their crucial and constructive criticisms and comments concerning the renal resistive index (RI). In response, we classified the primary composite end points into cardiovascular events, including nonfatal congestive heart failure, stroke, myocardial infarction, aortic dissection, and death, and renal events, including end-stage renal failure requiring regular hemodialysis, and found that, in a univariate Cox proportional-hazard model, a 1-SD increase of RI was a significant predictor of cardiovascular events (hazard ratio [HR], 5.47; 95% confidence interval [CI], 4.55–6.96; P <0.01) and renal events (HR, 10.79; 95% CI, 4.84–40.82; P <0.01). Multivariate analysis could not be performed because of the low number of occurrences of each end point, and thus, further investigation will be …