Abstract 15197: Renal Resistive Index Predicts Cardiovascular and Renal Outcomes in Essential Hypertension
Background-Increased renal restive index (RI) measured using Doppler ultrasonography has been shown to correlate with the degree of renal impairment in hypertensive patients; however, the prognostic role of RI in cardiovascular and renal outcomes remains to be elucidated. We investigated the predictive value of RI in essential hypertension.
Methods-A total of 426 essential hypertensive subjects (mean age, 63 years; 50% female) with no prior cardiovascular disease were included in this study. Renal segmental arterial RI was measured by duplex Doppler ultrasonography.
Results-During follow-up (mean, 3.1 years), 55 participants developed the primary composite endpoints including cardiovascular and renal outcomes. In multivariate Cox regression analysis, RI was an independent predictor of worse outcome in total subjects (hazard ratio [HR] 1.69 for 1 standard deviation [SD] increase) as well as in patients with estimated glomerular filtration rate (eGFR) <60 ml/min/1.73m2 (HR 2.04 for 1 SD increase) (p<0.01, respectively). When divided into four groups based on the respective sex-specific median levels of RI in the eGFR ≥60 and eGFR <60 ml/min/1.73m2 groups, the group with eGFR <60 and high RI (RI; male ≥0.72, female ≥0.70) had a significantly poorer event-free survival rate (χ2=111.4, p<0.01), and the adjusted-hazard ratio by multivariate Cox regression analysis was 8.10 (95% CI; 1.06-27.39, p<0.01).
Conclusion-Impairment of renal hemodynamics evaluated by increased RI is associated with an increased risk of primary composite endpoints, and the combination of high RI and low eGFR is a powerful predictor of these diseases in essential hypertension. In hypertensive patients with chronic kidney disease, RI evaluation may complement predictors of cardiovascular and renal outcomes.
- © 2012 by American Heart Association, Inc.