Common Carotid Artery Flow Parameters Predict the Incidence of Hypertension

The resistance index (RI) and pulsatility index (PI) in the common carotid artery (CCA) reflect vascular resistance and aortic stiffness. We investigated the association of these CCA flow parameters with the prevalence and incidence of hypertension, with comparison to the intima-media thickness (IMT). The cross-sectional analysis included 2660 participants who underwent carotid artery ultrasonography. Of those, 1249 normotensive participants at baseline were enrolled in the retrospective cohort analysis. A high RI, high PI, and increased IMT were indicated based on the optimal cutoff values in a receiver operating characteristic curve analysis. RI (β=0.158, P <0.001) and PI (β=0.130, P <0.001) were significantly associated with systolic blood pressure in the cross-sectional analysis. Over a mean 5.1-year follow-up period, 524 participants developed hypertension. A high RI (odds ratio [OR], 1.65; P <0.001), high PI (OR, 1.63; P <0.001), and increased IMT (OR, 1.40; P =0.017) were significant predicators for incident hypertension. Combining IMT and the PI, a high PI alone (OR, 1.52; P =0.008) was a significant predicator for incident hypertension, whereas increased IMT alone was not significantly associated with the risk of hypertension. The group with both increased IMT and a high PI had the highest risk of hypertension (OR, 2.24; P <0.001). Similar results were obtained from the analysis of IMT and RI, suggesting that CCA parameters evaluated by ultrasonography may help identify individuals at high risk of hypertension. In particular, CCA flow parameters are better predictors.