Relationships Between the Cardio-Ankle Vascular Index and Pulsatility Index of the Common Carotid Artery in Patients With Cardiovascular Risk Factors

BACKGROUND: Pulsatility index (PI) is a hemodynamic parameter determined using Doppler sonography; it reflects the degree of peripheral vascular resistance. Moreover, researchers have reported significant relationships between an increase in the PI of the common carotid artery (CCA) and ischemic stroke. This cross-sectional study aimed to clarify the relationships between cardio-ankle vascular index (CAVI) as a marker of arterial stiffness and the PI of the CCA in patients with cardiovascular risk factors for the primary prevention of ischemic stroke. METHODS: A total of 405 outpatients undergoing treatment for cardiovascular risk factors (152 men and 253 women; mean age ± standard deviation, 64 ± 9 years) with no history of cardiovascular events, including ischemic stroke, were enrolled. The CAVI and the PI of the CCA were measured using commercial devices, and their relationships to various clinical parameters were examined. RESULTS: A significant positive correlation was observed between the CAVI and the PI of the CCA (r = 0.44, P < 0.001). Further, multiple regression analysis revealed that the CAVI (β = 0.19, P < 0.001) was selected as independent factor for PI of the CCA as a subordinate factor. Meanwhile, high-sensitivity C-reactive protein, as an inflammation marker, and skin autofluorescence, as a marker of advanced glycation end products in the tissues, were selected as independent variables for either the CAVI or the PI of the CCA as a subordinate factor. The receiver-operating characteristic curve analysis indicated that the cut-off point of the CAVI for high PI of the CCA (> 1.60) as a risk value of stroke incidence by previous report was 9.1 (area under the curve = 0.750, P < 0.001). CONCLUSION: The present results indicate that the CAVI reflects cerebrovascular resistance in patients with cardiovascular risk factors. Moreover, the risk value of the CAVI for ischemic stroke incidence was considered to be 9.1 in these patients.