Brachial-ankle pulse wave velocity and cardio-ankle vascular index are associated with future cardiovascular events in a general population: The Nagahama study

Faster pulse wave velocity (PWV) is known to be associated with the incidence of cardiovascular diseases (CVD). The aim of this study was to clarify the hypothesis that PWV may be associated with future CVD events even when its time-dependent changes were adjusted. We also investigated a prognostic significance of cardio-ankle vascular index, another index of arterial stiffness. Study participants included 8850 community residents. The repeated measures of the clinical parameters at 5.0 years after the baseline were available for 7249 of the participants. PWV was calculated using the arterial waveforms measured at the brachia and ankles (baPWV). The cardio-ankle vascular index was calculated by estimated pulse transit time from aortic valve to tibial artery. During the 8.53 years follow-up period, we observed 215 cases of CVD. The incidence rate increased linearly with baPWV quartiles (per 10 000 person-years: Q1, 2.7; Q2, 12.6; Q3, 22.5; Q4, 76.2), and the highest quartile was identified as an independent determinant of incident CVD by conventional Cox proportional hazard analysis adjusted for known risk factors [hazard ratio (HR), 4.00; p = .007]. Per unit HR of baPWV (HR, 1.15; p < .001) remained significant in the time-dependent Cox regression analysis including baPWV and other clinical values measured at 5-year after the baseline as time-varying variables (HR, 1.14; p < .001). The cardio-ankle vascular index was also associated with CVD with similar manner though the associations were less clear than that of baPWV. baPWV is a good risk marker for the incidence of CVD.