Influence of blood pressure on cardio-ankle vascular index (CAVI) examined based on percentage change during general anesthesia

Cardio-ankle vascular index (CAVI) and brachial-ankle pulse wave velocity (baPWV) are non-invasive methods for estimating arterial distensibility. The purpose of this study is to evaluate whether CAVI as an index of true arterial stiffness is superior to baPWV based on the percentage change in hemodynamics under general anesthesia. CAVI (segment from heart to ankle), k-CAVI (heart to knee) and baPWV (brachial to ankle) in 30 oral surgery patients were measured to compare the decreased blood pressure (BP) after 10 min of tracheal intubation during general anesthesia with the control BP (after 5 min of rest). General anesthesia was performed under endotracheal intubation through intravenous injection of propofol, fentanyl and vecuronium or rocuronium. In both the elderly (⩾65 years) and middle-aged (<65 years) groups, CAVI and k-CAVI did not change during general anesthesia, whereas baPWV and systolic BP (SBP) showed a statistically significant decrease. Thus, the changes in CAVI (ΔCAVI) and k-CAVI (Δk-CAVI) showed no significant correlations with those of SBP (ΔSBP), whereas the changes in baPWV (ΔbaPWV) were significantly correlated with ΔSBP. ΔCAVI and Δk-CAVI showed no significant differences between the two groups, whereas ΔbaPWV and ΔSBP in the elderly group was much higher than that in the middle-aged group. Measurement of CAVI was not affected by the decrease in BP during general anesthesia. In contrast, baPWV was significantly influenced by changes in BP. These findings suggest that CAVI is a useful index of true arterial stiffness and is superior to baPWV.