Comparison of Cardio–Ankle Vascular Index (CAVI) and CAVI₀ in Large Healthy and Hypertensive Populations

Abstract

Original ArticleAim: The cardio-ankle vascular index (CAVI) represents the blood pressure-independent arterial stiffness from the origin of the aorta to the ankle. CAVI0 has been proposed as a variant index. We aimed to clarify the difference between CAVI and CAVI0 among large populations, and to explore reasons of the difference. Methods:The subjects were 5,293 Japanese healthy and 3,338 hypertensive people. Simple and multiple regression analyses were performed using age, sex, body mass index, systolic, and diastolic blood pressure (Pd) as variables. Sub-group analysis was performed by sex and age. The CAVI values with and without adjustment by reference pressure were also compared.Results: CAVI had a positive correlation with Pd, while CAVI0 had a negative correlation with Pd in the healthy population. The CAVI values of the hypertensive group were higher than those of healthy group in both men and women, but the CAVI0 values in women of the hypertensive group in the 30-39 age group was significantly lower than that of the corresponding healthy group. Differences of CAVI values with or without modification using the reference pressure were 1.09% 1.38% for the healthy group and 3.68% 1.66% for the hypertensive group.Conclusion: CAVI showed the expected values, but CAVI0 showed inexplicable results in the healthy and hypertensive populations. The differences were due to the strong dependency of CAVI0 on Pd. Differences of CAVI values with or without reference pressure were negligible. These results indicate that CAVI obtained by the VaSera system is appropriate, but CAVI0 is not. changes according to changes in blood pressure at the measuring time. This has been shown theoretically and also experimentally 4) . Therefore, PWV is an inappropriate index for research studying the effect of blood pressure on arterial stiffness.An attempt to establish an arterial stiffness index independent of blood pressure at measuring time was made by Hayashi et al. 5) . They found that the relationship between a change in vascular diameter and internal blood pressure showed an exponential curve,

Impact of Cardio-Ankle Vascular Index on Long-Term Outcome in Patients with Acute Coronary Syndrome

“…Recent studies showed that arterial stiffness has attracted attention as a potentially useful parameter for risk stratification of patients with ACS 3 , 4 ) . Cardio-ankle vascular stiffness index (CAVI) is a noninvasive measure of arterial stiffness that is not influenced by blood pressure at the time of examination 5 , 6 ) . We previously reported that high CAVI was an independent predictor of cardiovascular (CV) events and nonfatal ischemic stroke in patients with ACS 3 ) .…”

Using the Cardio-Ankle Vascular Index (CAVI) or the Mathematical Correction Form (CAVI0) in Clinical Practice

“…Another difference between CAVI and CAVI 0 is the use of P 0 in the formula of CAVI 0 . Although Spronck et al [3] claimed that the new formula of CAVI 0 is independent of blood pressure, in a large study on 5293 individuals, Shirai et al [5] recently showed that CAVI 0 is not accurate because of its strong dependency on P d . Another reason that CAVI 0 provides equivocal results is that Spronck et al [3] did not take into account the physiological properties of individuals, such as their body mass index (BMI).…”

Reply to Comments: Using the Cardio-Ankle Vascular Index (CAVI) or the Mathematical Correction Form (CAVI0) in Clinical Practice

“…In a recent study, Shirai et al compared CAVI and CAVI 0 in a large population of normotensive and hypertensive individuals [9]. While the use of large populations should be greatly applauded, all analyses presented in their study are cross-sectional, that is, in each individual, CAVI/CAVI 0 was measured only once.…”

“…Alizargar et al point out that Shirai et al observed a negative, "inexplicable" correlation between CAVI 0 and diastolic blood pressure (DBP) in healthy individuals, which Shirai et al then used as a reason to label CAVI 0 as "inappropriate" [1,9]. Again, this correlation is cross-sectional, and indicates (statistically) that subjects with a higher CAVI 0 on average have a lower DBP.…”