Coefficients in the CAVI Equation and the Comparison Between CAVI With and Without the Coefficients Using Clinical Data

Abstract

Aim: The Cardio-Ankle Vascular Index (CAVI) is a stiffness index of the arterial tree from the origin of the aorta to the ankle, independent of blood pressure at the time of measurement. The CAVI equation includes the coefficients “a” and “b” to adjust it to the value of Hasegawa's pulse wave velocity, which is compensated for at 80 mmHg of diastolic pressure. To verify this adjustment with the coefficients, the clinical significance of CAVI and CAVI without the coefficients (ha β ) were compared in both an epidemiological study and an acute clinical study. Methods: In the epidemiological study, the significances of CAVI and ha β among people with or without coronary risks such as hypertension, dyslipidemia, hyperglycemia, and abnormal electrocardiography change, were compared. In the acute clinical study, nitroglycerin was administered to subjects in a control group and to coronary artery disease patients, observing CAVI and ha β values over a 20-min period. Results: There was no discrepancy in terms of statistically significant differences between CAVI and ha β among subjects with or without risk factors. Furthermore, there was also no discrepancy in terms of statistically significant differences between CAVI and ha β during the changes of those values following nitroglycerin administration over a 20-min period. Conclusion: In both the epidemiologic and clinical studies, there was no discrepancy in terms of significant differences between CAVI and ha β . These results suggest that both are valid as indices of stiffness of the arterial tree from the origin of the aorta to the ankle.

Rationale, design, and baseline characteristics of the Cardiovascular Prognostic COUPLING Study in Japan (the COUPLING Registry)

“…BP at four extremities were then measured by the cuff‐oscillometric method. CAVI was calculated using the following formula, where P sys = SBP, P dia = DBP, ρ = blood density, haPWV is PWV from the origin of the aorta to tibial artery at the ankle through the femoral artery, and a and b are constants to convert the values of CAVI:…”

P152 Prediction of Death or Heart Failure-related Hospitalizations by Cardio-ankle Vascular Index (CAVI) and CAVI0

“…Subjects underwent arterial stiffness assessments (VaSera 1500 N, Fukuda Denshi Co., Tokyo, Japan). Left (L-CAVI) and right (R-CAVI) measurements were obtained from the device, CAVI 0 's were converted from CAVI's taking into account CAVI's scale coefficients [8,9]. We prospectively followed participants for a mean of 2.56 years for the composite endpoint of death or heart failure related hospital admission.…”

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

“…It is also interesting to know that the information about CAVI has been recently updated. Takahashi et al [8] showed that the CAVI without the coefficients (coefficients a and b in Equation (1)) is also a valid index of arterial stiffness (Equation (3)). CAVI without coefficients a and b is parameter β, which is referred to as haβ (heart to ankle beta).…”

“…CAVI without coefficients a and b is parameter β, which is referred to as haβ (heart to ankle beta). Takahashi et al [8] also revealed the coefficient "a" and "b" values that are being used in the CAVI calculation (Table 1). A review of this information raised some interesting discussion about the validity and use of the CAVI index.…”