Cardio-Ankle Vascular Index is a New Noninvasive Parameter of Arterial Stiffness

Abstract

tiffness of large arteries has been related to cardiovascular mortality, but the mechanisms underlying this relationship have not been established. 1 Methods are used to estimate this stiffness include carotid ultrasound (CU) and pulse-wave-velocity (PWV). 2 Carotid artery stiffness detected by CU is known to representative of systemic arteriosclerosis. The measurement of PWV is very useful for diagnosing arteriosclerosis in any part of the body 3-7 and a new method for measuring PWV has been proposed in Japan. Brachial -ankle PWV (baPWV) measures the PWV in the arm and leg by applying air pressure using the volume plethysmographic method. However, baPWV is reportedly influenced by several factors such as blood pressure (BP), autonomic nerve function etc and therefore does not reflect arteriosclerosis in some cases.The stiffness parameter is reported to be independent of BP. 8 Beta of the thoracic descending aorta (TDA) has been obtained previously only by transesophageal echocardiography (TEE), 9 but recently this problem has been solved with the advent of the cardio-ankle vascular index (CAVI). CAVI is a new parameter that is also independent of BP 10-12 and in the present study, we examined the accuracy and usefulness of CAVI and compared it with other parameters of arteriosclerosis, using CU and serum lipids measurement in patients with chest pain syndrome. Methods Principle of CAVI and Method of MeasurementCAVI was obtained by substituting the stiffness parameter in the following equation for determining vascular elasticity and PWV. The stiffness parameter indicates BPindependent patient-specific vascular stiffness measured by arterial US. The stiffness parameter is calculated as: (1) where Ps and Pd are respectively the systolic and diastolic BP in mmHg. D is the diameter of the blood vessel and ∆D is the change of D.Bramwell-Hill's formula expresses the relationship between volume elastic modulus and PWV as follows:where ∆P is pulse pressure, is blood density, V is the volume of the blood vessel and ∆V is the change of V.From equation (2), the following formula is derived:where D is the diameter of the blood vessel and ∆D is the change of D. If we substitute equation (3) for equation (1), we obtain the stiffness parameter:CAVI is measured as follows. PWV is obtained by dividing vascular length (L) by the time (T) taken for the pulse wave to propagate from the aortic valve to the ankle Circ J 2007; 71: 1710 -1714 (Received February 15, 2007 revised manuscript received June 20, 2007; accepted July 4, 2007) Division of Cardiology, Tokuyama Central Hospital, Shunan, *Division Methods and ResultsThe purpose of this study was to evaluate the accuracy and usefulness of CAVI and to compare it with other parameters of arteriosclerosis by carotid ultrasound (CU). The instantaneous dimensional change of the TDA on TEE was measured simultaneously with systemic pressure of the brachial artery in 70 patients in sinus rhythm. There were significant correlations between CAVI and age (r=0.65, p<0.01), and CAVI and...

Tissue Doppler Echocardiography for Predicting Arterial Stiffness Assessed by Cardio-Ankle Vascular Index

“…However, that study was performed by measuring carotid-femoral pulse wave velocity, which though noninvasive requires a complicated technique. Our data demonstrated similar results using CAVI, which has been recently established as a marker of arterial stiffness and is widely used in clinical settings (Kubozono et al 2007;Takaki et al 2007;Kadota et al 2008;Takaki et al 2008). Mizuguchi et al (2007) demonstrated that CAVI was more closely related to the LV diastolic functional parameter (early diastolic strain rate) obtained from tissue Doppler echocardiography than that obtained from conventional Doppler echocardiography, and concluded that arterial stiffness was associated with LV relaxation during early diastole.…”

Analysis of vascular function using the cardio–ankle vascular index (CAVI)

“…Blood pressure will decrease as a result. In addition, brachial-ankle pulse wave velocity will thus decrease because pulse wave velocity depends on blood pressure at the time of the measurement, as reported by Nye et al [2][3][4]6 Under these conditions, a decrease in CAVI might be due to the relaxation of smooth muscle cells induced by general anesthesia itself and by administration of propofol. The report by Kim described two important features of CAVI: (1) CAVI expression changes over a short period of time, depending on the circulatory condition; and (2) CAVI expression reflects the state of smooth muscle cell contraction.…”

“…This lack of dependence was predicted by theory and was confirmed by several experimental studies. [2][3][4] The CAVI is high in aging patients and in patients with arteriosclerotic diseases, such as coronary artery disease, 7 carotid arteriosclerosis, 3,8 chronic kidney disease 9 , and is related to many coronary risk factors such as hypertension, 3 diabetes mellitus, 8 dyslipidemia 8 and smoking. 10 Furthermore, the CAVI decreases with control of diabetes mellitus and hypertension, as well as with abstention from smoking.…”

“…The CAVI was developed as a new index of the stiffness of the artery as a whole, from the origin of the aorta to the ankle. [2][3][4] The authors observed that both systolic and diastolic blood pressure decreased during generalized anesthesia using propofol. Simultaneously, brachial-ankle pulse wave velocity decreased along with the decrease in blood pressure.…”

Cardio-Ankle Vascular Index Relates to Left Ventricular Ejection Fraction in Patients With Heart Failure

“…CAVI is superior to baPWV as an index of arterial stiffness in patients who have undergone coronary angiography. 9) CAVI is independently associated with left ventricular (LV) systolic and diastolic functions as well as the severity of coronary atherosclerosis in ischemic heart disease (IHD) patients.…”