Background Recently, arterial stiffness parameter called cardio-ankle vascular index (CAVI) has been developed. In the current study, using coronary angiographic (CAG) findings, the usefulness of CAVI as a marker of the severity of coronary atherosclerosis was compared with that of carotid atherosclerosis parameters obtained from high-resolution B-mode ultrasonography. Method and Result A total of 109 participants who underwent CAG were enrolled in the current study. They were divided into 4 groups according to the number of stenotic vessels on CAG; no lesion (0VD), 1-vessel (1VD), 2-vessel (2VD) and 3-vessel (3VD) groups. CAVI was significantly higher in 1VD group compared with the 0VD group (p<0.05), and was significantly higher in 2VD and 3VD group compared with the 1VD group. In single regression analysis, CAVI correlated positively with maximum intima-media thickness (IMT) (p<0.01) and plaque score (p<0.0001). A stepwise ordinal logistic regression analysis using mean IMT, maximum IMT, plaque score and CAVI as independent variables identified only CAVI as positively related to the severity of coronary atherosclerosis. The area under the receiver operating characteristic curve defined by CAVI was the greatest. Conclusion CAVI might be more useful for discriminating the probability of coronary atherosclerosis than findings of carotid atherosclerosis by high-resolution B-mode ultrasonography. (Circ J 2008; 72: 598 - 604)

The cardio-ankle vascular stiffness index (CAVI) is a new parameter that reflects the stiffness of the aorta, femoral artery and tibial artery as a whole. One of its conspicuous features is that CAVI is independent of blood pressure at measuring time, theoretically. But, it has not been experimentally proved yet. For confirmation, pharmacological studies were performed comparing with brachial-ankle pulse wave velocity (baPWV). Used drugs were a β1-adrenoceptor blocker, metoprorol and an α1- adrenoceptor blocker doxazosin. Both were administered to 12 healthy volunteer men. CAVI and baPWV were measured every one hour for 6 hours using VaSera. When metoprolol (80 mg) was administered to 12 healthy volunteer men, systolic blood pressure decreased from 131.4 ± 4.5 to 118.3 ± 4.1 mmHg (mean ± SE) (p < 0.05) at the 3rd hour, and diastolic blood pressure decreased from 85.3 ± 4.0 to 75.3 ± 3.0 mm Hg (p < 0.05). baP-WV decreased from 13.93 ± 0.46 to 12.46 ± 0.49 m/sec (p < 0.05), significantly, but CAVI did not change (8.16 ± 0.29 to 8.24 ± 0.27) (p = 0.449). ΔbaPWV at each time was significantly correlated with both Δsystolic and Δdiastolic blood pressures, but ΔCAVI was not correlated with either Δblood pressure. When doxazosin (4 mg) was administered to the same men, systolic blood pressure decreased from 130.2 ± 4.6 to 117.2 ± 4.8 mmHg (p < 0.05) at the 3rd hour. Diastolic blood pressure also decreased from 85.1 ± 4.1 to 74.2 ± 3.9 mmHg (p < 0.05). baPWV decreased from 13.98 ± 0.68 to 12.25 ± 0.53 m/sec (p < 0.05), significantly. CAVI also decreased from 8.15 ± 0.28 to 7.18 ± 0.37 (p < 0.05), significantly. These results suggested that CAVI was not affected by blood pressure at the measuring time directly, but affected by the changes of contractility of smooth muscle cells.

Background: Arterial stiffness is an important predictor of cardiovascular events; however, indexes for measuring arterial stiffness have not been widely incorporated into routine clinical practice. This study aimed to determine whether the cardio‐ankle vascular index (CAVI), based on the blood pressure–independent stiffness parameter β and reflecting arterial stiffness from the origin of the ascending aorta, is a good predictor of cardiovascular events in patients with cardiovascular disease risk factors in a large prospective cohort. Methods and Results: This multicenter prospective cohort study, commencing in May 2013, with a 5‐year follow‐up period, included patients (aged 40‒74 years) with cardiovascular disease risks. The primary outcome was the composite of cardiovascular death, nonfatal stroke, or nonfatal myocardial infarction. Among 2932 included patients, 2001 (68.3%) were men; the mean (SD) age at diagnosis was 63 (8) years. During the median follow‐up of 4.9 years, 82 participants experienced primary outcomes. The CAVI predicted the primary outcome (hazard ratio, 1.38; 95% CI, 1.16‒1.65; P <0.001). In terms of event subtypes, the CAVI was associated with cardiovascular death and stroke but not with myocardial infarction. When the CAVI was incorporated into a model with known cardiovascular disease risks for predicting cardiovascular events, the global χ ² value increased from 33.8 to 45.2 ( P <0.001), and the net reclassification index was 0.254 ( P =0.024). Conclusions: This large cohort study demonstrated that the CAVI predicted cardiovascular events. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01859897.