The cardio-ankle vascular index (CAVI) is a new index of the overall stiffness of the artery from the origin of the aorta to the ankle. The most conspicuous feature of CAVI is its independence of ...blood pressure at the time of measurement. CAVI increases with age and in many arteriosclerotic diseases, such as coronary artery disease, carotid arteriosclerosis, chronic kidney disease and cerebrovascular disease, and is related to many coronary risk factors, such as hypertension, diabetes mellitus, dyslipidemia and smoking. Furthermore, CAVI decreases by controlling diabetes mellitus and hypertension, and also by abstaining from smoking. This suggests that CAVI is a physiological surrogate marker of athero- or arteriosclerosis, and also might be an indicator of lifestyle modification. Recently, it has been reported that CAVI and several left ventricular functions are co-related, suggesting a connection between the heart muscle and vascular function. This review covers the principles of CAVI and our current knowledge about CAVI, focusing on its roles and future outlook.
Takotsubo syndrome is a sudden and an acute form of transient cardiac dysfunction, triggered by mental and physical stress. The treatment for Takotsubo syndrome is not well understood and is ...incompletely established. Takotsubo syndrome is partly thought to be caused by coronary ischemia under sympathetic nerve activation.
We report the case of an 80-year-old Japanese woman with recurrent Takotsubo syndrome complicated with ischemic enteritis. In this case, abdominal pain and dehydration due to ischemic enteritis is thought to have triggered Takotsubo syndrome. Her life was saved with rapid, adequate intravenous hydration. She was diagnosed with coronary vasospastic angina using coronary angiography on her second admission. This case highlights the potential of adequate intravenous hydration in increasing coronary blood flow. In our case, it should be noted that pulmonary congestion was mild and may have improved Takotsubo syndrome without the use of diuretics.
Adequate hydration must be considered for prompt improvement of cardiac function in Takotsubo syndrome. Replenishment of fluid to increase coronary blood flow, improvement of heart load without exacerbating heart failure, and stabilization of circulation dynamics can help treat patients with Takotsubo syndrome without using diuretics.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Aim: Stroke is well known to lead to hypertension; nevertheless, the role of vascular function in hypertension remains unclear. In this study, we aimed to clarify the mechanism underlying increased ...arterial stiffness following stroke. Methods: The cardio-ankle vascular index (CAVI) was measured in five New Zealand White rabbits. Under general anesthesia, intracranial pressure (ICP) was increased by injecting saline (15 mL) into the cisterna magna. ICP was monitored using a catheter inserted into the subarachnoid space via right frontal bone craniotomy. Blood pressure (BP), CAVI, and common carotid flow (CCF) were evaluated, and the responses of these parameters to increased ICP were analyzed. Results: Saline injection into the cisterna magna increased the ICP by over 20 mmHg. Both BP and CAVI increased from 63.2±4.84 to 128.8±14.68 mmHg and from 4.02±0.28 to 4.9±0.53, respectively. Similarly, BP and CCF increased. When hexamethonium was administered before the increase in ICP, the increase in BP (132.2±9.41 mmHg with 10 mg/kg hexamethonium vs. 105.6±11.01 mmHg with 100 mg/kg hexamethonium) and CAVI (5.02±0.64 with 10 mg/kg hexamethonium vs. 4.82±0.42 with 100 mg/kg hexamethonium) were suppressed in a dose-dependent manner. Conclusion: Increased ICP causes an increase in BP and CAVI, suggesting that enhanced stiffness of the muscular arteries contributes to high BP. Blocking the autonomic nervous system with hexamethonium suppresses the increase in BP and CAVI, indicating that these increases are mediated by activation of the autonomic nervous system.
We investigated gender differences in the optic nerve head (ONH) microcirculation status in association with obstructive sleep apnea (OSA) by using laser speckle flowgraphy (LSFG). We evaluated 150 ...men (60.5 ± 11.0 yrs) and 45 women (63.0 ± 10.6 yrs) who underwent overnight polysomnography. The mean blur rate (MBR), maximum (Max) MBR, and minimum (Min) MBR were evaluated. The parameters were analyzed separately for the tissues, vessels, and throughout the ONH (All). The apnea hypopnea index (AHI: times/hr), the lowest SpO2%, and the mean SpO2% were calculated as indicators of OSA. We investigated which MBR sections are correlated with OSA parameters separately in the men and women. All MBR sections in the women were significantly positively correlated with the lowest SpO2. In the men, no MBR section was correlated with any OSA parameters. The factors contributing independently to MBR-Tissue were height (β = 0.31) and lowest SpO2 (β = 0.30). The lowest SpO2 in the women was significantly positively correlated with Max MBR-Tissue, Max MBR-All, and Min MBR-All. Our results confirmed a gender difference in characteristics of ONH microcirculation in association with OSA.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Aim: In the TOHO Lipid Intervention Trial Using Pitavastatin (TOHO-LIP), a multicenter randomized controlled trial, pitavastatin significantly reduced cardiovascular (CV) events compared to ...atorvastatin in patients with hypercholesterolemia. To investigate the mechanism by which pitavastatin preferentially prevents CV events, we investigated the relationship between CV events and cardio-ankle vascular index (CAVI) using the TOHO-LIP database. Methods: For the subgroup analysis, we selected patients from a single center, Toho University Sakura Medical Center. After excluding those who had CV events at baseline or during the first year, 254 patients were enrolled. The primary end point was the same as that of TOHO-LIP, and three-point major cardiac adverse events (3P-MACE) was added as secondary end point. Results: The cumulative 5-year incidence of 3P-MACE (pitavastatin 1.6%, atorvastatin 6.1%, P=0.038) was significantly lower in pitavastatin group (2 mg/day) than in atorvastatin group (10 mg/day). CAVI significantly decreased only in pitavastatin group during the first year (9.50–9.34, P=0.042), while the change in low-density lipoprotein cholesterol (LDL-C) did not differ between the two groups. The change in CAVI during the first year positively correlated with 3P-MACE and tended to be an independent predictor of 3P-MACE in Cox proportional hazards model (hazard ratio, 1.736; P=0.079). The annual change in CAVI throughout the observation period was significantly higher in subjects with CV events compared to those without. Conclusions: In this subgroup analysis, the reduction in CV events tended to be associated with the CAVI-lowering effect of pitavastatin, which was independent of the LDL-C-lowering effect.
Although elasticity of the conduit arteries is known to be contribute effective peripheral circulation via Windkessel effects, the relationship between changes in intra-aortic blood volume and ...conduit artery elasticity remains unknown. Here we assessed the effects of change in intra-aortic blood volume induced by blood removal and subsequent blood transfusion on arterial stiffness and the involvement of autonomic nervous activity using our established rabbit model in the presence or absence of the ganglion blocker hexamethonium (100 mg/kg). Blood removal at a rate of 1 mL/min gradually decreased the blood pressure and blood flow of the common carotid artery but increased a stiffness indicator the cardio-ankle vascular index, which was equally observed in the presence of hexamethonium. These results suggest that arterial stiffness acutely responds to changes in intra-aortic blood volume independent of autonomic nervous system modification.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Layer-by-layer (LbL) films were prepared by an alternate deposition of phenylboronic acid-bearing poly(allylamine hydrochloride) (PBA–PAH) and poly(vinyl alcohol) (PVA) on the surface of a quartz ...slide to develop thin films that can be decomposed in response to hydrogen peroxide (H2O2). The PBA–PAH/PVA films decomposed in the presence of H2O2; the degree and kinetics of decomposition depend on the concentration of H2O2 and on the pH of the solution. For example, the film decomposition completely occurred in 30 min in 1.0 mM H2O2 solution at pH 7.4, while it took 180 min in 0.1 mM H2O2 solution. The H2O2-induced decomposition of the film can be explained in terms of the oxidative scission of the carbon–boron bond in PBA residues in the PBA–PAH chains. A potential use of the PBA–PAH/PVA films in developing H2O2-sensitive delivery systems was suggested.
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IJS, KILJ, NUK, PNG, UL, UM
Aim: 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). Methods: 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. Results: When metoprolol (80 mg) was administered to 12 healthy volunteer men, systolic blood pressure decreased from 131.4±4.5 to118.3±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±3.0mmHg (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 to117.2±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. Conclusion: 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.
We assessed effects of acetylcholine and Nω-Nitro-l-arginine methyl ester hydrochloride (l-NAME) on the cardio-ankle vascular index (CAVI), an indicator of arterial stiffness from origin of aorta to ...tibial artery, in halothane-anesthetized rabbits. Acetylcholine decreased the blood pressure, femoral vascular resistance and CAVI, whereas l-NAME did not affect the CAVI at a hypertensive dose. The acetylcholine-induced decrement of CAVI was completely suppressed by l-NAME. These results suggest that the arterial stiffness in rabbits may be independent from homeostatic production of nitric oxide, however, it can be decreased by large amounts of nitric oxide that are intrinsically produced by exogenously administered acetylcholine.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Propose
The purpose of this study was to determine whether there were significant correlations between the pulse waveform in the capillary area of the optic nerve head (ONH) microcirculation shown by ...laser speckle flowgraphy (LSFG) and parameters of the systemic condition, especially the cardio-ankle vascular index (CAVI).
Method
We studied 130 men (ages 60.5 ± 10.9 years) who visited the Vascular Function Section of the Department of Cardiovascular Center of Toho University Sakura Medical Center. We evaluated the skew and blowout time (BOT) — which are parameters of pulse waveform analyses — using LSFG in the capillary area of the ONH for each patient. The CAVI, the E/e’ ratio as the measure of diastolic left ventricular function, and the mean intima-media thickness (IMT) were evaluated as systemic parameters. We performed a Pearson’s correlation analysis and a multiple regression analysis to determine independent factors for skew and BOT.
Results
Heart rate, spherical refraction, and the CAVI (standard regression = 0.18,
t
= 2.61,
p
= 0.01) were revealed as factors contributing independently to the skew by multiple regression analysis. Heart rate, the CAVI (standard regression = −0.27,
t
= −3.92,
p
= 0.0002), the urinary albumin concentration, the mean IMT, spherical refraction, body mass index and pulse pressure were revealed as factors contributing independently to the BOT by multiple regression analysis.
Conclusion
The CAVI was demonstrated to be an independent factor contributing to both skew and BOT in the capillary area of the ONH. Our findings clarified that large arterial function shown by the CAVI contributes to smooth hemodynamics of microcirculation, shown by LSFG.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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