Kimihiko Ishimura

Comparison of Atherosclerotic Indicators Between Cardio Ankle Vascular Index and Brachial Ankle Pulse Wave Velocity

Background: Aortic pulse wave velocity has been used for evaluating atherosclerosis. Recently, the development of the volume plethysmographic method has made it possible to easily measure the index of the pulse wave velocity. The brachial ankle pulse wave velocity and cardio ankle vascular index are used for estimating the extent of atherosclerosis. The diagnostic usefulness of these indexes in predicting coronary artery disease was examined. Methods: The brachial ankle pulse wave velocity, the cardio ankle vascular index, and the high-sensitivity C-reactive protein were measured in 696 patients who had chest pain and underwent coronary angiography. Measurement values of brachial ankle pulse wave velocity were compared with those of cardio ankle vascular index in terms of the baseline covariates and the number of major coronary vessels involved (vessel disease). Results: The brachial ankle pulse wave velocity was significantly correlated with age, systolic blood pressure, and diastolic blood pressure but not with the high-sensitivity C-reactive protein. The cardio ankle vascular index was correlated only with age and the high-sensitivity C-reactive protein. The average of both brachial ankle pulse wave velocity and cardio ankle vascular index values was greater in 3 vessel disease group than in 0 vessel disease group. The receiver operating characteristic curve showed that the diagnostic accuracy of coronary artery disease was significantly higher in the cardio ankle vascular index than in the brachial ankle pulse wave velocity (area under the curve ± standard error: 0.691 ± 0.025 vs. 0.584 ± 0.026; P < .05). Conclusions: As a means of estimating the extent of atherosclerosis in large arteries, our results show that both brachial ankle pulse wave velocity and cardio ankle vascular index are useful and that cardio ankle vascular index may have some advantages in its application to patients taking blood pressure—lowering medication because of the minimum effect of blood pressure on its measurement values. The cardio ankle vascular index has increased performance over brachial ankle pulse wave velocity in predicting the coronary artery disease.

Cardio-ankle vascular index could reflect plaque burden in the coronary artery.

Cardio-ankle vascular index (CAVI) using the volume plethysmographic method is a noninvasive atherosclerotic indicator which is not influenced by blood pressure. Coronary intravascular ultrasound (IVUS) is a reliable technique to measure progression of atherosclerosis. The association between CAVI and IVUS has not been reported. The aim of this study was to evaluate the association between CAVI and the plaque burden measured by IVUS in the left main coronary artery (LMCA) in patients with coronary heart disease and normal LMCA. Cardio-ankle vascular index was significantly correlated with percentage plaque area (r = .649, P < .0001) measured by IVUS in the most diseased segment of LMCA. Cardio-ankle vascular index remained significant among cardiovascular disease risk factors included in the multiple regression analysis predicting percentage plaque area. Cardio-ankle vascular index was a good atherosclerotic indicator and associated with the plaque burden in nonculprit and angiographically normal LMCA.

Natriuretic peptide/natriuretic peptide receptor-A (NPR-A) system has inhibitory effects in renal fibrosis in mice

OBJECTnThis study was designed to examine whether natriuretic peptide/natriuretic peptide receptor-A (NPR-A) system attenuates renal fibrosis in a unilateral ureteral obstruction (UUO) model and also examined the mechanism involved.nnnMETHODSnThree groups were studied: untreated UUO in wild-type mice; untreated UUO in NPR-A KO mice; and ANP treated (0.05 microg/kg/min) UUO in wild-type mice. We measured histological and immunohistochemical findings (alpha-SMA and F4/80), tissue cGMP levels, various mRNA expression levels by real-time PCR analysis, and transcription factor levels (AP-1 and NF-kappaB) in renal tissue.nnnRESULTSnCompared with wild-type UUO mice, NPRA-KO UUO mice had abnormal morphological findings (fibrous area: +26%, alpha-SMA expression: +30%) with lower tissue cGMP levels and increases in the mRNA expression levels of TGF-beta, collagen I, collagen III, PAI-1, renin and angiotensinogen, whereas there were no differences in F4/80 positive cells or the mRNA expression levels of ICAM-1, osteopontin, or MCP-1 between the two groups. In contrast, ANP pre-treatment significantly improved morphological changes with increase of tissue cGMP levels and reduction in the mRNA expression level of TGF-beta, collagen I, collagen III, PAI-1, ICAM-1, osteopontin, MCP-1, renin, and angiotensinogen. NPRA-KO UUO mice had higher AP-1 levels than wild-type UUO mice and ANP pre-treatment reduced AP-1 and NF-kappaB activity.nnnCONCLUSIONnThe endogenous natriuretic peptide/NPR-A system may inhibit renal fibrosis partly via inhibition of the angiotensin/AP-1/TGF-beta/collagen pathway and exogenous ANP pre-treatment may inhibit it partly via both the angiotensin/AP-1/TGF-beta/collagen and NF-kappaB/inflammatory pathways.

Cardio-ankle vascular index (CAVI) correlates with aortic stiffness in the thoracic aorta using ECG-gated multi-detector row computed tomography

BACKGROUNDnThe cardio-ankle vascular index (CAVI) is an arterial stiffness index based on the stiffness parameter β, which is essentially independent of blood pressure. The objective of this study was to determine whether CAVI correlates with the regional stiffness parameter β and pulse wave velocity (PWV) in the thoracic aorta calculated from ECG-gated multi-detector row computed tomography (MDCT).nnnMETHODS AND RESULTSnForty-nine patients who underwent coronary MDCT for suspicious coronary artery disease were recruited. The largest and smallest vessel luminal cross-sectional areas of the thoracic aorta were measured from MDCT images to calculate PWV and stiffness parameter β of the ascending and descending aorta. CAVI was also measured by VaSera VS-1000. In univariate analysis, CAVI significantly correlated with regional stiffness parameter β and PWV, which was influenced by the inevitable part of the aging process in the ascending (r = 0.485, P < 0.001; r = 0.483, P < 0.001) and descending aortas (r = 0.304, P = 0.034; r = 0.327, P = 0.022), respectively. The regional stiffness parameter β did not correlate with systolic blood pressure (SBP), although the PWV correlated with SBP. In multivariate analysis, CAVI independently correlated with the stiffness parameter β, but not with the PWV.nnnCONCLUSIONnThese data suggest that CAVI, which correlated with stiffness parameter β in the thoracic aorta, has a potential role in evaluating integrated arterial stiffness including that of the central aorta.