Intima-media thickness and carotid resistive index: progression over 6 years and predictive value for cardiovascular events

Wavelet entropy of Doppler ultrasound blood velocity flow waveforms distinguishes nitric oxide-modulated states

Wavelet entropy assesses the degree of order or disorder in signals and presents this complex information in a simple metric. Relative wavelet entropy assesses the similarity between the spectral distributions of two signals, again in a simple metric. Wavelet entropy is therefore potentially a very attractive tool for waveform analysis. The ability of this method to track the effects of pharmacologic modulation of vascular function on Doppler blood velocity waveforms was assessed. Waveforms were captured from ophthalmic arteries of 10 healthy subjects at baseline, after the administration of glyceryl trinitrate (GTN) and after two doses of N(G)-nitro-L-arginine-methyl ester (L-NAME) to produce vasodilation and vasoconstriction, respectively. Wavelet entropy had a tendency to decrease from baseline in response to GTN, but significantly increased after the administration of L-NAME (mean: 1.60 ± 0.07 after 0.25 mg/kg and 1.72 ± 0.13 after 0.5 mg/kg vs. 1.50 ± 0.10 at baseline, p < 0.05). Relative wavelet entropy had a spectral distribution from increasing doses of L-NAME comparable to baseline, 0.07 ± 0.04 and 0.08 ± 0.03, respectively, whereas GTN had the most dissimilar spectral distribution compared with baseline (0.17 ± 0.08, p = 0.002). Wavelet entropy can detect subtle changes in Doppler blood velocity waveform structure in response to nitric-oxide-mediated changes in arteriolar smooth muscle tone.

Carotid intima-media thickness: Current evidence, practices, and Indian experience

As the developed and developing nations cope up with increasing predisposition to cardiovascular diseases (CVD) by adopting lifestyle changes the burden of coronary artery disease continues to rise globally. The presence of modifiable risk factors, which account for more than 90% of the cardiovascular (CV) risk, cannot always be interpreted as the presence of atherosclerotic heart disease and absence of modifiable risk factors do not guarantee absence of atherosclerotic changes in the arterial tree. Increasing awareness about primordial prevention and primary prevention of CVD is of vital importance in such scenarios. Ultrasonographic measurement of intima media thickness has been reported as a procedure to detect the early stages of atherosclerosis. Carotid intima media thickness (CIMT) testing is a safe, noninvasive and cost effective method to detect early atherosclerotic vascular diseases. This method of CV risk evaluation drew attention worldwide and of Indian physicians because of its feasibility in Indian population. Hence, detection and management of atherosclerosis in asymptomatic individuals will go a long way in preventing atherosclerotic diseases and prolonging survival and improving quality of life.

Carotid resistive index in treated hypertensive patients: relationship with target organ damage

AIM

The resistive index (RI) is a hemodynamic parameter that reflects local wall extensibility and related vascular resistance. We analyze the relationship between common carotid RI and target organ damage in treated hypertensive patients.

METHODS

We analyzed 265 consecutive hypertensive patients. Risk factors, cardiovascular history and treatments were collected; blood test, urinary albumin excretion (UAE), echocardiography to determine left ventricular mass index (LVMI), ankle-brachial index (ABI) and carotid echo-Doppler ultrasound to calculate the carotid intima-media thickness (IMT) and RI of both common carotids arteries were performed.

RESULTS

A positive correlation was found between carotid RI and age, systolic blood pressure, heart rate, carotid IMT, LVMI, UAE and a negative correlation was found with diastolic blood pressure and ABI. Subjects at the top quartile of carotid RI showed a higher prevalence of left ventricular hypertrophy and peripheral artery disease (increased IMT, carotid plaques and lower ABI) compared with those with low RI (p < 0.05). Multiple regression analysis demonstrated that age, systolic and diastolic blood pressure and LVMI independently influence carotid RI.

CONCLUSION

Carotid RI is related with age, systolic-diastolic blood pressure and LVMI in hypertensive patient. This evaluation could predict the presence of early cardiovascular damage and provide an accurate estimation of overall risk in this population.

Arterial stiffness is associated with increased monocyte expression of adiponectin receptor mRNA and protein in patients with coronary artery disease

BACKGROUND

Arterial stiffness and carotid intima-media thickness (IMT) constitute validated cardiovascular prognostic markers. Adiponectin and its receptors 1 (AdipoR1) and 2 (AdipoR2) are involved in coronary artery disease (CAD). We investigated whether AdipoR1 and R2 mRNA and protein expression are associated with arterial stiffness, IMT and extent of coronary atherosclerosis.

METHODS

We studied 71 patients (61 men, 10 women) with angiographically proven CAD. We measured: (i) monocyte expression of AdipoR1 and AdipoR2 mRNA (quantitative real-time PCR) and protein expression (flow cytometry) (iii) adiponectin, metalloproteinase-9 (MMP-9) and C-reactive protein (CRP) blood levels, (iv) carotid-femoral artery pulse wave velocity (PWV) and carotid IMT.

RESULTS

Patients with multi-vessel CAD had higher AdipoR1 and AdipoR2 mRNA than those with single-vessel (P < 0.05). PWV was associated with AdipoR1 mRNA (r = 0.474), AdipoR1 protein (r = 0.228), AdipoR2 mRNA (r = 0.716), AdipoR2-protein (r = 0.261), adiponectin (r = 0.236), and MMP-9 (r = 0.350) (P < 0.05, for all correlations). After adjustment for age, sex, waist-hip ratio, and mean blood pressure both AdipoR1 and AdipoR2 mRNA remained independent determinants of PWV (R(2) = 0.35 and R(2) = 0.57, P < 0.05). IMT was also associated with AdipoR2 mRNA, AdipoR2 protein, and MMP-9 (P < 0.05). Increased expression of ADR2 mRNA significantly related to MMP-9 (r = 0.210), and CRP (r = 0.531) (P < 0.05).

CONCLUSION

Increased mRNA and protein expression of adiponectin receptors is related with increased aortic stiffness, coronary and peripheral atherosclerosis in patients with CAD. The interrelation of AdipoR2 with inflammatory markers, PWV and IMT suggests a compensatory increase of these receptors to counteract the excess inflammatory and atherogenic process in CAD. Thus, adiponectin receptors may provide a potential therapeutic target of agents activating their beneficial action.American Journal of Hypertension 2012; doi:10.1038/ajh.2012.42.

Aging, components of metabolic syndrome and serum C-reactive protein showed significant relationship with carotid atherosclerosis

OBJECTIVE

metabolic syndrome (MetS) is known to be associated with an increased risk for cerebro- as well as cardio-vascular disease. Prediction of carotid atherosclerosis by components of MetS, serum C-reactive protein, aging and related factors was conducted for Japanese inhabitants.

METHODS

A total of 887 subjects (761 males, 126 females) were included in the present study. Early atherosclerosis was assessed by measurement of the intima-media thickness of the common carotid arteries.

RESULTS

The carotid arterial intima-media thickness on both the right and left sides significantly increased as the number of components of MetS increased. The maximum intima-media thickness values in the right (left) carotid arteries in the male and female subjects who fulfilled the criteria for MetS were 0.65 ± 0.18 (0.66 ± 0.17) mm and 0.58 ± 0.12 (0.59 ± 0.11) mm, respectively. After adjustment for several factors, the intima-media thickness related significantly with aging, some components of MetS and serum C-reactive protein by multiple regression analysis. β-coefficient of age was largest, presenting 0.457 in right side and 0.479 in left side.

CONCLUSIONS

Aging, metabolic components and serum C-reactive protein are independent predictors of intima-media thickness in subjects.

Sonographic examination of epiaortic vessels in patients with peripheral vertigo

INTRODUCTION

To evaluate the utility of echo-color-Doppler ultrasonography (CDU) of extracranial brain-supplying vessels in patients with peripheral vertigo of unknown origin.

MATERIALS AND METHODS

One-hundred-fifty-six patients (study group; 42 male and 114 female; mean age 61.86 ± 14.14) and 161 patients (control group; 80 male and 81 female; mean age 62.31 ± 13.69) were prospectively evaluated with CDU of extracranial brain-supplying vessels. Plaques in common and/or internal carotid artery (CA), arterial wall intima-media thickness (IMT) of common CA and peak systolic velocity (PSV) and resistive index (RI) of vertebral arteries (VA) were evaluated. Parametric (t-test) and non-parametric (Mann-Whitney U-test and Kolmogorov-Smirnov test) tests were applied. Logistic regression analysis was performed to provide odds ratio indicating the magnitude of risk of vertigo. Independent variables consisting of characteristics (age, sex), vascular risk factors (hypercholesterolemia, diabetes, hypertension) and CDU variables (IMT, plaque, PSV and RI of VA) were considered.

RESULTS

Plaques were found in 31 (19.8%) patients of study group and in 43 (26.7%) patients of control group. IMT > 1 mm was found in 98 (62.8%) patients of study group and in 125 (77.6%) patients of control group.Statistical tests, applied to PSV and RI, showed no significant difference (p-value >0.05). At logistic regression analysis, vertigo was associated with age, sex, hypercholesterolemia, diabetes, hypertension and IMT (p < .01) while plaque, PSV and RI of VA were not significant factors (p > .05).

DISCUSSION

IMT is the only CDU variable significantly associated with vertigo, especially in the lower age-classes (35-45 and 45-55) of study group.

The Prevalence of Peripheral Arteriopathy is Higher in Ischaemic Stroke as Compared with Transient Ischaemic Attack and Intracerebral Haemorrhage

Background:

There is little data on the association of peripheral arterial disease and stroke. We aimed to assess the prevalence of peripheral arterial disease in acute stroke and to identify the predisposing factors for peripheral arterial disease in a stroke cohort.

Methods:

We enrolled all consecutive patients who were admitted to our stroke- and neurocritical care units with the diagnosis of a transient ischaemic attack, ischaemic or haemorrhagic stroke over a period of 5 months. As controls, we analysed 50 nonvascular neurological patients who were matched to age. Upon admission, assessment of the ankle brachial index was performed in all patients. The only exclusion criteria was decompensated congestive heart failure.

Results:

Altogether, we compared 374 stroke patients (95 transient ischaemic attack, 231 ischaemic, and 48 haemorrhagic strokes) and 50 nonstroke controls. The prevalence of peripheral arterial disease in the control group was 14%. There was a trend towards a higher prevalence of peripheral arterial disease in stroke patients (χ2-test: P = 0.051; prevalence peripheral arterial disease in transient ischaemic attack: 16.8%, ischaemic stroke: 32%, and haemorrhagic stroke: 20.8%). A higher proportion of ischaemic stroke patients were peripheral arterial disease-positive, compared with transient ischaemic attack patients ( P = 0.005) and controls ( P = 0.011), respectively. Multivariate regression analyses identified the parameters age, arterial hypertension, current or former smokers and a history of cardiovascular events to be predisposing factors of peripheral arterial disease.

Conclusion:

This study represents the first systematic investigation of the prevalence of peripheral arterial disease in stroke. By now, it is clear that: • peripheral arterial disease is more commonly found in stroke than in nonstroke patients • ischaemic stroke patients show the highest prevalence of peripheral arterial disease, and • peripheral arterial disease in stroke is related to common vascular risk factors.