Intrarenal and carotid hemodynamics in patients with essential hypertension

BACKGROUND: The pulsatility index (PI) and resistive index (RI) are used as markers of peripheral vascular resistance. Recently intrarenal PI and RI were introduced for the evaluation of the severity of acute and chronic renal failure, as well as for the diagnosis of renal artery stenosis and kidney graft rejection. In the present study, we evaluated intrarenal PI and RI in patients with essential hypertension. METHODS: Fifty-one patients with essential hypertension participated. The intima-media thickness (IMT) and mean diastolic (Vd) and systolic velocity (Vs) in the common carotid artery (CCA) were measured using ultrasound and Doppler flow methods. Relative diastolic flow velocity (Vd/Vs) was calculated as an assessment of CCA hemodynamics. Renal Doppler flow was obtained from the interlobar arteries in each of two kidneys. The mean PI ([peak systolic velocity--end-diastolic velocity]/mean velocity) and mean RI ([peak systolic velocity--end-diastolic velocity]/peak systolic velocity) were calculated. RESULTS: Intrarenal PI and RI were positively correlated with IMT and negatively correlated with Vd/Vs in CCA, indicating that renal vascular resistance is related to carotid stiffness. A stepwise regression analysis revealed that age and pulse pressure were independently associated with intrarenal PI and RI. CONCLUSIONS: These results suggest that the measurement of PI and RI is useful for the evaluation of arterial stiffness in patients with essential hypertension.     

Long-term effects of angiotensin II receptor blockade with valsartan on carotid arterial stiffness and hemodynamic alterations in patients with essential hypertension

Increased arterial stiffness and intima media thickness (IMT) in the common carotid artery (CCA) are related to cardiovascular risk in essential hypertension. Angiotensin II plays an important role in structural and functional changes in the vasculature. In this study, we evaluated the long-term effect of the angiotensin II receptor blocker, valsartan, on IMT, arterial stiffness, and hemodynamics in the CCA in patients with essential hypertension. A prospective 24 month study of treatment with valsartan (80-160 mg/day) was performed in 24 hypertensive patients. An ultrasound of the CCA was carried out to determine IMT, the cross-sectional distensibility coefficient (CSDC), the carotid arterial stiffness index beta, and diastolic flow velocity to systolic flow velocity ratio (Vd/Vs). Treatment with valsartan for 24 months reduced systolic and diastolic blood pressure significantly. Compared to baseline, the decrease in pulse pressure was greater after 24 months treatment than after 12 months treatment. Valsartan did not influence IMT; however, after 24 months, it caused a significant increase in CSDC and a decrease in stiffness index beta compared to baseline. These changes were not observed after 12 months of treatment. In addition, Vd/Vs, a sensitive marker of relative diastolic blood flow, increased after 24 months' treatment with valsartan. These results suggest that long-term treatment with valsartan improves vascular wall function and hemodynamics in patients with essential hypertension.     

Augmentation index is related to white matter lesions

The augmentation index (AIx) is a measure of pulse wave reflection from peripheral muscular conduit arteries, and is assumed to increase with stiffened arteries. A white matter lesion (WML) is generally regarded as a chronic ischemic lesion, which is associated with cerebral small-vessel arteriosclerosis. The aim of this study is to elucidate the effect of pulse wave reflection on the brain. Carotid AIx was measured in a total of 205 neurologically normal adults. The correlations between AIx and WML were investigated. Two categories of WML were evaluated, periventricular hyperintensity (PVH) and deep and subcortical white matter hyperintensity (DSWMH). On univariate analysis, AIx was significantly correlated with the grades of PVH and DSWMH (P=0.0001, respectively). On multivariate analysis, AIx was correlated with PVH and DSWMH, independent of other risk factors such as age or blood pressure. Pulse wave reflection from small vessels may influence the genesis of WML.     

Association of Systolic Blood Pressure and Pulse Pressure with Carotid Intima Thickness in Elderly Japanese Patients

Many studies have demonstrated that increased carotid intima-media thickness (IMT) is related to future cardiovascular events and is influenced by cardiovascular risk factors such as sex, hypertension, diabetes, and hypercholesterolemia. Although aging is a well-known risk factor for an increase in carotid IMT, few studies have investigated which factors influence carotid IMT in the very elderly. In the present study, we investigated the relationship of pulse pressure (PP), blood pressure (BP), and its variability (six consecutive visits) with carotid IMT among 240 high-risk elderly in whom risk factors were managed clinically (average age was 79 ± 5 years). In the simple correlation, mean systolic BP (SBP) had a positive correlation with IMT and max IMT (P = .012 and P = .045), as did PP (P = .018 and P = .004), but did not diastolic BP or standard deviation of BP and coefficient of variation of BP. In multiple regression analyses, mean SBP and mean PP were each determinants of both IMT and max IMT, when each parameter was added separately to the regression model. We concluded that high SBP and wide PP still have an influence on increased carotid IMT in the very elderly Japanese patients.     

Long-Term Effects of Angiotensin II Receptor Blockade with Valsartan on Carotid Arterial Stiffness and Hemodynamic Alterations in Patients with Essential Hypertension

Increased arterial stiffness and intima media thickness (IMT) in the common carotid artery (CCA) are related to cardiovascular risk in essential hypertension. Angiotensin II plays an important role in structural and functional changes in the vasculature. In this study, we evaluated the long-term effect of the angiotensin II receptor blocker, valsartan, on IMT, arterial stiffness, and hemodynamics in the CCA in patients with essential hypertension. A prospective 24 month study of treatment with valsartan (80–160mg/day) was performed in 24 hypertensive patients. An ultrasound of the CCA was carried out to determine IMT, the cross-sectional distensibility coefficient (CSDC), the carotid arterial stiffness index β, and diastolic flow velocity to systolic flow velocity ratio (Vd/Vs). Treatment with valsartan for 24 months reduced systolic and diastolic blood pressure significantly. Compared to baseline, the decrease in pulse pressure was greater after 24 months treatment than after 12 months treatment. Valsartan did not influence IMT; however, after 24 months, it caused a significant increase in CSDC and a decrease in stiffness index β compared to baseline. These changes were not observed after 12 months of treatment. In addition, Vd/Vs, a sensitive marker of relative diastolic blood flow, increased after 24 months' treatment with valsartan. These results suggest that long-term treatment with valsartan improves vascular wall function and hemodynamics in patients with essential hypertension.     

Serum magnesium concentrations in type 1 diabetic patients: relation to early atherosclerosis

Hypomagnesemia and sub-clinical atherosclerosis are common in type 1 diabetic patients, and are especially common in poorly controlled and chronically treated diabetics. The aim of this study was to evaluate the relationships between serum magnesium (Mg) and intima-media thickness (IMT), and functions of common carotid artery (CCA), accepted as markers of early carotid atherosclerosis in type 1 diabetic patients. Serum magnesium levels were measured in 51 diabetic patients (26 girls and 25 boys). Age, duration of diabetes as well as major cardiovascular risk factors, including anthropometric and metabolic parameters were matched between girls and boys. CCA structure and functions were measured by ultrasonography as IMT, cross-sectional compliance (CSC), cross-sectional distensibility (CSD), diastolic wall stress (DWS), and incremental elastic modulus (IEM). The difference for serum Mg was significant between diabetic girls and boys (0.75+/-0.09 mmol/l versus 0.86+/-0.14 mmol/l; p=0.02). Mg levels were correlated with IMT (r=-0.58, p=0.004) and DWS (r=-0.49, p=0.01) in girls and with IMT (r=-0.55, p=0.007) and DWS (r=-0.46, p=0.03) in boys. In a multivariate regression model, Mg, systolic blood pressure and waist-hip ratio emerged as independent correlates for mean IMT in girls with the total variance explained being 63%, and Mg and triglycerides emerged as independent correlates for mean IMT in boys with the total variance explained being 68%. Mg did not emerge as independent correlates for mean DWS in both girls and boys. Serum magnesium levels in children and adolescent patients with type 1 diabetes are associated with early atherosclerosis.     

Carotid atherosclerosis,intima media thickness and risk factors--an analysis of 1781 asymptomatic subjects in Taiwan

The aim of this study was to investigate the association of intima media thickness (IMT) and plaque with risk factors for atherosclerosis in asymptomatic subjects in Taiwan. Between 1998 and 2001, the study recruited 1781 asymptomatic subjects (1131 men and 650 women [mean age, 49 years; range 18-85 years]). These were examined by B-mode ultrasound to measure the IMT at the far wall of the common carotid artery (CCA) and the extent of plaque formation. A wide range of vascular risk factors including age, gender, smoking, body mass index, blood chemistry, and previous history were surveyed. The mean (+/-S.D.) IMT observed was 0.68 (+/-0.12) and 0.66 (+/-0.11) mm for men and women, respectively, (P=0.0008). The mean (S.D.) IMT of the CCA was 0.66 (+/-0.12) mm on the right side and 0.68 (+/-0.12) mm on the left side (P=0.0004). IMT increased with aging, according to the equation IMT=(0.005xage in years)+0.403 [corrected]. Higher IMT was associated with male gender, and IMT was greater in the left CCA. About 36.9% of subjects had carotid plaques. The percentage of plaque increased with aging. The plaque prevalence was positively associated with IMT. The value of IMT over the cut point of 0.68 mm correlated with obviously increased risk of carotid atherosclerosis. Age, systolic blood pressure and fasting blood sugar were independent risk factors related to both carotid atherosclerosis and thick IMT.     

Intima-Media Thickness and Flow-Mediated Vasodilation in Asymptomatic Subjects with Newly Detected Severe Hypercholesterolemia

Background: The aim was to establish the predictors of early functional and structural vascular alterations (using intima-media thickness (IMT)) and flow-mediated vasodilation (%FMD) as well as to investigate the interrelationship between IMT and %FMD in asymptomatic, never-treated, severe hypercholesterolemia (HH). Methods: One hundred and twenty patients with asymptomatic, severe, untreated HH and 100 controls were included. ELISA was used for asymmetric dimethylarginine (ADMA) and cellular adhesion molecules, and fluid chromatography for total homocysteine (tHcy). Hewlett Packard SONOS 5500 with a 7.5 MHz transducer and MedicaSoft IMT software were used for evaluation of %FMD and IMT of common carotid artery (CCA). Results: Patients and controls differ with respect to all tested biomarkers (P < 0.05), except for P-selectin and E-selectin (P < 0.05). %FMD was lower in patients (P < 0.001). The IMT of the CCA was higher in patients (P < 0.001). Inverse correlations were found between %FMD and IMT mean and age, ADMA, Apo-B, Apo-B/Apo-A₁, and tHcy. ADMA was established as the most important factor related to %FMD. Age and Apo-B were established as the most important factors related to IMT mean. An inverse correlation was established between %FMD and IMT mean (r_xy= 0.546; P < 0.001)). If cases with IMT mean ≥1 were excluded, the correlation weakened. In patients with IMT mean ≥1 mm, the correlation did not change. Conclusion: In conclusion, asymptomatic, untreated patients with severe hypercholesterolemia are at high risk of having increased IMT of the CCA, especially if there is endothelial dysfunction, verified by %FMD of the brachial artery.     

White‐Coat Isolated Systolic Hypertension Is a Risk Factor for Carotid Atherosclerosis

The clinical importance of white‐coat hypertension (WCH) remains a controversial issue. The aim of this study was to evaluate the association of isolated systolic, isolated diastolic, and systolic/diastolic WCH with common carotid artery intima‐media thickness (CCA‐IMT) and to compare each subgroup of WCH against other blood pressure (BP) phenotypes in terms of CCA‐IMT values. A total of 1382 consecutive patients underwent 24‐hour ambulatory BP monitoring and carotid artery ultrasonographic measurements. According to the type of elevated office BP, WCH was divided into three groups: isolated systolic, isolated diastolic, and systolic/diastolic WCH. Patients with isolated systolic WCH (n=112) had significantly higher CCA‐IMT values (0.737 mm) than those with isolated diastolic WCH (n=66) (0.685 mm) and nonsignificantly greater compared with those with systolic/diastolic WCH (n=228) (0.708 mm). Patients with isolated systolic WCH had CCA‐IMT values similar to those with hypertension, patients with isolated diastolic WCH had similar values to those with normotension, and patients with systolic/diastolic WCH had an intermediate risk between normotension and hypertension.     

Early detection of silent ischemia and diastolic dysfunction in asymptomatic young hypertensive patients

Background: There is an association between coronary artery disease (CAD) and increased carotid‐intima media thickness (IMT), a surrogate index of atherosclerosis. This association is poorly studied in asymptomatic subjects with risk factors of CAD. Aim: To study the relationship between carotid‐IMT, coronary flow reserve (CFR) and cardiac function in asymptomatic young hypertensive subjects. Methods: This study includes 82 asymptomatic young subjects with essential hypertension, and 78 healthy control subjects. Carotid‐IMT was assessed with B‐mode ultrasonography. Treadmill exercise test, CFR and echo Doppler study were performed for all subjects. Results: Hypertensive group had a significantly higher carotid‐IMT (0.91 + 0.13 vs. 51 ± 0.09, P < 0.01), and a significantly lower coronary flow velocity reserve (1.9 ± 0.44 vs. 3.2 ± 0.44, P < 0.003) than in control subjects, especially in those with stress induced myocardial ischemia. Multiple linear regression analyses shows that increased carotid‐IMT was related to a reduced CFR (r = ? 843, P < 0.001) and a lower diastolic function (E/e″, r = ? 512, P < 0.003) in asymptomatic hypertensives. In addition the carotid‐IMT showed a significant correlation with family history of hypertension in these subjects (r = 653, P < 0.002). Conclusion: Carotid‐IMT increases significantly in asymptomatic young hypertensive patients. It has a relationship with stress‐induced myocardial ischemia, decrease CFR and incipient diastolic dysfunction in those patients. It could be considered as an index for subclinical atherosclerosis and diastolic dysfunction in asymptomatic subjects with risk factors for CADs. (Echocardiography 2011;28:564‐569)     

Quality control of ultrasonic measurement of carotid artery intima-media thickness

Background To report quality control methods and baseline reproducibility data of the ultrasound measurements of carotid artery intima-media thickness in the project of Establishment of an Integrated System for Coronary Heart Disease Prevention and Treatment. Methods Standard ultrasound scanning and measuring protocols were established by the study group. All sonographers and readers were trained by the carotid ultrasound core lab and all digital ultrasound images were centrally read. Ten subjects were scanned twice （with 1 week interval） by 2 sonographers independently and images were read by a single reader to evaluate the sonographer variability. Twenty subjects＇ images were read twice （with 1 week interval） by a single reader to assess the reader variability and the reproducibility of IMT measured at different carotid segments. Results The intraclass correlation （ICC） of intra- and inter-sonographer and intra- reader for mean IMT measurements was 0.99, 0.98 and 0.97 respectively; while for max IMT, it was 0.97, 0.99 and 0.95 respectively. Among different carotid segments and sites, ICC for mean 1MT measurements of common carotid （CCA）, carotid artery bulb （Bulb）, internal carotid artery （ICA）, overall near wall and overall far wall was 0.97, 0.99, 0.89, 0.93 and 0.98 respectively. Conclusion The reproducibility of IMT measurements according to our protocol is acceptable, although better reproducibility is found when measuring the mean IMT than max IMT, CCA and Bulb IMT than ICA IMT, and far wall IMT than near wall IMT.     

Subclinical atherosclerosis in rheumatoid arthritis in India

OBJECTIVE: Patients with rheumatoid arthritis (RA) have high cardiovascular morbidity and mortality as compared to the general population. Indians are also at increased risk of developing early and severe atherosclerotic coronary artery disease. Carotid intima-media thickness as measured by ultrasound is a validated surrogate marker of atherosclerosis. We studied the prevalence of subclinical atherosclerosis in Indian patients with RA. METHODS: Common carotid IMT (CCA IMT) was measured at the level of carotid bifurcation along with fasting lipid profile in 57 RA patients and 45 age and sex matched controls. Values of mean CCA IMT above mean + 2 SD of the control group were defined as abnormal IMT. Variables of disease activity and severity were measured in RA patients. Patients and controls with known traditional cardiovascular risk factors were excluded from the study. Student t test and chi-square test for proportion were used for statistical analysis. A logistic regression analysis was done to find out independent predictors of abnormal IMT. RESULTS: Nineteen RA patients (33.3%) and 2 controls (4.44%) had abnormal IMT values. RA patients had significantly increased mean CCA IMT (0.558 +/- 0.137 mm) as compared to controls (0.416 +/- 0.002 mm; p < 0.0001). Age > or = 42 years, duration of disease > or= 6 years, and tender joint count > or = 5 predicted increased risk of having abnormal CCA IMT in a logistic regression analysis. CONCLUSION: One-third of Indian RA patients had subclinical atherosclerosis. Age and tender joint count were independent predictors of abnormal CCA IMT.     

Dietary quality and carotid intima media thickness in type 1 and type 2 diabetes: Follow-up of a randomised controlled trial

Background and aims

The relationship between dietary intake and carotid intima media thickness (IMT) and pulse wave velocity (PWV) in individuals with type 1 and type 2 diabetes has not been well studied. We investigated the association between dietary intake and common carotid artery intima media thickness (CCA IMT) and PWV in a cohort with type 1 and type 2 diabetes.

Correlations between plasma homocysteine and folate concentrations and carotid atherosclerosis in high-risk individuals: baseline data from the Homocysteine and Atherosclerosis Reduction Trial (HART)

Homocysteine has been proposed as a risk factor for atherosclerosis. The association between plasma total homocysteine (tHcy) concentration and carotid atherosclerosis has not been thoroughly studied in high-risk populations with vascular disease. For this study, carotid atherosclerosis was assessed by measurements of carotid intima-media thickness (IMT) and plaque calcification in 923 patients with vascular disease or diabetes. Associations with tHcy and plasma folate concentrations were examined. The mean and single maximum carotid IMT were 1.27 +/- 0.34 mm and 2.41 +/- 0.83 mm, respectively. The mean segment plaque calcification score was 27.8%. tHcy correlated with mean (r = 0.13; p < 0.001) and single maximum (r = 0.12; p < 0.001) carotid IMT. There was a progressive increase in mean and single maximum carotid IMT across quartiles of tHcy (p < 0.0001 for trend). These associations were no longer significant after adjusting for other CV risk factors. A trend towards an inverse association between plasma folate and mean max carotid IMT was found in both univariate and multivariable analyses. However, the plaque calcification score increased across quartiles of tHcy (p < 0.01) and decreased across quartiles of plasma folate concentrations (p < 0.05) after multiple adjustments. In conclusion, in high-risk individuals, tHcy and low folate concentrations were only weakly associated with carotid IMT. In contrast, we found an independent association with the plaque calcification score, a measure of more advanced atherosclerosis. The effect of tHcy lowering on carotid atherosclerosis and stroke prevention warrants further investigation.     

Changing associations between progressive cardiovascular autonomic neuropathy and carotid atherosclerosis with increasing duration of type 2 diabetes mellitus

To clarify associations between cardiovascular autonomic neuropathy (CAN) and the progression of carotid artery atherosclerosis in Type 2 diabetic patients, cardiovascular autonomic nerve function was related to carotid artery ultrasound in 61 Type 2 diabetic patients, 5 and 8 years after the diagnosis of diabetes. Between 5 and 8 years after diagnosis, age-adjusted acceleration index (AI) decreased (from -0.306+/-1.034 to -0.702+/-1.072; P=.0139), whereas age-adjusted expiration/inspiration (E/I) ratio was unchanged (-0.583+/-1.038 and -0.828+/-1.028; P=.1164). Intima-media thickness (IMT) increased in both the common carotid artery (CCA; from 0.854+/-0.219 to 0.913+/-0.241 mm; P<.0001) and the carotid bulb (from 1.789+/-0.714 to 2.128+/-0.881 mm; P<.0001), corresponding to a yearly IMT increase of 0.032+/-0.039 mm in the CCA and 0.146+/-0.204 mm in the carotid bulb. This value did not correlate with the AI or E/I ratios. In age-controlled partial correlation in the first examination, AI correlated inversely with mean (r=-.33, P=.018) IMT in the CCA, but not with IMT in the carotid bulb (r=-.14, P=.303). However, in contrast to the first examination, at follow-up, AI correlated inversely with the mean IMT of the carotid bulb (r=-.40, P=.007), lumen diameter of the CCA (r=-.31, P=.034), and plaque score (r=-.29, P=.041), but not with IMT of the CCA (r=-.04, P=.861). There were no correlations between the E/I ratio and carotid variables. In conclusion, CAN was associated with features of carotid atherosclerosis, which, in the carotid bulb, might affect baroreceptor function with the progression of Type 2 diabetes.     

原发性高血压患者经颅多谱勒脑动脉血流变化特征分析

目的 探讨原发性高血压患者脑动脉血流变化特征及其影响因素,为高血压防治提供依据。方法 对29名原发性高血压患者和16名健康人进行了经颅彩色多普勒脑血流成像技术（TCI）监测分析,观察大脑中动脉（MCA）的收缩期血流速度（Vs)平均血流速度（Vm)、舒张期血流速度（Vd)、搏动指数（PI）、阻力指数（RI）的变化特征,并与收缩压（SBP）、舒张压（DBP）、平均动脉压（MBP）、脉压进行了直线相关分析。结果 与健康对照组相比,高血压组患者收缩压（SBP）、舒张压（DBP）、平均动脉压（MBP）、脉压和体重指数（BMI）及PI、RI均明显升高（P＜0．01）;高血压组中DBP与Vs,Vm,Vd,PI,RI呈明显正相关（P＜0．05）,脉压与Vs,Vm,Vd及PI呈明显正相关（P＜0．05）。SBP、MBP均与脑血流指标相关不明显（P＞0．05）。结论 高血压患者脑动脉血流变化特征主要表现为PI和RI的显著升高,舒张压和脉压是影响脑血流变化的两个主要因子。TCI是一种简便的、有价值的检查方法。     

Effect of contrast enhancement on measurement of carotid artery intimal medial thickness

Previous studies have used standard B-mode ultrasound to quantify the aggregate mean intimal medial thickness (IMT) of the near and far wall of the common carotid artery (CCA). Many investigators have had difficulty in accurately evaluating the near wall IMT secondary to difficulty in discerning the vessel lumen and intima. The purpose of this study is to determine the effect of contrast enhanced ultrasound on IMT measurement when compared with non-enhanced images. Twenty-six patients who had standard carotid ultrasounds completed over a 6-month period were evaluated, with 24 imaged by the same sonographer. Five to six measurements of the near and far walls were obtained over a 1 cm distance, beginning and ending 0.5 cm and 1.5 cm proximal to the carotid bifurcation. The measurements were made with and without the contrast agent Optison (perflutren protein type-A microspheres), which was given as an i.v. bolus (0.5-0.7 cc). Of those imaged by the same sonographer, 40 carotid arteries were examined and a total of 867 measurements were obtained. A total of 10% of the carotid ultrasounds were restudied approximately 1 month after the initial interpretation to assess observer accuracy. The near wall CCA mean (SD) IMT was 0.075 (0.019) cm for left with contrast versus 0.067 (0.023) cm for left without contrast and 0.089 (0.024) cm for right with versus 0.071 (0.022) cm for right without, p < or = 0.0001 both sides. For the far wall of the CCA, the mean (SD) IMT comparison was 0.075 (0.021) cm for left with versus 0.070 (0.016) cm for left without, p = 0.005, and 0.070 (0.023) cm for right with versus 0.070 (0.016) cm for right without, p = 0.68. In conclusion, contrast-enhanced IMT measurement showed a highly statistically significant difference in near carotid wall thickness determinations versus non-contrast values. The thicker measurement is in agreement with previously reported data showing that non-contrast images underestimated near wall common carotid IMT in histologic samples.     

Association of carotid hemodynamics with risk of coronary heart disease in a Taiwanese population with essential hypertension

BACKGROUND: The resistive index (RI) of the carotid artery is a hemodynamic parameter that depends on the degree of vascular resistance in hypertensive patients. The pulsatility index (PI) of the carotid artery was shown to be associated with microangiopathy in diabetic patients. In contrast to carotid intima-media thickness (IMT), no study has yet applied the carotid RI and PI to estimate coronary heart disease (CHD) risk. METHODS: Framingham risk scores (FRS) were determined for 62 patients (32 women; mean age 65 years (range 35-83)) with essential hypertension. Duplex sonography of the common carotid artery (CCA) was performed, with determination of RI, PI, and IMT. RESULTS: The mean FRS of all patients was 14.3% (range 1-30%), the mean IMT value of CCA was 0.89 +/- 0.23 mm, the mean RI was 0.71 +/- 0.07, and the mean PI was 1.46 +/- 0.39. FRS was found to have highly significant correlations with RI and PI (r = 0.47, P < 0.001 and r = 0.45, P < 0.001, respectively). The correlation between FRS and IMT was also significant (r = 0.41, P = 0.001). Multiple stepwise regression analysis showed that RI was an independent determinant of the risk of CHD. CONCLUSIONS: Although RI indirectly reflected the atherosclerotic process, the correlation between RI and CHD risk was comparable to the well-known correlation between cardiovascular event and carotid IMT. Hence, carotid RI can be used as a tool for risk stratification in Taiwanese patients with essential hypertension.     

Baseline reproducibility of B-mode ultrasonic measurement of carotid artery intima-media thickness: the European Lacidipine Study on Atherosclerosis (ELSA)

BACKGROUND AND OBJECTIVE: The European Lacidipine Study of Atherosclerosis (ELSA) is a prospective, randomized, double-blind, multi-national interventional trial to determine the effect of four-year treatment using the calcium antagonist lacidipine versus the beta-blocker atenolol on the progression of carotid atherosclerosis in 2259 asymptomatic hypertensive patients. B-mode ultrasound is used to measure the primary and secondary endpoints including the mean maximum intima-media thickness (IMT) of the carotid bifurcations and the common carotid arteries (CBM(max)), the mean maximum IMT of 12 standard carotid sites (M(max)) and the overall maximum IMT (T(max)). This paper reports the cross-sectional reproducibility of ultrasound measurements at baseline. METHOD: To evaluate measurement reliability, each patient is scanned twice at baseline and again at four annual visits, with 80% of the replicate scans performed by the same sonographer and 20% by a different sonographer; 50% of the replicate scans are read by the same reader and the other 50% by different readers. RESULTS: The overall coefficient of reliability (R) was 0.859 for CBM(max), 0.872 for M(max) and 0.794 for T(max). The reliability for CBM(max) was stable during the 1 3/4-year baseline period (R = 0.848 to 0.953) and was uniform among the 23 field centres (R = 0.798 to 0.926). Intra- and inter-reader reliability were 0.915 and 0.872 respectively, and intra-sonographer reliability was 0.866. CONCLUSION: The results demonstrate that by implementing standardized protocols and strict quality control procedures, highly reliable ultrasonic measurements of carotid artery IMT can be achieved in large multi-national trials.     

Dissociation between microalbuminuria and common carotid thickness in essential hypertensive men

BACKGROUND: The reasons why microalbuminuria (albuminuria > or = 15 microg/min), an expression of a renal microcirculatory abnormality, predicts cardiovascular disease in essential hypertension are unsettled. To test the hypothesis that microalbuminuria represents a marker of subclinical atherosclerosis, we evaluated its association with common carotid artery (CCA) intima media thickness (IMT), a measure of preclinical atherosclerosis and an independent predictor of cardiac and cerebrovascular events, in uncomplicated essential hypertensive individuals. MATERIALS AND METHODS: Albuminuria, ultrasonographic CCA IMT (the mean of six bilateral far wall measurements within 1.5 cm proximally to the flow divider), brachial blood pressure (BP), smoking habits and lipids were evaluated in 136 stage 1-3 untreated essential hypertensive men free of cardiovascular disease. RESULTS: CCA IMT did not differ between normo- (n = 99) and microalbuminuric (n = 37) patients. The correlation between CCA IMT and albuminuria was not significant, and the prevalence of microalbuminuria across IMT quartiles was not different. Microalbuminuric patients showed higher systolic BP and that parameter was the only independent correlate in a multivariate logistic regression model including also age, CCA IMT, diastolic BP, lipids and smoking habits as independent variables and microalbuminuria as the dependent one. CONCLUSION: This cross-sectional study in hypertensive subjects free of cardiovascular disease has shown a dissociation between microalbuminuria and CCA IMT, a surrogate measure of subclinical atherosclerosis, and a parameter linearly related to cardiovascular events. The data do not support the theory of microalbuminuria as a surrogate measure of subclinical atherosclerosis, while confirming the importance of systolic BP levels as an independent correlate of increased albuminuria in essential hypertension. Journal of Human Hypertension (2000) 14, 831-835