Clinical application of noninvasive vascular ultrasound in cardiovascular risk stratification: a report from the American Society of Echocardiography and the Society of Vascular Medicine and Biology

Relation of epicardial fat thickness and brachial flow-mediated vasodilation with coronary artery disease

OBJECTIVE

The purpose of this study is to investigate the presence of a statistical association between epicardial fat thickness (EFT) and coronary artery disease (CAD) and between flow-mediated vasodilation (FMD) and CAD.

METHODS

We measured the EFT and FMD in 64 subjects with suspected stable angina pectoris. The patients were separated into two groups according to their coronary angiography results: 34 patients with CAD and 30 patients with normal coronary arteries (NCA).

RESULTS

EFT was significantly higher in the patients with CAD than the NCA group (6.43 ± 0.90 mm vs. 5.35 ± 0.75 mm, p<0.001) while FMD was significantly lower in the patients with CAD than those in the NCA group (6.41 ± 2.51% vs. 8.33 ± 3.45%, p=0.015). No significant correlation was found between EFT and FMD. After adjustment for EFT, FMD, age, sex, ejection fraction, glucose, and low-density lipoprotein cholesterol through multivariate logistic regression analysis, EFT (odds ratio: 6.325, 95% confidence interval 2.289-17.476, p<0.001) and age (odds ratio: 1.093, 95% confidence interval 1.008-1.185, p=0.032) remained significant predictors of CAD. A cut-off value of EFT≥5.8mm predicted the presence of CAD with 77% sensitivity and 70% specificity.

CONCLUSION

An echocardiographic EFT assessment is independently associated with the presence of CAD. Thus, EFT may be helpful in cardiometabolic risk stratification and therapeutic interventions.

Anti-CCP antibody in patients with established rheumatoid arthritis: Does it predict adverse cardiovascular profile?

BACKGROUND

Rheumatoid arthritis (RA) is an independent risk factor for adverse cardiovascular (CV) events that accounts for a significant proportion of mortality among these patients. Anti-CCP antibodies are associated with higher frequency of extra-articular manifestations and poorer outcomes in RA.

AIMS

To determine the role of anti-cyclic citrullinated peptide (CCP) antibody as an independent risk factor for developing CV complications as documented by carotid intima medial thickness and abnormal echocardiography in established RA patients.

MATERIALS AND METHODS

Eighty patients of RA having disease duration of at least 3 years participated in this hospital-based, cross-sectional, and observational study. Forty patients were anti-CCP antibody positive. Patients of established RA having known CV risk factors, known heart disease, or family history of premature ischemic heart disease were excluded.

RESULTS

Anti-CCP positive group had early morning stiffness, tender and swollen joint count, and c-reactive protein (CRP) level significantly higher than those in anti-CCP negative group. Average intima-medial thicknesses of common carotid arteries were also significantly higher among anti-CCP positive group (P = 0.029) and were positively correlated with patients' age and disease duration. Lower left ventricular ejection fraction and left ventricular diastolic dysfunction were more commonly dispersed among the anti-CCP positive patients with P values of 0.01 and 0.034, respectively. Mild pericardial thickening was documented among 12.5% patients of anti-CCP positive group, while none of the anti-CCP negative patients had similar findings in echocardiography.

CONCLUSION

This study stressed on the important role of anti-CCP antibody in myocardial dysfunction due to inflammation in RA patients. Both atherosclerotic vascular involvement and cardiac abnormalities including pericardial, myocardial, and endocardial involvements were higher among anti-CCP positive RA patients. Hence, patients with high titer of anti-CCP antibody associated with prolonged disease duration and increased disease activity should be evaluated for CV morbidity more meticulously.

Arterial stiffness, carotid atherosclerosis and left ventricular diastolic dysfunction in postmenopausal women

BACKGROUND

Postmenopausal women have an increased cardiovascular morbidity that may be due to the increase in classical cardiovascular risk factors and also to the arterial structure and function alterations. The aim of our study was to evaluate the association of aortic pulse wave velocity (PWV), and carotid intima-media thickness (IMT), with left ventricular diastolic dysfunction (LVDD) in postmenopausal women.

PATIENTS AND METHODS

In 96 women without overt cardiovascular disease (age 62±7.7 years), and with normal left ventricular systolic function, aortic PWV was assessed by using an oscillometric device, intima-media thickness was measured by B-mode ultrasonography and the parameters of left ventricular diastolic function were evaluated by a transthoracic echocardiographic study.

RESULTS

LVDD, defined as an E/A ratio≤1 was found in 50 patients (52%). All of them had mild LVDD. In these patients we found significant increase in age (p<0.001), aortic PWV (p<0.001), carotid IMT (p=0.002) and plaque score (p=0.004) when compared with patients without LVDD. In a logistic regression analyzed, after adjusting for age, only aortic PWV was a significant predictor of LVDD (2.15, 95% CI 1.39-3.31, p=0.0006).

CONCLUSIONS

This study among postmenopausal women provides evidence that increased arterial stiffness as measured by aortic PWV and not carotid IMT may be a marker or a risk factor for LVDD, independent of other classical risk factors.

Differential impact of metabolic syndrome on subclinical atherosclerosis according to the presence of diabetes

Background

Metabolic syndrome (MS) is associated with increased risks of diabetes and atherosclerotic cardiovascular disease. However, data on the impact of MS and its individual components on subclinical atherosclerosis (SCA) according to diabetes status are scarce.

Methods

Surrogate markers of SCA, brachial–ankle pulse wave velocity (baPWV), and carotid intima–medial thickness (IMT) and plaque were assessed in 2,560 subjects (60 ± 8 years, 33% men) who participated in baseline health examinations for a community-based cohort study.

Results

The participants included 2,149 non-diabetics (84%) and 411 diabetics (16%); 667 non-diabetics (31%) and 285 diabetics (69%) had MS, respectively. Diabetics had significantly higher baPWV and carotid IMT, and more plaques than non-diabetics (p < 0.001, respectively). Individuals with MS had significantly higher baPWV and carotid IMT than those without MS only among non-diabetics (p < 0.001, respectively). Among MS components, increased blood pressure was significantly associated with the exacerbation of all SCA markers in non-diabetics. The number of MS components was significantly correlated with both baPWV and carotid IMT in non-diabetics (baPWV: r = 0.302, p < 0.001; carotid IMT: r = 0.217, p < 0.001). Multiple regression showed both MS and diabetes were significantly associated with baPWV (p < 0.001, respectively), carotid IMT (MS: p < 0.001; diabetes: p = 0.005), and the presence of plaque (MS: p = 0.041; diabetes: p = 0.002).

Conclusions

MS has an incremental impact on SCA in conditions without diabetes. The identification of MS and its individual components is more important for the risk stratification of CVD in non-diabetic individuals.

Endothelial function and weight loss: comparison of low-carbohydrate and low-fat diets

OBJECTIVE

The effect of weight loss on obesity-associated endothelial dysfunction is not clear because of conflicting data, demonstrating both improvement and no change in endothelial function after weight loss in obese subjects. A 2-year prospective study (n = 121) was conducted to examine: (1) the effect of obesity and weight loss (either a low-carbohydrate or and low-fat diet) on flow mediated vasodilatation (FMD), a measure of endothelial function.

DESIGN AND METHODS

Participants reduced body weight by 7.1% ± 4.4%, 8.7% ± 6.8%, 7.1% ± 7.8%, and 4.1% ± 7.7% at 3, 6, 12, and 24 months, respectively with no significant differences between the low-fat and low-carbohydrate groups.

RESULTS

Endothelial function was inversely correlated with waist circumference, triglyceride level, and directly correlated with leptin in obese persons prior to weight loss. These weight losses did not confer any improvements in FMD. There were no differences between the low-fat and low-carbohydrate diets in FMD at any time point. At 6 months (r = 0.26, P = 0.04) and 1 year (r =0.28, P = 0.03), there were positive correlations between change in FMD and change in leptin but not at 2 years.

CONCLUSION

There was no significant improvement in endothelial function after 7.1% ± 7.8% weight loss at 1 year and 4.1% ± 7.7% at 2 years, achieved by either a low carbohydrate or a low fat diet.

Treatment to lipid targets in patients with inflammatory joint diseases in a preventive cardio-rheuma clinic

OBJECTIVES

To perform cardiovascular risk stratification in patients with inflammatory joint diseases (IJD) and treat to lipid targets according to recommendations.

METHODS

We initiated a preventive cardio-rheuma clinic based on the unmet need of adequate cardiovascular prevention in IJD patients. A full cardiovascular risk stratification was performed at the first consultation (history of conventional risk factors and of cardiovascular disease, lipid measurement, blood pressure and ultrasound examination of both carotid arteries), and the patient was classified to either a primary or secondary cardiovascular prevention regime, or to have a low risk (no intervention). Lipid-lowering treatment was adjusted until at least two lipid targets were achieved.

RESULTS

Of the 426 patients referred, 36.6% had a systematic coronary risk evaluation less than 5% (no lipid-lowering intervention). The remaining 270 patients ((rheumatoid arthritis (RA), n=165; ankylosing spondylitis (AS), n=70; and psoriatic arthritis (PsA), n=35) were assigned to either primary (n=63) or secondary prevention (n=207). There were significant differences between the patient groups regarding age (p<0.001), sex (p<0.001) and disease duration (p<0.001). Lipid changes in IJD patients were: total cholesterol -1.86±1.20 mmol/l (p<0.001); low-density lipoprotein cholesterol -1.74±1.11 (p<0.001); high-density lipoprotein cholesterol 0.01±0.30 (p=0.61); triglycerides -0.28±0.72 (p<0.001). The proportions of patients reaching at least two lipid targets were for RA 92.1%, AS 90.0% and PsA 82.9%. No serious adverse events were observed.

CONCLUSIONS

There was indication for cardiovascular prevention in a high proportion of IJD patients referred for cardiovascular risk stratification. Treatment to lipid targets was successful in approximately 90% of patients with IJD.

Novel non-invasive method of measurement of endothelial function: enclosed-zone flow-mediated dilatation (ezFMD)

Measurement of flow-mediated dilatation (FMD) is the conventional non-invasive method for assessment of endothelial function; however, it requires an expensive ultrasound system and high levels of technical skill. Therefore, we developed a novel method for measurement of endothelial function, namely, measurement of ezFMD. ezFMD estimates the degree of vasodilatation from the oscillation signals transmitted to a sphygmomanometer cuff attached to the upper arm. The objective of this study was to validate the principle underlying the measurement of ezFMD, and to evaluate the repeatability of the ezFMD measurements. We observed the blood vessel behavior and oscillometric pattern in ten subjects. When the cuff was inflated to the level of the mean blood pressure, the oscillation amplitude increased with increasing degree of vasodilatation. In experiment to evaluate the repeatability of the ezFMD measurement, the average difference between the paired measurements was 3.7 %, the standard deviation was 11.5 %, and the average coefficient of variation value for the 11 paired measurements was 23.7 %. These results suggest the validity of the principle underlying the measurement of the ezFMD for the assessment of endothelial function. And, this study suggests that the repeatability of the ezFMD measurements is superior to that of the conventional measurement of FMD.

High prevalence of subclinical atherosclerosis by carotid ultrasound among Mexican Americans: discordance with 10-year risk assessment using the Framingham risk score

BACKGROUND

Framingham risk scores (FRS) were validated in a mostly Caucasian population. Evaluation of subclinical atherosclerosis by carotid ultrasound may improve ascertainment of risk in nonwhite populations. This study aimed to evaluate carotid intima-media thickness (cIMT) and carotid plaquing among Mexican Americans, and to correlate these markers with coronary risk factors and the FRS.

METHODS/RESULTS

Participants (n = 141) were drawn from the Cameron County Hispanic Cohort. Carotid artery ultrasound was performed and cIMT measured. Carotid plaque was defined as areas of thickening >50% of the thickness of the surrounding walls. Mean age was 53.1 ± 11.7 years (73.8% female). Most were overweight or obese (88.7%) and more than half (53.2%) had the metabolic syndrome. One third (34.8%) had abnormal carotid ultrasound findings (either cIMT ≥75th percentile for gender and age or presence of plaque). Among those with abnormal carotid ultrasound, the majority were classified as being at low 10-year risk for cardiovascular events. Carotid ultrasound reclassified nearly a third of the cohort as being at high risk. This discordance between 10-year FRS and carotid ultrasound was noted whether risk was assessed for hard coronary events or global risk. Concordance between FRS and carotid ultrasound findings was best when long-term (30-year) risk was assessed and no subject with an abnormal carotid ultrasound was categorized as low risk by the 30-year FRS algorithm.

CONCLUSIONS

Integration of carotid ultrasound findings to coronary risk assessments and use of longer term prediction models may provide better risk assessment in this minority population, with earlier initiation of appropriate therapies.

Idiopathic deep venous thrombosis and arterial endothelial dysfunction in the elderly

Arterial and venous thrombosis have always been regarded as different pathologies and epidemiological studies have examined the association between venous thrombosis and indicators of atherosclerosis and/or arterial thromboembolic events. We measured the flow-mediated dilation (FMD), a well-known marker of arterial endothelial dysfunction, in young-middle-aged and old-aged patients with and without unprovoked deep venous thrombosis (DVT). The aim of this study was to investigate whether DVT was a significant predictor for impaired FMD, considering all the patients and young-middle-aged (age < 65 years) and old-aged (age ≥ 65 years) patients separately. FMD was measured in the brachial artery on a population of 120 subjects with the same atherosclerosis risk factors, 68 male and 52 female, 70 young-middle-aged subjects (mean age ± SD 49.5 ± 10.5 years) and 50 old-aged subjects (76.2 ± 7.7 years). Patients with DVT showed a significant decrease of FMD compared to patients without DVT (6.8 ± 5.5% vs. 10.9 ± 3.5%, p < 0.001). Moreover, old-aged patients showed a significant decrease of FMD compared to the young-middle-aged subjects (7.4 ± 4.1% vs. 9.8 ± 5.3%, p = 0.005). In the whole study population, DVT was strongly associated with FMD (risk factors adjusted β = -4.14, p < 0.001). A significant interaction between age and the presence of DVT on predicting FMD was found (p = 0.003) suggesting a differential behavior of DVT as predictor of FMD. In young-middle-aged group, multivariate model confirmed that DVT was the most significant predictor of continuous FMD (β = -6.06, p < 0.001). On the contrary, DVT was no more a predictor of FMD in the old age group (β = -0.73, p = 0.556). Furthermore, old-aged patients without DVT showed a statistically significant decrease of FMD compared to the young-middle-aged subjects without DVT (8.2 ± 2.1% vs. 12.6 ± 2.7%, p<0.001) and old-aged patients with DVT showed a not statistically significant decrease of the FMD compared to the young-middle-aged patients with DVT (6.7 ± 5.3% vs. 6.8 ± 5.7%, p = 0.932). In conclusion, young-middle-aged patients with spontaneous DVT show an impaired FMD, whereas this impairment in old-aged subjects is evident independently from the presence or absence of DVT. Aging per se may be associated with physiologic abnormalities in the systemic arteries and with endothelial dysfunction.

Preoperative microvascular dysfunction: a prospective, observational study expanding risk assessment strategies in major thoracic surgery

BACKGROUND

Brachial artery reactivity testing (BART)--a surrogate test of microvascular function--predicts cardiac risk in the nonsurgical population and associates it with adverse outcome after vascular surgery. This pilot study investigated BART-derived variables, including flow-mediated dilation (FMD), in preoperative risk stratification for major thoracic surgery.

METHODS

After institutional review board approval, BART was performed in 63 patients before major thoracic surgery. Ultrasonography recorded two-dimensional images and Doppler flow signals of the brachial artery preoperatively at baseline and after induced reactive hyperemia. Variables derived using BART were correlated with preoperative risk factors, established risk scores, and postoperative complications.

RESULTS

The median preoperative FMD value in patients without postoperative complications was 11.5%. This value was used to delineate all patients into two groups: low (FMD < 11.5%) and high (FMD ≥ 11.5%) FMD cohorts. Patients in the low FMD group experienced more postoperative complications: 54% versus 30% had one or more adverse postoperative event, and 11% versus 0% had three or more adverse postoperative events (p < 0.001), respectively. The low FMD group required longer intensive care unit (3.9 ± 2.0 days versus 0.9 ± 0.3 days; p = 0.015) and hospital (14.0 ± 3.3 days versus 6.8 ± 0.6 days; p = 0.007) stays. This cutoff point for FMD accurately predicted 71% of the patients with adverse postoperative events, achieving 71.4% (95% confidence interval, 54.7 to 88.2) sensitivity and 48.6% (95% confidence interval, 32.0 to 65.1) specificity.

CONCLUSIONS

Using BART, preoperative microvascular dysfunction can be identified in patients at increased risk for postoperative complications. These data suggest that larger observational studies and studies exploring preoperative optimization strategies aimed at improving microvascular function are warranted.

Mechanisms of premature vascular aging in children with Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome is a rare, segmental premature aging syndrome of accelerated atherosclerosis and early death from myocardial infarction or stroke. This study sought to establish comprehensive characterization of the fatal vasculopathy in Hutchinson-Gilford progeria syndrome and its relevance to normal aging. We performed cardiovascular assessments at a single clinical site on the largest prospectively studied cohort to date. Carotid-femoral pulse wave velocity was dramatically elevated (mean: 13.00±3.83 m/s). Carotid duplex ultrasound echobrightness, assessed in predefined tissue sites as a measure of arterial wall density, was significantly greater than age- and sex-matched controls in the intima-media (P<0.02), near adventitia (P<0.003), and deep adventitia (P<0.01), as was internal carotid artery mean flow velocity (P<0.0001). Ankle-brachial indices were abnormal in 78% of patients. Effective disease treatments may be heralded by normalizing trends of these noninvasive cardiovascular measures. The data demonstrate that, along with peripheral vascular occlusive disease, accelerated vascular stiffening is an early and pervasive mechanism of vascular disease in Hutchinson-Gilford progeria syndrome. There is considerable overlap with cardiovascular changes of normal aging, which reinforces the view that defining mechanisms of cardiovascular disease in Hutchinson-Gilford progeria syndrome provides a unique opportunity to isolate a subset of factors influencing cardiovascular disease in the general aging population.

Vascular biomarkers in the prediction of clinical cardiovascular disease: the Strong Heart Study

We compared the ability of separately measured intimal-medial thickness and atherosclerotic plaque to predict incident cardiovascular disease. American Indian men and women from the Strong Heart Study who were free of cardiovascular disease were evaluated with carotid ultrasound and cardiovascular disease risk factor assessment. End-diastolic intimal-medial thickness of the common carotid arteries was measured and averaged. Arterial mass (cross-sectional area) was calculated from intimal-medial thickness and end-diastolic diameter. Atherosclerosis was defined by focal plaque (discrete thickening >50% relative to the adjacent wall) and the number of carotid segments containing plaque (plaque score); 2441 participants (age 63±8 years) were followed-up for a mean of 7.7±2.8 years, during which time 495 experienced incident cardiovascular disease events. Time-to-event analyses were performed in groups stratified according to diabetes and hypertension status. Cardiovascular disease events were predicted by presence and extent of atherosclerosis in all groups; intima-medial thickness and arterial mass were only associated with outcomes when neither hypertension nor diabetes was present. Unequivocal evidence of atherosclerosis (plaque) and its extent (plaque score) are independently associated with incident cardiovascular disease events in individuals without preexisting cardiovascular disease regardless of diabetes and hypertension status. Hypertension-related increases in intima-media thickness and arterial mass appear to limit their use as measures of early or diffuse atherosclerosis and, hence, association with cardiovascular disease outcomes. These findings support the utility of separate assessment of focal atherosclerosis and intimal-medial thickness in epidemiological studies, trials, and risk stratification protocols.

Evaluation of gender differences in endothelium-independent dilation using peripheral arterial tonometry

BACKGROUND

A change in peripheral arterial tonometry (PAT) in response to reactive hyperaemia is often used to provide a non-invasive measure of endothelium-dependent dilation (EDD). Reactive hyperaemia does not allow one to quantify endothelium-independent dilation (EID), which is part of overall vascular function. Although most research examining vascular function and cardiovascular disease has focused on EDD, there is evidence that cardiovascular risk factors may impair EID.

PURPOSE

To examine the microvascular vasodilation response to nitroglycerin (NTG) in healthy adults using PAT.

METHODS

Microvascular responses to reactive hyperaemia and NTG were evaluated in 86 (41 female and 45 male) healthy subjects (age 37 ± 5 years). Beat-to-beat plethysmographic measurements of finger arterial pulse waves were recorded for 5 min following reactive hyperaemia. After a 10-min rest period, sublingual NTG (0.4 mg) was administered and PAT signal changes were measured for 10 min. Peak reactive hyperaemic index (RHI) and peak NTG-mediated index (NMI) were determined in all subjects.

RESULTS

There were no significant gender differences in peak RHI (females: 2.07 ± 0.56 versus males: 1.91 ± 0.58, P = 0.20). Mean peak NMI for all subjects was 2.78 (± 1.49). Peak NMI was significantly greater in females than in males (3.11 ± 1.59 versus 2.50 ± 1.34, P = 0.05). Time to peak NMI was not significantly different between genders (7 min, 28 s [± 1 min, 47 s], versus 7 min, 14 s [± 1 min, 49 s], P = 0.58).

CONCLUSION

In this population of healthy adults, peak NMI was significantly greater in females than in males. These findings suggest that gender differences exist in the microvascular vasodilation responses to NTG using PAT.

Microvascular coronary dysfunction in women: pathophysiology, diagnosis, and management

Women exhibit a greater symptom burden, more functional disability, and a higher prevalence of no obstructive coronary artery disease compared to men when evaluated for signs and symptoms of myocardial ischemia. Microvascular coronary dysfunction (MCD), defined as limited coronary flow reserve and/or coronary endothelial dysfunction, is the predominant etiologic mechanism of ischemia in women with the triad of persistent chest pain, no obstructive coronary artery disease, and ischemia evidenced by stress testing. Evidence shows that approximately 50% of these patients have physiological evidence of MCD. MCD is associated with a 2.5% annual major adverse event rate that includes death, nonfatal myocardial infarction, nonfatal stroke, and congestive heart failure. Although tests such as adenosine stress cardiac magnetic resonance imaging may be a useful noninvasive method to predict subendocardial ischemia, the gold standard test to diagnose MCD is an invasive coronary reactivity testing. Early identification of MCD by coronary reactivity testing may be beneficial in prognostication and stratifying these patients for optimal medical therapy. Currently, understanding of MCD pathophysiology can be used to guide diagnosis and therapy. Continued research in MCD is needed to further advance our understanding.

Differential impacts of blood pressure and lipid lowering on regression of ventricular and arterial mass: the Stop Atherosclerosis in Native Diabetics Trial

The relative impacts of lowering blood pressure versus lowering low-density lipoprotein (LDL) cholesterol on regression of ventricular and arterial mass have not been systematically examined. Changes in left ventricular mass and arterial mass (common carotid artery cross-sectional area) after 36 months of simultaneous lowering of systolic blood pressure and LDL cholesterol were examined in the Stop Atherosclerosis in Native Diabetics Trial of standard versus aggressive LDL cholesterol and blood pressure targets in American Indians with type 2 diabetes mellitus. The 2 treatment groups were combined to examine changes in left ventricular and arterial mass over a spectrum of achieved blood pressure and lipid levels. Among the combined group of 413 Stop Atherosclerosis in Native Diabetics Trials participants, systolic blood pressure, LDL cholesterol, and left ventricular mass were all significantly reduced, whereas arterial mass significantly increased, after 36 months of therapy (P<0.001 for all). In linear regression models, a decrease in arterial mass was significantly related to achieved systolic blood pressure and, to a lesser extent, achieved LDL cholesterol, after adjustment for important covariates. Left ventricular mass progressively decreased with lower achieved levels of systolic blood pressure, independent of baseline levels of left ventricular mass. In conclusion, achieved levels of systolic blood pressure are important determinants of the extent of regression of arterial and ventricular mass during prolonged therapy in diabetic individuals. Achieved levels of LDL cholesterol influence regression of arterial but not ventricular mass. Our findings suggest that there is no threshold of systolic blood pressure below which regression of cardiovascular target organ damage cannot be achieved.

Acute change in vascular tone alters intima-media thickness

Atherosclerosis is a lifelong process involving artery wall thickening. Increased wall thickness has been widely adopted as a preclinical surrogate marker of atherosclerosis. A prerequisite for such a surrogate marker is that it is a structural characteristic of the vessel wall that is not subject to acute changes. The purpose of this study was to examine the acute effects of vasodilator drug administration on wall thickness of the carotid and superficial femoral arteries. High-resolution ultrasound was used to examine carotid and femoral artery diameters and wall thickness in 15 young (25±4 years of age) and 15 older (70±6 years of age) healthy men who were administered sublingual glyceryl trinitrate. Diameter and wall thickness were collected before and across a 10-minute period after glyceryl trinitrate administration. Glyceryl trinitrate induced a significant increase in carotid and femoral artery diameter and a decrease in wall thickness in both young and older men (both P<0.001). The latter was significantly larger than in young men (both P<0.01). The changes in carotid artery wall thickness in both young (35±23 μm) and older men (71±46 μm) approximate those considered prognostically relevant. Collectively, our data suggest that vasodilator drug administration induces a rapid and marked decrease in wall thickness, which mirrors conduit artery vasodilation in both young and older men. This finding confirms the presence of acute changes in wall thickness and has important implications for future studies that assess artery wall characteristics as a surrogate measure of atherosclerosis.

Endothelium-independent dilation in children and adolescents

Peak brachial artery dilation post-nitroglycerin (NTG) administration occurs between 3 and 5 min in adults. The purpose of this study was to identify the time to peak dilation response to sublingual NTG (0·3 mg) in youth. Endothelium-independent dilation (EID) was measured in 198 healthy (113 males, 85 females) youth (6-18 years) via ultrasound imaging of the brachial artery following NTG administration. Time to peak EID was 268 s following NTG administration, with no significant (P = 0·6) difference between males and females. There was a significant (P<0·001) difference between EID post-NTG at the 3 versus 4 min, 4 versus 5-min, and 3 versus 5 min time points. Peak EID (males: 24·8 ± 0·5 versus females: 25·3 ± 0·6%, P = 0·6) was not significantly different after accounting for baseline diameter. Peak response to NTG administration occurs between 4 and 5 min. The results demonstrate the importance of measuring EID up to 5-min post-NTG administration in youth.

Common carotid artery intima-media thickness is as good as carotid intima-media thickness of all carotid artery segments in improving prediction of coronary heart disease risk in the Atherosclerosis Risk in Communities (ARIC) study

AIMS

Carotid intima-media thickness (CIMT) and plaque information can improve coronary heart disease (CHD) risk prediction when added to traditional risk factors (TRF). However, obtaining adequate images of all carotid artery segments (A-CIMT) may be difficult. Of A-CIMT, the common carotid artery intima-media thickness (CCA-IMT) is relatively more reliable and easier to measure. We evaluated whether CCA-IMT is comparable to A-CIMT when added to TRF and plaque information in improving CHD risk prediction in the Atherosclerosis Risk in Communities (ARIC) study.

METHODS AND RESULTS

Ten-year CHD risk prediction models using TRF alone, TRF + A-CIMT + plaque, and TRF + CCA-IMT + plaque were developed for the overall cohort, men, and women. The area under the receiver operator characteristic curve (AUC), per cent individuals reclassified, net reclassification index (NRI), and model calibration by the Grønnesby-Borgan test were estimated. There were 1722 incident CHD events in 12 576 individuals over a mean follow-up of 15.2 years. The AUC for TRF only, TRF + A-CIMT + plaque, and TRF + CCA-IMT + plaque models were 0.741, 0.754, and 0.753, respectively. Although there was some discordance when the CCA-IMT + plaque- and A-CIMT + plaque-based risk estimation was compared, the NRI and clinical NRI (NRI in the intermediate-risk group) when comparing the CIMT models with TRF-only model, per cent reclassified, and test for model calibration were not significantly different.

CONCLUSION

Coronary heart disease risk prediction can be improved by adding A-CIMT + plaque or CCA-IMT + plaque information to TRF. Therefore, evaluating the carotid artery for plaque presence and measuring CCA-IMT, which is easier and more reliable than measuring A-CIMT, provide a good alternative to measuring A-CIMT for CHD risk prediction.

Surrogate markers of cardiovascular disease in CKD: what's under the hood?

Although clinical cardiovascular outcomes, such as heart attack, stroke, and sudden cardiac death, have a dramatic onset, they result from prolonged exposure to an ever-growing array of risk factors. Several noninvasive procedures are available to assess the cumulative effect of these exposures with the goal of more precisely estimating a person's cardiovascular risk. These include ankle-brachial index, which provides an estimation of obstruction in major-vessel lumen caliber; carotid ultrasound, which evaluates carotid intima-media thickness and plaque, visibly quantifying atherosclerotic burden; aortic pulse wave velocity, which provides a measure of large-artery stiffness; and echocardiography, which measures left ventricular mass, providing a measure of subclinical hypertensive heart disease. In this narrative review, we discuss the role of each of these measures, with a particular emphasis on patients with chronic kidney disease.

Anti-tumor necrosis factor-α therapy and changes of flow-mediated vasodilatation in psoriatic and rheumatoid arthritis patients

For a long time, the endothelial covering of the vessels has been considered an inert surface. On the contrary, the endothelial cells are active and dynamic elements in the interaction between blood and tissues. The control of the vessel basal tone is obtained by the complex balance between the relaxing and contracting endothelial factors. Previous clinical studies show that patients suffering from rheumatoid arthritis and other autoimmune rheumatologic pathologies are at high risk of death being prematurely affected by atherosclerosis and cardiovascular diseases. Blocking tumor necrosis factor (TNF)-α by biological drugs improves the endothelial function. The aim of our study was to evaluate the effects of two anti-TNF-α drugs (infliximab and etanercept) on the endothelial function by evaluating the flow-mediated dilatation (FMD), which was measured in the brachial artery before and after treatment and after 8-12 weeks. We enrolled 36 patients (average age 52 ± 9.8 years, 12 men and 24 women), 25 of them were affected by rheumatoid arthritis (RA) and 11 were affected by psoriatic arthritis (PsA) and they were divided into three groups: 10 patients were treated with etanercept, 13 patients were treated with infliximab, 13 patients were treated with DMARDs. We measured the common carotid intimal-medial thickness (ccIMT) and the endothelial function was evaluated by FMD measurement in the brachial artery, before treatment, 1 h after the beginning of treatment and after 8-12 weeks. No statistically significant difference between the three groups was found for the ultrasonographic evaluation of the carotid IMT. On the contrary, the differences between FMD values before and after the treatment in the patients treated with etanercept (13.1 ± 0.01 vs. 18.8 ± 0.01%, p < 0.01) and in the patients treated with infliximab (11.8 ± 0.09 vs. 16.7 ± 0.09%, p < 0.01) were statistically significant. Long-term evaluation for infliximab and etanercept was performed by comparing the FMD values, respectively, 8 and 12 weeks after the first treatment. After 8 weeks, FMD value was similar to the value recorded at enrollment in the infliximab group (11.9 ± 0.03 vs. 13.54 ± 0.04%, p = 0.236) and the FMD values in the etanercept group after 12 weeks showed a not statistically significant reduction of vasodilatating effect (13.01 ± 0.03 vs. 15.67 ± 0.02%, p = 0.197). In conclusion, the use of biological drugs in patients affected by autoimmune arthritis can modify the endothelial function, as indicated by the induced FMD changes, but the long-term effect tends to be considerably reduced.

Acute hyperhomocysteinaemia blunts endothelial dependent and endothelial independent vasodilatation in diabetic patients

The aim of this study was to investigate the effects of acute, methionine-induced hyperhomocysteinaemia on endothelial function of skin microcirculation in diabetic compared with non-diabetic persons. Endothelial- and non-endothelial-dependent vasodilatation of the skin microcirculation were evaluated in 20 persons with type 2 diabetes (59.95+/-2.36 years old) and 24 age- and gender-matched controls using laser Doppler flowmetry, during fasting and four hours after 0.1 g/kg methionine-induced acute hyperhomocysteinaemia. Methionine loading caused a comparable increase of homocysteine in the two groups. Four hours after induction of acute hyperhomocysteinaemia, endothelial-dependent vasodilatation (acetylcholine effect) was lower in the diabetic patients compared with the controls ([mean+/-SEM] 8.09+/-1.18-fold increase in diabetic patients vs. 11.11+/-1.33-fold increase in controls, p=0.027). The same was observed for the endothelial-independent vasodilatation (sodium-nitroprusside effect, 7.55+/-0.80-fold increase in the diabetic patients vs. 12.19+/-1.26-fold increase in controls, p=0.008). Acute hyperhomocysteinaemia causes a decreased response of both endothelial-dependent and endothelial-independent vasodilatation of the skin microcirculation in diabetic compared with non-diabetic persons. These alterations might contribute to the vascular complications of hyperhomocysteinaemia in diabetes, and especially the microvascular ones.

Aortic pulse pressure is associated with carotid IMT in chronic kidney disease: report from Chronic Renal Insufficiency Cohort

BACKGROUND

Patients with chronic kidney disease (CKD) have a disproportionate risk of cardiovascular disease. This study was designed to assess the association between two noninvasive measures of cardiovascular risk, pulse wave analysis (PWA), and carotid intima-media thickness (IMT), in a cohort of CKD patients enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study.

METHODS

Three hundred and sixty-seven subjects with CKD enrolled in the CRIC study at the University of Pennsylvania site (mean age 59.9 years, blood pressure 129/74 mm Hg, estimated glomerular filtration rate 48 ml/min/1.73 m2, IMT 0.8 mm) had both carotid IMT and PWA measurements. Carotid ultrasound was also used to determine the presence of plaque. PWA was used to determine augmentation index (AI), amplification ratio (AMPR), aortic pulse pressure (C_PP), and central aortic systolic pressure (C_SP).

RESULTS

IMT was significantly associated with all PWA-derived measures. However, on multivariable linear regression analysis, only AMPR (regression coefficient -0.072, P = 0.006), C_PP (regression coefficient 0.0025, P < 0.001), and C_SP (regression coefficient 0.0017, P < 0.001) remained significantly associated with IMT. The prevalence of carotid plaque in the cohort was 59%. Of the PWA-derived measures, only C_PP was significantly associated with the presence of carotid plaque (P < 0.001).

CONCLUSIONS

PWA-derived measures are associated with carotid IMT and plaque in the CKD. Of these measures, C_PP was most associated with carotid IMT and plaque.

Screening for subclinical coronary artery disease measuring carotid intima media thickness

Traditional coronary risk assessment is based on major cardiovascular risk factors using the Framingham risk score. Carotid intima-media thickness (CIMT) measured by ultrasonography is a noninvasive test used to assess for the presence of coronary atherosclerosis. CIMT has been shown to be an independent predictor of future cardiovascular events and is used in research trials as a surrogate for the presence as well as regression of coronary artery disease. The objectives of this report are to review the published reports on CIMT and to help establish the role of CIMT as a screening tool for coronary artery disease in selected patients. CIMT measurement can modify cardiovascular risk prediction in patients initially classified with the Framingham risk score, with reclassification into higher or lower risk categories. It is most useful for refining risk assessment in patients at intermediate risk. The Screening for Heart Attack Prevention and Education (SHAPE) Task Force recommends screening all asymptomatic middle-aged and older men and women using noninvasive imaging. The American Society of Echocardiography established a consensus on the methodologic aspects of CIMT measurement. Sequential scanning of CIMT to assess atherosclerosis is currently not recommended, because of interscan variability and small expected changes over time. In conclusion, in the primary prevention of coronary artery disease, CIMT measurement reclassifies patients into higher or lower risk categories, allowing early appropriate management.

High prevalence of subclinical cardiovascular abnormalities in patients with systemic lupus erythematosus in spite of a very low clinical damage index

BACKGROUND AND AIM

To evaluate the prevalence of subclinical cardiovascular (CV) abnormalities in systemic lupus erythematosus (SLE) stratified according to SLE-related organ damage using the Systemic Lupus International Collaborating Clinics (SLICC) damage index.

METHODS AND RESULTS

We selected SLE patients without clinically overt CV events (n=45, 56% with SLICC=0, 44% with SLICC=1-4). CV evaluation was performed using cardiac and vascular echo-Doppler techniques. Post-ischemic flow-mediated dilation (FMD) over nitroglycerine-mediated dilation (NMD) of the brachial artery <0.70 defined endothelial dysfunction. The prevalence of preclinical CV abnormalities (CVAbn, including at least one of the following-carotid atherosclerosis, left ventricular (LV) hypertrophy, low arterial compliance, LV wall motion abnormalities, aortic regurgitation, FMD/NMD<0.70)-was 64% (16/25) in patients with SLICC=0 and 80% (16/20) in those with SLICC>0 (p=not significant (NS)). In particular, the prevalence of carotid atherosclerosis (28% vs. 16%), of LV hypertrophy (12% vs. 6%) and of LV wall motion abnormalities (15% vs. 12%), of low global arterial compliance (18% vs. 10%), prevalence of aortic regurgitation (30% vs. 18%) and/or aortic valve fibrosclerosis (10% vs. 8%), FMD<10% (14+/-5% vs. 14%+/-6) and prevalence of FMD/NMD<0.70 (53% vs. 52%) were comparable in SLE patients with SLICC>0 and in those with SLICC=0 (all p=NS). Of the SLE patients without carotid atherosclerosis, LV hypertrophy, low arterial compliance, LV wall motion abnormalities and aortic regurgitation (n=17), endothelial dysfunction was detected in 50% of those with SLICC=0 (6/12) and in 40% of those with SLICC>0 (2/5, p=NS).

CONCLUSIONS

SLE patients with SLICC=0 often have an elevated CV risk profile due to subclinical manifestations of CV disease detectable by cardiac and vascular echo-Doppler evaluations.

Subclinical atherosclerosis in rheumatoid arthritis and systemic lupus erythematosus

Rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) are associated with increased mortality, largely as a consequence of cardiovascular disease. Increased cardiovascular morbidity and mortality in patients with RA and SLE cannot be entirely explained by traditional risk factors, suggesting that the systemic inflammation that characterizes these diseases may accelerate atherosclerosis. We used carotid ultrasonography to investigate the prevalence and correlates to preclinical atherosclerosis in patients with RA and SLE. Because atherosclerosis is a systemic disease, assessment of carotid plaque by ultrasonography provides a robust, direct measure of systemic atherosclerosis. We observed a substantially increased prevalence of carotid plaque in RA and SLE patients compared with age- and sex-matched controls, which remained after adjustment for traditional risk factors. The presence of carotid atherosclerosis was associated with disease duration in both RA and SLE and damage in SLE. These data support the hypothesis that inflammation associated with RA and SLE contributes to accelerated atherosclerosis and argue that RA and SLE disease activity should be more aggressively managed.

Examining the time course of endothelium-independent dilation by nitroglycerin

Arterial smooth muscle function is commonly assessed by measuring the dilation response to sublingual nitroglycerin (NTG), and is referred to as endothelium-independent dilation (EID). The time point at which the brachial artery dilates maximally after NTG administration is generally believed to occur somewhere between three and five minutes. The aim of this study was to examine the time course of brachial artery dilation response to a single dose of sublingual NTG to identify the time point at which maximal dilation occurs and to assess factors effecting EID. Endothelial independent dilation was measured in 125 normal, healthy subjects (male = 67, female = 58) via high-resolution ultrasound on the brachial artery. Mean time to maximal EID was 279.0 +/- 26.9 s. There was a significant (p < 0.0001) difference between brachial EID at three minutes vs. five minutes post NTG. There was also a significant gender difference in EID response (p < 0.0001). The results of this study indicate that maximal EID occurs approximately five minutes after NTG administration. Measuring EID at three minutes after NTG administration likely underestimates the true dilation capacity of the artery.