Background Common carotid artery intima–media thickness (IMT) can be measured either by hand or with an automated edge detector. We performed a direct comparison of these 2 approaches and studied their respective associations with coronary heart disease outcomes. Methods and Results We studied 5468 participants of the Multi-Ethnic Study of Atherosclerosis, composed of white, Chinese, Hispanic, and black participants with an average age of 61.9 years (47.8% men) and who were free of coronary heart disease at baseline. Manual-traced and edge-detected IMT measurements were made in the same location on ultrasound images of the right common carotid artery far wall in an area free of plaque. Manual-traced and edge-detected common carotid artery IMT measurements were added separately to multivariable Cox proportional hazards models with time to incident coronary heart disease as the outcome and adjusted for traditional coronary heart disease Framingham risk factors, lipid-lowering therapy, blood pressure–lowering therapy, and race or ethnicity. Additional models were generated after adding clinic site and reader. There were 349 events during a median follow-up of 10.2 years. In adjusted models, the hazard ratio was not significant (1.31; 95% CI 0.84 to 2.06) for each millimeter increase in manual-traced IMT but was significant for edge-detected IMT (hazard ratio 1.63; 95% CI 1.12 to 2.37). Edge-detected IMT remained statistically associated with outcomes after additional adjustment for clinic site and reader performing the IMT measurement (hazard ratio 1.59; 95% CI 1.07 to 2.35). Conclusions Edge-detected common carotid artery far wall IMT has similar if not stronger associations with coronary heart disease outcomes when compared with manual-traced IMT. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT00063440.

Resting heart rate is an easily measured, noninvasive vital sign that is associated with cardiovascular disease events. The pathophysiology of this association is not known. We investigated the relationship between resting heart rate and stiffness of the carotid (a peripheral artery) and the aorta (a central artery) in an asymptomatic multi-ethnic population. Resting heart rate was recorded at baseline in the Multi-Ethnic Study of Atherosclerosis (MESA). Distensibility was used as a measure of arterial elasticity, with a lower distensibility indicating an increase in arterial stiffness. Carotid distensibility was measured in 6484 participants (98% of participants) using B-mode ultrasound, and aortic distensibility was measured in 3512 participants (53% of participants) using cardiac MRI. Heart rate was divided into quintiles and we used progressively adjusted models that included terms for physical activity and atrioventricular nodal blocking agents. Mean resting heart rate of participants (mean age, 62 years; 47% men) was 63 bpm (SD, 9.6 bpm). In unadjusted and fully adjusted models, carotid distensibility and aortic distensibility decreased monotonically with increasing resting heart rate ( P for trend <0.001 and 0.009, respectively). The relationship was stronger for carotid versus aortic distensibility. Similar results were seen using the resting heart rate taken at the time of MRI scanning. Our results suggest that a higher resting heart rate is associated with an increased arterial stiffness independent of atrioventricular nodal blocker use and physical activity level, with a stronger association for a peripheral (carotid) compared with a central (aorta) artery.

Background: Ectopic fat depots may have direct paracrine effects on local vasculature. Neck circumference is a proxy for upper body subcutaneous fat, a distinct fat depot that encases the carotid a...

BackgroundFine particulate matter (PM2.5) has been linked to cardiovascular disease, possibly via accelerated atherosclerosis. We examined associations between the progression of the intima-medial thickness (IMT) of the common carotid artery, as an indicator of atherosclerosis, and long-term PM2.5 concentrations in participants from the Multi-Ethnic Study of Atherosclerosis (MESA).Methods and resultsMESA, a prospective cohort study, enrolled 6,814 participants at the baseline exam (2000-2002), with 5,660 (83%) of those participants completing two ultrasound examinations between 2000 and 2005 (mean follow-up: 2.5 years). PM2.5 was estimated over the year preceding baseline and between ultrasounds using a spatio-temporal model. Cross-sectional and longitudinal associations were examined using mixed models adjusted for confounders including age, sex, race/ethnicity, smoking, and socio-economic indicators. Among 5,362 participants (5% of participants had missing data) with a mean annual progression of 14 µm/y, 2.5 µg/m(3) higher levels of residential PM2.5 during the follow-up period were associated with 5.0 µm/y (95% CI 2.6 to 7.4 µm/y) greater IMT progressions among persons in the same metropolitan area. Although significant associations were not found with IMT progression without adjustment for metropolitan area (0.4 µm/y [95% CI -0.4 to 1.2 µm/y] per 2.5 µg/m(3)), all of the six areas showed positive associations. Greater reductions in PM2.5 over follow-up for a fixed baseline PM2.5 were also associated with slowed IMT progression (-2.8 µm/y [95% CI -1.6 to -3.9 µm/y] per 1 µg/m(3) reduction). Study limitations include the use of a surrogate measure of atherosclerosis, some loss to follow-up, and the lack of estimates for air pollution concentrations prior to 1999.ConclusionsThis early analysis from MESA suggests that higher long-term PM2.5 concentrations are associated with increased IMT progression and that greater reductions in PM2.5 are related to slower IMT progression. These findings, even over a relatively short follow-up period, add to the limited literature on air pollution and the progression of atherosclerotic processes in humans. If confirmed by future analyses of the full 10 years of follow-up in this cohort, these findings will help to explain associations between long-term PM2.5 concentrations and clinical cardiovascular events.

CONTEXTThe evidence that measurement of the common carotid intima-media thickness (CIMT) improves the risk scores in prediction of the absolute risk of cardiovascular events is inconsistent.OBJECTIVETo determine whether common CIMT has added value in 10-year risk prediction of first-time myocardial infarctions or strokes, above that of the Framingham Risk Score.DATA SOURCESRelevant studies were identified through literature searches of databases (PubMed from 1950 to June 2012 and EMBASE from 1980 to June 2012) and expert opinion.STUDY SELECTIONStudies were included if participants were drawn from the general population, common CIMT was measured at baseline, and individuals were followed up for first-time myocardial infarction or stroke.DATA EXTRACTIONIndividual data were combined into 1 data set and an individual participant data meta-analysis was performed on individuals without existing cardiovascular disease.RESULTSWe included 14 population-based cohorts contributing data for 45,828 individuals. During a median follow-up of 11 years, 4007 first-time myocardial infarctions or strokes occurred. We first refitted the risk factors of the Framingham Risk Score and then extended the model with common CIMT measurements to estimate the absolute 10-year risks to develop a first-time myocardial infarction or stroke in both models. The C statistic of both models was similar (0.757; 95% CI, 0.749-0.764; and 0.759; 95% CI, 0.752-0.766). The net reclassification improvement with the addition of common CIMT was small (0.8%; 95% CI, 0.1%-1.6%). In those at intermediate risk, the net reclassification improvement was 3.6% in all individuals (95% CI, 2.7%-4.6%) and no differences between men and women.CONCLUSIONThe addition of common CIMT measurements to the Framingham Risk Score was associated with small improvement in 10-year risk prediction of first-time myocardial infarction or stroke, but this improvement is unlikely to be of clinical importance.

Background: Common carotid artery (CCA) diameter is believed to be associated with left ventricular (LV) mass through ventricular-arterial coupling. It is not clear if CCA diameter is also predictive of incident congestive heart failure. Materials and Methods: CCA lumen diameters were measured following ultrasound examinations in 2965 individuals free of prevalent cardiovascular disease (mean age 57.9 years; 54.9% women) of the Framingham Offspring Study, a community based cohort followed longitudinally. Incident congestive heart failure (CHF) was determined after an average follow-up of 10.3 years. Multivariable Cox proportional hazards models were generated after adjustment for age, gender, and Framingham risk factors. Results: Incident CHF occurred in 99 individuals only 10 of which had interval myocardial infarction. After adjustment for risk factors, CCA diameter was a significant predictor of incident CHF, 43% increased risk per mm. Results of a multivariable Cox proportional hazards model are shown...

Background: Common carotid artery (CCA) intima-media thickness (IMT) is a surrogate measure of atherosclerosis. Pharmacologic intervention decreases IMT progression in intervention trials but these...

Background: Internal carotid artery plaque defined as maximum intima-media thickness (IMT) >1.5 mm is a predictor of cardiovascular events. Risk factors predicting new plaque formation are not well...

Changes in common carotid artery intima-media thickness (IMT) are associated with stroke incidence in a multiethnic cohort, according to findings from the Multi-Ethnic Study of Atherosclerosis [MESA; NCT00005487] ancillary study for progression of IMT.

OBJECTIVE:The goal of this study was to determine whether computerized tomographic (CT) images of cadavers could be used in addition to images from patients to develop virtual patients (VPs) to enhance integrated learning of basic and clinical science.METHODS:We imaged 13 cadavers on a Siemens CT system. The DICOM images from the CT were noted to be of high quality by a radiologist who systematically identified all abnormal and pathological findings. The pathological findings from the CT images and the cause of death were used to develop plausible clinical cases and study questions. Each case was designed to highlight and explain the abnormal anatomic findings encountered during the cadaveric dissection. A 3D reconstruction was produced using OsiriX and then formatted into a QuickTime movie which was then stored on the Tufts University Sciences Knowledgebase (TUSK) as a VP.RESULTS AND CONCLUSIONS:We conclude that CT scanning of cadavers produces high-quality images that can be used to develop VPs. Although the use of the VPs was optional and fewer than half of the students had an imaged cadaver for dissection, 59 of the 172 (34%) students accessed and reviewed the cases and images positively and were very encouraging for us to continue.

Carotid artery intima-media thickness (IMT) measurements are now recognized as a surrogate measure of atherosclerosis. The measurement is performed on high-resolution ultrasound images of the carotid artery at the level of the carotid bifurcation. Increased IMT values indicate a higher likelihood of having had a stroke or myocardial infarction. In epidemiological studies, IMT measurements made in asymptomatic individuals also predict future cardiovascular events. Intima-media thickness measurements have also been used in clinical trials as a means of gauging the effects of interventions that modify cardiovascular risk factors, low-density lipoprotein cholesterol for example. A positive response to the intervention is defined as a measurable difference in IMT values of the treated group as compared with a control group.The technique has also shown the possibility of identifying certain high-risk individuals with evidence of more advanced atherosclerosis or with a high risk for cardiovascular events. This paper reviews the basic history of the development of carotid artery IMT measurements and discusses some technical aspects of the measurement.

OBJECTIVE:To evaluate the association of physical activity with left ventricular structure and function in the general population in a community setting. DESIGN:Cross-sectional study. SETTING:The Multi-Ethnic Study of Atherosclerosis (MESA), a population-based study of subclinical atherosclerosis. PARTICIPANTS:A multiethnic sample of 4992 participants (aged 45-84 years; 52% female) free of clinically apparent cardiovascular disease. INTERVENTIONS:Physical activity induces beneficial physiological cardiac remodelling in a cross-sectional study of non-athlete individuals. MAIN OUTCOME MEASURES:Left ventricular mass, volumes and function were assessed by cardiac magnetic resonance imaging. Physical activity, defined as intentional exercise and total moderate and vigorous physical activity, was assessed by a standard semiquantitative questionnaire. RESULTS:Left ventricular mass and end-diastolic volume were positively associated with physical activity (eg, 1.4 g/m(2) (women) and 3.1 g/m(2) (men) greater left ventricular mass in the highest category of intentional exercise compared with individuals reporting no intentional exercise; p = 0.05 and p<0.001, respectively). Relationships were non-linear, with stronger positive associations at lower levels of physical activity (test for non-linearity; p = 0.02 and p = 0.03, respectively). Cardiac output and ejection fraction were unchanged with increased physical activity levels. Resting heart rate was lower in women and men with higher physical activity levels (eg, -2.6 beats/minute lower resting heart rate in the highest category of intentional exercise compared with individuals reporting no intentional exercise; p<0.001). CONCLUSIONS:In a community-based population free of clinically apparent cardiovascular disease, higher physical activity levels were associated with proportionally greater left ventricular mass and end-diastolic volume and lower resting heart rate.

Results of a six-year evaluation carried out in the Czech Republic (CR) for resistance of apricot cvs Harlayne and Betinka to six different strains and isolates of PPV are presented. Two-year-old trees of both cultivars wereinoculated by chip budding with PPV-M (type strain), PPV-D (type strain), PPV-Rec (originally recovered in the CR as PPV-W), PPV-M (isolated in the CR from peach), PPV-D (isolated in the CR from Prunus insititia), and PPV-Rec (isolated in the CR from P insititia). PPV susceptible apricot cvs Karola and Velkopavlovicka were used as controls and were chip-bud inoculated with PPV strains. No symptoms appeared in the leaves and fruits of cv. Betinka during six years of observation following inoculation with PPV-D (type), PPV-D (P insititia), PPV-Rec (PPV-W), PPV-M (peach) and PPV-Rec strains, and in two trees inoculated with PPV-M (type) strain. Likewise, ELISA did not detect the presence of PPV in the leaves of both cultivars. RT-PCR gave a slight positive reaction from the leaves of a symptomless tree of cv. Harlayne inoculated with PPV-Rec (PPV-W) and from leaves of a symptomless tree of cv. Betinka inoculated with PPV-D (R insititia). The presence of PPV in these trees is under investigation. Mild diffuse rings and spots appeared occasionally in the leaves and fruits of one tree of cv. Betinka after inoculation of PPV-M (type). The presence of PPV was confirmed by ELISA and RT-PCR. The relative concentration of PPV-M (type) protein in the leaves of a tree of cv. Betinka determined by ELISA was low (2.5x10(-1)) in comparison with the control (cv. Karola, 1.95x10(-3)). Severe symptoms appeared in the leaves and fruits of susceptible control cvs Karola and Velkopavlovicka. The presence of different PPV strains in control cultivars was confirmed by ELISA and RTPCR. Thus, cvs Harlayne and Betinka displayed durable resistance to the six different strains and isolates of PPV over the six year trial.

BACKGROUND:Our purpose was to study the association between the intracranial atherosclerosis as measured by cavernous carotid artery calcification (ICAC) observed on head CT and atrophic changes of supra-tentorial brain demonstrated by MRI.METHODS:Institutional review board approval was obtained for this retrospective study incorporating 65 consecutive patients presenting acutely who had both head CT and MRI. Arterial calcifications of the intracranial cavernous carotids (ICAC) were assigned a number (1 to 4) in the bone window images from CT scans. These 4 groups were then combined into high (grades 3 and 4) and low calcium (grades 1 and 2) subgroups. Brain MRI was independently evaluated to identify cortical and central atrophy. Demographics and cardiovascular risk factors were evaluated in subjects with high and low ICAC. Relationship between CT demonstrated ICAC and brain atrophy patterns were evaluated both without and with adjustment for cerebral ischemic scores and cardiovascular risk factors.RESULTS:Forty-six of the 65 (71%) patients had high ICAC on head CT. Subjects with high ICAC were older, and had higher prevalence of hypertension, diabetes, coronary artery disease (CAD), atrial fibrillation and history of previous stroke (CVA) compared to those with low ICAC. Age demonstrated strong correlation with both supratentorial atrophy patterns. There was no correlation between ICAC and cortical atrophy. There was correlation however between central atrophy and ICAC. This persisted even after adjustment for age.CONCLUSION:Age is the most important determinant of atrophic cerebral changes. However, high ICAC demonstrated age independent association with central atrophy.

ISEE-253 Objective: Chronic exposure to particulate air pollution has been associated with cardiovascular mortality, but underlying mechanisms are not fully understood. Effects of air pollution on arterial stiffness could partially explain this association. We hypothesized that estimated chronic exposure to particles would be positively associated with current arterial stiffness in 4933 MESA participants. Material and Methods: Chronic exposure to PM10 was estimated from the ambient monitor nearest participants' residence(s) during 2 decades preceding a clinical examination (2000–2002). Two measures of arterial stiffness were derived from carotid artery ultrasonography: the distensibility coefficient (DC) and Young's modulus (YM). Lower DC and higher YM signify greater arterial stiffness; YM accounts for wall thickness. Both variables were log-transformed and linear splines fit for 2-decade PM10 exposure. Analyses were adjusted for age, race, sex, smoking status, waist-to-hip ratio, environmental tobacco smoke, physical activity, diabetes, fasting blood glucose, systolic blood pressure, and triglycerides. Results: In exploratory analyses with a nonparametric spline, the association of arterial stiffness with PM10 was nonlinear, with an inflection point at 37 mg/m3. Eighty percent of participants had exposures below this level. Below 37 mg/m3, chronic PM10 exposure was associated with greater arterial stiffness measured by YM [adjusted relative difference: 8% per 10 mg/m3 increment in PM10 95% confidence interval (CI): 4%–12%)] but not for DC (relative difference of −1% per 10 mg/m3 PM10 increment 95% CI: −4% to 3%). At PM10 above 37 mg/m3, there was no association between PM10 and arterial stiffness. Similarly, current smoking was associated with less arterial stiffness. Patterns of association with PM10 were similar in analyses restricted to never smokers. Conclusions: Long-term air pollution exposure below 37 mg/m3 was associated with greater arterial stiffness measured by YM. The relationship of smoking and higher pollution exposures with arterial stiffness in this sample needs further exploration.