Association of traditional and nontraditional cardiovascular risk factors with coronary artery calcification

Machine Learning Approach for Cardiovascular Risk and Coronary Artery Calcification Score

Coronary artery calcification (CAC) could assist in the discovery of new risk elements for coronary artery disorder. CAC evaluation, on the other hand, is difficult due to the wide range of CAC in the populations. As a reason, evaluating and analysing data among research have become complicated. In the Research of Inherited Risk Factors for Coronary Atherosclerosis, we used CAC information to test the effects of different analytical methodologies on the correlation with recognized cardiovascular risk elements in asymptomatic patients. Cardiac computed tomography (CT) is also seeing an increase in examinations, and machine learning (ML) could assist with the growing amount of extracted data. Furthermore, there are other sectors in cardiac CT where machine learning could be crucial, including coronary calcium scoring, perfusion, and CT angiography. The establishment of risk evaluation algorithms based on information from CAC utilizing machine learning could assist in the categorization of patients undergoing cardiovascular into distinct risk groups and effectively adapt their treatments to their unique situations. Our findings imply that for forecasting CVD occurrences in asymptomatic people, age-sex segmentation by CAC percentile rank is as effective as absolute CAC scoring. Longitudinal population-based investigations are currently underway and would offer further definitive findings. While machine learning is a strong technology with a lot of possibilities, its implementations in the domain of cardiac CAC are generally in the early stages of development and are not currently commonly accessible in medical practise because of the requirement for substantial verification. Enhanced machine learning will, however, have a significant effect on cardiovascular and coronary artery calcification in the upcoming years.

Exercise and Coronary Atherosclerosis: Observations, Explanations, Relevance, and Clinical Management

Physical activity and exercise training are effective strategies for reducing the risk of cardiovascular events, but multiple studies have reported an increased prevalence of coronary atherosclerosis, usually measured as coronary artery calcification, among athletes who are middle-aged and older. Our review of the medical literature demonstrates that the prevalence of coronary artery calcification and atherosclerotic plaques, which are strong predictors for future cardiovascular morbidity and mortality, was higher in athletes compared with controls, and was higher in the most active athletes compared with less active athletes. However, analysis of plaque morphology revealed fewer mixed plaques and more often only calcified plaques among athletes, suggesting a more benign composition of atherosclerotic plaques. This review describes the effects of physical activity and exercise training on coronary atherosclerosis in athletes who are middle-aged and older and aims to contribute to the understanding of the potential adverse effects of the highest doses of exercise training on the coronary arteries. For this purpose, we will review the association between exercise and coronary atherosclerosis measured using computed tomography, discuss the potential underlying mechanisms for exercise-induced coronary atherosclerosis, determine the clinical relevance of coronary atherosclerosis in middle-aged athletes and describe strategies for the clinical management of athletes with coronary atherosclerosis to guide physicians in clinical decision making and treatment of athletes with elevated coronary artery calcification scores.

The Association of Water-Pipe Smoking and Coronary Artery Calcium in a Community-Based Sample

BACKGROUND

Water-pipe smoking is increasing in popularity, driven partly by a perception of reduced harm compared with cigarette smoking. This study evaluates the association of water-pipe smoking with coronary artery calcium (CAC), a marker of coronary heart disease (CHD) risk, in a community-based sample.

METHODS

A total of 175 exclusive water-pipe smokers and 170 nonsmokers, ≥ 35 years of age, were recruited from the community in Lebanon and Qatar. Water-pipe smoking was assessed using a validated questionnaire. CAC score was assessed using multidetector CT scan. The association of water-pipe smoking with the presence and extent of CAC was evaluated using regression analyses adjusted for CHD risk factors.

RESULTS

CAC was present in 41% of water-pipe smokers vs 28% of nonsmokers (P = .01), with an average CAC score ± SD of 90.6 ± 400.3 Agatston units (AUs) in water-pipe smokers and 52.4 ± 218.6 AUs in nonsmokers. In adjusted analyses, water-pipe smokers had significantly higher adjusted odds of having CAC (OR = 2.20; 95% CI, 1.20-4.01; P = .01) and being in the high CHD risk category defined by CAC > 300 AUs (OR = 3.41; 95% CI, 1.08-10.77; P = .04) or CAC > 75% of age, sex, and race-predicted (OR = 3.11; 95% CI, 1.55-6.24; P = .001) than nonsmokers. CAC extent was significantly associated with water-pipe smoking extent measured by smoking duration (β = 0.17/year; 95% CI, 0.05-0.29; P = .004) or the product of smoking duration and the number of water pipes smoked daily (β = 0.04/water-pipe-year; 95% CI, 0.003-0.07; P = .03).

CONCLUSIONS

Exclusive water-pipe smoking was associated with the presence and extent of CAC, with twice the risk of having CAC and three times the risk of being in the high CHD risk category while accounting for other risk factors.

25-Year Physical Activity Trajectories and Development of Subclinical Coronary Artery Disease as Measured by Coronary Artery Calcium: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

OBJECTIVE

To evaluate 25-year physical activity (PA) trajectories from young to middle age and assess associations with the prevalence of coronary artery calcification (CAC).

PATIENTS AND METHODS

This study includes 3175 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study who self-reported PA by questionnaire at 8 follow-up examinations over 25 years (from March 1985-June 1986 through June 2010-May 2011). The presence of CAC (CAC>0) at year 25 was measured using computed tomography. Group-based trajectory modeling was used to identify PA trajectories with increasing age.

RESULTS

We identified 3 distinct PA trajectories: trajectory 1, below PA guidelines (n=1813; 57.1%); trajectory 2, meeting PA guidelines (n=1094; 34.5%); and trajectory 3, 3 times PA guidelines (n=268; 8.4%). Trajectory 3 participants had higher adjusted odds of CAC>0 (adjusted odds ratio [OR], 1.27; 95% CI, 0.95-1.70) vs those in trajectory 1. Stratification by race showed that white participants who engaged in PA 3 times the guidelines had higher odds of developing CAC>0 (OR, 1.80; 95% CI, 1.21-2.67). Further stratification by sex showed higher odds for white males (OR, 1.86; 95% CI, 1.16-2.98), and similar but nonsignificant trends were noted for white females (OR, 1.71; 95% CI, 0.79-3.71). However, no such higher odds of CAC>0 for trajectory 3 were observed for black participants.

CONCLUSION

White individuals who participated in 3 times the recommended PA guidelines over 25 years had higher odds of developing coronary subclinical atherosclerosis by middle age. These findings warrant further exploration, especially by race, into possible biological mechanisms for CAC risk at very high levels of PA.

Circulating Sex Steroids and Vascular Calcification in Community-Dwelling Men: The Framingham Heart Study

CONTEXT

The relationship between sex steroids and atherosclerosis is poorly understood.

OBJECTIVE

To describe the association of serum total T (TT), calculated free T (cFT), estrone (E1), estradiol (E2), and SHBG to vascular calcification in adult men.

DESIGN

Observational study (Framingham Heart Study). Analyses are cross-sectional. TT, E1, and E2 were measured by liquid chromatography-tandem mass spectrometry, and SHBG by immunofluorometric assay. Estimates of association were obtained by Tobit regression, which acknowledges the influence of floor effects on outcomes.

SETTING

General community.

PARTICIPANTS

A total of 1654 community-dwelling men from the Offspring and Third Generation cohorts of the Framingham Heart Study.

MAIN OUTCOME MEASURES

Coronary artery calcification (CAC), abdominal aortic calcification, and thoracic aortic calcification were measured by computed tomography.

RESULTS

Mean (standard deviation [SD]) age was 49 (10) years. Mean (SD) TT, cFT, and SHBG were: 616 (224) ng/dL, 111 (45) pg/mL, and 46 (23) nmol/L, respectively. Mean (SD) E2 and E1 were 28 (10) and 39 (14) pg/mL. Vascular calcification at all sites was negatively associated with TT and cFT and positively associated with E2 and E1. A 100-ng/dL between-subjects increase in TT was associated with a mean (95% confidence interval) age-adjusted difference in CAC of -23% (-41%, -4%) (P = .02). After model adjustment for other cardiovascular risk factors, the estimated associations between T and vascular calcification scores were statistically nonsignificant.

CONCLUSIONS

Decreased circulating T and E2 levels are associated with an age-adjusted increase in CAC, but these associations appear to express relationships either attributable to or mediated by established cardiovascular risk factors.

Walking and Calcified Atherosclerotic Plaque in the Coronary Arteries: The National Heart, Lung, and Blood Institute Family Heart Study

OBJECTIVE

Studies have reported mixed findings on the association between physical activity and subclinical atherosclerosis. We sought to examine whether walking is associated with prevalent coronary artery calcification (CAC) and aortic calcification.

APPROACH AND RESULTS

In a cross-sectional design, we studied 2971 participants of the National Heart, Lung, and Blood Institute Family Heart Study without a history of myocardial infarction, coronary artery bypass grafting, or percutaneous transluminal angioplasty. A standardized questionnaire was used to ascertain the number of blocks walked daily to compute walking metabolic equivalent hours. CAC was measured by cardiac computed tomography. We defined prevalent CAC and aortic calcification using an Agatston score of at least 100 and used generalized estimating equations to calculate adjusted prevalence ratios. Mean age was 55 years, and 60% of participants were women. Compared with the ≤3.75-Met-h/wk group, prevalence ratios for CAC after adjusting for age, sex, race, smoking, alcohol use, total physical activity (excluding walking), and familial clustering were 0.53 (95% confidence interval, 0.35-0.79) for >3.75 to 7.5 Met-h/wk, 0.72 (95% confidence interval, 0.52-0.99) for >7.5 to 15 Met-h/wk, and 0.54 (95% confidence interval, 0.36-0.81) for >15 to 22.5 Met-h/wk, (P trend=0.01). The walking-CAC relationship remained significant for those with body mass index ≥25 (P trend=0.02) and persisted with CAC cutoffs of 300, 200, 150, and 50 but not 0. When examined as a continuous variable, a J-shaped association between walking and CAC was found. The walking-aortic calcification association was not significant.

CONCLUSIONS

Our findings suggest that walking is associated with lower prevalent CAC (but not aortic calcification) in adults without known heart disease.

HIV and coronary artery calcium score: comparison of the Hawaii Aging with HIV Cardiovascular Study and Multi-Ethnic Study of Atherosclerosis (MESA) cohorts

OBJECTIVES

To determine the association of HIV, immunologic, and inflammatory factors on coronary artery calcium (CAC), a marker of subclinical atherosclerosis.

METHODS

Cross-sectional study comparing baseline data of males from Hawaii Aging with HIV - Cardiovascular Study (HAHCS) with the Multi-Ethnic Study of Atherosclerosis (MESA) cohort. The cohorts were pooled to determine effects of HIV on CAC and explore immunologic and inflammatory factors that may explain development of CAC in HIV. Multivariable regression models compared CAC prevalence in HAHCS with MESA adjusting for coronary heart disease (CHD) risk profiles.

RESULTS

We studied 100 men from HAHCS and 2733 men from MESA. Positive CAC was seen in 58% HAHCS participants and 57% MESA participants. Mean CAC was 260.8 in HAHCS and 306.5 in MESA. Using relative risk (RR) regression, HAHCS participants had a greater risk (RR = 1.20, P < 0.05) of having positive CAC than MESA when adjusting for age, smoking status, diabetes, antihypertensive therapy, BMI, systolic blood pressure, total cholesterol, and HDL cholesterol. Among participants with positive CAC, HIV infection was not associated with larger amounts of CAC. Among HAHCS participants, current HIV viral load, CD4, length of HIV, interleukin 6 (IL-6), fibrinogen, C-reactive protein (CRP), and D-dimer were not associated with the presence or amount of CAC.

DISCUSSION

HIV was independently associated with a positive CAC in men with increased likelihood occurring between 45 and 50 years of age. Current HIV viral load, CD4 count, length of HIV, and inflammatory markers were unrelated to either presence or amount of CAC.

Association between metabolic syndrome, smoking status and coronary artery calcification

Coronary artery calcification (CAC), an indicator of coronary artery stenosis, is an independent risk factor of ischemic heart disease. Smoking increases the risk of metabolic syndrome (MS) and cardiovascular disease. Almost no previous studies have evaluated the combined effect of MS and smoking status on CAC. Therefore, in this study we examined the relationships between CAC, MS, and smoking. This study included 775 adult males without histories of cardiovascular disease who visited the Health Promotion Center at the University Hospital in Gyeonggi-do, Republic of Korea from January 2, 2010 to December 31, 2012. All subjects were screened for CAC by multi-detector computed tomography (MDCT). CAC increased significantly with age and body mass index (BMI). Among MS components, abdominal obesity and elevated fasting blood glucose were correlated with CAC. After adjusting for age and BMI, MS was associated with a 1.46-fold increase in CAC (95% CI:1.02-2.09), abdominal obesity was associated with a 1.45-fold increase (95% CI:1.04-2.04), elevated fasting blood glucose was associated with a 2-fold increase (95% CI:1.36-2.94), and MS and smoking combined were associated with 2.44-fold increase in CAC. Thus, the combination of smoking and MS had a greater impact on CAC than any single factor alone. MS is correlated with an increased risk of CAC, and a combination of MS and smoking is associated with even greater risk. These findings can be used to prevent cardiovascular disease in adults.

Individual-level concentrations of fine particulate matter chemical components and subclinical atherosclerosis: a cross-sectional analysis based on 2 advanced exposure prediction models in the multi-ethnic study of atherosclerosis

Long-term exposure to outdoor particulate matter with an aerodynamic diameter less than or equal to 2.5 µm (PM2.5) has been associated with cardiovascular morbidity and mortality. The chemical composition of PM2.5 that may be most responsible for producing these associations has not been identified. We assessed cross-sectional associations between long-term concentrations of PM2.5 and 4 of its chemical components (sulfur, silicon, elemental carbon, and organic carbon (OC)) and subclinical atherosclerosis, measured as carotid intima-media thickness (CIMT) and coronary artery calcium, between 2000 and 2002 among 5,488 Multi-Ethnic Study of Atherosclerosis participants residing in 6 US metropolitan areas. Long-term concentrations of PM2.5 components at participants' homes were predicted using both city-specific spatiotemporal models and a national spatial model. The estimated differences in CIMT associated with interquartile-range increases in sulfur, silicon, and OC predictions from the spatiotemporal model were 0.022 mm (95% confidence interval (CI): 0.014, 0.031), 0.006 mm (95% CI: 0.000, 0.012), and 0.026 mm (95% CI: 0.019, 0.034), respectively. Findings were generally similar using the national spatial model predictions but were often sensitive to adjustment for city. We did not find strong evidence of associations with coronary artery calcium. Long-term concentrations of sulfur and OC, and possibly silicon, were associated with CIMT using 2 distinct exposure prediction modeling approaches.

Self-reported and accelerometer-derived physical activity levels and coronary artery calcification progression in older women: results from the Healthy Women Study

OBJECTIVE

Despite the well-supported biological link between physical activity (PA) and atherosclerosis, most previous studies have reported a null association between PA and coronary artery calcification (CAC). The aim of this study was to examine the relationship between PA and CAC progression in 148 Healthy Women Study (HWS) participants over 28 years of observation.

METHODS

The HWS was designed to examine cardiovascular risk factor changes from premenopause to postmenopause. Based on CAC scores collected on two follow-up visits (electron beam tomography [EBT] 1 and EBT4) scheduled 12 years apart, participants were classified into one of three groups: (1) no-detectable CAC group (n = 37; 0 CAC on both visits); (2) incident CAC group (n = 46; 0 CAC on the first visit and >0 CAC on the last visit); or (3) prevalent CAC group (n = 65; >0 CAC on both visits). PA data were collected regularly throughout the study using self-report questionnaires and accelerometers on EBT4.

RESULTS

The percentage of HWS participants with no detectable CAC decreased from 56.1% on EBT1 to 25.0% on EBT4. Times spent per day in accumulated moderate- to vigorous-intensity PA (MVPA) and bouts of MVPA were each significantly higher in the no-detectable CAC group when compared with the prevalent CAC group (both P ≤ 0.01). After covariate adjustment, these differences remained statistically significant (both P < 0.05). Although self-reported summary estimates collected throughout the study were significantly associated with accelerometer data on EBT4, there were no significant differences in self-reported PA levels by CAC group after covariate adjustment.

CONCLUSIONS

Study findings suggest that low levels of accelerometer-derived MVPA may be indicative of subclinical disease in older women.

Influence of cigarette smoking on coronary artery and aortic calcium among random samples from populations of middle-aged Japanese and Korean men

BACKGROUND

Cigarette smoking is a risk factor of coronary heart disease. Vascular calcification such as coronary artery calcium (CAC) and aortic calcium (AC) is associated with coronary heart disease. The authors hypothesised that cigarette smoking is associated with coronary artery and aortic calcifications in Japanese and Koreans with high smoking prevalence.

METHODS

Random samples from populations of 313 Japanese and 302 Korean men aged 40-49 years were examined for calcification of the coronary artery and aorta using electron beam CT. CAC and AC were quantified using the Agatston score. The authors examined the associations of cigarette smoking with CAC and AC after adjusting for conventional risk factors and alcohol consumption. Current and past smokers were combined and categorised into two groups using median pack-years as a cut-off point in each of Japanese and Koreans. The never-smoker group was used as a reference for the multiple logistic regression analyses.

RESULTS

The ORs of CAC (score ≥10) for smokers with higher pack-years were 2.9 in Japanese (p<0.05) and 1.3 in Koreans (non-significant) compared with never-smokers. The ORs of AC (score ≥100) for smokers with higher pack-years were 10.4 in Japanese (p<0.05) and 3.6 in Koreans (p<0.05).

CONCLUSION

Cigarette smoking with higher pack-years is significantly associated with CAC and AC in Japanese men, while cigarette smoking with higher pack-years is significantly associated with AC but not significantly with CAC in Korean men.

Objectively assessed physical activity, sedentary time, and coronary artery calcification in healthy older adults

OBJECTIVE

Physical activity is related to lower risk of cardiovascular disease, but data relating to coronary lesions have been conflicting. These inconsistencies may in part be due to unreliable assessment of physical activity and limitations imposed by self-reported data. The purpose of this study was to determine the relationship between objectively measured physical activity and coronary artery calcium (CAC).

METHODS AND RESULTS

Participants were 443 healthy men and women (mean age=66±6 years), without history or objective signs of coronary heart disease, drawn from the Whitehall II epidemiological cohort. Physical activity was objectively measured using accelerometers worn during waking hours for 7 consecutive days (average daily wear time=889±68 minutes/day). CAC was measured in each participant using electron beam computed tomography and was quantified according to the Agatston scoring system. On average, 54.4% of the sample recorded at least 30 minutes/day of moderate to vigorous physical activity (MVPA). There was no association between MVPA and presence of detectable CAC. For the participants with detectable CAC (n=283) a weak inverse relationship between MVPA (minutes/day) and log Agatston score was observed (B=-0.008, 95% CI: -0.16 to 0.00, P=0.05), although the association was no longer present after adjustments for age, sex, and conventional risk factors. No associations were seen for light activity or sedentary time.

CONCLUSIONS

Our results confirm no association between objectively assessed physical activity and CAC. Because CAC measures cannot identify more vulnerable lesions, additional studies are required to examine whether physical activity can promote plaque stability.

Relation of cardiovascular risk factors and angina status to obstructive coronary artery disease according to categorical coronary artery calcium score

Coronary artery calcium (CAC) is associated with the presence of coronary artery disease (CAD) and cardiovascular risk factors. However, the relation between cardiovascular risk factors and CAD has not yet been fully elucidated in patients with a zero or low coronary artery calcium score (CACS). The purpose of this study was to evaluate the relation of cardiovascular risk factors and angina status to obstructive CAD according to categorical CACS. A total of 753 patients were enrolled in this study. CAC scoring and coronary computed tomographic angiography (CCTA) were performed with dual-source 64-slice CT scanners. The number of patients with a CACS ≤10 and ≤100 were 358 and 528, respectively. Patients with a higher CACS were older and more frequently male, and had a greater frequency of hypertension, diabetes, and hypercholesterolemia. The prevalence of obstructive CAD increased with the CACS. Among patients with a CACS ≤100, age, male gender, diabetes, hypercholesterolemia, and typical angina pectoris were related to obstructive CAD. The presence of hypercholesterolemia was relatively strongly associated with obstructive CAD (OR 6.67, 95% CI 2.91-15.3, p < 0.001) on multivariate analysis. Among patients with a CACS ≤10, men, hypercholesterolemia, and typical angina pectoris were significantly more frequent in patients with than in those without obstructive CAD (p < 0.01). Our data suggest that neither the absence nor low of coronary calcium burden may reliably exclude obstructive CAD in typical symptomatic male patients with hypercholesterolemia. This result may be useful to interpret the relation of CACS to obstructive CAD.

Associations of D-dimer and von Willebrand factor with atherosclerosis in Japanese and white men

OBJECTIVE

D-dimer and von Willebrand factor (vWF) are associated with atherosclerosis. We recently reported that in a post-World War II birth cohort, Japanese men in Japan had lower levels of atherosclerosis than white men in the United States (U.S.). We examined whether the differences in D-dimer and vWF levels are associated with differences in atherosclerosis between the two populations.

METHODS AND RESULTS

Population-based samples of 99 Japanese and 100 white American men aged 40-49 years were examined for coronary artery calcification (CAC), carotid intima-media thickness (IMT), D-dimer, vWF, and other factors using a standardized protocol. When compared to white American men,Japanese had similar levels of D-dimer (0.22 +/- 0.28 vs. 0.19 +/- 0.24 microg/L, respectively, P = 0.39) but significantly higher levels of vWF (124.1 +/- 36.6 vs. 91.3 +/- 48.8%, respectively, P < 0.01). Japanese as compared to white American men had significantly lower prevalence of CAC (13.1 vs. 28.0%, P < 0.01, respectively) and significantly lower IMT (0.61 +/- 0.07 vs. 0.66 +/- 0.08 mm, P < 0.01, respectively). Japanese men had a significant positive association of D-dimer with the prevalence of CAC and a negative association of vWF with IMT, whereas white American men did not have any significant associations.

CONCLUSIONS

In men aged 40-49 years, Japanese as compared to white Americans had similar levels of D-dimer and higher levels of vWF although Japanese had a significantly lower prevalence of CAC and IMT. These haemostatic factors are unlikely to explain the difference in atherosclerosis in these populations.

Physical activity and coronary artery calcification in two cohorts of women representing early and late postmenopause

OBJECTIVE

The aim of this study was to examine the association between physical activity (PA) and coronary artery calcification (CAC) among two cohorts of postmenopausal (PM) women representing early and late postmenopause.

METHODS

The cross-sectional relationship between PA and CAC was examined in 173 younger PM women (mean age ± SD, 56.8 ± 2.9 y) from the Women on the Move Through Activity and Nutrition (WOMAN) study and 121 older PM women (mean age ± SD, 73.9 ± 3.8 y) from the Walking Women Follow-up (WWF) study who had complete PA and CAC data. PA was measured objectively using a pedometer over a 7-day period in both cohorts. CAC was assessed using electron beam tomography. Descriptive statistics were used to describe median levels of PA and CAC, as well as proportions of detectable CAC (0 vs > 0).

RESULTS

Fifty-seven percent of WOMAN study participants and 74% of WWF study participants had detectable CAC. The median (interquartile range) CAC score was 1.4 (0-23.3) for participants in the WOMAN study and 38.8 (0-264.4) among WWF study participants. Median (interquartile range) step counts were 6,447 (4,823-8,722) steps per day in the WOMAN study and 5,466 (3,610-7,576) steps per day for WWF study participants. Among WWF study participants, there was a statistically significant inverse association between pedometer steps and CAC (P for trend = 0.002); no association was found among WOMAN study participants.

CONCLUSIONS

Among older PM women, higher levels of PA were associated with lower CAC. However, the relationship was not observed in PM women, likely due to the lower prevalence of CAC in this age group.

Walking speed and subclinical atherosclerosis in healthy older adults: the Whitehall II study

Objective

Extended walking speed is a predictor of incident cardiovascular disease (CVD) in older individuals, but the ability of an objective short-distance walking speed test to stratify the severity of preclinical conditions remains unclear. This study examined whether performance in an 8-ft walking speed test is associated with metabolic risk factors and subclinical atherosclerosis.

Design

Cross-sectional.

Setting

Epidemiological cohort.

Participants

530 adults (aged 63±6 years, 50.3% male) from the Whitehall II cohort study with no known history or objective signs of CVD.

Main outcome

Electron beam computed tomography and ultrasound was used to assess the presence and extent of coronary artery calcification (CAC) and carotid intima-media thickness (IMT), respectively.

Results

High levels of CAC (Agatston score >100) were detected in 24% of the sample; the mean IMT was 0.75 mm (SD 0.15). Participants with no detectable CAC completed the walking course 0.16 s (95% CI 0.04 to 0.28) faster than those with CAC ≥400. Objectively assessed, but not self-reported, faster walking speed was associated with a lower risk of high CAC (odds ratio 0.62, 95% CI 0.40 to 0.96) and lower IMT (β=−0.04, 95% CI −0.01 to −0.07 mm) in comparison with the slowest walkers (bottom third), after adjusting for conventional risk factors. Faster walking speed was also associated with lower adiposity, C-reactive protein and low-density lipoprotein cholesterol.

Conclusions

Short-distance walking speed is associated with metabolic risk and subclinical atherosclerosis in older adults without overt CVD. These data suggest that a non-aerobically challenging walking test reflects the presence of underlying vascular disease.

Differential associations between soluble cellular adhesion molecules and atherosclerosis in the Dallas Heart Study: a distinct role for soluble endothelial cell-selective adhesion molecule

OBJECTIVE

Endothelial cell-selective adhesion molecule (ESAM) is a junctional-type cellular adhesion molecule (CAM) that is uniquely expressed in vascular endothelium and activated platelets and mediates neutrophil and monocyte diapedesis across the endothelium. Given its role in endothelial pathobiology, we hypothesized that soluble ESAM (sESAM) would be independently associated with atherosclerosis and vascular stiffness.

METHODS AND RESULTS

We measured sESAM, soluble intercellular adhesion molecule (sICAM)-1, and soluble vascular cell adhesion molecule (sVCAM)-1 in 3222 subjects participating in the Dallas Heart Study, a probability-based population sample. Coronary artery calcium (CAC) was measured by electron beam computed tomography, and abdominal aortic wall thickness (AWT), aortic plaque burden (APB), and aortic compliance (AC) by MRI. Increasing levels of sESAM were associated with all major cardiovascular risk factors as well as with inflammatory markers such as monocyte chemoattractant protein-1, but only weakly correlated with sICAM-1 and sVCAM-1. In multivariate analyses, sESAM was independently associated with prevalent CAC (OR 1.2 per SD increase, 95% CI 1.1 to 1.3; P=0.005), AWT (P=0.035), and AC (P=0.006), but not APB (P=0.15). In contrast, no independent associations were observed between sICAM-1 or sVCAM-1 and any of the atherosclerosis phenotypes.

CONCLUSIONS

In this first reported clinical study of sESAM in humans, sESAM levels were independently associated with CAC, AWT, and AC, whereas sICAM-1 and sVCAM-1 were not. These findings support a unique role of this cellular adhesion molecule in atherosclerosis and suggest the need for further exploration of sESAM as a predictive biomarker and potential mediator of atherosclerosis.

Associations of inflammatory markers with coronary artery calcification: results from the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

Inflammatory markers predict coronary heart disease (CHD). However, associations with coronary artery calcium (CAC), a marker of subclinical CHD, are not established.

METHODS

We examined cross-sectional associations of C-reactive protein (CRP), interleukin-6 (IL-6) and fibrinogen with CAC presence (Agatston score>0 by computed tomography) in 6783 Multi-Ethnic Study of Atherosclerosis (MESA) participants.

RESULTS

In all participants, those in the highest, compared to lowest, quartile of CRP had a relative risk (RR, 95% confidence interval) of 1.13 (1.06-1.19; p<0.01) for CAC in age, sex and ethnicity adjusted models. For highest versus lowest quartiles, relative risks were 1.22 (1.15-1.30; p<0.01) for IL-6 and 1.18 (1.11-1.24; p<0.01) for fibrinogen. Adjusting for CHD risk factors (smoking, diabetes, blood pressure, obesity and dyslipidemia) attenuated RRs. RRs for CAC were 1.05 (0.99-1.12; p=0.63) for CRP, 1.12 (1.06-1.20; p<0.01) for IL-6 and 1.09 (1.02-1.16; p=0.01) for fibrinogen in multivariable adjusted models. Results were similar for men and women and across ethnic groups.

CONCLUSION

Inflammatory markers were weakly associated with CAC presence and burden in MESA. Our data support the hypothesis that inflammatory biomarkers and CAC reflect distinct pathophysiology.

Cardiorespiratory fitness and coronary artery calcification in young adults: The CARDIA Study

Whether cardiorespiratory fitness relates to early subclinical atherosclerotic vascular disease remains unknown. We investigated the relation of cardiorespiratory fitness to coronary artery calcification (CAC) in 2373 African-American and White young adults from the Coronary Artery Risk Development in Young Adults (CARDIA) Study. We measured cardiorespiratory fitness in 1985-1986 (baseline) using a symptom-limited exercise test on a treadmill. Coronary calcium scores were measured in 2001-2002 (year 15) using electron-beam or multi-detector computed tomography. CAC was classified as present or absent, while cardiorespiratory fitness was classified as sex-specific low, moderate, and high fitness categories. After adjustment for age, sex, race, clinical center, education, cigarette smoking, waist girth, alcohol intake, physical activity, systolic blood pressure, antihypertensive medication use, diabetes mellitus, and fasting insulin, baseline cardiorespiratory fitness was inversely associated with prevalence of CAC in young adults (P for trend=0.03). The odds ratios of having CAC for persons in the moderately and highly fit individuals were 0.80 (95% confidence interval (CI), 0.55-1.15) and 0.59 (95% CI, 0.36-0.97), respectively, as compared with the low-fit individuals. High levels of cardiorespiratory fitness were associated with a lower risk of having coronary calcification 15 years later in African-American and White young adults.

The association between physical activity and subclinical atherosclerosis: the Multi-Ethnic Study of Atherosclerosis

Prior reports regarding the association between physical activity and subclinical cardiovascular disease have not been consistent. The authors assessed physical activity and walking pace via questionnaire among 6,482 US adults aged 45-84 years without prior clinical cardiovascular disease participating in the Multi-Ethnic Study of Atherosclerosis from 2000 to 2002. Ankle-brachial index (ABI), coronary artery calcification, and internal and common carotid intima-media thickness (IMT) were measured. Metabolic equivalent-hours/week of physical activity were calculated. These data were analyzed by using multivariable linear or relative prevalence regression in gender-specific strata. After adjustment for age, race/ethnicity, clinic site, education, income, and smoking (model 1), increasing total, moderate + vigorous, and intentional-exercise physical activity were not associated with IMT or coronary artery calcification in either gender. These factors were associated with increased ABI (P<0.05) in women only. Walking pace was associated favorably with common carotid IMT, ABI, and coronary artery calcification in men and with common carotid IMT and ABI in women (all P<0.05) after adjustment for model 1 variables. These associations were attenuated and, for common carotid IMT, no longer significant when lipids, hypertension, diabetes, and body mass index were added to the model. These data suggest that walking pace is associated with less subclinical atherosclerosis; these associations may be mediated by cardiovascular disease risk factors.

Proliferative diabetic retinopathy in type 2 diabetes is related to coronary artery calcium in the Veterans Affairs Diabetes Trial (VADT)

OBJECTIVE

Increasing evidence suggests that macrovascular disease and retinopathy may be more closely linked than previously believed. We determined the relationship between retinopathy and coronary atherosclerosis as measured by computed tomography-detectable coronary artery calcium (CAC).

RESEARCH DESIGN AND METHODS

The cross-sectional association between CAC and retinopathy was assessed on a Veteran Affairs Diabetes Trial subsample of 204 subjects with a mean duration of type 2 diabetes of 12.3 +/- 8.3 years.

RESULTS

Retinopathy was correlated with CAC (r = 0.19, P = 0.006). Median CAC increased across retinopathy categories: 197 in those with no retinopathy, 229 in those with microaneurysms only, 364 in those with mild nonproliferative diabetic retinopathy (NPDR), 300 in those with moderate to severe NPDR, and 981 in those with proliferative diabetic retinopathy (PDR). Stepwise multivariable linear regression analysis was performed to find a parsimonious subset of relevant risk factors to include along with PDR in predicting CAC. After adjustment for either this subset of standard factors (P = 0.047) or a more extensive panel of risk factors (P = 0.035), PDR was significantly associated with CAC. Moreover, using logistic regression, individuals with PDR were approximately sixfold more likely to have CAC >400 than those with no PDR, even after adjustment for other CVD risk factors.

CONCLUSIONS

These data indicate an important relationship between retinopathy and extent of CAC and suggest the potential to identify and treat shared risk factors for these common micro- and macrovascular complications.

Incident coronary artery calcium among postmenopausal women

Recent studies have shown that individuals with 0 coronary artery calcium (CAC) scores have very low risk of coronary heart disease. In the Healthy Women Study, we evaluated development of new CAC among postmenopausal women (n=272) over a 6-year period, age 62 at the 1st and 68 at the 3rd electron beam tomography (EBT) examination. At the 1st EBT, 155 of 272 (57%) women had 0 CAC. By the 3rd, 56 (36%) of these women had developed new CAC, including 38 with >or=5 Agatston units. There was practically no regression from having CAC at the 1st EBT to no CAC at the 3rd EBT. The risk of developing new CAC over 6 years among women with 0 CAC on their 1st EBT was strongly and significantly related to presence of both aortic calcium and carotid plaque at the time of 1st EBT. Baseline premenopausal risk factors, age 47, apolipoprotein B, body mass index (BMI) and triglycerides, were significant predictors of incident CAC as were the changes in BMI and low density lipoprotein cholesterol between premenopause and the 1st post exam, age 53. Risk factors measured premenopause and change in risk factors from premenopause to the 1st post exam and the extent of subclinical disease in other vascular beds are primary determinants of the risk of developing incident CAC in women over a 6-year period.

Association of sICAM-1 and MCP-1 with coronary artery calcification in families enriched for coronary heart disease or hypertension: the NHLBI Family Heart Study

Background

Data accumulated from mouse studies and in vitro studies of human arteries support the notion that soluble intercellular adhesion molecule-1 (sICAM-1) and monocyte chemoattractant protein-1 (MCP-1) play important roles in the inflammation process involved in atherosclerosis. However, at the population level, the utility of sICAM-1 and MCP-1 as biomarkers for subclinical atherosclerosis is less clear. In the follow-up exam of the NHLBI Family Heart Study, we evaluated whether plasma levels of sICAM-1 and MCP-1 were associated with coronary artery calcification (CAC), a measure of the burden of coronary atherosclerosis.

Methods

CAC was measured using the Agatston score with multidetector computed tomography. Information on CAC and MCP-1 was obtained in 2246 whites and 470 African Americans (mean age 55 years) without a history of coronary heart disease (CHD). Information on sICAM-1 was obtained for white participants only.

Results

In whites, after adjustment for age and gender, the odds ratios (ORs) of CAC (CAC > 0) associated with the second, third, fourth, and fifth quintiles of sICAM-1 compared to the first quintile were 1.22 (95% confidence interval [CI]: 0.91–1.63), 1.15 (0.84–1.58), 1.49 (1.09–2.05), and 1.72 (1.26–2.36) (p = 0.0005 for trend test), respectively. The corresponding ORs for the second to fifth quintiles of MCP-1 were 1.26 (0.92–1.73), 0.99 (0.73–1.34), 1.42 (1.03–1.96), and 2.00 (1.43–2.79) (p < 0.0001 for trend test), respectively. In multivariable analysis that additionally adjusted for other CHD risk factors, the association of CAC with sICAM-1 and MCP-1 was attenuated and no longer statistically significant. In African Americans, the age and gender-adjusted ORs of CAC associated with the second and third tertiles of MCP-1 compared to the first tertile were 1.16 (0.64–2.08) and 1.25 (0.70–2.23) (p = 0.44 for trend test), respectively. This result did not change materially after additional adjustment for other CHD risk factors. Test of race interaction showed that the magnitude of association between MCP-1 and CAC did not differ significantly between African Americans and whites. Similar results were obtained when CAC ≥ 10 was analyzed as an outcome for both MCP-1 and sICAM-1.

Conclusion

This study suggests that sICAM-1 and MCP-1 are biomarkers of coronary atherosclerotic burden and their association with CAC was mainly driven by established CHD risk factors.

A comparison of risk factors for calcified atherosclerotic plaque in the coronary, carotid, and abdominal aortic arteries: the diabetes heart study

The extent of shared risk factors for calcified atherosclerotic plaque (CAP) of the coronary, carotid, and abdominal aortic arteries is unknown. CAP was measured by computed tomography in 1,125 individuals in families affected with diabetes. Statistical methods adjusted for the lack of independence between observations. CAP scores were standardized, and tests of interaction were conducted to compare risk factor relations across vascular beds. The average age of the cohort was 61 years, and 84% had diabetes. The correlation in CAP scores across vascular beds ranged from 0.59 to 0.72. Age, albumin/creatinine ratio, hemoglobin A1c, diabetes, hypertension, and lipid-lowering therapy were correlated with quantity of CAP in all vascular beds (all p<0.05); no differences in the strength of these relations were noted. In contrast, other significant correlates differed in the strength of their relations with CAP. The risk factor pack-years of smoking was most strongly correlated with CAP in the abdominal aorta (p<0.005). Male gender, previous myocardial infarction, and coronary revascularization were most strongly correlated with CAP in the coronary arteries (p<0.0001). In summary, CAPs of the coronary, carotid, and abdominal aortic arteries generally share common risk factors, even though several of these factors have a greater impact on CAP in one vascular bed than another.

Less subclinical atherosclerosis in Japanese men in Japan than in White men in the United States in the post-World War II birth cohort

Coronary heart disease incidence and mortality remain very low in Japan despite major dietary changes and increases in risk factors that should have resulted in a substantial increase in coronary heart disease rates (Japanese paradox). Primary genetic effects are unlikely, given the substantial increase in coronary heart disease in Japanese migrating to the United States. For men aged 40-49 years, levels of total cholesterol and blood pressure have been similar in Japan and the United States throughout their lifetimes. The authors tested the hypothesis that levels of subclinical atherosclerosis, coronary artery calcification, and intima-media thickness of the carotid artery in men aged 40-49 years are similar in Japan and the United States. They conducted a population-based study of 493 randomly selected men: 250 in Kusatsu City, Shiga, Japan, and 243 White men in Allegheny County, Pennsylvania, in 2002-2005. Compared with the Whites, the Japanese had a less favorable profile regarding many risk factors. The prevalence ratio for the presence of a coronary calcium score of > or =10 for the Japanese compared with the Whites was 0.52 (95% confidence interval: 0.35, 0.76). Mean intima-media thickness was significantly lower in the Japanese (0.616 mm (standard error, 0.005) vs. 0.672 (standard error, 0.005) mm, p < 0.01). Both associations remained significant after adjusting for risk factors. The findings warrant further investigations.

Influence of a Lipid-Lowering Therapy on Calcified and Noncalcified Coronary Plaques Monitored by Multislice Detector Computed Tomography

PURPOSE

Multislice detector computed tomography (MSCT) is an accurate noninvasive modality to detect and classify different stages of atherosclerosis. The aim of the New Age II Study was to detect coronary lesions in men without established coronary artery disease (CAD) but with a distinct cardiovascular risk profile. We also sought to assess the effect after 1 year of a lipid-lowering therapy (LLT) using 20 mg of atorvastatin.

METHODS

Forty-sixe male patients (mean, 61 +/- 10 years) with an elevated risk for CAD (PROCAM score >3 quintile) without LLT were included. Native and contrast-enhanced scans were performed in all patients. A total of 27 of 46 patients received a follow-up scan (after 488 +/- 138 days). Coronary plaque burden (CPB) was assessed volumetrically.

RESULTS

The prevalence of CAD was 83% (38/46 patients), and 11% (5/46) without coronary calcifications still had noncalcified plaques. Total cholesterol and low-density lipoprotein cholesterol levels decreased significantly under LLT (225 +/- 41 mg/dL vs. 162 +/- 37 mg/dL, P < 0.0001 and 148 +/- 7 mg/dL vs. 88 +/- 5 mg/dL, P < 0.001, respectively). On follow-up, calcium score and CPB remained unchanged (Agatston score: 261 +/- 301 vs. 282 +/- 360; CPB: 0.149 +/- 0.108 vs. 0.128 +/- 0.075 mL, P > 0.05), whereas mean plaque volume of noncalcified plaques decreased significantly from 0.042 +/- 0.029 mL versus 0.030 +/- 0.014 mL (P < 0.05, mean reduction 0.012 +/- 0.017 mL or 24 +/- 13%).

CONCLUSIONS

Statin therapy led to a significant reduction of noncalcified plaque burden that was not reflected in calcium scoring or total plaque burden. This finding might explain the risk reduction after the initiation of statin therapy. Using multislice detector computed tomography, physicians have the potential to monitor medical treatment in patients with coronary atherosclerosis.

Coronary artery calcification, common carotid artery intima-media thickness and aortic pulse wave velocity in patients on peritoneal dialysis

An increasing body of evidence suggests that atherosclerosis in patients with uremia differs from that found in general population in terms of advancement and localization of vascular lesions. It has also been suggested that different non-invasive techniques of vascular system evaluation are designed to show different types of lesions (i.e. vascular calcification, stiffness or 'classical' atherosclerosis). The aim of the study was to search for possible associations between results obtained with three different non-invasive methods of vascular system assessment in three different vascular sites in patients treated with peritoneal dialysis (PD). 61 patients (28 F, 33 M), mean age of 50.4+/-13.6 years, on maintenance PD for a median period of 10 months (range 1-96 months) were included. Coronary artery disease (CAD) was present in 21 subjects. In all subjects coronary artery calcification score (CaSc) using multi-row spiral computed tomography (MSCT), aortic pulse wave velocity (AoPWV) and ultrasound-based common carotid artery intima-media thickness (CCA-IMT) were performed as methods for assessing coronary calcium burden, arterial stiffness and atherosclerosis, respectively. Median value of CaSc equaled 11.5 Agatston units (range 0-5502.8 units). Median AoPWV was 10.4 m/s (range 7.56-18.1 m/s), and median CCA-IMT-0.6 mm (range 0.3-1.0 mm). In 16 patients (26.2%) at least one plaque in at least one common carotid artery was found on ultrasound. CaSc correlated with AoPWV (R=0.32, p<0.01) and with CCA-IMT (R=0.35, p<0.005), whereas no association was found between AoPWV and CCA-IMT. AoPWV, but not CaSc nor IMT correlated with blood pressure. The values of CCA-IMT and AoPWV increased together with consecutive Agatston categories (with p<0.001 for differences in AoPWV and p<0.05 for CCA-IMT). Patients with at least one plaque found in at least one CCA and patients with CAD were characterized with significantly higher values of CaSc, IMT and PWV, when compared to plaque-free and CAD- negative subjects, respectively. Association between CaSc and both IMT and PWV may suggest that the mechanism of three assessed vascular pathologies may be based, to some extent, on the process of pathologic calcium-phosphate deposition. Lack of correlation found between PWV and IMT may suggest that aortic stiffness and carotid atherosclerosis may partially differ in their pathologic background and/or are dissociated in time.

The clinical trial of Women On the Move through Activity and Nutrition (WOMAN) study

The Women On the Move through Activity and Nutrition (WOMAN) study is the first randomized clinical trial of nonpharmacological intervention designed to modify lipoproteins, weight loss and exercise among postmenopausal women using noninvasive measures of atherosclerosis as the primary endpoint. The trial was initially designed to test whether intervention as compared to health education would be more effective in slowing progression of subclinical atherosclerosis among women on hormone therapy (HT), estrogen or estrogen+progestin. It was designed and implemented prior to the results of the Women's Health Initiative (WHI). The trial was since modified to include women who had been on HT but went off after the results of the WHI were reported. Eligible women were between the ages of 52-62, had waist circumference>or=80 cm, low density lipoprotein cholesterol between 100-160 mg% and controlled blood pressure. The intervention is low in total and saturated fat, trans fats, higher in fiber and promotes loss of 7-10% of body weight and includes at least 150 min of physical activity per week. The study has recruited 508 women. The primary endpoints are change in extent of carotid intima-media wall thickness as measured by carotid ultrasound, pulse wave velocity as a measure of vascular stiffness and coronary artery calcium using electron beam computed tomography. Body composition is measured by dual-energy X-ray absorptiometry.

The Frequency and Determinants of Calcification in Intracranial Arteries in Chinese Patients Who Underwent Computed Tomography Examinations

BACKGROUND

Intracranial artery calcification is common but the prevalence and determinants are not well established. We aim to describe the prevalence and location of calcification in intracranial arteries according to brain multi-detector-row computed tomography (MDCT) images, and to investigate its correlation with potential risk factors.

METHODS

We studied consecutive men and women referred for brain CT in December 2004. All patients received a questionnaire regarding their medical history related to atherosclerosis, including traditional risk factors of atherosclerosis, serum chemistry values and inflammatory markers. All CT examinations were done with a 16-slice MDCT and the severity of intracranial artery calcification was categorized.

RESULTS

Four hundred and ninety patients aged 1.4-101 years (62.92+/-19.04; mean+/-SD) were included in our study. There were 340 patients (69.4%) who had intracranial artery calcification. The highest prevalence of intracranial artery calcification was seen in the internal carotid artery (60%), followed by vertebral artery (20%), middle cerebral artery (5%) and basilar artery (5%). Patients with calcification were significantly older than those without calcification (p<0.001). A significantly higher prevalence of calcification was present among patients with hypertension (p<0.001), diabetes (p<0.001), renal failure (p<0.05), atrial fibrillation (p<0.05), smoking (p<0.05), hyperlipidemia (p<0.001), ischemic heart disease (p<0.05) and ischemic stroke (p<0.001). Mean values of serum phosphate, serum urea and CRP level were also significantly higher in patients with intracranial artery calcification (p<0.05, respectively), and there was a trend that patients with intracranial calcification had a higher white blood cell count (p=0.070). Stepwise multiple logistic regression showed age (RR=2.795 per 10 years), a history of ischemic stroke (RR=3.915), and white blood cell count (RR=1.107) to be independently associated with intracranial artery calcification.

CONCLUSIONS

Calcification of the intracranial arteries is associated with age, history of ischemic stroke and white blood cell count. Further prospective studies to investigate the clinical significance of intracranial artery calcification are needed.

Non-invasive multislice computed tomography coronary angiography for imaging coronary arteries, stents and bypass grafts

Abstract Multislice computed tomography (MSCT) is evolving rapidly and available data suggest that MSCT coronary angiography may be a reliable and accurate non-invasive imaging modality of coronary arteries. Current generations of MSCT scanners have high sensitivity and specificity for diagnosing native coronary artery disease and coronary bypass graft occlusion. The performance of MSCT in the evaluation of stent patency is still being assessed. In comparison with conventional selective coronary angiography (SCA), MSCT is non-invasive, cheaper and it has the advantages of imaging plaque compositions as well as assessment of luminal patency. Nevertheless, the role of MSCT in the management of coronary artery disease is yet to be fully defined.