Bone mineral density and long-term progression of aortic valve and mitral annular calcification: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND AND AIMS: Bone and mineral metabolism has been implicated in the pathophysiology of cardiac valve calcification. Whether bone demineralization, a common aging-related disorder, promotes calcific valve disease remains uncertain. We tested the hypothesis that low bone mineral density (BMD) is associated with greater incidence/progression of cardiac valve calcification in the Multi-Ethnic Study of Atherosclerosis. METHODS: Using linear mixed-effects models, we related baseline measurement of BMD of the thoracic vertebrae by computed tomography (CT) in 6768 participants to serial CT assessments of aortic valve calcification (AVC) and mitral annular calcification (MAC) obtained over a >10-year period. RESULTS: After multivariable adjustment, lower BMD (per SD decrement) was associated with accelerated increase in AVC over time in women (0.76 [95% CI 0.42,1.09] Agatston -units [AU]/year) and men (1.41 [95% CI 0.48,2.33] AU/year), as well as for MAC in women (3.22 [95% CI 1.16,5.28] AU/year) and men (3.59 [95% CI 2.09,5.09] AU/year). Significant effect modification was observed, with more pronounced BMD-related acceleration of AVC and MAC progression in older or white participants of one or both sexes, as well as by estimated glomerular filtration rate, though the latter differed by sex for AVC and MAC. CONCLUSIONS: In this multi-ethnic cohort, low thoracic BMD was significantly, but modestly, associated with increased AVC and MAC progression. This suggests that altered bone mineral metabolism does not have a major impact on calcific valve disease in the general population, but the possibility of a more meaningful influence in higher-risk individuals with osteoporosis will require further investigation.

Association of Aspirin and Other Nonsteroidal Anti-inflammatory Drugs With Vertebral Trabecular Bone: Data From Multiethnic Study of Atherosclerosis, a Population-Based Multicenter Cohort Study.

OBJECTIVE: The objective of this article was to study the association of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) with bone mineral density (BMD). METHODS: Spine BMD was evaluated in a subset of 2028 participants from the Multiethnic Study of Atherosclerosis cohort who were NSAID users (including aspirin) and underwent both lumbar and thoracic imaging. Multiethnic Study of Atherosclerosis is a prospective cohort study that includes 4 ethnic groups (white, Asian, African American, and Hispanic). Trabecular BMD was evaluated by quantitative computed tomography based on cardiac computed tomography images, which were obtained during coronary calcium scans. The analyses were cross sectional using baseline examination data for exposure and outcomes. RESULTS: After adjustment for potential confounders including age, sex, race, and traditional cardiovascular risk factors, a small association between trabecular BMD and baseline use of COX-2-selective NSAID was observed. COX-2-selective NSAID use was associated with 7.4 mg/cm (95% confidence interval [CI], 1.6-13.3; P = 0. 013) higher trabecular BMD in thoracic spine and 10.6 mg/cm higher at lumbar spine (95% CI, 5.1-16.1; P < 0.001). Among regular aspirin users, there was no association between drug use and trabecular BMD. Considering all spine fractures together, the prevalence ratio of fractures among aspirin users was 1.0 (95% CI, 0.6-1.6) and 1.1 (95% CI, 0.5-2.3) among COX-2-selective NSAID users. CONCLUSIONS: Regular use of aspirin has no significant association with trabecular BMD in either the thoracic or lumbar spine and no association with fracture prevalence. COX-2-selective NSAIDs may have modest positive association with BMD, but the mechanisms were not assessed and the observational study design makes residual confounding a possible alternate explanation. Potential pathological mechanisms warrant further longitudinal exploration.

Left ventricular area on non-contrast cardiac computed tomography as a predictor of incident heart failure - The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: The use of non-contrast cardiac computed tomography measurements to predict heart failure (HF) has not been studied. In the present study we evaluated the prognostic value of left ventricular area adjusted for the body surface area (LVA-BSA) measured by non-contrast cardiac CT to predict incident HF and cardiovascular disease (CVD) events. METHODS: We studied left ventricular dimensions and calculated LVA-BSA in 6781 participants of the MESA study (mean age: was 62 ± 10 years, 53% females; 62% non-white) free from prior HF who underwent non-contrast cardiac CT to evaluate the coronary artery calcium score (CAC) at baseline and were followed up for a median of 10.2 years. RESULTS: During follow up, 237 (3.5%) incident HF and 475 (7.0%) CVD events occurred. After adjustment for clinical variables and CAC, LVA-BSA was significantly associated with incident HF (hazard ratio [HR]: 1.10 per 100 mm2/m2, p < 0.001) and CVD events (HR: 1.07 per 100 mm2/m2, p < 0.001). The area under the ROC curve for the prediction of incident HF improved from 0.787 on a model including only risk factors to 0.798 when CAC was added (p = 0.02), and to 0.816 with the additional inclusion of LVA-BSA (p = 0.007). Similar improvements for the prediction of CVD events were noted. CONCLUSION: In an ethnically diverse population of asymptomatic individuals free from baseline CVD or HF, the left ventricular area measured by non-contrast cardiac CT is a strong predictor of incident HF events beyond traditional risk factors and CAC score.

[Preliminary reports of noninvasive accurate method to measure pulmonary vascular capacity in normal volunteers].

OBJECTIVE: Because the traditional loop of breathing control and regulation effect on blood circulation, there was rare study of pulmonary vein capacity. We need a noninvasive and accurate pulmonary vascular capacity measurement and analysis method. METHODS: Twelve normal volunteers were performed a total lung CT scan, image data analysis processing by computer software, the whole lungs from the apex to the base of lung with 40-50 layers by hand-cut, the connection between adjacent layers automatically by a computer simulation, the full pulmonary vascular (≥ 0.6 mm) were treated by high-accuracy three-dimensional imaging technology after removing the interference, and then calculate the whole lung and pulmonary vascular. RESULTS: The whole lung of the 12 normal volunteers from the apex to the base of lung CT scan image layers was 530 ± 98 (range, 431-841). The total capacity of lung and pulmonary vascular blood was 3705 ± 857 (range, 2398-5383) ml, and the total volume of the pulmonary vascular blood was 125 ± 32 (range, 94-201) ml. The pulmonary vein vascular blood volume was 63 ± 16 (range, 47-100) ml. CONCLUSION: The method of measuring the three-dimensional imaging of pulmonary vascular capacity by analyzing lung CT scan data is available and accurate.

[Normal reference values and predict equations of heart function].

OBJECTIVE: For heart functional parameters, we commonly used normal range. The reference values and predict formulas of heart functional parameters and their relationships with individual characteristics are still lack. METHODS: Left ventricular (LV) volumes (end-diastolic volume and end-systolic volume), stroke volume (SV), ejection fraction (EF) and cardiac output (CO) were measured by cardiac CT angiography (CAT) in 1 200 healthy Caucasian volunteers, men 807 and women 393, and age 20-90yr. The results are analyzed by high-accuracy three-dimensional imaging technology, and then measured the dynamic changes of the volumes of each atriam and ventricule during their contractions and relaxations. The gender, age, height and weight were analyzed by multiple linear regression to predict LV functional parameters. RESULTS: Except the LVEF was lower in man than in women (P < 0.001), all other LV functional parameters of EDV, ESV, SV, FE and CO were higher in man (P < 0.001). Multiple linear regression indicated that age, gender, height and weight are all independent factors of EDV, ESV and SV (P < 0.001). CO could be significantly predicted by age, gender and weight (P < 0.001), but not height (P > 0.05). The predict equation for CO (L x min(-1)) = 6.963+0.446 (Male) -0.037 x age (yr) +0.013 x weight (kg). CONCLUSION: Age, gender, height and weight are predictors of heart functions. The reference values and predict equations are important for noninvasive and accurate evaluation of cardiovascular disease and individualized treatment.

[The correlation of the stroke volume with pulmonary venous volume and left atrial volume].

OBJECTIVE: The same person's pulmonary venous blood volume, left atrial volume and stroke volume were measured by lung CT scans and cardiac CT angiography (CTA). Then their relationships were analyzed in order to investigate the mechanism of breathing control. METHODS: As we described before, full pulmonary vascular (-0.6mm) volume was accurately calculated by three-dimensional imaging technology from lung CT scan; left atrial volume and stroke volume of left ventricle were calculated from the CTA data. Then the relationships among them were analyzed for estimation of the lung-artery time. RESULTS: The total volume of lung and pulmonary vascular blood was 3486 ± 783 (2156-4418) ml, and the pulmonary vascular blood volume was 141 ± 20 (105-163) ml. The estimated pulmonary venous volume was 71 ± 10 (52-81) ml. Left atrial volume at the end diastolic was 97 ± 39 (53-165) ml, Stroke volume of left ventricle was 86 ± 16 (60-106) ml. Pulmonary venous volume and the left atrial volume were double of stroke volume(1.7-2.4). CONCLUSION: The estimated lung-artery time was three heart beat.

Sex-specific biatrial volumetric measurements obtained with use of multidetector computed tomography in subjects with and without coronary artery disease.

Atrial volumetric measurement has proven clinical implications. Advances in cardiac imaging, notably the precision enabled by multidetector computed tomography (MDCT), herald the need for new criteria of what constitutes normal volumetric measurements. With use of 64-slice MDCT, we compared the atrial volumes in healthy individuals with those in individuals with coronary artery disease. By means of manual segmentation, we measured biatrial volume in 686 participants who underwent retrospective electrocardiographic-gated MDCT angiographic evaluation. The study population included a control group of 203 persons with no cardiac abnormalities, and a study group of 483 patients with obstructive coronary artery disease. All variables were compared between men and women and between the groups. We found a significant difference in left atrial end-systolic and end-diastolic volumes between men and women in the control group (P <0.05); however, right atrial volumes were similar. In comparison with the entire control group, the coronary artery disease group had significantly higher left atrial volume, significantly lower right atrial stroke volume, and significantly lower biatrial ejection fraction, except for left atrial ejection fraction in men. Right atrial volume and left atrial stroke volume were not significantly different. The results imply that a sex-specific reference value is necessary for left atrial volumetric evaluation, and that left atrial volume and biatrial ejection fraction (excluding left atrial ejection fraction in men) might be useful during diagnosis and prognosis in patients who have coronary artery disease.

Relation of thoracic aortic distensibility to left ventricular area (from the Multi-Ethnic Study of Atherosclerosis [MESA]).

Decreased arterial compliance is an early manifestation of adverse structural and functional changes within the vessel wall. Its correlation with left ventricular (LV) area on computed tomography, a marker of LV remodeling, has not been well demonstrated. The aim of this study was to test the hypothesis that decreasing aortic compliance and increasing arterial stiffness are independently associated with increased LV area. The study population consisted of 3,540 patients (mean age 61 ± 10 years, 46% men) from the Multi-Ethnic Study of Atherosclerosis (MESA) who underwent aortic distensibility (AD) assessment on magnetic resonance imaging and LV area measurement on computed tomography (adjusted to body surface area). Multivariate logistic regression was performed to assess the association between body surface area-normalized LV area >75th percentile and AD after adjusting for baseline clinical, historical, and imaging covariates. Mean LV area index was 2,153 cm(2), and mean AD was 1.84 × 10(3) mm Hg(-1). Subjects in the lowest AD quartile were older, with higher prevalence rates of hypertension, diabetes, and hypercholesterolemia (p <0.05 for all comparisons). Using multivariate linear regression adjusting for demographics, traditional risk factors, coronary artery calcium, and C-reactive protein, each SD decrease was associated with an 18-cm(2) increase in LV area. In addition, decreasing AD quartiles were independently associated with increasing LV area index, defined as >75th percentile. In conclusion, in this multiethnic cohort, reduced AD was associated with increased LV area. Longitudinal studies are needed to determine if decreased distensibility precedes and directly influences increased LV area.

Physical activity, hormone replacement therapy, and the presence of coronary calcium in midlife women.

BACKGROUND: Atherosclerotic calcification is a risk factor for cardiovascular events, independent of other traditional risk factors. Studies of the relation of menopausal hormone therapy to cardiovascular events have had inconsistent results, and often have been confounded by lifestyle behaviors and the "healthy user" effect. The authors evaluated the cross-sectional association of hormone therapy use with the presence and severity of atherosclerosis in postmenopausal women, independent of lifestyle factors, including diet and physical activity levels. METHODS: The authors consecutively enrolled postmenopausal asymptomatic women who were referred for coronary artery calcium scanning to measure cardiovascular risk. After consent was obtained, women were interviewed prior to their cardiac scan about cardiac risk factors, hormone therapy use, menopausal status, diet, and physical activity. Coronary artery calcium prevalence was defined as any calcification present (score >0). RESULTS: Of the 544 enrolled women aged 50-80 years, 252 (46.3%) were hormone therapy users. Hormone therapy users had a significantly lower prevalence of any coronary artery calcium (defined as coronary artery calcium score >0; 37%), than non-users (50%, p = 0.04), as well as significantly lower mean calcium scores (p = 0.02). Multiple logistic regression models demonstrated a significantly reduced odds of coronary artery calcium in hormone therapy users compared to non-users with an adjusted odds ratio of 0.58 (p = 0.04), adjusting for traditional cardiac risk factors and body mass index. Women who reported consuming a vegetarian or a high-protein diet had almost two-fold odds of coronary artery calcium compared with women who reported regular, mixed, or low-fat, low-salt diets (OR = 1.78, p = 0.02). Severity of coronary artery calcium was less with increasing levels of physical activity, and a significant association was observed between physical activity and hormone therapy use (adjusted OR = 4.05, p = 0.03), independent of coronary artery calcium severity. CONCLUSION: This cross-sectional study demonstrated a protective association of hormone therapy with the presence and severity of coronary artery calcium. Although a strong relationship was observed between hormone therapy and physical activity, their complex interplay may affect mechanistic biochemical and physiological processes that have yet to be clearly delineated. Thus, physical activity and diet should be taken into account in prospective studies of the relation of hormone therapy use to coronary artery calcium.

Myocardial hypo-enhancement on resting computed tomography angiography images accurately identifies myocardial hypoperfusion.

OBJECTIVE: The objective of this study was to test the diagnostic accuracy of myocardial CT perfusion (CTP) imaging using color and gray-scale image analysis. BACKGROUND: Current myocardial CTP techniques have varying diagnostic accuracy and are prone to artifacts that impair detection. This study evaluated the diagnostic accuracy of color and/or gray-scale CTP and the application of artifact criteria to detect hypoperfusion. METHODS: Fifty-nine prospectively enrolled patients with abnormal single-photon emission computed tomography (SPECT) studies were analyzed. True hypoperfusion was defined if SPECT hypoperfusion corresponded to obstructive coronary stenoses on CT angiography (CTA). CTP applied color and gray-scale myocardial perfusion maps to resting CTA images. Criteria for identifying artifacts were also applied during interpretation. RESULTS: Using combined SPECT plus CTA as the diagnostic standard, abnormal myocardial CTP was present in 33 (56%) patients, 19 suggesting infarction and 14 suggesting ischemia. Patient-level color and gray-scale myocardial CTP sensitivity to detect infarction was 90%, with specificity 80%, and negative and positive predictive value of 94% and 68%. To detect ischemia or infarction, CTP specificity and positive predictive value were 92% whereas sensitivity was 70%. Gray-scale myocardial CTP had slightly lower specificity but similar sensitivity. Myocardial CTP artifacts were present in 88% of studies and were identified using our criteria. CONCLUSIONS: Color and gray-scale myocardial CTP using resting CTA images identified myocardial infarction with high sensitivity as well as infarction or ischemia with high specificity and positive predictive value without additional testing or radiation. Color and gray-scale CTP had slightly better specificity than gray-scale alone.

Measurement of thoracic bone mineral density with quantitative CT.

PURPOSE: To create standard thoracic bone mineral density (BMD) values for patients undergoing cardiac computed tomography (CT) by using thoracic quantitative CT and to compare these BMDs (in a subpopulation) with those obtained by using lumbar spine quantitative CT. MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant study. A total of 9585 asymptomatic subjects (mean age, 56 years; age range, 30-90 years) who underwent coronary artery calcium scanning, including 4131 women, were examined. Patients with vertebral deformities or fractures were excluded. Six hundred forty-four subjects (322 of whom were female) also underwent lumbar quantitative CT. The mean thoracic vertebral BMDs for both sexes were reported separately in a subgroup of subjects aged 30 years and in 29 age-based subgroups in 2-year intervals from ages 30 to 90 years. The formulas used to calculate the female T score (T(f)) and the male T score (T(m)) on the basis of thoracic quantitative CT measurements were as follows: T(f) = (BMD(im) - 222)/36, and T(m) = (BMD(im) - 215)/33, where BMD(im) is the individual mean BMD. Comparisons between thoracic quantitative CT and lumbar quantitative CT measurements, as well as analyses of intraobserver, interobserver, and interscan variability, were performed. RESULTS: The young-subgroup mean BMD was 221.9 mg/mL ± 36.2 (standard deviation) for the female subjects and 215.2 mg/mL ± 33.2 for the male subjects. The mean thoracic BMDs for the female and male subjects were found to be 20.7% higher and 17.0% higher, respectively, than the values measured with lumbar quantitative CT (P < .001 for both comparisons). A significant positive association between the thoracic and lumbar quantitative CT measurements (r > 0.85, P < .001) was found. Intraobserver, interobserver, and interscan variabilities in thoracic quantitative CT measurements were 2.5%, 2.6%, and 2.8%, respectively. CONCLUSION: There was a significant association between the mean thoracic and lumbar BMDs. Therefore, standard derived measurements (young-subgroup BMD ± standard deviation) based on these data can be used with thoracic CT images to estimate the bone mineral status.

Coronary artery calcium and plaque association with left ventricular mass, assessed by multi-row detector computed tomography.

INTRODUCTION: Few studies have been published describing the association of coronary plaques and coronary artery calcium (CAC) to left ventricular (LV) mass and LV function using multi-detector computed tomography (MDCT). Coronary plaques can potentially influence the LV function. We sought to evaluate LV mass and function on MDCT and its correlation with CAC and plaque burden in the coronary arteries. METHODS: We included 197 symptomatic patients from the multicenter ACCURACY Study. The LV mass was measured manually using Advantage 4.4 workstation. Interobserver variability of LV mass was assessed using 34 randomly selected studies. LV mass was indexed to the body surface area. The coronary plaque severity was assessed in each segment using MDCT, following the 15 segment American Heart Association model. Plaque and segment scores were calculated accordingly. Statistical analysis using multiple logistic regression analysis was performed. RESULTS: We divided the cohort into those with CAC=0 [n=67 (34%)] and those with CAC greater than 0 [n=130 (66%)]. A significant correlation was found between indexed LV mass and CAC, plaque, and segment scores in both adjusted and unadjusted models. A significant association was observed between nonindexed LV mass with CAC, MDCT plaque score and segment score upon adjusting for various cardiovascular risk factors. A significant correlation was found between hyperlipidemia, hypertension, family history of CAD, and greater than 50% and greater than 70% stenosis on invasive cardiac catheterization with LV mass (all P<0.05). CONCLUSION: To our knowledge, this is the first study evaluating coronary plaque on computed tomographic angiography with LV mass. We were able to show a significant correlation of LV mass with CAC score, and with total plaque and total segment scores. The poor prognosis associated with increased CAC scores may be partially explained by this association with increased LV mass.

Accuracy in quantification of coronary calcification with CT: a cork-dog heart phantom study.

RATIONALE AND OBJECTIVES: Coronary artery calcium is a sensitive risk predictor of cardiac events. However, measurement of calcium foci is affected by partial-volume effects, which ultimately have an effect on accuracy and reproducibility of calcium scores. In this study, we describe the accuracy of quantification of calcium foci of known size and density using cork-dog heart phantoms. MATERIALS AND METHODS: Five study phantoms were constructed from cork chests and dog hearts containing 135 calcium hydroxyapatite (CaHA) foci of known volume, mass, and concentration located in the coronary arteries or the myocardium. Hearts were separated into two groups: (1) three hearts containing large, high-density foci and (2) two hearts containing small, low-density foci. The phantoms were scanned using a standard coronary artery calcium (CAC) protocol and the volume and mean intensity of foci were measured. RESULTS: In group 1, the total volume of 87 CaHA foci measured was 4284 and 3779 mm(3) with electron beam computed tomography (EBCT); multidetector computed tomography (MDCT), respectively (P < .001). Both were significantly larger than the true volume (2713.9 mm(3), P < .001). In Group 2, the total volume of 57 CaHA foci measured was 592.6 and 702.9 mm(3) with EBT and MDCT, respectively (P < .001). Both were significantly smaller than the true volume (1733.2 mm(3), P < .001). We found that EBCT values for volume were approximately generally higher than MDCT values, but strongly correlated (r = 0.95, P < .0001). Agatston scores were found to be nearly equivalent between EBCT and MDCT and were similarly strongly correlated (r = 0.97, P < .0001). CONCLUSIONS: Computed tomography images overestimate the volume of large, dense CaHA foci while underestimating the volume of smaller (<6.6 mm(3)), less dense foci. This may have significant implications on CAC scoring and volume measurement. EBCT overestimated calcium more than MDCT, most likely from increased image noise.

Prospective randomized trial of venous cardiac computed tomographic angiography for facilitation of cardiac resynchronization therapy.

BACKGROUND: Cardiovascular computed tomographic angiography (CTA) can visualize the coronary veins. We sought to assess the ability of CTA to facilitate resynchronization therapy (CRT) procedures using a prospective randomized single-center pilot study. METHODS: Patients underwent CTA for characterization of cardiomyopathy prior to biventricular implantable cardiac-defibrillator implant. Randomization was performed with operator review of the CTA for coronary venous anatomy prior to CRT in one-half of the cases. Invasive coronary venous angiograms were used in all procedures. Analysis included procedure times and utilization of contrast, fluoroscopy, and guide catheters. RESULTS: Characteristics of the 26 patients enrolled were mean age 55 ± 11 years, male 76.9%, ischemic etiology 35%, ejection fraction 25 ± 3%, class III congestive heart failure 100%, and QRS duration 179 ± 29 ms. Of patients enrolled, 22 had both CTA and procedure initiation. Three patients (two with CTA review and one without CTA review) had aborted procedures due to hemodynamic issues. Analysis of the 22 patients (nine with preprocedure CTA review and 13 without CTA review) demonstrated that preprocedure review of CTA coronary venous anatomy led to significantly decreased procedure times and utilization of contrast, fluoroscopy, and guide catheters. CONCLUSIONS: Preprocedure review of CTA coronary venous anatomy may lead to decreased procedural times and utilization of contrast, fluoroscopy, and guide catheters. These preliminary results will need to be evaluated in larger heart failure populations undergoing CRT.

Comparison of left ventricular size by computed tomography with magnetic resonance imaging measures of left ventricle mass and volumes: the multi-ethnic study of atherosclerosis.

BACKGROUND: A non-contrast-enhanced cardiac computed tomography (NCE-CCT) scan for assessing coronary artery calcification (CAC) is being increasingly used for assessing underlying burden of atherosclerosis. Although many studies document the potential value of measuring CAC, little is known about the other measures such as left ventricular (LV) geometry that can be obtained from the same scan data. OBJECTIVES: We sought to evaluate the accuracy of noncontrast CT-derived LV size (LVS; sum of LV volume and mass) compared with magnetic resonance imaging (MRI)-derived measures as the clinical reference standard. METHODS: Participants (n = 5004) in the Multi-Ethnic Study of Atherosclerosis (MESA) who underwent cardiac MRI studies from August 2000 to September 2002 were included. CT-derived LVS was defined as the sum of LV mass and LV intracavitary volume. The calculated LVS was taken from a measurement of a single slice from noncontrast images. Multivariate analysis adjusting for demographics was used to identify predictors of the relation between CT LVS and MRI LVS, and Bland-Altman analysis was performed comparing MRI-derived measures with CT-derived measure of LVS. RESULTS: The mean CT LVS was 187.8 +/- 56.8 mL (range, 33.6-486.4 mL). The correlation was 0.73 (P = 0.01) for MRI-derived LV volume and 0.74 (P = 0.01) for MRI-derived LV mass. The correlation between CT LVS and MRI-derived LV end-diastolic total volume (mass + volume) was 0.79. CONCLUSION: A single NCE-CT scan used to detect and quantify coronary calcification can also estimate LVS with reasonable accuracy compared with MRI. This provides a new method to study ventricular size in epidemiologic studies and potentially provide additional information for clinical screening of cardiac risk.

Inflammation and descending thoracic aortic calcification as detected by computed tomography: the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Inflammation is related to many stages of atherosclerosis, and inflammatory markers have been associated with both atherosclerosis and future cardiovascular events. Descending thoracic aortic calcification (DTAC) is a manifestation of atherosclerosis, however, no previous study has examined the relationship of inflammatory markers and DTAC as detected by computed tomography (CT) in a large study. We examined whether C-reactive protein (CRP) and interleukin-6 (IL-6) are independently associated with DTAC. METHODS: The Multi-Ethnic Study of Atherosclerosis (MESA) is a prospective cohort study that includes 6814 women and men ages 45-84 years old, all free of baseline cardiovascular disease. The inflammation markers CRP and IL-6, and DTAC by CT, quantified by Agatston score, were measured at baseline in all participants. RESULTS: We studied 6613 participants with complete data (3112 men, 3501 women, mean age 62+/-10 years). The prevalence of DTAC was 27%. Participants with DTAC had significantly higher levels of both CRP and IL-6. After adjustment for baseline risk factors, CRP was not correlated with presence or severity of DTAC (Adjusted RR per S.D., 1.01; 95% confidence intervals 0.97; 1.05) while IL-6 associations remained significant (adjusted RR per S.D., 1.07; 95% confidence intervals 1.02; 1.14). CONCLUSIONS: IL-6, a systemic inflammatory marker, is related to the presence and extent of DTAC. Further studies are needed to evaluate the interaction between DTAC and inflammation markers as predictors of future cardiovascular events.

Comparison of three generations of electron beam tomography on image noise and reproducibility, a phantom study.

UNLABELLED: The detection of coronary artery calcification (CAC) using the electron beam tomography (EBT) scanner provides a noninvasive indicator for coronary artery disease (CAD). Physicians interested in preventative medicine also are using this modality to track atherosclerosis over time. Two new iterations of the EBT scanner have been introduced. We sought to evaluate the image quality of each machine to examine whether patients scanned on a previous model would have similar image quality and results to those scanned on the newest scanner. METHODS: This study used the C-150 XP, C300, and the e-Speed EBT scanners in high-resolution volume mode. A cork chest phantom was constructed for use as a human chest. A mixture of calcium phosphate, cornstarch and glue was placed inside the wells to simulate coronary calcium. The foci masses were 3, 5, 7, 10, 15, 20, 40, 60, 80, 100, and 200 mg (calcium mass), which provided the 55 foci of different masses and densities to simulate coronary calcium in the chest phantom. Each phantom was scanned multiple times, using both 1.5- and 3-mm slice thickness and table collimation settings with each scanner. RESULTS: There were no statistical differences found between the 1.5-mm and 3.0-mm slice thickness calcium foci scores (Agatston & volumetric) for all 3 EBT scanners. The C-150 XP scanner had a variability of 6.01% between 1.5-mm and 3.0-mm slice thickness. Analysis by t test revealed that the mean noise value of C-150 XP was significantly higher than the C300, e-Speed (50 milliseconds), and e-Speed (100 milliseconds) with P values of 0.001, 0.025, and 0.001, respectively. Comparison of 1.5-mm versus 3.0-mm slice thickness noise value showed a significant difference only for the C-150 XP scanner (P < 0.05). CONCLUSIONS: The use of the 3 EBT scanners in longitudinal studies of patients coronary calcium score is feasible to obtain similar calcium score values. The C-150 XP has the greatest noise effect in comparison to the C300 and e-Speed scanners. Improved image noise should improve reproducibility of the calcium measurement with these newer devices.

Multiphase contrast medium injection for optimization of computed tomographic coronary angiography.

RATIONALE AND OBJECTIVES: Electron beam angiography is a minimally invasive imaging technique. Adequate vascular opacification throughout the study remains a critical issue for image quality. We hypothesized that vascular image opacification and uniformity of vascular enhancement between slices can be improved using multiphase contrast medium injection protocols. MATERIALS AND METHODS: We enrolled 244 consecutive patients who were randomized to three different injection protocols: single-phase contrast medium injection (Group 1), dual-phase contrast medium injection with each phase at a different injection rate (Group 2), and a three-phase injection with two phases of contrast medium injection followed by a saline injection phase (Group 3). Parameters measured were aortic opacification based on Hounsfield units and uniformity of aortic enhancement at predetermined slices (locations from top [level 1] to base [level 60]). RESULTS: In Group 1, contrast opacification differed across seven predetermined locations (scan levels: 1st versus 60th, P < .05), demonstrating significant nonuniformity. In Group 2, there was more uniform vascular enhancement, with no significant differences between the first 50 slices (P > .05). In Group 3, there was greater uniformity of vascular enhancement and higher mean Hounsfield units value across all 60 images, from the aortic root to the base of the heart (P < .05). CONCLUSIONS: The three-phase injection protocol improved vascular opacification at the base of the heart, as well as uniformity of arterial enhancement throughout the study.

Reproducibility of CT measurements of aortic valve calcification, mitral annulus calcification, and aortic wall calcification in the multi-ethnic study of atherosclerosis.

RATIONALE AND OBJECTIVES: Extracoronary calcifications may have clinical significance. The error in extracoronary calcification measurements is still unknown. Accurate quantification of calcifications of the aortic valve (AVC), mitral annulus (MAC), and aortic wall (AWC) may be possible by using cardiac computed tomography (CT). We sought to establish the interscan, interobserver, and intraobserver reproducibility of these measures in all cardiac CT scans in the Multi-Ethnic Study of Atherosclerosis. MATERIALS AND METHODS: We measured extracoronary calcifications in 100 randomly selected participants to assess interobserver, interscan, and intraobserver variability. Two scans were available for analysis in 99 of these participants, and we quantified thoracic aorta and valvular calcifications. RESULTS: Mean interscan variability of AVC was 9.7% +/- 11.4% and 8% +/- 10.3% for Agatston and volume scores, with variability of the median at 6.4% and 5.5%, respectively (P > .05). MAC inter-reader variability was 8.2% and 8.9%, with interscan variability of 28% and 33% and intrareader variability of 4% and 4.1%, respectively. For AWC, inter-reader variability was 3%-7.1%, interscan variability was 17%-18%, and intrareader variability was 0.4%-1.4%. CONCLUSION: AVC, MAC, and AWC measurements are sufficiently reproducible to allow serial investigations over a time suitable for clinical studies.

Ethnic differences of the presence and severity of coronary atherosclerosis.

BACKGROUND: Although cardiovascular risk factor levels are substantially different in Caucasians, African-American, Hispanics, and Asians, the relative rates of coronary heart disease in these groups are not consistent with these differences. The objective of the study is to assess the differences in the prevalence and severity of coronary artery calcification, as a measure of atherosclerosis, in these different ethnic groups. METHODS: Electron-beam tomography was performed in 16,560 asymptomatic men and women (Asians=1336, African-Americans=610, Hispanics=1256) aged >or=35 years referred by their physician for cardiovascular risk evaluation. The study population encompassed 70% males, aged 52+/-8 years. RESULTS: Caucasians were more likely to present with dyslipidemia (p<0.0001), while African-Americans and Hispanics had a higher prevalence of smoking, diabetes, and hypertension (all p<0.001). After adjustment for age, gender, risk factors, and treatment for hypercholesterolemia, compared with Caucasians, the relative risks for men having coronary calcification were 0.64 (95% CI: 0.48-0.86) in African-Americans, 0.88 (95% CI: 0.67-1.15) in Hispanics, and 0.66 (95% CI: 0.55-0.80) in Asians. After similar adjustments, the relative risks for women having coronary calcification, were 1.58 (95% CI: 1.13-2.19) for African-Americans, 0.84 (95% CI: 0.66-1.06) in Hispanics, and 0.71 (95% CI: 0.56-0.89) in Asian women. After adjusting for age and risk factors using multivariable analysis, African-American men were least likely to have any coronary calcium while African-American women had significantly higher OR of any calcification. Asian men and women had significantly lower OR of any calcification. There was no significant difference in prevalence or severity of atherosclerosis between Hispanics and Caucasians, in men or women. CONCLUSIONS: Our study results demonstrate significant difference in the presence as well as severity of calcification according to ethnicity, independent of atherosclerotic risk factors. Results from this study (physician referred) closely parallel the results from MESA (population based, measured risk factors). Ethnic specific data on the predictive value of differing coronary calcium scores are needed.