Ethnic differences in the prognostic value of coronary artery calcification for all-cause mortality.

OBJECTIVES: The purpose of this study was to evaluate the prognostic value of coronary artery calcium (CAC), a known marker of subclinical atherosclerosis, in a large, ethnically diverse cohort of 14,812 patients for the prediction of all-cause mortality. BACKGROUND: Disparities in case fatality rates for heart disease among ethnic groups are well known. In 2001, rates of death from heart disease were 30% higher among African Americans (AA) than non-Hispanic whites (NHW). Some of this variability may be due to differing pathophysiological mechanisms and effects of underlying atherosclerosis. METHODS: Ten-year death rates from all causes (total deaths = 505) were compared using risk-adjusted Cox proportional hazards models in AA (n = 637), Hispanic (HS, n = 1,334), Asian (AS, n = 1,065), and NHW (n = 11,776) populations. RESULTS: Ethnic minority patients were generally younger (0.3 to 4 years), more often persons with diabetes (p < 0.0001), hypertensive (p < 0.0001), and female (p < 0.0001). The prevalence of CAC scores > or =100 was highest in NHW (31%) and lowest for HS (18%) (p < 0.0001). Overall survival was 96%, 93%, and 92% for AS, NHW, and HS, respectively, as compared with 83% for AA (p < 0.0001). When comparing prognosis by CAC scores in ethnic minorities as compared with NHW, relative risk ratios were highest for AA with CAC scores > or =400 exceeding 16.1 (p < 0.0001). Hispanics with CAC scores > or =400 had relative risk ratios from 7.9 to 9.0, whereas AS with CAC scores > or =1,000 had relative risk ratios 6.6-fold higher than NHW (p < 0.0001). CONCLUSIONS: Consistent with population evidence, AA with increasing burden of subclinical coronary artery disease were the highest-risk ethnic minority population. These data support a growing body of evidence noting substantial differences in cardiovascular risk by ethnicity.     

Ethnic differences in coronary artery calcium in a healthy cohort aged 60 to 69 years

Measurement of coronary artery calcium (CAC) has been proposed as a screening tool, but CAC levels may differ according to race and gender. Racial/ethnic and gender distributions of CAC were examined in a randomly selected cohort of 60- to 69-year-old healthy subjects. Demographic, race/ethnicity (R/E), and clinical characteristics and assessment of CAC were collected. There were 723 white/European, 105 African-American, 73 Hispanic, and 67 East Asian subjects (597 men, 369 women) included in this analysis. Men had a significantly higher prevalence of any CAC (score>10) than women (76% vs 41%; p<0.0001). For men, the unadjusted odds of having any CAC was 2.2 (95% confidence interval [CI] 1.3 to 3.8) for whites compared with African-Americans. For women, CAC scores were not significantly different across ethnic groups. After adjustment for coronary risk factors, African-American and East Asian R/E remained associated with a lower prevalence of CAC in men (adjusted odds ratios [ORs] 0.33 and 0.47, respectively), as well as older age (OR 1.2, 95% CI 1.1 to 1.3), known hyperlipidemia (OR 1.7, 95% CI 1.1 to 2.7), and history of hypertension (OR 2.2, 95% CI 1.4 to 3.3). In women, Asian R/E (OR 2.5, 95% CI 1.1 to 5.7), history of smoking (adjusted OR 2.8, 95% CI 1.3 to 6.1), and known hyperlipidemia (adjusted OR 2.0, 95% CI 1.3 to 3.1) were associated with a higher prevalence of CAC independent of other risk factors. In conclusion, our data indicate that the presence of CAC varied significantly across selected race/ethnic groups independent of traditional cardiovascular risk factors.     

Coronary artery calcium evaluation by electron beam computed tomography and its relation to new cardiovascular events

Electron beam computed tomography is widely used to screen for coronary artery calcium (CAC). We evaluated the relation of CAC to future cardiovascular disease events in 926 asymptomatic persons (735 men and 191 women, mean age 54 years) who underwent a baseline electron beam computed tomographic scan. All subjects included in this report returned a follow-up questionnaire 2 to 4 years (mean 3.3) after scanning, inquiring about myocardial infarction, stroke, and revascularizations. Sixty percent of men and 40% of women had a positive scan at baseline. Twenty-eight cardiovascular events occurred and were confirmed by blinded medical record review. The presence of CAC (a total calcium score of >0) and increasing score quartiles were related to the occurrence of new myocardial infarction (p <0.05), revascularizations (p <0.001), and total cardiovascular events (p <0.001). Those with scores at or above the median (score of 5) had a relative risk of 4.5 (p <0.01) for new events. From Cox regression models, adjusted for age, gender, and coronary risk factors, the relative risks for those with scores of 81 to 270 and -271 (compared with 0) for cardiovascular events were 4.5 (p <0.05) and 8.8 (p <0.001), respectively. These data support previous reports showing CAC to be a modest predictor of future cardiovascular events.     

Racial differences in coronary artery calcification in older adults

Reports on race-related differences in coronary artery calcium (CAC) are just beginning to emerge and have not been well studied in the elderly. This study was undertaken to assess whether such differences exist and the relationship between CAC and cardiovascular risk factors in a cohort of elderly community-dwelling adults. CAC was measured by using electron-beam tomography in 614 adults (aged 67 to 99 years), of whom 59% were women and 23% were black. The median CAC score was lower in blacks than in whites for men (159 versus 787, respectively; P<0.001) and for women (134 versus 233, respectively; P=0.02) after adjustment for age, cardiovascular disease, and risk factors for cardiovascular disease, although this difference was stronger and remained significant among men only. Lower CAC scores were also observed in the subgroup of blacks with a history of myocardial infarction. The lower CAC scores in blacks compared with whites observed in this study is consistent with either a lower prevalence of coronary artery disease or a lower extent of calcification of coronary artery disease.     

Comparison of prognostic usefulness of coronary artery calcium in men versus women (results from a meta- and pooled analysis estimating all-cause mortality and coronary heart disease death or myocardial infarction)

Women with coronary heart disease (CHD) have higher mortality compared with men. Atherosclerotic imaging risk markers are associated with higher mortality and relative risk of CHD events in women compared with men. However, data on the predictive accuracy of coronary artery calcium (CAC) in women are scarce. We performed a systematic review of the published literature from 2003 to 2006 on the prognostic value of CAC in women and men. Two investigators reviewed Medline for prospective registries on annual rates of CHD death or myocardial infarction (MI) by CAC results. Three studies in 6,481 women and 13,697 men reported results by gender. We also analyzed 2 observational registries for annual all-cause death rates by CAC scores in women (n = 17,779) and men (n = 17,850). Summary relative risk ratios and 95% confidence intervals were calculated using a random effects model. For all-cause mortality, rates were 0.1% to 1.6% per year for women and 0.1% to 2.6% for men with CAC scores from 0 to 10 to > or =1,000, respectively (p <0.0001). For CHD death or MI, annual rates were 0.2% to 1.3% in women and 0.3% to 2.4% for men with low- to high-risk CAC scores. For women with a CAC score of 0, annual CHD death or MI rates were 0.16%, similar to that of men (p = 0.55). Summary relative risk ratios increased 4.9-fold (p = 0.006), 5.5-fold (p = 0.002), and 8.7-fold (p <0.0001) for mild-, moderate-, and high-risk CAC scores, respectively. A comparative analysis of gender differences showed no significant differences between women and men for mild- to high-risk CAC scores (p = 0.66), suggesting an equivalent ability to risk stratify by gender. In conclusion, this meta- and pooled analysis revealed that CAC screening is equally accurate in stratifying risk in women and men.     

Relation of mitral annular calcium and coronary calcium (from the Multi-Ethnic Study of Atherosclerosis [MESA])

Atherosclerosis is a complex diffuse disorder. The close correlation between coronary artery calcium (CAC) score on computed tomogram and extent and severity of coronary atherosclerosis is well established. It has been suggested that mitral annular calcification (MAC) may be a manifestation of generalized atherosclerosis. The MESA population included a population-based sample of 4 ethnic groups (12% Chinese, 38% white, 22% Hispanic, and 28% black) of 6,814 women and men 45 to 84 years of age. Computed tomographic scans were performed for all participants. The calcium score of each lesion was calculated by multiplying lesion area by a density factor derived from maximal Hounsfield units. A total calcium score was determined by summing individual lesion scores at each anatomic site. Relative risk regression was used to model the probability of MAC as a function of CAC >0 and CAC categories (0, 1 to 99, 100 to 399, and ≥400) with the referent group being CAC 0. The final study population consisted of 6,814 subjects (mean age 62 ± 10 years, 47% men). Overall 9% and 50% had detectable MAC and CAC, respectively. Of those with absent CAC, only 4% had MAC, whereas 9%, 19%, and 15% had MAC scores with increasing CAC scores of 1 to 99, 100 to 399, and ≥400, respectively (p<0.0001 for trend). After taking into account demographics and other risk factors, the prevalence ratio of MAC in those with mild CAC (1 to 99) was 2.13 (95% confidence interval 1.69 to 2.69) and increased to 7.57 (95% confidence interval 5.95 to 9.62) for CAC ≥400. Similar statistically significant increased risk of MAC was found when CAC was assessed as a continuous variable. In conclusion, we observed a strong association between MAC and increasing burden of CAC. This association weakened but persisted after adjustment for age, gender, and other traditional cardiovascular risk factors. These findings suggest that presence of MAC is an indicator of atherosclerotic burden rather than just a degenerative change of the mitral valve.     

Defining normal distributions of coronary artery calcium in women and men (from the Framingham Heart Study)

Coronary artery calcium (CAC) may improve risk stratification for patients with coronary heart disease (CHD) beyond traditional risk factors. Subjects from the Framingham Heart Study Offspring and Third Generation cohorts (48% women; mean age 53 years) underwent noncontrast electrocardiographically triggered cardiac multidetector computed tomography. The prevalence of absolute CAC (Agatston score [AS] >0, >100, and >400) and relative age- and gender-specific strata (25th, 50th, 75th, 90th, and 95th percentiles) were determined in a healthy subset free of clinically apparent cardiovascular disease or CHD risk factors (n = 1,586), the overall sample at risk (n = 3,238), and subjects at intermediate Framingham risk score (FRS; 6% to 20% 10-year CHD event risk; n = 1,177). Absolute AS and relative cutoffs for CAC increased with age and FRS, were higher in men compared with women in each of the 3 cohorts, and increased from the healthy subset to the overall cohort to subjects at intermediate risk. However, in subjects with CAC, there was substantial disagreement between absolute and relative cut-off values for labeling subjects as having increased CAC. In general, more subjects were considered to have increased CAC using relative cut-off values, especially in women and younger subjects. Fewer subjects at intermediate FRS had increased CAC using comparable absolute versus relative cutoffs (men 32% at AS >100 vs 36% at >75th percentile; women 24% at AS >100 vs 34% at >75th percentile). In conclusion, we provided distributions of CAC in a healthy subset, the overall cohort, and subjects at intermediate risk from the Framingham Heart Study for both absolute and relative cut-off values for CAC. Absolute cutoffs underestimated the proportion of subjects with increased CAC, specifically in women, younger persons, and persons at intermediate CHD risk.     

Comparing coronary artery calcium among U.S. South Asians with four racial/ethnic groups: The MASALA and MESA studies

Objectives

South Asians (individuals from India, Pakistan, Bangladesh, Nepal, and Sri Lanka) have high rates of cardiovascular disease which cannot be explained by traditional risk factors. Few studies have examined coronary artery calcium (CAC) in South Asians.

Methods

We created a community-based cohort of South Asians in the United States and compared the prevalence and distribution of CAC to four racial/ethnic groups in the Multi-Ethnic Study of Atherosclerosis (MESA). We compared 803 asymptomatic South Asians free of cardiovascular disease to the four MESA racial/ethnic groups (2622 Whites, 1893 African Americans, 1496 Latinos and 803 Chinese Americans).

Results

The age-adjusted prevalence of any CAC was similar between White and South Asian men, but was lower in South Asian women compared to White women. After adjusting for all covariates associated with CAC, South Asian men were similar to White men and had higher CAC scores compared to African Americans, Latinos and Chinese Americans. In fully adjusted models, CAC scores were similar for South Asian women compared to all women enrolled in MESA. However, South Asian women ≥70 years had a higher prevalence of any CAC than most other racial/ethnic groups.

Conclusions

South Asian men have similarly high CAC burden as White men, but higher CAC than other racial/ethnic groups. South Asian women appear to have similar CAC burden compared to other women, but have somewhat higher CAC burden in older age. The high burden of subclinical coronary atherosclerosis in South Asians may partly explain higher rates of cardiovascular disease in South Asians.     

Low-density lipoprotein subfractions and cardiovascular risk in hypertension: relationship to endothelial dysfunction and effects of treatment

Although hypertensive patients are at particular risk of vascular complications, the possible contribution of an atherogenic lipoprotein profile and endothelial dysfunction to this risk is unclear. We investigated this by measuring LDL subfractions and flow-mediated dilation (FMD) (reflecting endothelial dysfunction) in a cohort of high-risk hypertensive patients. We studied 84 hypertensive patients (74 men; mean age, 64 years; SD 8). Chylomicron-free LDL subfractions were analyzed by disc polyacrylamide gel electrophoresis, producing an LDL score, with higher scores being equivalent to a greater proportion of the more atherogenic LDL subfractions. High-resolution ultrasound was used to assess endothelium-dependent brachial artery FMD after reactive hyperemia after vessel occlusion. Baseline levels were compared with 61 age- and gender-matched healthy normotensive control subjects. Mean LDL score was higher and FMD impaired in hypertensive subjects compared with control subjects. These indexes were significantly improved after 6 months of cardiovascular risk factor management. LDL score correlated significantly with the 10-year Framingham coronary heart disease risk score, with a negative correlation with FMD (both P<0.001). Abnormal atherogenesis and endothelial dysfunction are both present in hypertension and appear to be related to each other, potentially leading to vascular complications. The abnormal LDL scores also correlate with the 10-year cardiovascular risk and can be positively influenced by cardiovascular risk management.     

The prevalence and severity of coronary artery calcification on coronary artery computed tomography in black and white subjects

OBJECTIVES: We studied the relationship between coronary artery calcium (CAC) and race in asymptomatic, active-duty personnel in the Prospective Army Coronary Calcium (PACC) project. BACKGROUND: Valid cardiovascular risk assessments in black Americans using coronary artery computed tomography (coronary CT) require the generalizability of population-based CAC score distributions derived from primarily white patient populations. METHODS: Among 1,000 consecutive participants (mean age, 42 +/- 2 years; range, 40 to 45 years), 999 participants underwent coronary CT and indicated a specific racial affiliation. This included white, non-Hispanic in 699 (69.9%) participants and black, non-Hispanic in 194 (19.4%) participants. Univariate associations between race and cardiovascular risk variables were entered into a logistic regression model for CAC that also controlled for socioeconomic status and education. RESULTS: Coronary artery calcium was nearly twice as prevalent in white (19.2%) than in black participants (10.3%) (p = 0.004). Black individuals had a threefold greater prevalence of hypertension, left ventricular hypertrophy, ST-T-wave abnormalities, and current cigarette smoking. Black subjects also had significantly greater blood pressure, high-density lipoprotein cholesterol, glycosylated hemoglobin, lipoprotein(a) and fibrinogen levels, and lower triglyceride levels and waist girth than white subjects. After adjustment for these differences, and socioeconomic adjusters, black individuals were 39% as likely to have any CAC present (odds ratio, 0.39; 95% confidence interval, 0.20 to 0.78; p = 0.007). CONCLUSIONS: Despite a worse cardiovascular risk profile, black Americans have significantly less CAC than white Americans. The use of coronary CT as an accurate risk prediction tool in black Americans will require ethnic-specific data on the presence and severity of CAC.     

Comparison of coronary calcium in firefighters with abnormal stress test findings and in asymptomatic nonfirefighters with abnormal stress test findings

Firefighters are known to have an elevated rate of sudden cardiac death compared to the general population. It is unclear whether this finding is related to underlying cardiovascular risk factors or whether firefighting inherently carries additional risk. Our objective was to determine whether Los Angeles county firefighters have higher coronary artery calcium (CAC) scores and increased atherosclerosis as determined using 64-slice cardiac, multidetector computed tomography. A total of 647 asymptomatic firefighters evaluated as a part of a wellness protocol were referred for cardiac multidetector computed tomography to evaluate abnormal exercise treadmill test findings. They were matched by age and cardiovascular risk factors, with 2,533 asymptomatic subjects undergoing cardiac computed tomography because of abnormal electrocardiographic or exercise treadmill test findings. CAC and the prevalence of obstructive coronary artery disease by vessel were derived. Finally, the predictors of CAC were analyzed using regression analysis. Of the firefighters, 49% had detectable CAC compared to 43% of controls (p = 0.015). Although the lesions were most prevalent in the left anterior descending artery in both groups, more firefighters had any left anterior descending artery stenosis compared to the controls (p <0.0001). The firefighters also had more left main coronary artery lesions than did the controls (p <0.0001). The firefighters had significantly greater CAC scores than did with the controls (p <0.001). Furthermore, the firefighters had significantly greater mean CAC scores (66 ± 8 in firefighters vs 33 ± 4 for controls, p <0.001). Firefighter status was independently associated with a 41-point increase in the CAC score (p <0.001). In conclusion, asymptomatic firefighters had more atherosclerosis and CAC than the matched controls.     

Coronary artery calcification at electron beam computed tomography is increased in asymptomatic type 2 diabetics independent of traditional risk factors

BACKGROUND: The risk of cardiovascular disease (CVD) is two- to fourfold greater in type 2 diabetics than in non-diabetics and cannot be accounted for by traditional risk factors alone. Coronary artery calcification (CAC) at electron beam computed tomography (EBCT) is a non-invasive index of coronary atherosclerosis. We hypothesized that the presence and extent of CAC would be greater in asymptomatic type 2 diabetics than in non-diabetics independent of traditional risk factors. METHODS: We reviewed CAC data of all asymptomatic subjects referred for EBCT between 1996-1999 and compared CAC scores in type 2 diabetics ( n= 71) to all non-diabetics ( n= 1481) and to a randomly selected group of non-diabetics matched for all traditional CVD risk factors ( n= 71). RESULTS: CAC scores were greater in type 2 diabetics (272 +/- 472, median 41) than in all non-diabetics (104 +/- 288, median 4; < 0.01) and matched non-diabetics (188 +/- 354; < 0.05, median 12; < 0.05). The odds ratio (OR) for the presence of CAC (scores > 0) in type 2 diabetics was 2.9 [95% confidence intervals (CI) 1.1-7.8] after adjustment for traditional CVD risk factors. Type 2 diabetes was also associated (adjusted OR 2.15, 95%CI 1.3-3.6) with the extent of CAC when categorized as an ordinal outcome (CAC scores 0, 1-79, 80-399 and > 400). In type 2 diabetics, age, sex and body mass index were associated with extent of CAC. CONCLUSIONS: CAC scores at EBCT are greater in type 2 diabetics than non-diabetic subjects, cannot be accounted for by traditional risk factors alone and may be useful for identifying novel factors for coronary atherosclerosis in type 2 diabetes.     

Prevalence of coronary atherosclerosis in asymptomatic middle-age men with high aerobic fitness

Good aerobic fitness is associated with favorable cardiovascular outcomes. However, it is not well known whether aerobic fitness correlates to the degree of coronary atherosclerosis, which affects cardiovascular prognosis. The aim of the present study was to investigate the relation between aerobic fitness and coronary atherosclerosis. A total of 8,565 apparently healthy men underwent routine health screening, including both cardiopulmonary function testing and coronary calcium scoring. The subjects with clinical cardiovascular disease or abnormal exercise electrocardiographic findings were excluded. A treadmill exercise test was done using the modified Bruce protocol, and the Agatston coronary artery calcium (CAC) score was measured using multidetector computed tomography. Advanced CAC was defined as a score > 75th percentile according to the age group. The mean age was 51 ± 7 years, the average maximum oxygen uptake was 32 ± 5 ml/kg/min, and 34% had a positive CAC score. On univariate analysis, age, blood pressure, lipid profile, body mass index, hemoglobin A1c, fasting glucose, calculated 10-year risk for coronary disease, and maximum oxygen uptake were significantly associated with advanced CAC. In the multiple logistic regression model, the subjects in the highest quartile of the maximum oxygen uptake for age were less likely to have advanced CAC for age compared to those in the lowest quartile (odds ratio 0.60, 95% confidence interval 0.48 to 0.73), with adjustment for age, hypertension, hemoglobin A1c, current smoking, body mass index, and regular exercise habit. In conclusion, greater aerobic fitness was associated with less prevalent advanced coronary atherosclerosis in an asymptomatic male population. The degree of subclinical coronary artery disease might be 1 of the mechanisms connecting aerobic fitness and cardiovascular outcome.     

Age and gender are the strongest clinical correlates of prevalent coronary calcification (R1)

OBJECTIVE: To determine which of the standard cardiovascular risk factors have the strongest associations with prevalent coronary artery calcification (CAC). STUDY DESIGN AND SETTING: A cross-sectional study of 6086 consecutive subjects who underwent electron beam computed tomography for CAC at a private, university-affiliated disease prevention center in San Diego, CA. RESULTS: The correlation between age and coronary calcium score in men (r=0.463) was twice that of the next highest correlation (0.218) for percent body fat. A similar relationship was found for women (0.413 vs. 0.238). Calcium scores increased incrementally by age category in both men and women. This pattern of increase was not present for LDL cholesterol. Men and women over the age of 74 had highly elevated risks for the presence of any calcified coronary atherosclerosis compared to those under the age of 45 (OR [95% CI]: 11.08 [6.186-19.859] and 11.81 [6.718-20.746], respectively). Addition of the other traditional cardiovascular risk factors did not significantly increase the discriminatory power beyond that provided by age on ROC analysis. CONCLUSION: Age and gender are significant independent clinical correlates of coronary calcium beyond that provided by the other risk factors. These results support the hypothesis that age is the predominant risk factor for coronary calcification.     

C-reactive protein is not associated with the presence or extent of calcified subclinical atherosclerosis

BACKGROUND: Both high-sensitivity C-reactive protein (hsCRP) and electron beam computed tomography (EBCT) coronary artery calcification (CAC) are valid markers of cardiovascular risk. It is unknown whether hsCRP is a marker of atherosclerotic burden or whether it reflects a process (eg, inflammatory fibrous cap degradation) leading to acute coronary events. METHODS: A nested case-control study was performed of 188 men enrolled in the Prospective Army Coronary Calcium study. The serum hsCRP levels (latex agglutination assay) were evaluated in subjects with CAC (CAC score >0, n = 94) and compared with age- and smoking status-matched control subjects (CAC score 0, n = 94). RESULTS: Levels of hsCRP in the highest quartile were related to the following coronary risk factors: smoking status, low-density lipoprotein cholesterol, body mass index, glycosylated hemoglobin, fibrinogen, and homocysteine. The mean hsCRP level was similar in cases (+CAC, 0.20 +/- 0.22 mg/dL) and controls (-CAC, 0.19 +/- 0.21 mg/dL; P =.81) and was unrelated to the log-transformed CAC score (r < 0.01, P =.91). Multivariable analysis controlling for standard risk factors, aspirin, and statin therapy found only that low-density lipoprotein cholesterol was related to CAC. CONCLUSIONS: Despite associations with standard and emerging cardiovascular risk factors, hsCRP is unrelated to the presence and extent of calcified subclinical atherosclerosis. This implies that CAC (a disease marker) and hsCRP (a process marker) may be complementary for the prediction of cardiovascular risk.     

Sex Differences in Coronary Artery and Thoracic Aorta Calcification and Their Association With Cardiovascular Mortality in Heavy Smokers

ObjectivesThe aim of this study was to investigate sex differences in the prevalence, extent, and association of coronary artery calcium (CAC) and thoracic aorta calcium (TAC) scores with cardiovascular mortality in a population eligible for lung screening.BackgroundCAC and TAC scores derived from chest computed tomography (CT) might be useful biomarkers for individualized cardiovascular disease prevention and could be especially relevant in high-risk populations such as heavy smokers. Therefore, it is important to know the prevalence of arterial calcifications in male and female heavy smokers, and if there are differences in the predictive value calcifications carry.MethodsWe performed a nested case–control study with 5,718 participants of the CT arm of the NLST (National Lung Screening Trial). Prevalence and extent of CAC and TAC were resampled to the full cohort to provide unbiased estimates of the typical calcium burden of male and female heavy smokers. Weighted Cox proportional hazards regression was used to assess differences in the association of CAC and TAC scores with all-cause and cardiovascular mortality.ResultsCAC was substantially more common and more severe in men (prevalence: 81% vs. 60%; median volume: 104 mm³ vs. 12 mm³). Women had CAC comparable to that of men who were 10 years younger. TAC was equally common in men and women, with a tendency to be more pronounced in women (prevalence: 92% vs. 93%; median volume: 388 mm³ vs. 404 mm³). Both types of calcification were associated with increased cardiovascular and all-cause mortality. TAC scores improved the prediction of coronary heart disease mortality over CAC in men, but not in women. In both sexes, TAC, but not CAC, was associated with cardiovascular mortality other than coronary heart disease.ConclusionsCAC develops later in women, whereas TAC develops equally in both sexes. CAC is strongly associated with coronary heart disease, whereas TAC is especially associated with extracardiac vascular mortality in either sex.     

Alcohol consumption is negatively associated with the prevalence of coronary heart disease in the New Mexico Elder Health Survey

OBJECTIVE: To compare the prevalence of coronary heart disease (CHD) and the effects of various risk factors, including alcohol consumption, on prevalence rates in a randomly selected sample of older Hispanic and non-Hispanic white (NHW) men and women. DESIGN AND SETTING: A cross-sectional study of equal numbers of Hispanic and NHW men and women, selected randomly from Health Care Financing Authority (Medicare) rolls, recruited for a home interview followed by a 4-hour interview/examination in a senior health clinic. PARTICIPANTS: A total of 883 volunteers, mean age 74.1, years were interviewed/examined. MEASUREMENTS: CHD was identified by interview and electrocardiogram. Risk factors were identified by interview (hypertension, diabetes, medications, smoking, alcohol consumption) and by direct measurements (glucose tolerance, serum lipids, blood pressure, anthropometry). RESULTS: The age-adjusted prevalences of CHD were not significantly different when Hispanic men and women were compared with their NHW counterparts. Age-, ethnicity-, and gender-adjusted relative risk of CHD was inversely associated with alcohol consumption (OR .46; 95% CI, .28-.73; P < .001). Hypertension, diabetes mellitus, and male gender were also significant risk factors; age, anthropometric measurements, smoking, serum lipid concentrations, and level of education were not. HDL cholesterol levels were significantly lower in nondrinkers; other lipid levels were not associated with alcohol consumption. The type of alcoholic beverage was not associated with the prevalence of CHD. CONCLUSIONS: No significant differences in CHD prevalence existed between Hispanic and NHW participants despite a higher prevalence of diabetes and central obesity in Hispanics. Alcohol consumption was strongly negatively associated with the prevalence of CHD identified in this older, biethnic population.     

Evidence for an association between metabolic cardiovascular syndrome and coronary and aortic calcification among women with polycystic ovary syndrome

Women with polycystic ovary syndrome (PCOS) exhibit an adverse cardiovascular risk profile, characteristic of the metabolic cardiovascular syndrome (MCS). The aim of this study was to determine the prevalence of coronary artery (CAC) and aortic (AC) calcification among middle-aged PCOS cases and controls and to explore the relationship among calcification, MCS, and other cardiovascular risk factors assessed 9 yr earlier. This was a prospective study of 61 PCOS cases and 85 similarly aged controls screened in 1993-1994 for risk factors and reevaluated in 2001-2002. The main outcome measures were CAC and AC, measured by electron beam tomography. Women with PCOS had a higher prevalence of CAC (45.9% vs. 30.6%) and AC (68.9% vs. 55.3%) than controls. After adjustment for age and body mass index, PCOS was a significant predictor of CAC (odds ratio = 2.31; P = 0.049). PCOS subjects were also 4.4 times more likely to meet the criteria for MCS than controls. High-density lipoprotein cholesterol and insulin appeared to mediate the PCOS influence on CAC. Interestingly, total testosterone was an independent risk factor for AC in all subjects after controlling for PCOS, age, and body mass index (P = 0.034). We conclude that women with PCOS are at increased risk of MCS and demonstrate increased CAC and AC compared with controls. Components of MCS mediate the association between PCOS and CAC, independently of obesity.     

Machine Learning Adds to Clinical and CAC Assessments in Predicting 10-Year CHD and CVD Deaths

ObjectivesThe aim of this study was to evaluate whether machine learning (ML) of noncontrast computed tomographic (CT) and clinical variables improves the prediction of atherosclerotic cardiovascular disease (ASCVD) and coronary heart disease (CHD) deaths compared with coronary artery calcium (CAC) Agatston scoring and clinical data.BackgroundThe CAC score provides a measure of the global burden of coronary atherosclerosis, and its long-term prognostic utility has been consistently shown to have incremental value over clinical risk assessment. However, current approaches fail to integrate all available CT and clinical variables for comprehensive risk assessment.MethodsThe study included data from 66,636 asymptomatic subjects (mean age 54 ± 11 years, 67% men) without established ASCVD undergoing CAC scanning and followed for cardiovascular disease (CVD) and CHD deaths at 10 years. Clinical risk assessment incorporated the ASCVD risk score. For ML, an ensemble boosting approach was used to fit a predictive classifier for outcomes, followed by automated feature selection using information gain ratio. The model-building process incorporated all available clinical and CT data, including the CAC score; the number, volume, and density of CAC plaques; and extracoronary scores; comprising a total of 77 variables. The overall proposed model (ML all) was evaluated using a 10-fold cross-validation framework on the population data and area under the curve (AUC) as metrics. The prediction performance was also compared with 2 traditional scores (ASCVD risk and CAC score) and 2 additional models that were trained using all the clinical data (ML clinical) and CT variables (ML CT).ResultsThe AUC by ML all (0.845) for predicting CVD death was superior compared with those obtained by ASCVD risk alone (0.821), CAC score alone (0.781), and ML CT alone (0.804) (p < 0.001 for all). Similarly, for predicting CHD death, AUC by ML all (0.860) was superior to the other analyses (0.835 for ASCVD risk, 0.816 for CAC, and 0.827 for ML CT; p < 0.001).ConclusionsThe comprehensive ML model was superior to ASCVD risk, CAC score, and an ML model fitted using CT variables alone in the prediction of both CVD and CHD death.     

Determinants of progression of coronary artery calcifications in asymptomatic men at high cardiovascular risk

Extended coronary artery calcifications (CAC) are predictive for cardiovascular complications but little is known about factors likely to influence CAC deposit. An analysis was undertaken to assess the cardiovascular risk factors that are capable of predicting CAC change over time. A retrospective analysis of CAC change was carried out in 55 asymptomatic men who underwent sequential electron beam computed tomographic measurement of CAC score a mean of 3.3 years apart. To ensure maximal accuracy in CAC change analysis, patients were included who had an initial CAC score of 10 or greater and with difference between both scores of 20% or greater of the initial score. The annual change rate in CAC score was calculated by dividing the change in CAC score by the interval between scores. Subjects' risk factors were analyzed and included body mass index, blood pressure, blood lipids and glucose, plasma lipoprotein(a) and fibrinogen, smoking status, and family history of coronary heart disease. The annual change rate in CAC score correlated positively with lipoprotein(a) (r = 0.42, p<0.01) and with initial CAC score (r = 0.46, p<0.001) and these associations persisted in multivariate analysis (p = 0.01, p = 0.001 respectively, R2 = 0.31). In contrast, no association existed between annual CAC change and baseline values and follow-up changes of other risk factors. The association of lipoprotein(a) with CAC progression in symptom-free patients with preexisting coronary calcifications provides new insights into the progression of coronary artery disease and may be useful for planning therapy and follow-up.