The prevalence and distribution of coronary artery calcium in asymptomatic Korean population

Coronary Artery Calcium in Assessment of Atherosclerotic Cardiovascular Disease Risk and its Role in Primary Prevention

Coronary artery calcium (CAC), which is detected using computed tomography scanning, is a well-established indicator of subclinical atherosclerosis. The CAC score is independently associated with atherosclerotic cardiovascular disease (ASCVD) outcomes and provides improved predictive values for estimating the risk of ASCVD beyond traditional risk factors. Thus, CAC is considered to have important implications for reclassification as a decision aid among individuals in the preclinical phase and as the primary prevention of ASCVD. This review is focused on epidemiological evidence on CAC in asymptomatic population-based samples from Western countries and Japan. We also discuss the usability of CAC as a tool for assessing ASCVD risk and its role in the primary prevention of ASCVD. A lack of evidence for the CAC score in ASCVD risk assessment beyond traditional risk factors in populations other than those in Western countries (including Japan) warrants further investigation. Clinical trials are also necessary to demonstrate the usefulness and safety of CAC screening in the primary prevention of ASCVD.

Association between osteosarcopenia and coronary artery calcification in asymptomatic individuals

Osteoporosis and sarcopenia are substantially interrelated with shared cardiovascular risk factors. However, the relationship between osteosarcopenia and coronary artery disease is largely unexplored. We aimed to investigate the association between osteosarcopenia and coronary artery calcification (CAC) scores in asymptomatic adults. A total of 5969 asymptomatic adults without cardiovascular disease who underwent a health examination including estimation of CAC scores by cardiac tomography were analyzed. Osteoporosis was defined as low bone mineral density T-score ≤  − 2.5 standard deviation, and sarcopenia as appendicular skeletal muscle mass < 5.7 kg/m² for women and < 7.0 kg/m² for men, and osteosarcopenia as the copresence of both osteoporosis and sarcopenia. Participants were divided into four groups according to the presence of osteoporosis and/or sarcopenia as control, sarcopenia alone, osteoporosis alone, and osteosarcopenia. Prevalence of CAC was 22.0% in control, 23.6% in sarcopenia alone, 38.5% in osteoporosis alone, and 48.3% in osteosarcopenia group, with the osteosarcopenia group showing the highest (p < 0.0001). After adjustments for possible confounders, mean of log (CAC score + 1) in osteosarcopenia group was higher than other three groups (Bonferroni p < 0.0001). Using multivariate-adjusted analysis, subjects with osteosarcopenia had the highest risk for having CAC > 0 (odds ratio [OR] 2.868; 95% confidence interval [CI] 1.717–4.790). Furthermore, subjects with osteosarcopenia had a significant risk of moderate-to-extensive CAC (CAC score ≥ 100) (OR 2.709; 95% CI 1.128–6.505). We demonstrated that osteosarcopenia was independently associated with a higher prevalence of subclinical coronary atherosclerosis. Our results suggest osteosarcopenia as a predisposing factor for coronary heart disease.

Use of Coronary CT Angiography as a Screening Tool for Coronary Artery Disease in Asymptomatic Healthy Individuals or Patients

심장 돌연사 환자들은 종종 흉통 또는 운동성 호흡곤란 등의 전조증상이 나타나지 않기 때문에 잠재적인 무증상 관상동맥 질환을 조기에 발견하는 것이 매우 중요하다. 관상동맥 전산화단층촬영 혈관조영술은 방사선 노출로 인한 위험성 때문에 무증상 환자에서 스크리닝 검사로 정당화되지 못했었지만 최근에 전산화단층촬영 기술의 비약적인 발전으로 방사선량을 1 mSv 미만으로 최소화함으로써 무증상 환자의 관상동맥 질환 선별 검사의 유용성에 대한 많은 연구가 진행되어 왔다. 그러나, 여전히 무증상 정상인 또는 환자의 관상동맥 질환 선별 검사에 대한 관상동맥 전산화단층촬영 혈관조영술의 유용성에 대해서는 다양한 의견들이 있다. 이 종설에서는 무증상 정상인 또는 환자들에게 관상동맥 질환 선별 검사로 관상동맥 칼슘 점수와 관상동맥 전산화단층촬영 혈관조영술 유용성에 대해서 다양한 문헌고찰을 통해서 알아보았다. 관상동맥 전산화단층촬영 혈관조영술상 무증상 정상인의 2.6%에서 70% 이상의 유의한 관상동맥 협착이 발견되었고, 선별 목적의 관상동맥 전산화단층촬영 혈관조영술이 무증상 건강한 사람의 미래의 심혈관 질환 발생을 예측할 수 있다. 그러나 현재 미국국립보건원에서 진행하고 있는 SCOT-HEART 2 연구가 끝나면 관상동맥 전산화단층촬영 혈관조영술이 무증상 성인의 심혈관 예방에 선별 검사로 적절한지 결정을 내릴 수 있을 것으로 생각된다.

Predictive Model for High Coronary Artery Calcium Score in Young Patients with Non-Dialysis Chronic Kidney Disease

Cardiovascular disease is a major complication of chronic kidney disease. The coronary artery calcium (CAC) score is a surrogate marker for the risk of coronary artery disease. The purpose of this study is to predict outcomes for non-dialysis chronic kidney disease patients under the age of 60 with high CAC scores using machine learning techniques. We developed the predictive models with a chronic kidney disease representative cohort, the Korean Cohort Study for Outcomes in Patients with Chronic Kidney Disease (KNOW-CKD). We divided the cohort into a training dataset (70%) and a validation dataset (30%). The test dataset incorporated an external dataset of patients that were not included in the KNOW-CKD cohort. Support vector machine, random forest, XGboost, logistic regression, and multi-perceptron neural network models were used in the predictive models. We evaluated the model’s performance using the area under the receiver operating characteristic (AUROC) curve. Shapley additive explanation values were applied to select the important features. The random forest model showed the best predictive performance (AUROC 0.87) and there was a statistically significant difference between the traditional logistic regression model and the test dataset. This study will help identify patients at high risk of cardiovascular complications in young chronic kidney disease and establish individualized treatment strategies.

Distributions and burden of coronary calcium in asymptomatic Saudi patients referred to computed tomography

Background

Unlike Western and Asian populations, the prevalence and severity of coronary artery calcification (CAC) have not been adequately examined in Saudi Arabia and other nearby Arab Gulf countries.

Objectives

To estimate the age and gender specific percentiles of coronary calcium score (CCS) and to study the severity of CAC in relation to patient risk in a large sample of asymptomatic Saudi patients.

Methods

Retrospective cross-sectional study was conducted between July 2007 and December 2017 at a large Cardiac Centre in Riyadh, Saudi Arabia. The target was adult patients without pre-existing CAD referred to (64 multidetector spiral) computed tomography for standard indications.

Results

A total 2863 patients were included in the current analysis. The 90th percentile of CCS was 95.0 in males compared with 53.2 in females and was 823.95 in patients aged ≥ 75 years compared with zero in patients < 40 years. Extensive CAC (CCS > 400) were 3.1% in males compared with 1.6% in females and 14.0% in patients aged ≥ 75 years compared with 0.0% in patients < 40 years. CCS was steadily higher with increasing European systematic coronary risk evaluation; 3.1 ± 22.5 in mild risk, 37.1 ± 201.9 in moderate risk, 116.1 ± 256.1 in high risk, and 131.0 ± 222.0 in very high risk.

Conclusions

As expected, the findings confirm the higher burden of CAC in males, older age, and higher CAD risk. The burden of CAC in current patients is much lower than reported in US and other Western patients. Local cardiologist should consider using local rather than US percentiles of CCS.

Genome-wide association study of coronary artery calcification in asymptomatic Korean populations

Epidemiologic evidence indicates that the prevalence and severity of coronary artery disease vary depending on ethnicity. In this study, a genome-wide association study for coronary artery calcification (CAC) was performed in a Korean population-based sample of 400 subjects without prior coronary artery disease and replicated in another of 1,288 subjects. CAC score, as assessed by multi-detector computed tomography, was evaluated in volunteers for screening purposes as part of a routine health examination. CAC score greater than the 90th percentile across the age in each sex group was considered severe CAC. Single nucleotide polymorphisms (SNPs) associated with severe CAC after adjusting for age, sex, hypertension, and diabetes were investigated using the additive model of logistic regression. One SNP (rs10757272 in the intronic region of the CDKN2B-AS1 gene in chromosome 9p21.3) met Bonferroni correction in the discovery set (p = 7.55E-08) and was also significant in the validation set by TaqMan assay (p = 0.036). Subjects with rs10757272 were found to have an increased odds ratio (OR) of having severe CAC in multivariate logistic regression analysis after adjusting for age, sex, hypertension, and diabetes (adjusted OR 3.24 and 95% CI 2.11–4.97). In conclusion, SNP rs10757272 in chromosome 9p21.3 was associated with severe CAC based on age and sex in an asymptomatic community-based Korean population. Therefore, it was associated with promotion of coronary artery calcification in subclinical state.

Coexistence of Colorectal Adenomas and Coronary Calcification in Asymptomatic Men and Women

GOALS

Because of shared risk factors between clinically manifest cardiovascular disease and colorectal cancer, we hypothesized the coexistence of subclinical atherosclerosis measured by coronary artery calcium (CAC) and colorectal adenoma (CRA) and that these 2 processes would also share common risk factors.

BACKGROUND

No study has directly compared the risk factors associated with subclinical coronary atherosclerosis and CRA.

STUDY

This was a cross-sectional study using multinomial logistic regression analysis of 4859 adults who participated in a health screening examination (2010 to 2011; analysis 2014 to 2015). CAC scores were categorized as 0, 1 to 100, or >100. Colonoscopy results were categorized as absent, low-risk, or high-risk CRA.

RESULTS

The prevalence of CAC>0, CAC 1 to 100 and >100 was 13.0%, 11.0%, and 2.0%, respectively. The prevalence of any CRA, low-risk CRA, and high-risk CRA was 15.1%, 13.0%, and 2.1%, respectively. The adjusted odds ratios (95% confidence interval) for CAC>0 comparing participants with low-risk and high-risk CRA with those without any CRA were 1.35 (1.06-1.71) and 2.09 (1.29-3.39), respectively. Similarly, the adjusted odds ratios (95% confidence interval) for any CRA comparing participants with CAC 1 to 100 and CAC>100 with those with no CAC were 1.26 (1.00-1.6) and 2.07 (1.31-3.26), respectively. Age, smoking, diabetes, and family history of CRC were significantly associated with both conditions.

CONCLUSIONS

We observed a graded association between CAC and CRA in apparently healthy individuals. The coexistence of both conditions further emphasizes the need for more evidence of comprehensive approaches to screening and the need to consider the impact of the high risk of coexisting disease in individuals with CAC or CRA, instead of piecemeal approaches restricted to the detection of each disease independently.

Serum cystatin C levels are associated with coronary artery calcification in women without chronic kidney disease

BACKGROUND

Chronic renal disease (CKD) is a determinant of coronary artery calcification (CAC), which is a predictor of cardiovascular events. However, in a population without CKD, the association between CAC and renal function is unclear. CAC is affected by sex. This study aimed to determine whether serum cystatin C, a sensitive marker of kidney function, or sex differences are associated with CAC in patients without CKD.

METHODS

We evaluated 456 consecutive patients (61±13 years, 42% women) without CKD and evidence of coronary artery disease. The CAC (Agatston) score was examined by multidetector computed tomography.

RESULTS

When patients were categorized into three CAC groups based on the Agatston score, mild (<10), moderate (11-399), and severe (≥400) in each sex, serum cystatin C levels gradually increased by severity of CAC in women, but not men. Receiver operating characteristic curve analysis showed that, in women, a cut-off value of 0.97mg/l for cystatin C discriminated patients with severe CAC with a sensitivity of 71% and specificity of 77% (area under the curve, 0.74; 95% CI: 0.62-0.86; p<0.01). Multivariate logistic analysis showed that serum cystatin C was not associated with severe CAC in all patients and men, but this association was observed in women (OR: 7.80 for cystatin C≥0.97mg/l, 95% CI: 1.76-34.6, p<0.01).

CONCLUSION

Higher serum cystatin C levels are associated with greater CAC in women without CKD. Measurement of cystatin C may be useful for identifying women who are at high risk for cardiovascular disease.

Coronary atherosclerosis in indigenous South American Tsimane: a cross-sectional cohort study

BACKGROUND

Conventional coronary artery disease risk factors might potentially explain at least 90% of the attributable risk of coronary artery disease. To better understand the association between the pre-industrial lifestyle and low prevalence of coronary artery disease risk factors, we examined the Tsimane, a Bolivian population living a subsistence lifestyle of hunting, gathering, fishing, and farming with few cardiovascular risk factors, but high infectious inflammatory burden.

METHODS

We did a cross-sectional cohort study including all individuals who self-identified as Tsimane and who were aged 40 years or older. Coronary atherosclerosis was assessed by coronary artery calcium (CAC) scoring done with non-contrast CT in Tsimane adults. We assessed the difference between the Tsimane and 6814 participants from the Multi-Ethnic Study of Atherosclerosis (MESA). CAC scores higher than 100 were considered representative of significant atherosclerotic disease. Tsimane blood lipid and inflammatory biomarkers were obtained at the time of scanning, and in some patients, longitudinally.

FINDINGS

Between July 2, 2014, and Sept 10, 2015, 705 individuals, who had data available for analysis, were included in this study. 596 (85%) of 705 Tsimane had no CAC, 89 (13%) had CAC scores of 1-100, and 20 (3%) had CAC scores higher than 100. For individuals older than age 75 years, 31 (65%) Tsimane presented with a CAC score of 0, and only four (8%) had CAC scores of 100 or more, a five-fold lower prevalence than industrialised populations (p≤0·0001 for all age categories of MESA). Mean LDL and HDL cholesterol concentrations were 2·35 mmol/L (91 mg/dL) and 1·0 mmol/L (39·5 mg/dL), respectively; obesity, hypertension, high blood sugar, and regular cigarette smoking were rare. High-sensitivity C-reactive protein was elevated beyond the clinical cutoff of 3·0 mg/dL in 360 (51%) Tsimane participants.

INTERPRETATION

Despite a high infectious inflammatory burden, the Tsimane, a forager-horticulturalist population of the Bolivian Amazon with few coronary artery disease risk factors, have the lowest reported levels of coronary artery disease of any population recorded to date. These findings suggest that coronary atherosclerosis can be avoided in most people by achieving a lifetime with very low LDL, low blood pressure, low glucose, normal body-mass index, no smoking, and plenty of physical activity. The relative contributions of each are still to be determined.

FUNDING

National Institute on Aging, National Institutes of Health; St Luke's Hospital of Kansas City; and Paleocardiology Foundation.

Prevalence and severity of coronary artery calcification based on the epidemiologic pattern: A propensity matched comparison of asymptomatic Korean and Chinese adults

BACKGROUND

Lifestyle, environmental, and genetic factors substantially influence cardiovascular disease (CVD) risk. We aimed to explore epidemiologic trends in coronary artery calcium scores (CACS), as a marker of CVD, along with possible differences by geographic area and study period in separate East Asian populations.

METHODS

We generated 3 matched groups (n=702) using a propensity scoring approach derived from a Korean (N=48,901) and Chinese cohort (N=927) as follows: (1) A recent Chinese group and (2) recent Korean group, both of whom underwent CACS scanning from 2012-2014; and (3) a past Korean group who underwent CACS scanning 8-10years before the index group (2002-2006). We used logistic regression to generate odds ratios (OR) with 95% confidence intervals (95% CI) to estimate the likelihood of having CACS between the groups, based on CACS stratified by severity: >0 (any), >100 (moderate), and >400 (severe).

RESULTS

The prevalence of any, moderate, or severe CACS did not differ significantly between the recent Chinese and Korean groups. Notably, the odds of the presence of moderate CACS in the recent Chinese group (OR: 3.05, 95% CI: 1.49-6.71, P-value<0.001) and the presence of any CACS in the recent Korean group (OR: 1.58, 95% CI: 1.17-2.15, P-value<0.001) were significantly higher than in the past Korean group.

CONCLUSIONS

In this study involving separate East Asian populations, there were no geographic differences in the prevalence of CACS. However, changes in other unmeasured factors over time are likely the culprits for the elevated prevalence of CACS in asymptomatic East Asians.

[Prevalence and extent of coronary artery calcification in an asymptomatic cardiovascular Mexican population: Genetics of Atherosclerotic Disease study]

OBJECTIVE

The prevalence of coronary artery calcification (CAC), a specific marker of atherosclerosis, is unknown in Mexico. Our aim was to investigate the prevalence and quantity of CAC and their association with cardiovascular risk factors in a Mexican population.

METHODS

CAC was measured by multidetector computed tomography in asymptomatic subjects who participated in the Genetics of Atherosclerotic Disease study. Cardiovascular risk factors and medication were recorded.

RESULTS

The sample included 1,423 individuals (49.5% men), aged 53.7±8.4 years. Those with CAC showed a higher prevalence of dyslipidaemia, diabetes, hypertension, and other risk factors. The prevalence of CAC>0 Agatston units was significantly higher among men (40%) than among women (13%). Mean values of CAC score increased consistently with increasing age and were higher in men than women in each age group. Age and high low density lipoprotein cholesterol were independently associated with prevalence of CAC>0 in men and women, while increasing systolic blood pressure in women and age in both genders showed an independent association with CAC extension.

CONCLUSIONS

In the Mexican population the prevalence and extent of CAC were much higher in men than in women, and strongly increased with age. Independent predictors of CAC prevalence were age and low density lipoprotein cholesterol (LDL-C).

Coronary Artery Calcium and Carotid Artery Intima Media Thickness and Plaque: Clinical Use in Need of Clarification

Atherosclerosis begins in early life and has a long latent period prior to onset of clinical disease. Measures of subclinical atherosclerosis, therefore, may have important implications for research and clinical practice of atherosclerotic cardiovascular disease (ASCVD). In this review, we focus on coronary artery calcium (CAC) and carotid artery intima-media thickness (cIMT) and plaque as many population-based studies have investigated these measures due to their non-invasive features and ease of administration. To date, a vast majority of studies have been conducted in the US and European countries, in which both CAC and cIMT/plaque have been shown to be associated with future risk of ASCVD, independent of conventional risk factors. Furthermore, these measures improve risk prediction when added to a global risk prediction model, such as the Framingham risk score. However, no clinical trial has assessed whether screening with CAC or cIMT/plaque will lead to improved clinical outcomes and healthcare costs. Interestingly, similar levels of CAC or cIMT/plaque among various regions and ethnic groups may in fact be associated with significantly different levels of absolute risk of ASCVD. Therefore, it remains to be determined whether measures of subclinical atherosclerosis improve risk prediction in non-US/European populations. Although CAC and cIMT/plaque are promising surrogates of ASCVD in research, we conclude that their use in clinical practice, especially as screening tools for primary prevention in asymptomatic adults, is premature due to many vagaries that remain to be clarified.

Cross-sectional comparison of coronary artery calcium scores between Caucasian men in the United States and Japanese men in Japan: the multi-ethnic study of atherosclerosis and the Shiga epidemiological study of subclinical atherosclerosis

The incidence of coronary heart disease in the United States has declined, and prevalences of several coronary disease risk factors have become comparable to those in Japan. Therefore, the burden of coronary atherosclerosis may be closer among younger persons in the 2 countries. We aimed to compare prevalences of coronary atherosclerosis, measured with coronary artery calcium scores, between men in the 2 countries by age group (45-54, 55-64, or 65-74 years). We used community-based samples of Caucasian men in the United States (2000-2002; n = 1,067) and Japanese men in Japan (2006-2008; n = 832) aged 45-74 years, stratifying them into groups with 0, 1, 2, or ≥3 of the following risk factors: current smoking, overweight, diabetes, dyslipidemia, and hypertension. We calculated adjusted odds ratios of US Caucasian men's having Agatston scores of ≥10, ≥100, and ≥400 with reference to Japanese men. Overall, the odds of Caucasian men having each Agatston cutoff point were greater. The ethnic difference, however, became smaller in younger age groups. For example, adjusted odds ratios for Caucasian men's having an Agatston score of ≥100 were 2.05, 2.43, and 3.86 among those aged 45-54, 55-64, and 65-74 years, respectively. Caucasian men in the United States had a higher burden of coronary atherosclerosis than Japanese men, but the ethnic difference was smaller in younger age groups.

Metabolically-healthy obesity and coronary artery calcification

OBJECTIVES

The purpose of this study was to compare the coronary artery calcium (CAC) scores of metabolically-healthy obese (MHO) and metabolically healthy normal-weight individuals in a large sample of apparently healthy men and women.

BACKGROUND

The risk of cardiovascular disease among obese individuals without obesity-related metabolic abnormalities, referred to as MHO, is controversial.

METHODS

We conducted a cross-sectional study of 14,828 metabolically-healthy adults with no known cardiovascular disease who underwent a health checkup examination that included estimation of CAC scores by cardiac tomography. Being metabolically healthy was defined as not having any metabolic syndrome component and having a homeostasis model assessment of insulin resistance <2.5.

RESULTS

MHO individuals had a higher prevalence of coronary calcification than normal weight subjects. In multivariable-adjusted models, the CAC score ratio comparing MHO with normal-weight participants was 2.26 (95% confidence interval: 1.48 to 3.43). In mediation analyses, further adjustment for metabolic risk factors markedly attenuated this association, which was no longer statistically significant (CAC score ratio 1.24; 95% confidence interval: 0.79 to 1.96). These associations did not differ by clinically-relevant subgroups.

CONCLUSIONS

MHO participants had a higher prevalence of subclinical coronary atherosclerosis than metabolically-healthy normal-weight participants, which supports the idea that MHO is not a harmless condition. This association, however, was mediated by metabolic risk factors at levels below those considered abnormal, which suggests that the label of metabolically healthy for obese subjects may be an artifact of the cutoff levels used in the definition of metabolic health.

Differential association between obesity and coronary artery disease according to the presence of diabetes in a Korean population

BACKGROUND

Coronary artery disease (CAD) is a major cardiovascular complication in diabetic patients. Despite the significant association between obesity and diabetes, the majority of the diabetic subjects are not obese in an Asian population. This study evaluated the association between obesity and coronary artery disease (CAD) according to the diabetes status in a Korean population.

METHODS

The association between obesity and CAD using the parameters of any plaque, obstructive plaque, and coronary artery calcium score (CACS) >100 according to the presence of diabetes was evaluated in 7,234 Korean adults who underwent multi-detector computed tomography for general health evaluations. Obesity was defined as a body mass index (BMI) ≥25 kg/m(2).

RESULTS

The prevalence of obesity was significantly higher in diabetic subjects than in non-diabetic subjects, but the majority of the diabetic subjects were non-obese (48% vs. 37%, p <0.001). The incidence of any plaque (58% vs. 29%), obstructive plaque (20% vs. 6%), and CACS >100 (20% vs. 6%) were significantly higher in diabetic patients than in non-diabetic subjects (p <0.001, respectively). Incidence of any plaque (33% vs. 26%, p <0.001), obstructive plaque (7% vs. 6%, p = 0.014), and CACS >100 (8% vs. 6%, p = 0.002) was significantly higher in non-diabetic subjects with obesity than in those without obesity, but the incidence of all coronary parameters was not different in diabetic subjects according to the obesity status. After adjusting for confounding risk factors including age, gender, hypertension, dyslipidemia, current smoking, and mild renal dysfunction, obesity was independently associated with increased risks of any plaque (OR 1.14) and CACS >100 (OR 1.31) only in non-diabetic subjects (p <0.05, respectively). Multiple logistic regression models revealed that diabetes was independently associated with all coronary parameters.

CONCLUSION

Despite a significantly higher prevalence of obesity in diabetic subjects than in non-diabetic subjects, obesity is associated with the presence of any plaque and severe coronary calcification only in subjects without established diabetes among Korean population.

A cross-sectional association of obesity with coronary calcium among Japanese, Koreans, Japanese Americans, and U.S. whites

AIMS

Conflicting evidence exists regarding whether obesity is independently associated with coronary artery calcium (CAC), a measure of coronary atherosclerosis. We examined an independent association of obesity with prevalent CAC among samples of multi-ethnic groups whose background populations have varying levels of obesity and coronary heart disease (CHD).

METHODS AND RESULTS

We analysed a population-based sample of 1212 men, aged 40-49 years free of clinical cardiovascular disease recruited in 2002-06; 310 Japanese in Japan (JJ), 294 Koreans in South Korea (KN), 300 Japanese Americans (JA), and 308 Whites in the USA (UW). We defined prevalent CAC as an Agatston score of ≥10. Prevalent CAC was calculated by tertile of the body mass index (BMI) in each ethnic group and was plotted against the corresponding median of tertile BMI. Additionally, logistic regression was conducted to examine whether an association of the BMI was independent of conventional risk factors. The median BMI and crude prevalence of CAC for JJ, KN, JA, and UW were 23.4, 24.4, 27.4, and 27.1 (kg/m2); 12, 11, 32, and 26 (%), respectively. Despite the absolute difference in levels of BMI and CAC across groups, higher BMI was generally associated with higher prevalent CAC in each group. After adjusting for age, smoking, alcohol, hypertension, lipids, and diabetes mellitus, the BMI was positively and independently associated with prevalent CAC in JJ, KN, UW, but not in JA.

CONCLUSION

In this multi-ethnic study, obesity was independently associated with subclinical stage of coronary atherosclerosis among men aged 40-49 years regardless of the BMI level.

Relation between cardio-ankle vascular index and coronary artery calcification or stenosis in asymptomatic subjects

AIM

The cardio-ankle vascular index (CAVI) is an index of arterial stiffness. We investigated the association of CAVI with the severity of coronary artery calcification (CAC) and coronary stenosis by coronary computed tomography angiography (CTA) in an asymptomatic population.

METHODS

A total of 549 asymptomatic Korean individuals who underwent CAVI and CTA were analyzed retrospectively. CAC and coronary stenosis were measured by CTA and assessed for the correlation with CAVI.

RESULTS

The degree of CAC and coronary stenosis demonstrated a significant correlation with CAVI (r= 0.187, p<0.001 and r= 0.212, p<0.001 for the CAC score and stenosis, respectively). After adjustment for potential confounders, including age, gender, hypertension, diabetes mellitus, and dyslipidemia, a predefined cutoff value of CAVI ≥8 was associated with advanced CAC (CAC ≥300) and significant coronary stenosis (stenosis ≥50%). Specifically, the adjusted odds ratio (95% confidence interval) of CAC ≥300 and coronary stenosis ≥50% was 3.57 (1.92-6.66) and 2.81 (1.13-7.00), respectively. Additional inclusion of CAVI improved the predictive power of the receiver operating characteristic curves for predicting coronary atherosclerosis based on traditional risk factors; the area under the curve for predicting CAC ≥300 and coronary stenosis ≥50% increased from 0.739 to 0.791 (p for difference= 0.023), and from 0.761 to 0.842 (p= 0.032), respectively.

CONCLUSIONS

CAVI reflects coronary atherosclerosis and may be used as a screening tool for assessing subclinical atherosclerotic burden in an asymptomatic population.

Coronary artery calcification by computed tomography in epidemiologic research and cardiovascular disease prevention

Both American and European guidelines recommend coronary artery calcification (CAC) as a tool for screening asymptomatic individuals at intermediate risk for coronary heart disease (CHD). These recommendations are based on epidemiologic studies mostly in the United States. We review (1) the use of CAC in primary prevention of CHD in the United States, (2) epidemiologic studies of CAC in asymptomatic adults outside of the United States, and (3) international epidemiologic studies of CAC. This review will not consider clinical studies of CAC among patients or symptomatic individuals. US studies have shown that CAC is a strong independent predictor of CHD in both sexes among middle-aged and old age groups, various ethnic groups, and individuals with and without diabetes and that CAC plays an important role in reclassifying individuals from intermediate to high risk. Studies in Europe support these conclusions. The Electron-Beam Tomography, Risk Factor Assessment Among Japanese and US Men in the Post-World-War-II birth cohort (ERA JUMP) Study is the first international study to compare subclinical atherosclerosis, including CAC among Japanese, Japanese Americans, Koreans, and whites. It showed that as compared with whites, Japanese had lower levels of atherosclerosis, whereas Japanese Americans had similar or higher levels. CAC is being increasingly used as a screening tool for asymptomatic individuals in Europe and the United States. CAC is a powerful research tool, because it enables us to describe differences in atherosclerotic burden across populations. Such research could identify factors responsible for differences among populations, which may improve CHD prevention.