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

Current status and future perspective of coronary artery calcium score in asymptomatic individuals

Atherosclerotic cardiovascular disease remains a major cause of death, and it is important to accurately estimate the cardiovascular events risk stratification even in asymptomatic patients. The coronary artery calcium score (CACS), which is quantitatively evaluated by electrocardiogram (ECG)-gated non-contrast chest computed tomography (CT) imaging, has been reported to be useful for cardiovascular event risk stratification in large studies. In the USA and Europe, guidelines recommend the use of the CACS in borderline or intermediate-risk asymptomatic individuals based on a high level of evidence. In Japan, however, the use of CACS in clinical practice is currently limited. Although it has been reported that the prevalence and distribution of coronary artery calcification (CAC) may differ by race and ethnicity, there are few data on its usefulness in stratifying the risk of cardiovascular events in asymptomatic Japanese individuals. While it is important to establish evidence for the usefulness of CACS in the Japanese population, for widespread clinical dissemination it would be beneficial to evaluate CAC and to perform accurate cardiovascular event risk stratification from non-ECG-gated non-contrast chest CT imaging performed during medical check-up and routine clinical practice. There have been reports on the usefulness of CAC assessed by non-ECG-gated chest CT imaging and on the relationship of CAC between ECG-gated and non-ECG-gated chest CT imaging. In recent years, a more accurate method of evaluating CACS from non-ECG-gated chest CT imaging has been developed using artificial intelligence, and further development is expected in the future.

Association of nocturnal oxygen saturation with coronary artery calcification: cross-sectional evidence from the population-based SESSA study among Japanese men

OBJECTIVE

We investigated the associations of nocturnal oxygen saturation (SpO2) with prevalence of coronary artery calcification (CAC) and its level of burden, and whether the associations differ by obesity and mediate through diabetes mellitus (DM), dyslipidaemia and hypertension.

DESIGN

Observational study.

SETTING

Kusatsu, Shiga.

PARTICIPANTS

We analysed data from 510 Japanese men (aged 46-76 years) with no history of myocardial infarction.

PRIMARY AND SECONDARY OUTCOMES

Mean SpO2, minimum SpO2 and oxygen desaturation index (ODI) were measured using overnight pulse oximetry (primary exposures), while CAC was assessed using CT. Prevalence of CAC (>0) and its burden (CAC 0, >0-100, >100-400 and>400) were evaluated as outcomes. Body mass index≥25.0 kg/m2 defined as obesity.

RESULTS

Mean±SD age was 66.7±7.2 years. The prevalence of CAC was 64.7% (CAC scores>0-100, 31.4%; >100-400, 20.0% and>400, 13.3%). In multivariable binary logistic regression, the OR and 95% CI for the prevalence of CAC were 1.25 (1.02 to 1.53) per 1-SD decrement in mean SpO2 and 1.25 (1.01 to 1.55) per 1-SD increment in ODI. The associations lost their significance while further adjusted for DM and dyslipidaemia. Similar trends were observed for the level of CAC burden in multivariable ordinal logistic regression. Obesity did not show significant interaction with SpO2 on CAC. In mediation analysis, the OR (95% CI) for natural indirect effect; percentage mediated through dyslipidaemia in association of 1-SD decrement in mean SpO2 with prevalence of CAC were 1.06 (1.01 to 1.10); 25.4%. These estimates for mediation through DM and dyslipidaemia for 1-SD increment in ODI in the associations were 1.07 (1.01 to 1.12); 29.6% and 1.04 (1.00 to 1.08); 17.5%, respectively.

CONCLUSIONS

Lower mean SpO2 and higher ODI are associated with CAC among Japanese men, independent of age, lifestyle factors and obesity. The associations became non-significant after adjusting for diabetes and dyslipidaemia, but were mediated through these factors.

Circulating CD31 and resistin levels reflect different stages of coronary atherosclerosis in patients with psoriasis

Psoriasis is a skin disease with a complicated pathophysiology that includes an extensive inflammatory cytokine network. Nevertheless, the relationship between psoriasis severity, cytokine levels, and coronary artery atherosclerosis remains poorly understood. Our aim was to find serum markers as potential candidates for cardiovascular disease (CVD) risk monitoring in patients with psoriasis. Therefore, we examined coronary artery atherosclerosis via coronary computed tomography angiography (CCTA), serum cytokine levels via multiple immunoassays, and the patients' psoriasis state. Our findings reveal for the first time that the mainstream psoriasis cytokines interleukin 17A (IL-17A), IL-19, and IL-36 in the sera of Japanese patients with psoriasis showed a linear regression association with the Psoriasis Area and Severity Index score. Furthermore, the serum level of IL-19 was remarkably correlated to Th2-related serum cytokines such as IL-4 and IL-17E. When we investigated potential markers to monitor CVD in patients with psoriasis, circulating cluster of differentiation 31 (CD31) and resistin, but not psoriasis-related cytokines, were expressed differently at each stage of coronary atherosclerosis by CCTA. CD31 and resistin levels rose dramatically in individuals with psoriasis vulgaris (PV) and noncalcified atherosclerosis. In contrast, CD31 was negatively correlated with the coronary artery calcification score (CACS) in patients with PV, whereas resistin was inversely correlated with CACS in patients with psoriatic arthritis. In conclusion, the axis of IL-17A, IL-19, and IL-36 remains associated with the severity of psoriasis during the chronic phase of the disease, regardless of the application of topical or systemic treatment. Monitoring the levels of these cytokines can accurately determine the severity of skin inflammation. Resistin and CD31 are linked to coronary artery lesions and might be good candidates for tracking the progression of coronary atherosclerosis in patients with psoriasis.

Structural and social determinants of health: The multi-ethnic study of atherosclerosis

BACKGROUND

Researchers have increasingly recognized the importance of structural and social determinants of health (SSDOH) as key drivers of a multitude of diseases and health outcomes. The Multi-Ethnic Study of Atherosclerosis (MESA) is an ongoing, longitudinal cohort study of subclinical cardiovascular disease (CVD) that has followed geographically and racially/ethnically diverse participants starting in 2000. Since its inception, MESA has incorporated numerous SSDOH assessments and instruments to study in relation to CVD and aging outcomes. In this paper, we describe the SSDOH data available in MESA, systematically review published papers using MESA that were focused on SSDOH and provide a roadmap for future SSDOH-related studies.

METHODS AND FINDINGS

The study team reviewed all published papers using MESA data (n = 2,125) through January 23, 2023. Two individuals systematically reviewed titles, abstracts, and full text to determine the final number of papers (n = 431) that focused on at least one SSDOH variable as an exposure, outcome, or stratifying/effect modifier variable of main interest (discrepancies resolved by a third individual). Fifty-seven percent of the papers focused on racialized/ethnic groups or other macrosocial/structural factors (e.g., segregation), 16% focused on individual-level inequalities (e.g. income), 14% focused on the built environment (e.g., walking destinations), 10% focused on social context (e.g., neighborhood socioeconomic status), 34% focused on stressors (e.g., discrimination, air pollution), and 4% focused on social support/integration (e.g., social participation). Forty-seven (11%) of the papers combined MESA with other cohorts for cross-cohort comparisons and replication/validation (e.g., validating algorithms).

CONCLUSIONS

Overall, MESA has made significant contributions to the field and the published literature, with 20% of its published papers focused on SSDOH. Future SSDOH studies using MESA would benefit by using recently added instruments/data (e.g., early life educational quality), linking SSDOH to biomarkers to determine underlying causal mechanisms linking SSDOH to CVD and aging outcomes, and by focusing on intersectionality, understudied SSDOH (i.e., social support, social context), and understudied outcomes in relation to SSDOH (i.e., sleep, respiratory health, cognition/dementia).

The gut microbiota and coronary artery calcification in Japanese men

BACKGROUND

The gut microbiota differs between patients with coronary artery disease (CAD) and healthy controls; however, it currently remains unclear whether these differences exist prior to the onset of CAD. We herein investigated the gut microbiota associated with subclinical coronary artery calcification (CAC) in a Japanese population.

METHODS

A total of 663 Japanese men were enrolled in this cross-sectional study. Computed tomography and gut microbiology tests were performed, and CAC scores were calculated using the Agatston method. Participants were categorized into 4 groups based on their CAC scores: CAC = 0, 0

RESULTS

The mean age of participants was 68.4 years (46-83 years). The numbers of participants in CAC = 0, 0

CONCLUSIONS

The gut microbiota significantly differed from the phylum to genus level in a manner that was dependent on CAC scores, even before the onset of CAD.

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MESH Headings

• Male
• Humans
• Aged
• Coronary Artery Disease/diagnostic imaging
• Coronary Artery Disease/epidemiology
• Coronary Artery Disease/complications
• Gastrointestinal Microbiome
• Cross-Sectional Studies
• Japan/epidemiology
• Risk Factors
• Vascular Calcification/diagnostic imaging
• Vascular Calcification/epidemiology

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Affiliation(s)

Yukiko Okami NCD Epidemiology Research Center, Shiga University of Medical Science, Otsu, Japan..
Hisatomi Arima Department of Preventive Medicine and Public Health, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
Keiko Kondo NCD Epidemiology Research Center, Shiga University of Medical Science, Otsu, Japan
Zhang Hexun Department of Surgery, Shiga University of Medical Science, Otsu, Japan
Yuichiro Yano NCD Epidemiology Research Center, Shiga University of Medical Science, Otsu, Japan
Aya Kadota NCD Epidemiology Research Center, Shiga University of Medical Science, Otsu, Japan
Sayuki Torii NCD Epidemiology Research Center, Shiga University of Medical Science, Otsu, Japan
Takashi Hisamatsu Department of Public Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
Akira Fujiyoshi Department of Hygiene, Wakayama Medical University, Wakayama, Japan
Sayaka Kadowaki NCD Epidemiology Research Center, Shiga University of Medical Science, Otsu, Japan
Yoshiyuki Watanabe Department of Radiology, Shiga University of Medical Science, Otsu, Japan
Akira Andoh Department of Gastroenterology, Shiga University of Medical Science, Otsu, Japan
Yoshihisa Nakagawa Department of Cardiovascular Medicine, Shiga University of Medical Science, Otsu, Japan
Hirotsugu Ueshima NCD Epidemiology Research Center, Shiga University of Medical Science, Otsu, Japan
Katsuyuki Miura NCD Epidemiology Research Center, Shiga University of Medical Science, Otsu, Japan

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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.

The Correlation between the Vascular Calcification Score of the Coronary Artery and the Abdominal Aorta in Patients with Psoriasis

Psoriasis is known as an independent risk factor for cardiovascular disease due to its chronic inflammation. Studies have been conducted to evaluate the progress of atherosclerotic plaques in psoriasis. However, inadequate efforts have been made to clarify the relationship between atherosclerosis progress in coronary arteries and other important blood vessels. For that reason, we investigated the correlation and development of the coronary artery calcification score (CACS) and the abdominal aortic calcification score (AACS) during a follow-up examination. Eighty-three patients with psoriasis underwent coronary computed tomography angiography (CCTA) for total CACS and abdominal computed tomography (AbCT) for total AACS. PASI score, other clinical features, and blood samples were collected at the same time. The patients' medical histories were also retrieved for further analysis. Linear regression was used to analyze the CACS and AACS associations. There was a moderate correlation between CACS and AACS, while both calcification scores relatively reflected the coronary plaque number, coronary stenosis number, and stenosis severity observed with CCTA. Both calcification scores were independent of the PASI score. However, a significantly higher CACS was found in psoriatic arthritis, whereas no similar phenomenon was recorded for AACS. To conclude, both CACS and AACS might be potential alternative tests to predict the presence of coronary lesions as confirmed by CCTA.

Evaluating the use of coronary artery calcium scoring as a tool for coronary artery disease (CAD) risk stratification and its association with coronary stenosis and CAD risk factors: a single-centre, retrospective, cross-sectional study at a tertiary centre in Pakistan

OBJECTIVE

Coronary artery disease (CAD) risk stratification plays a fundamental role in the early detection and optimal management of CAD. The aim of our study is to investigate the use of coronary artery calcium scoring (CACS) as a tool for CAD risk stratification through evaluation of its correlation with the degree of coronary stenosis and its association with conventional cardiovascular risk factors in asymptomatic patients.

DESIGN

Single-centre, retrospective, cross-sectional study.

SETTING

The study was conducted at a tertiary centre (Shifa International Hospital) in Islamabad, Pakistan, through review of medical records of patients who underwent coronary CT between the years 2016 and 2020.

PARTICIPANTS

A total of 1014 patients were included in the study. The study population was analysed for presence of conventional risk factors (gender, age, diabetes, hypertension, body mass index, dyslipidaemia) and association with CACS (zero: n=534; minimal: 0 to ≤10, n=70; mild: >10 to ≤100, n=130; moderate: >100 to ≤400, n=118; and severe: >400, n=49). The association of CACS with the degree of coronary artery stenosis seen on CT scan (significant: ≥50% stenosis, n=216; non-significant: <50% stenosis, n=685) was also analysed.

OUTCOME MEASURES

The main outcome was the association of coronary artery stenosis with CACS. The secondary outcome was the association of CACS with conventional CAD risk factors.

RESULTS

A significant positive association was shown between CACS and coronary artery stenosis (zero vs minimal: OR 0.39, 95% CI 0.20 to 0.79, p=0.01; zero vs mild: OR 0.16, 95% CI 0.10 to 0.27, p<0.0001; zero vs moderate: OR 0.05, 95% CI 0.03 to 0.08, p<0.0001; zero vs severe: OR 0.02, 95% CI 0.01 to 0.050, p<0.0001). Age >45 (OR 1.03, 95% CI 1.01 to 1.05, p<0.0001), hypertension (OR 1.16, 95% CI 0.79 to 1.71, p=0.001) and diabetes (OR 1.33, 95% CI 0.88 to 1.99, p<0.0001) were associated with an increased risk of coronary artery stenosis. Moreover, plaques with higher calcium burden were found in the left anterior descending artery (mean CACS: 386.15±203.89), followed by right coronary (239.77±219.83) and left circumflex (175.56±153.54) arteries.

CONCLUSION

The results indicate a strong positive association of CACS with coronary artery stenosis. CACS was also significantly associated with conventional CAD risk factors in this population.

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.

Relationship between Kidney Function and Subclinical Atherosclerosis Progression Evaluated by Coronary Artery Calcification

Aims: The roles of urinary albumin, eGFRcystatin (eGFRcys), and eGFRcreatinine (eGFRcre) in the progression of coronary artery calcification (CAC) remain unclear. Therefore, the present study investigated the relationship between kidney function and CAC progression.

Methods: A total of 760 Japanese men aged 40-79 years were enrolled in this population-based study. Kidney function was measured using eGFRcre, eGFRcys, and the urine albumin-to-creatinine ratio. CAC scores were calculated using the Agatston method. CAC progression was defined as an annual increase of ＞10 Agatston units (AU) among men with 0＜CAC＜100 AU at baseline, that of ＞10% among those with CAC ≥ 100 AU, and any progression for those with CAC=0 at baseline. The relative risk (RR) of CAC progression based on kidney function was assessed using a robust Poisson regression model.

Results: The mean follow-up period was 4.9 years. CAC progression was detected in 45.8% of participants. Positive associations between CAC progression and albuminuria (＞30mg/g) (RR: 1.29; 1.09 to 1.53;p=0.004) and low eGFRcys (＜60ml/min/1.73m²) (RR: 1.27; 1.05 to 1.53;p=0.012) remained significant after adjustments for age, the follow-up time, and computerized tomography type. Following further adjustments for hypertension, diabetes mellitus, dyslipidemia, C-reactive protein, and lifestyle factors, CAC progression was associated with albuminuria (RR: 1.20; 1.01 to 1.43;p=0.04) and low eGFRcys (RR: 1.19; 0.99 to 1.43;p=0.066), but not with eGFRcre.

Conclusion: CAC progression was associated with albuminuria; however, its relationship with eGFRcys was weakened by adjustments for risk factors.

Future stroke risk in the chronic phase of post-percutaneous coronary intervention

A percutaneous coronary intervention (PCI) is widely performed for acute coronary syndromes or chronic coronary syndromes. Periprocedural stroke is a clinically significant complication during PCI. The incidence of cerebrovascular events (CVEs) after PCI in the chronic phase is obscure. This study aimed to investigate the prevalence of CVEs after PCI in the chronic phase and evaluate the usefulness of a simple coronary artery calcification (CAC) evaluation method. This prospective observational study included 179 patients who underwent PCI between January 2016 and December 2018. The incidence of cerebral infarction was examined from one month after PCI to December 2019. In total, 171 individuals (134 men; mean age, 69.8 ± 9.8 years) were recruited. During a median follow-up period of 33 months, the onset of cerebral infarction was observed in 20 individuals (11.7%). More CAC sites (p = 0.009) and post-PCI for the chronic coronary syndrome (p = 0.049) showed a significant association with future CVEs. There was no significant cervical internal carotid artery stenosis for patients who occurred CVEs. The cutoff value for the number of CAC sites for predicting future CVEs was 4.5. The new and easy method accurately reflected future CVEs risk and may be clinically applicable.

Epidemiological Research Advances in Vascular Calcification in Diabetes

Vascular calcification is the transformation of arterial wall mesenchymal cells, particularly smooth muscle cells (SMCs), into osteoblast phenotypes by various pathological factors. Additionally, vascular transformation mediates the abnormal deposition of calcium salts in the vascular wall, such as intimal and media calcification. Various pathological types have been described, such as calcification and valve calcification. The incidence of vascular calcification in patients with diabetes is much higher than that in nondiabetic patients, representing a critical cause of cardiovascular events in patients with diabetes. Because basic research on the clinical transformation of vascular calcification has yet to be conducted, this study systematically expounds on the risk factors for vascular calcification, vascular bed differences, sex differences, ethnic differences, diagnosis, severity assessments, and treatments to facilitate the identification of a new entry point for basic research and subsequent clinical transformation regarding vascular calcification and corresponding clinical evaluation strategies.

X-ray Micro-Computed Tomography: An Emerging Technology to Analyze Vascular Calcification in Animal Models

Vascular calcification describes the formation of mineralized tissue within the blood vessel wall, and it is highly associated with increased cardiovascular morbidity and mortality in patients with chronic kidney disease, diabetes, and atherosclerosis. In this article, we briefly review different rodent models used to study vascular calcification in vivo, and critically assess the strengths and weaknesses of the current techniques used to analyze and quantify calcification in these models, namely 2-D histology and the o-cresolphthalein assay. In light of this, we examine X-ray micro-computed tomography (µCT) as an emerging complementary tool for the analysis of vascular calcification in animal models. We demonstrate that this non-destructive technique allows us to simultaneously quantify and localize calcification in an intact vessel in 3-D, and we consider recent advances in µCT sample preparation techniques. This review also discusses the potential to combine 3-D µCT analyses with subsequent 2-D histological, immunohistochemical, and proteomic approaches in correlative microscopy workflows to obtain rich, multifaceted information on calcification volume, calcification load, and signaling mechanisms from within the same arterial segment. In conclusion we briefly discuss the potential use of µCT to visualize and measure vascular calcification in vivo in real-time.

Proteinuria and Reduced Estimated Glomerular Filtration Rate are Independently Associated With Lower Cognitive Abilities in Apparently Healthy Community-Dwelling Elderly Men in Japan: A Cross-sectional Study

BACKGROUND

The association of proteinuria and reduced estimated glomerular filtration rate (eGFR) with cognition needs more clarification. We cross-sectionally examined whether proteinuria and reduced eGFR, even in moderate stages, were independently associated with lower cognition in a community-based sample of elderly men.

METHODS

Our cohort initially comprised 1,094 men aged 40-79 years from a random sample from Shiga, Japan in 2006-2008. Of 853 men who returned for the follow-up examination (2009-2014), we analyzed 561 who were ≥65 years, free of stroke, and completed the Cognitive Abilities Screening Instrument (CASI) at follow-up (higher CASI scores [range 0 to 100] indicate better cognition). Proteinuria was assessed via dipstick. eGFR was calculated according to the Chronic Kidney Disease Epidemiology Collaboration Equation. Participants were divided into three groups either by eGFR (≥60, 59-40, and <40 mL/min/1.73 m2) or by proteinuria (no, trace, and positive), considered normal, moderate, and advanced, respectively. Using linear regression, we computed mean CASI score, with simultaneous adjustment for proteinuria and eGFR in addition to other potential confounders.

RESULTS

Significant trends of lower cognition were observed across the groups of worse proteinuria and lower eGFR independently: multivariable-adjusted mean CASI scores were 90.1, 89.3, and 88.4 for proteinuria (Ptrend = 0.029), and 90.0, 88.5, and 88.5 for eGFR (Ptrend = 0.015) in mutual-adjustment model.

CONCLUSIONS

Proteinuria and reduced eGFR, even in their moderate stages, were independently associated with lower cognition in a community-based sample of elderly men. The results suggest the importance of proteinuria and low eGFR for early detection and prevention of cognitive decline.

Blood Metabolite Signatures of Metabolic Syndrome in Two Cross-Cultural Older Adult Cohorts

Metabolic syndrome (MetS) affects an increasing number of older adults worldwide. Cross-cultural comparisons can provide insight into how factors, including genetic, environmental, and lifestyle, may influence MetS prevalence. Metabolomics, which measures the biochemical products of cell processes, can be used to enhance a mechanistic understanding of how biological factors influence metabolic outcomes. In this study we examined associations between serum metabolite concentrations, representing a range of biochemical pathways and metabolic syndrome in two older adult cohorts: The Tsuruoka Metabolomics Cohort Study (TMCS) from Japan (n = 104) and the Baltimore Longitudinal Study of Aging (BLSA) from the United States (n = 146). We used logistic regression to model associations between MetS and metabolite concentrations. We found that metabolites from the phosphatidylcholines-acyl-alkyl, sphingomyelin, and hexose classes were significantly associated with MetS and risk factor outcomes in both cohorts. In BLSA, metabolites across all classes were uniquely associated with all outcomes. In TMCS, metabolites from the amino acid, biogenic amines, and free fatty acid classes were uniquely associated with MetS, and metabolites from the sphingomyelin class were uniquely associated with elevated triglycerides. The metabolites and metabolite classes we identified may be relevant for future studies exploring disease mechanisms and identifying novel precision therapy targets for individualized medicine.

Coronary Artery Calcium Progression Among the US and Japanese Men

Background The risk of coronary heart disease remains low in Japan, although distributions of several coronary risk factors have become comparable with those in the United States. We prospectively compared coronary atherosclerosis burden, measured with coronary artery calcium (CAC) progression, between men in the 2 countries. Methods In 2 population-based samples of 1712 US White, Black, Hispanic, Chinese men (baseline, 2000-2002) and 697 Japanese men in Japan (2006-2008) aged 45-74 years without clinical cardiovascular disease, we quantified CAC progression by serial computed tomography with medians of 3.4 and 5.2 years between scans, respectively. Results Among White, Black, Hispanic, Chinese, and Japanese men free of baseline CAC, CAC incidence was observed in 35.2%, 26.9%, 29.2%, 18.9%, and 29.2%, respectively. After adjustment for times between scans, demographics, behaviors, coronary risk factors, and their changes between scans, White men had significantly higher CAC incidence than Japanese men (relative risk, 1.68; 95% CI, 1.13-2.50). Among those with detectable baseline CAC, after similar adjustments, all the US race/ethnic groups had significantly greater annual changes in CAC score (mean [95% CI]: 39.4 [35.2-43.6] for White, 26.9 [21.4-32.4] for Black, 30.6 [24.7-36.5] for Hispanic, and 30.2 [22.6-37.8] for Chinese men) than Japanese men (15.9 [10.1-21.8]). Conclusions We found a higher CAC incidence among US White men and greater increases in existing CAC among all the US race/ethnic groups than among Japanese men in Japan. These differences persisted despite adjustment for differences in coronary risk factors.

Long-Term Prognostic Value of Coronary Computed Tomography Angiography in an Asymptomatic Elderly Population

Background

The prognostic value of coronary computed tomographic angiography (CCTA) for evaluating coronary artery disease in asymptomatic older adults is controversial. We investigated the prognostic value of CCTA in community‐dwelling elderly Koreans.

Methods and Results

Participants (n=470; mean age: 75.1±7.3 years) who underwent CCTA were enrolled from KLoSHA (Korean Longitudinal Study on Health and Aging), a community‐based prospective cohort. Using CCTA, coronary artery disease was classified as normal, nonobstructive, or obstructive according to the presence of 0%, <50%, or ≥50% stenosis, respectively. Coronary artery calcium scores were investigated together with Framingham risk score, atherosclerotic cardiovascular disease score, and individual risk factors. Major adverse cardiac events (MACE) were defined as a composite of cardiac event–related death or nonfatal myocardial infarction. During a median follow‐up of 8.2 years (interquartile range: 7.7–10.1 years), MACE occurred in 24 participants (5.1%). Compared with the normal group, participants in the obstructive group showed higher incidence of MACE (hazard ratio: 5.65; 95% CI, 1.22–26.16; P=0.027), whereas there were no significant differences in MACE between the normal and nonobstructive groups. The 8‐year event‐free survival rates were 98.1±1.1%, 94.9±1.6%, and 81.7±4.8% in the normal, nonobstructive, and obstructive groups, respectively. Compared with the Framingham risk score and coronary artery calcium score model, CCTA improved risk prediction by C‐index (from 0.698 to 0.749) and category‐free net reclassification index (0.478; P=0.022).

Conclusions

CCTA showed better long‐term prognostic value for MACE than coronary artery calcium score in this asymptomatic older population.

The Role of Vascular Smooth Muscle Cells in Arterial Remodeling: Focus on Calcification-Related Processes

Arterial remodeling refers to the structural and functional changes of the vessel wall that occur in response to disease, injury, or aging. Vascular smooth muscle cells (VSMC) play a pivotal role in regulating the remodeling processes of the vessel wall. Phenotypic switching of VSMC involves oxidative stress-induced extracellular vesicle release, driving calcification processes. The VSMC phenotype is relevant to plaque initiation, development and stability, whereas, in the media, the VSMC phenotype is important in maintaining tissue elasticity, wall stress homeostasis and vessel stiffness. Clinically, assessment of arterial remodeling is a challenge; particularly distinguishing intimal and medial involvement, and their contributions to vessel wall remodeling. The limitations pertain to imaging resolution and sensitivity, so methodological development is focused on improving those. Moreover, the integration of data across the microscopic (i.e., cell-tissue) and macroscopic (i.e., vessel-system) scale for correct interpretation is innately challenging, because of the multiple biophysical and biochemical factors involved. In the present review, we describe the arterial remodeling processes that govern arterial stiffening, atherosclerosis and calcification, with a particular focus on VSMC phenotypic switching. Additionally, we review clinically applicable methodologies to assess arterial remodeling and the latest developments in these, seeking to unravel the ubiquitous corroborator of vascular pathology that calcification appears to be.

Association of blood levels of marine omega-3 fatty acids with coronary calcification and calcium density in Japanese men

BACKGROUND/OBJECTIVES

Clinical trials of eicosapentaenoic acid (EPA) among high-risk groups in Japan in which consumption of mairne-omega-3 fatty acids (OM3) is much higher than other countries showed slower progression of coronary atherosclerosis. We aimed to determine the cross-sectional associations of coronary artery calcification (CAC) and calcium density with OM3, EPA, and docosahexaenoic acid (DHA), two principal OM3, in the general population in Japan.

SUBJECTS/METHODS

The Shiga Epidemiological Study of Subclinical Atherosclerosis examined a population-based sample of 1074 men aged 40-79 in 2006-08 for computed tomography-measured CAC score (CCS), a well-established biomarker of coronary atherosclerosis, CAC density score (CDS), a potential marker of plaque stabilization, serum levels of OM3, and risk factors.

RESULTS

Prevalence of CCS > 0, ≥ 100, and ≥ 300 was 65.8%, 25.9%, and 12.9%, respectively; the mean (SD) OM3, EPA, and DHA were 10.1% (3.2), 3.2% (1.7), and 5.9% (1.6), respectively. Odds ratios (95% CI, p-value) of CCS 0, 100, and 300 in ordinal logistic regression associated with 1 SD increase of OM3, EPA, and DHA were 0.91 (0.81-1.03, p = 0.12), 0.99 (0.88-1.11, p = 0.87) and 0.84 (0.74-0.94, p = < 0.01), respectively. The inverse association of DHA with CCS remained significant in multivariate-adjusted model: odds ratio of 0.87 (0.77-0.99, p = 0.03). Blood levels of OM3, EPA, or DHA did not have any significant associations with CDS.

CONCLUSIONS

DHA but not EPA had a significant inverse association with coronary atherosclerosis in the general population with high levels of OM3. Future trials are warranted comparing the effect of high-dose DHA and EPA on atherosclerosis and cardiovascular outcomes.

Racial Disparities in the Cardiac Computed Tomography Assessment of Coronary Artery Disease: Does Gender Matter

Coronary heart disease (CHD) represents a significant healthcare burden in terms of hospital resources, morbidity, and mortality. Primary prevention and early detection of risk factors for the development of CHD are pivotal to successful intervention programs and prognostication. Yet, there remains a paucity of evidence regarding differences in the assessment of these risk factors and the tools of assessment among different ethnicities. We conducted a narrative review to assess the utility of cardiac computed tomography, particularly coronary artery calcification (CAC), in different ethnicities. We also looked to see whether age, sex, comorbidities, and genetic background have peculiar influences on CAC. In this review, we highlight some of the pivotal studies regarding the question of CAC in relation to the development of CHD among different ethnicities. We identify several key trends in the literature showing that although African Americans have high rates of CHD, their risk of CAC may be relatively lower compared with other ethnicities. Similarly, South Asian patients may be at a high risk for adverse cardiac events due to elevated CAC. We also note that several studies are limited by small sample size and were based on 1 large cohort study. Future studies should include a large international prospective cohort to truly evaluate the effects of ethnicity on CAC and CHD risk. To appropriately apply CAC in the clinical practice, the variations in its scoring based on a subject's age, sex, comorbidity, and ethnicity should be addressed and interpreted beforehand.

Differences Between Coronary Artery Calcification and Aortic Artery Calcification in Relation to Cardiovascular Disease Risk Factors in Japanese Men

AIMS

Calcification in the coronary and aortic arteries has been linked to cardiovascular morbidity and mortality. The pathophysiological influence of aortic artery calcification (AAC) differs from that of coronary artery calcification (CAC). We aimed to compare the relationships between CAC and AAC and cardiovascular disease (CVD) risk factors.

METHODS

We examined a random sample of 1035 Japanese men aged 40-79 years. CAC and AAC were measured by computed tomography and scored according to the Agatston method. Using a logistic regression, we calculated the odds ratio (OR) as being in the highest quintile (Q5) of the calcification score compared to the lower quintiles (Q1-Q4) per 1 standard deviation higher CVD risk factor. Models were simultaneously adjusted for age, body mass index (BMI), systolic blood pressure, smoking (pack-year), alcohol intake, hemoglobin A1c, uric acid, estimated glomerular filtration rate (eGFR), serum lipids, and C-reactive protein. Differences in ORs were investigated using a generalized estimating equation. We performed a multiple linear regression using log-transformed CAC and AAC values as dependent variables.

RESULTS

CAC and AAC were independently associated with age (OR, 95% CI: 2.30 [1.77-2.98] for CAC and 3.48 [2.57-4.73] for AAC), p for difference ＜0.001), systolic blood pressure (1.29 [1.08-1.53] and 1.28 [1.07-1.54], p for difference=0.270), and smoking (1.22, [1.04-1.43] and 1.34 [1.13-1.58]) p for difference=0.071). Alcohol correlated with AAC only (1.17 [0.97-1.41] for CAC and 1.42 [1.16-1.73] for AAC, p for difference= 0.020).

CONCLUSIONS

CAC and AAC were associated with similar CVD risk factors. The strength of association slightly differed between CAC and AAC.

Association of Coronary Artery Calcification with Estimated Coronary Heart Disease Risk from Prediction Models in a Community-Based Sample of Japanese Men: The Shiga Epidemiological Study of Subclinical Atherosclerosis (SESSA)

AIM

The clinical significance of coronary artery calcification (CAC) is not fully determined in general East Asian populations where background coronary heart disease (CHD) is less common than in USA/Western countries. We cross-sectionally assessed the association between CAC and estimated CHD risk as well as each major risk factor in general Japanese men.

METHODS

Participants were 996 randomly selected Japanese men aged 40-79 y, free of stroke, myocardial infarction, or revascularization. We examined an independent relationship between each risk factor used in prediction models and CAC score ≥100 by logistic regression. We then divided the participants into quintiles of estimated CHD risk per prediction model to calculate odds ratio of having CAC score ≥100. Receiver operating characteristic curve and c-index were used to examine discriminative ability of prevalent CAC for each prediction model.

RESULTS

Age, smoking status, and systolic blood pressure were significantly associated with CAC score ≥100 in the multivariable analysis. The odds of having CAC score ≥100 were higher for those in higher quintiles in all prediction models (p-values for trend across quintiles ＜0.0001 for all models). All prediction models showed fair and similar discriminative abilities to detect CAC score ≥100, with similar c-statistics (around 0.70).

CONCLUSIONS

In a community-based sample of Japanese men free of CHD and stroke, CAC score ≥100 was significantly associated with higher estimated CHD risk by prediction models. This finding supports the potential utility of CAC as a biomarker for CHD in a general Japanese male population.

Relation of heart rate recovery after exercise testing to coronary artery calcification

BACKGROUND

We examined whether slow heart rate recovery (HRR) after exercise testing as an estimate of impaired autonomic function is related to coronary artery calcification (CAC), an emerging marker of coronary atherosclerosis.

METHODS

We evaluated 2088 men who participated in a health-screening program that included measures of CAC and peak or symptom-limited cardiopulmonary exercise testing. HRR was calculated as the difference between peak heart rate (HR) during exercise testing and the HR at 2 min of recovery after peak exercise. We measured CAC using multidetector computed tomography to calculate the Agatston coronary artery calcium score. Advanced CAC was defined as a mean CAC >75th percentile for each age group.

RESULTS

HRR was negatively correlated with CAC (r = -.14, p < .01). After adjusting for conventional risk factors, participants in the lowest quartile of HRR (<38 bpm) were 1.59 times (95% CI: 1.17-2.18; p < .05) more likely to have advanced CAC than their counterparts in the highest quartile of HRR (>52 bpm). Each 1 bpm decrease in HRR was associated with 1% increase in advanced CAC after adjusting for potential confounders.

CONCLUSIONS

An attenuated HRR after exercise testing is associated with advanced CAC, independent of coronary risk factors and other related hemodynamic response. KEY MESSAGES Slow heart rate recovery (HRR) after maximal exercise testing, indicating decreased autonomic function, is associated with an increased risk of cardiovascular event and mortality. Slow HRR has been linked with the occurrence of malignant ventricular arrhythmias, but it remains unclear whether slow HRR is associated with an increased risk of coronary artery calcification (CAC), an emerging marker of coronary atherosclerosis. An attenuated HRR after exercise testing was associated with advanced CAC, independent of coronary risk factors and other potential hemodynamic confounder, supporting the hypothesis that slow HRR is related to the burden of atherosclerotic coronary artery 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.

On-Treatment Blood Pressure and Cardiovascular Outcomes in Older Adults With Isolated Systolic Hypertension

Our aim was to assess optimal on-treatment blood pressure (BP) at which cardiovascular disease (CVD) and all-cause mortality risks are minimized in Japanese older adults with isolated systolic hypertension. We used data from the VALISH study (Valsartan in Elderly Isolated Systolic Hypertension) that recruited older adults (n=3035; mean age, 76 years) with systolic BP (SBP) of ≥160 mm Hg and diastolic BP of <90 mm Hg. Patients were treated by valsartan. Patients were also categorized into 3 groups based on achieved on-treatment SBP of <130 mm Hg (n=317), 130 to <145 mm Hg (n=2025), or ≥145 mm Hg (n=693). The primary outcome was composite CVD (coronary heart disease, stroke, heart failure, cardiovascular deaths, other vascular diseases, and kidney diseases) with secondary outcome being all-cause mortality. Cox proportional hazards models were used to assess the CVD risk for each group. Over a median 3-year follow-up (8022 person-years), 93 CVD events and 52 deaths occurred. Using the on-treatment SBP of 130 to <145 mm Hg as reference stratum, the multivariable-adjusted hazard ratios and 95% confidence intervals of CVD and all-cause mortality risks for those with SBP<130 mm Hg were 2.08 (1.12–3.83) and 2.09 (0.93–4.71) and for those with SBP≥145 mm Hg were 2.29 (1.44–3.62) and 2.51 (1.35–4.66), respectively. On-treatment diastolic BP yielded no relationships with CVD or all-cause mortality risk. In conclusion, among Japanese older adults with isolated systolic hypertension, SBP in the range between 130 and 144 mm Hg was associated with minimal adverse outcomes and a reduction in CVD and all-cause mortality. The BP range will need to be confirmed in randomized controlled trials.

Clinical Trial Registration—

URL: https://www.clinicaltrials.gov . Unique identifier: NCT00151229.

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.

Warranty Period of Zero Coronary Artery Calcium Score for Predicting All-Cause Mortality According to Cardiac Risk Burden in Asymptomatic Korean Adults

BACKGROUND

The aim of this study was to examine whether zero coronary artery calcium (CAC) score is associated with favorable prognosis of all-cause mortality (ACM) according to a panel of conventional risk factors (RF) in asymptomatic Korean adults.

METHODS AND RESULTS

A total of 48,215 individuals were stratified according to presence/absence of CAC, and the following RF were examined: hypertension, diabetes, current smoking, high low-density lipoprotein cholesterol, and low high-density lipoprotein cholesterol. The RF were summed on composite score as 0, 1-2, or ≥3 RF present. The warranty period was defined as the time to cumulative mortality rate >1%. Across a median follow-up of 4.4 years (IQR, 2.7-6.6), 415 (0.9%) deaths occurred. Incidence per 1,000 person-years for ACM was consistently higher in subjects with any CAC, irrespective of number of RF. The warranty period was substantially longer (eg, 9 vs. 5 years) for CAC=0 compared with CAC >0. The latter observation did not change materially according to pre-specified RF, but difference in warranty period according to presence/absence of CAC reduced somewhat when RF burden increased.

CONCLUSIONS

In asymptomatic Korean adults, the absence of CAC evoked a strong protective effect against ACM as reflected by longer warranty period, when no other RF were present. The usefulness of zero CAC score and its warranty period requires further validation in the presence of multiple RF. (Circ J 2016; 80: 2356-2361).

Prevalence and Distribution of Coronary Artery Calcification in Asymptomatic United States and Korean Adults - Cross-Sectional Propensity-Matched Analysis

BACKGROUND

The incidence of coronary artery disease (CAD) varies depending on ethnicity, but the precise differences remain to be firmly established. This study therefore evaluated the disparity in coronary artery calcification (CAC), as a marker of CAD, in asymptomatic US and Korean adults.

METHODS AND RESULTS

CAC score was compared between asymptomatic Korean (n=15,128) and US (n=7,533) adults. Propensity score matching was performed according to age, gender, hypertension, diabetes, dyslipidemia, and current smoking, which generated 2 cohorts of 5,427 matched pairs. Both cohorts were categorized according to age group: 45-54, 55-64, and 65-74 years. Overall, the prevalence of CAC score >0, >100, and >400 in Korean adults was lower than in US adults (P<0.001, all). According to increasing age groups, the likelihood of CAC was most often lower in Korean adults, especially in Korean women. The odds of having CAC >400 in Korean adults aged 65-74 years was 0.66 (95% CI: 0.48-0.91) overall, 0.78 (95% CI: 0.52-1.19) in men, and 0.50 (95% CI: 0.29-0.86) in women, compared with US counterparts.

CONCLUSIONS

Korean adults have a lower prevalence and severity of atherosclerotic burden as assessed on CAC, compared with US adults, but the disparity in CAC according to ethnicity may decline with older age. (Circ J 2016; 80: 2349-2355).

Smoking, Smoking Cessation, and Measures of Subclinical Atherosclerosis in Multiple Vascular Beds in Japanese Men

Background

Smoking is an overwhelming, but preventable, risk factor for cardiovascular diseases (CVD), although smoking prevalence remains high in developed and developing countries in East Asia.

Methods and Results

In a population‐based sample of 1019 Japanese men aged 40 to 79 years, without CVD, we examined cross‐sectional associations of smoking status, cumulative pack‐years, daily consumption, and time since cessation, with subclinical atherosclerosis at 4 anatomically distinct vascular beds, including coronary artery calcification, carotid intima‐media thickness (CIMT) and plaque, aortic artery calcification (AoAC), and ankle‐brachial index. Current, former, and never smoking were present in 32.3%, 50.0%, and 17.7%, respectively. Compared to never smokers, current smokers had significantly higher risks of subclinical atherosclerosis in all 4 circulations (eg, odds ratios for coronary artery calcification >0, 1.79 [95% CIs, 1.16–2.79]; CIMT >1.0 mm, 1.88 [1.02–3.47]; AoAC >0, 4.29 [2.30–7.97]; and ankle‐brachial index <1.1, 1.78 [1.16–2.74]) and former smokers did in carotid and aortic circulations (CIMT >1.0 mm, 1.94 [1.13–3.34]; and AoAC >0, 2.55 [1.45–4.49]). Dose–response relationships of pack‐years and daily consumption, particularly with CIMT, carotid plaque, AoAC, and ankle‐brachial index, were observed among both current and former smokers, and even a small amount of pack‐years or daily consumption among current smokers was associated with coronary artery calcification and AoAC, whereas time since cessation among former smokers was linearly associated with lower burdens of all atherosclerotic indices.

Conclusions

Cigarette smoking was strongly associated with subclinical atherosclerosis in multiple vascular beds in Japanese men, and these associations attenuated with time since cessation.

Lipoprotein-associated phospholipase A2 is related to risk of subclinical atherosclerosis but is not supported by Mendelian randomization analysis in a general Japanese population

OBJECTIVE

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an enzyme predominantly bound to low-density lipoprotein (LDL). Lp-PLA2 is recognized as playing a key role in inflammatory processes and the development of atherosclerosis. This study aimed to investigate whether Lp-PLA2 is related to subclinical atherosclerosis, independently from traditional risk factors, in a general Japanese population by analyses of both the observational study and Mendelian randomization using V279F polymorphism.

METHODS AND RESULTS

We cross-sectionally examined community-based sample of 929 Japanese men aged 40-79 years, without statin treatment, who were randomly selected from the resident registration. Multiple regression analyses of Lp-PLA2 activity and concentration were undertaken separately for men aged 40-49 years and 50-79 years, to clarify interactions of age and Lp-PLA2. Lp-PLA2 activity for men aged 50-79 years was significantly and positively related to intima-media thickness (IMT) (P = 0.013) and plaque index (P = 0.008) independent of traditional risk factors including small LDL particles, but not to coronary artery calcification (CAC) score. Associations with Lp-PLA2 concentration were qualitatively similar to those of activity. Corresponding relationships were not observed in men aged 40-49 years. Mendelian randomization analyses based on V279F genotype did not show any significant associations with subclinical atherosclerosis, although the homozygote and heterozygote of V279F showed low Lp-PLA2 activity and concentration.

CONCLUSIONS

Lp-PLA2 activity in Japanese men aged 50-79 years was associated significantly and positively with IMT and plaque in the carotid artery but Mendelian randomization did not support that Lp-PLA2 is a causative factor for subclinical atherosclerosis.

Reassessing the Usefulness of Coronary Artery Calcium Score among Varying Racial and Ethnic Groups by Geographic Locations: Relevance of the Korea Initiatives on Coronary Artery Calcification Registry

There is some disparity in the morbidity and mortality rates of cardiovascular disease (CVD) according to race, ethnicity, and geographic regions. Although prediction algorithms that evaluate risk of cardiovascular events have been established using traditional risk factors, they have also demonstrated a number of differences along with race and ethnicity. Of various risk assessment modalities, coronary artery calcium (CAC) score is a sensitive marker of calcific atherosclerosis and correlates well with atherosclerotic plaque burden. Although CAC score is now utilized as a useful tool for early detection of coronary artery disease, prior studies have suggested some variability in the presence and severity of coronary calcification according to race, ethnicity, and/or geographic regions. Among Asian populations, it would appear necessary to reappraise the utility of CAC score and whether it remains superior over and above established clinical risk prediction algorithms. To this end, the Korea initiatives on coronary artery calcification (KOICA) registry has been designed to identify the effectiveness of CAC score for primary prevention of CVD in asymptomatic Korean adults. This review discusses the important role of CAC score for prognostication, while also describing the design and rationale of the KOICA registry.

Incremental benefit of coronary artery calcium score above traditional risk factors for all-cause mortality in asymptomatic Korean adults

BACKGROUND

Coronary artery calcium score (CACS) is a well-recognized marker for subclinical coronary atherosclerosis, particularly in asymptomatic populations. To date, however, the added prognostic benefit of CACS compared with traditional risk factors in an Asian population remains unknown. This study therefore investigated the benefit of CACS over traditional risk factors for all-cause mortality in a large multicenter registry of asymptomatic Korean adults.

METHODS AND RESULTS

A total of 34,386 individuals were retrospectively enrolled to participate in a general health examination. The Framingham 10-year risk score (FRS) was calculated according to the traditional risk stratification algorithm and CACS was calculated in log(CACS+1) for continuous data and categorized as 0, 1-100, 101-400 and >400. During a median follow-up of 4.9 years (IQR, 3.0-7.1), there were 303 all-cause deaths (0.9%). Following adjustment, CACS was independently associated with all-cause death (hazard ratio, 1.10; 95% confidence interval (CI): 1.05-1.17; P<0.001). Notably, CACS added further prognostic value above and beyond FRS (likelihood ratio, χ(2)=75.42, P<0.001; continuous net reclassification improvement=0.40, 95% CI: 0.29-0.51, P≤0.001; improving C-statistic from 0.64, 95% CI: 0.61-0.67 to 0.68, 95% CI: 0.64-0.71; ∆C=0.04, 95% CI: 0.01-0.06, P=0.002).

CONCLUSIONS

In an asymptomatic Korean population, CACS improved prediction of all-cause mortality over and above that of a conventional risk tool.