Subclinical atherosclerosis in a community-based elderly cohort: the Korean Longitudinal Study on Health and Aging

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.

Cerebral Arterial Stiffness as A New Marker of Early Stage Atherosclerosis of The Cerebral Large Artery in Acute Stroke

Aim: Carotid–cer ebral pulse wave velocity (ccPWV) reflects the segment (C-M segment) stiffness between the common carotid artery and ipsilateral middle cerebral artery. C-M segment atherosclerosis (CMSA) is regarded the most frequent cause of anterior circulation ischemic stroke. We aimed to evaluate the association of ccPWV with early stage CMSA in this study.

Methods: Eighty-one acute ischemic stroke (AIS) patients with 154 C-M segments who were successfully evaluated with digital subtraction angiography, ccPWV, carotid intima–media thickness (cIMT), and brachial–ankle pulse wave velocity were enrolled into this study. Patient demographics and clinical data were retrieved from our AIS databases.

Results: Multivariate analyses showed that CMSA was independently associated with higher systolic BP, ccPWV, and cIMT. ccPWV and cIMT presented good diagnostic values for evaluating early stage CMSA in the receiver operating characteristic curve analyses. The areas under the curve (AUCs) of ccPWV were significantly higher than that of cIMT (Z = 2.204, P = 0.007). The AUC, sensitivity, specificity, Youden index, and cutoff of ccPWV for detecting early stage CMSA were 0.815 (P < 0.001), 86%, 70.7%, 0.567, and 5.4 m/s, respectively. Furthermore, ccPWV was significantly correlated with the stenosis of CMSA at the early stage in Spearman's correlation analyses (r = 0.877, P < 0.001) and fractional polynomial plot with 95% confidence intervals.

Conclusions: Cerebral arterial stiffness has the potential to be a new marker of early stage atherosclerosis of the cerebral large artery. This finding may help us prevent the occurrence of stroke and decrease the burden of society from stroke patients.

Effect of Rosuvastatin on Cholesterol Efflux Capacity and Endothelial Function in Type 2 Diabetes Mellitus and Dyslipidemia

BACKGROUND

Quality and quantity of high-density lipoprotein cholesterol (HDL-C) may be associated with cardiovascular risk. We investigated the effect of rosuvastatin on cholesterol efflux (CE) for HDL function and vascular health.Methods and Results:We enrolled 30 dyslipidemic patients with type 2 diabetes mellitus and 20 healthy subjects as controls. Vascular health was assessed on flow-medicated dilation (FMD), nitroglycerin-induced dilatation of the brachial artery and carotid artery intima-media thickness (cIMT). These parameters were compared between patients and controls, and between baseline and at 12 weeks of treatment with rosuvastatin 20 mg. Age and body mass index were 49.8±11.3 years and 25.8±3.7 kg/m²in the patients, and 28.8±3.2 years and 22.4±2.4 kg/m²in the controls, respectively. The biomarkers related to lipid and glucose metabolism and lipoprotein (a), high-sensitivity C-reactive protein, and cIMT were significantly higher, and CE and FMD were significantly lower in the patients than in the controls. In the patients, rosuvastatin 20 mg decreased low-density lipoprotein cholesterol by 54.1% and increased HDL-C by 4.8%. The CE increased significantly after rosuvastatin treatment (12.26±2.72% vs. 14.05±4.14%). FMD also increased, and lipoprotein (a) and cIMT decreased significantly and were associated with changes of CE.

CONCLUSIONS

Rosuvastatin-induced changes in HDL function are significantly associated with cardiovascular benefit.

Impact of Advanced Modeled Iterative Reconstruction on Coronary Artery Calcium Quantification

RATIONALE AND OBJECTIVES

To evaluate the influence of advanced modeled iterative reconstruction (ADMIRE) on the coronary artery calcium (CAC) scores by computed tomography (CT).

MATERIALS AND METHODS

Sixty patients underwent CAC imaging with dual-source 192-slice CT. Agatston, volume and mass score were calculated from filtered back projection (FBP) and iterative reconstructions with different levels of ADMIRE. Friedman test and Wilcoxon rank sum test were used for multiple comparisons of CAC values and the difference ratio among different ADMIRE groups using FBP as reference.

RESULTS

The median Agatston score (range) using FBP was 115 (0.1-3047) and significantly decreased with incremental ADMIRE levels 1-5: 96 (0.1-2813), 91 (0-2764), 87 (0-2699), 80 (0-2590), 70 (0-2440); all P < 0.001. In comparison with FBP Agatston, volume and mass scores significantly decreased with increasing ADMIRE levels 1-5 (P < 0.001): from -12% to -39%, from -14% to -41%, and from -13% to -40%, respectively. In four patients with low calcium burden, the use of ADMIRE 2 or higher resulted in the disappearance of calcium that was detectable using FBP or ADMIRE 1. The decrease of CAC in high-level ADMIRE resulted in a reassignment to a lower Agatston risk group in 27%.

CONCLUSIONS

ADMIRE causes a substantial reduction of the CAC scores measured by cardiac CT, which leads to an underestimation of cardiovascular risk scores in some patients.

Circulating adiponectin and carotid intima-media thickness: A systematic review and meta-analysis

BACKGROUND

Adiponectin (APN) is an adipokine with insulin-sensitizing, anti-inflammatory, and vasculoprotective properties. Hypoadiponectinemia has been linked with disease states, such as obesity, type 2 diabetes, and cardiovascular disease. Carotid intima-media thickness (cIMT) is a strong and independent predictor of both coronary and cerebrovascular events, and has been used as a surrogate marker of subclinical atherosclerosis. The aim of this report is to systematically review the evidence on the relationship between APN and cIMT in a wide range of individuals.

MATERIALS AND METHODS

Medline, Embase, Biosis, Scopus, Web of Science, and Pubmed were searched for published studies and conference abstracts. The "sign test" and "vote count" methods were used to estimate the direction and significance of the relationship between APN and cIMT. The quality of the eligible studies was evaluated using an adapted version of the New Castle Ottawa quality assessment scale.

RESULTS

Fifty-five articles fulfilled the inclusion criteria, comprised of only cross-sectional studies, including healthy subjects, general population, and individuals with metabolic, inflammatory, or other chronic diseases. Most associations between APN and cIMT followed a negative direction in the healthier and general populations, and also in cohorts with metabolic disorders and other chronic diseases, but not in those with inflammatory diseases (sign test). These associations were generally found to be weak or non-significant among all cohort groups studied (vote count).

CONCLUSION

Our results are suggestive but not conclusive for an inverse association between APN levels and cIMT in diseased and non-diseased populations.

Association of Television Viewing Time with Body Composition and Calcified Subclinical Atherosclerosis in Singapore Chinese

Objective

Sedentary behavior such as television viewing may be an independent risk factor for coronary heart disease. However, few studies have assessed the impact of television viewing time on coronary artery calcification and it remains unclear how body fat contributes to this relationship. The aim of this study is to evaluate the association between television viewing time and subclinical atherosclerosis and whether effects on visceral or subcutaneous fat may mediate any associations observed.

Methods

This was a cross-sectional study of 398 Chinese participants (192 men and 206 women) from Singapore prospective study. Participants were free from known cardiovascular diseases and underwent interview, health screening, computed tomography scans of coronary arteries and abdomen. Spearman’s correlation was used to test the correlation between television viewing time, physical activity, body composition and abdominal fat distribution. The association between television viewing time and subclinical atherosclerosis was assessed by multiple logistic regression analysis.

Results

In men, television viewing time was significantly correlated with higher body fat mass index, percent body fat, subcutaneous and visceral fat. These associations were in the same direction, but weaker and not statistically significant in women. Television viewing time (hours/day) was associated with subclinical atherosclerosis in men (odds ratio: 1.41, 95% CI: 1.03-1.93) but no significant association was observed in women (odds ratio: 0.88, 95% CI: 0.59-1.31) after adjusting for potential socio-demographic and lifestyle confounders. Further adjustments for biological factors did not affect these associations.

Conclusions

Television viewing time was associated with greater adiposity and higher subcutaneous and visceral fat in men. TV viewing time was also associated with subclinical atherosclerosis in men and the potential mechanisms underlying this association require further investigation.

Medical and Revascularization Therapies for Asymptomatic Carotid Stenosis

Asymptomatic internal carotid artery stenosis increases with age and is more common in men. Carotid endarterectomy and stenting have reduced stroke rates in patients with asymptomatic carotid stenosis in clinical trials. A variety of risk stratification methods are available for selection of patients with carotid stenosis for revascularization. In the past decade, there is increasing evidence that the rate of stroke declined with the use of aggressive multi-modal medical therapy. These developments have led to new clinical trials to compare revascularization versus aggressive medical therapy in patients with asymptomatic carotid stenosis.

Association between urinary 8-OHdG and pulse wave velocity in hypertensive patients with type 2 diabetes mellitus

INTRODUCTION

Oxidative stress, assessed using 8-hydroxy-2'-deoxyguanosine (8-OHdG), can be associated with arterial stiffness in patients with type 2 diabetes mellitus (T2DM) and/or hypertension (HT). We investigated the correlation between urinary 8-OHdG and pulse wave velocity (PWV) in hypertensive and non-hypertensive T2DM patients with fair glycaemic control to determine the clinical significance of HT as a comorbidity in the diabetic state.

METHODS

Clinical data, including traditional cardiovascular risk factors, diabetic complications, prescribed agents, urinary 8-OHdG level and brachial-ankle PWV, was collected from T2DM patients with and without HT.

RESULTS

There were 76 patients (45 men, 31 women; mean age 61 years; mean haemoglobin A1c level 6.5%) in the study cohort. T2DM patients with HT had significantly higher mean PWV than patients without HT (1,597 cm/s vs 1,442 cm/s; p < 0.05). Patients with HT showed no significant difference in 8-OHdG levels relative to those without HT (median 7.9 ng/mg creatinine vs 8.8 ng/mg creatinine; p > 0.05). Simple linear correlation and stepwise multiple linear regression analyses revealed that 8-OHdG levels correlated independently, significantly and positively with PWV among T2DM patients with HT (r = 0.33, p < 0.05; β= 0.23, p < 0.05). No significant correlation was observed between 8-OHdG levels and PWV among T2DM patients without HT.

CONCLUSION

In the hypertensive state, oxidative stress can be responsible for the development of arterial stiffness, even in patients with fairly well controlled T2DM. Oxidative stress management may be necessary for the prevention of cardiovascular disease in this population.

Radiation dose reduction at coronary artery calcium scoring by using a low tube current technique and hybrid iterative reconstruction

PURPOSE

The aim of this study was to compare the accuracy of coronary artery calcium scoring (CACS) on cardiac computed tomographic images using hybrid iterative reconstruction (hIR) and a low tube current as well as on images acquired with a filtered back projection (FBP) algorithm and a normal tube current.

SUBJECTS AND METHODS

Patients (N = 77) with suspected coronary artery disease were subjected to 2 CACS evaluations based on their Agatston, volume, and mass scores. One CACS evaluation was performed on images obtained with a 364-mA tube current and reconstructed with FBP; the other was performed on images obtained with a 73-mA tube current and reconstructed with hIR at iDose4. All scans were performed with the prospective electrocardiogram-triggered method using a 256-slice computed tomographic scanner (Brilliance iCT; Philips). We assessed agreement between calcium scores obtained with FBP and with IR using the percentage difference and Bland-Altman analysis.

RESULTS

The effective radiation doses for CACS at 80 mA s with FBP and at 16 mA s with IR were 1.20 and 0.24 mSv, respectively (k = 0.014). The mean Agatston, volume, and mass scores at 80 mA s with FBP as well as at 16 mA s with IR were 390.7, 146.5, and 63.2 as well as 377.7, 142.5, and 62.2, respectively. The percentage difference between FBP and hIR for the Agatston, volume, and mass score was 20.7%, 20.7%, and 27.1%, respectively. Bland-Altman analysis showed that there was no systemic bias.

CONCLUSIONS

The radiation dose for CACS can be reduced at a low tube current and hIR without affecting the calcium score.

Aging, the metabolic syndrome, and ischemic stroke: redefining the approach for studying the blood-brain barrier in a complex neurological disease

The blood-brain barrier (BBB) has many important functions in maintaining the brain's immune-privileged status. Endothelial cells, astrocytes, and pericytes have important roles in preserving vasculature integrity. As we age, cell senescence can contribute to BBB compromise. The compromised BBB allows an influx of inflammatory cytokines to enter the brain. These cytokines lead to neuronal and glial damage. Ultimately, the functional changes within the brain can cause age-related disease. One of the most prominent age-related diseases is ischemic stroke. Stroke is the largest cause of disability and is third largest cause of mortality in the United States. The biggest risk factors for stroke, besides age, are results of the metabolic syndrome. The metabolic syndrome, if unchecked, quickly advances to outcomes that include diabetes, hypertension, cardiovascular disease, and obesity. The contribution from these comorbidities to BBB compromise is great. Some of the common molecular pathways activated include: endoplasmic reticulum stress, reactive oxygen species formation, and glutamate excitotoxicity. In this chapter, we examine how age-related changes to cells within the central nervous system interact with comorbidities. We then look at how comorbidities lead to increased risk for stroke through BBB disruption. Finally, we discuss key molecular pathways of interest with a focus on therapeutic targets that warrant further investigation.

Cardiovascular risk factor profiles for peripheral artery disease and carotid atherosclerosis among Chinese older people: a population-based study

OBJECTIVES

Epidemiological data concerning atherosclerotic disease among older people in rural China are sparse. We seek to determine prevalence and cardiovascular risk factor profiles for peripheral artery disease (PAD) and carotid atherosclerosis (CAS) among Chinese older people living in a rural community.

METHODS

This cross-sectional study included 1499 participants (age ≥60 years, 59.0% women) of the Confucius Hometown Aging Project in Shandong, China. From June 2010-July 2011, data were collected through interviews, clinical examinations, and laboratory tests. PAD was defined as an ankle-brachial index ≤0.9. Carotid intima-media thickness (cIMT) and carotid artery stenosis were assessed by ultrasonography. We defined moderate stenosis as carotid stenosis ≥50%, and severe stenosis as carotid stenosis ≥70%. cIMT≥1.81 mm was considered as an increased cIMT (a measure of CAS). Data were analyzed with multiple logistic models.

RESULTS

The prevalence was 5.7% for PAD, 8.9% for moderate stenosis, 1.8% for severe stenosis, and 11.2% for increased cIMT. After controlling for multiple potential confounders, diabetes, an increased low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio, and hypertension were significantly or marginally associated with PAD. Ever smoking, hypertension, and an increased LDL-C/HDL-C ratio were significantly associated with an increased likelihood of increased cIMT. An increasing number of those cardiovascular risk factors were significantly associated with an increasing odds ratio of PAD and increased cIMT, respectively (p for linear trend <0.001).

CONCLUSION

Among Chinese older people living in a rural community, PAD, carotid artery stenosis, and an increased cIMT are relatively uncommon. Cardiovascular risk factor profiles for PAD and CAS are slightly different, with hypertension and an increased LDL-C/HDL-C ratio being associated with an increased likelihood of both PAD and increased cIMT.

Low socioeconomic status increases short-term mortality of acute myocardial infarction despite universal health coverage

BACKGROUND

This nationwide population-based study investigated the relationship between individual and neighborhood socioeconomic status (SES) and mortality rates for acute myocardial infarction (AMI) in Taiwan.

METHODS

A population-based follow-up study included 23,568 patients diagnosed with AMI from 2004 to 2008. Each patient was monitored for 2 years, or until their death, whichever came first. The individual income-related insurance payment amount was used as a proxy measure of patient's individual SES. Neighborhood SES was defined by household income, and neighborhoods were grouped as advantaged or disadvantaged. The Cox proportional hazards model was used to compare the mortality rates between the different SES groups after adjusting for possible confounding risk factors.

RESULTS

After adjusting for potential confounding factors, AMI patients with low individual SES had an increased risk of death than those with high individual SES who resided in advantaged neighborhoods. In contrast, the cumulative readmission rate from major adverse cardiovascular events did not differ significantly between the different individual and neighborhood SES groups. AMI patients with low individual SES had a lower rate of diagnostic angiography and subsequent percutaneous coronary intervention (P<0.001). The presence of congestive heart failure, chronic kidney disease, chronic obstructive pulmonary disease, pneumonia, septicemia, and shock revealed an incremental increase with worse SES (P<0.001).

CONCLUSIONS

The findings indicate that AMI patients with low individual SES have the greatest risk of short-term mortality despite being under a universal health-care system. Public health strategies and welfare policies must continue to focus on this vulnerable group.

CT coronary angiography: impact of adapted statistical iterative reconstruction (ASIR) on coronary stenosis and plaque composition analysis

To assess the impact of adaptive statistical iterative reconstruction (ASIR) on coronary plaque volume and composition analysis as well as on stenosis quantification in high definition coronary computed tomography angiography (CCTA). We included 50 plaques in 29 consecutive patients who were referred for the assessment of known or suspected coronary artery disease (CAD) with contrast-enhanced CCTA on a 64-slice high definition CT scanner (Discovery HD 750, GE Healthcare). CCTA scans were reconstructed with standard filtered back projection (FBP) with no ASIR (0 %) or with increasing contributions of ASIR, i.e. 20, 40, 60, 80 and 100 % (no FBP). Plaque analysis (volume, components and stenosis degree) was performed using a previously validated automated software. Mean values for minimal diameter and minimal area as well as degree of stenosis did not change significantly using different ASIR reconstructions. There was virtually no impact of reconstruction algorithms on mean plaque volume or plaque composition (e.g. soft, intermediate and calcified component). However, with increasing ASIR contribution, the percentage of plaque volume component between 401 and 500 HU decreased significantly (p < 0.05). Modern image reconstruction algorithms such as ASIR, which has been developed for noise reduction in latest high resolution CCTA scans, can be used reliably without interfering with the plaque analysis and stenosis severity assessment.

Coronary artery calcium scoring: Influence of adaptive statistical iterative reconstruction using 64-MDCT

OBJECTIVE

Assessment of coronary artery calcification is increasingly used for cardiovascular risk stratification. We evaluated the reliability of calcium-scoring results using a novel iterative reconstruction algorithm (ASIR) on a high-definition 64-slice CT scanner, as such data is lacking.

METHODS AND RESULTS

In 50 consecutive patients Agatston scores, calcium mass and volume score were assessed. Comparisons were performed between groups using filtered back projection (FBP) and 20-100% ASIR algorithms. Calcium score was measured in the coronary arteries, signal and noise were measured in the aortic root and left ventricle. In comparison with FBP, use of 20%, 40%, 60%, 80%, and 100% ASIR resulted in reduced image noise between groups (7.7%, 18.8%, 27.9%, 39.86%, and 48.56%, respectively; p<0.001) without difference in signal (p=0.60). With ASIR algorithms Agatston coronary calcium scoring significantly decreased compared with FBP algorithms (837.3 ± 130.3; 802.2 ± 124.9, 771.5 ± 120.7; 744.7 ± 116.8, 724.5 ± 114.2, and 709.2 ± 112.3 for 0%, 20%, 40%, 60%, 80%, and 100% ASIR, respectively, p<0.001). Volumetric score decreased in a similar manner (p<0.001) while calcium mass remained unchanged. Mean effective radiation dose was 0.81 ± 0.08 mSv.

CONCLUSION

ASIR results in image noise reduction. However, ASIR image reconstruction techniques for HDCT scans decrease Agatston coronary calcium scores. Thus, one needs to be aware of significant changes of the scoring results caused by different reconstruction methods.

Comparison of regional body composition and its relation with cardiometabolic risk between BMI-matched young and old subjects

OBJECTIVE

Difference in regional body composition between young and old people may be related with differential cardiometabolic risks. We investigated regional body composition in BMI-matched young and old subjects to compare its relation with cardiometabolic risk.

METHODS

We recruited 1:3 gender- and BMI-matched 86 young subjects (mean age 27.3 ± 2.9 years) and 258 older subjects (75.6 ± 8.2 years) from a community. Abdominal visceral (VAT) and subcutaneous adipose tissue (SAT) and muscle area at mid-thigh level were evaluated by computed tomography. Fat depots in the gynoid area and lower extremity were measured by dual energy X-ray absorptiometry. Adiponectin, retinol binding protein-4 (RBP-4), and C-reactive protein (CRP) concentrations, pulse wave velocity (PWV) and ankle-brachial index (ABI) were measured for cardiometabolic risk.

RESULTS

VAT was greater in older subjects while SAT was almost the same, resulting in twice higher VAT/SAT ratio in older men and women (1.03 ± 0.37 and 0.57 ± 0.18) than younger counterparts (0.55 ± 0.24 and 0.23 ± 0.23) (both P < 0.01). Fat mass in the gynoid area and lower extremity was smaller in older subjects than younger subjects. The VAT correlated with adiponectin level negatively and RBP-4 level positively while gynoid fat correlated with them in opposite direction. The CRP levels negatively correlated with mid-thigh muscle in older subjects. Older subjects had higher PWV and lower ABI compared to BMI-matched younger counterparts.

CONCLUSION

In conclusion, older adults in this cohort had increased visceral fat and decreased gynoid and lower extremity fat, along with less muscle mass. These findings may help explain the worse cardiometabolic profiles in the elderly who have the same BMI as the young.