The prevalence of coronary artery calcium among diabetic individuals without known coronary artery disease

OBJECTIVES: We sought to examine the age and gender distribution of coronary artery calcium (CAC) by diabetes status in a large cohort of asymptomatic individuals. BACKGROUND: Among individuals with diabetes, coronary artery disease (CAD) is a major cause of morbidity and mortality. Electron-beam tomography (EBT) quantifies CAC, a marker for atherosclerosis. METHODS: Screening for CAC by EBT was performed in 30,904 asymptomatic individuals stratified by their self-reported diabetes status, gender, and age. The distribution of CAC across the strata and the association between diabetes and CAC were examined. RESULTS: Compared with nondiabetic individuals (n = 29,829), those with diabetes (n = 1,075) had higher median CAC scores across all but two age groups (women 40 to 44 years old and men and women > or =70 years old). Overall, the likelihood of having a CAC score in the highest age/gender quartile was 70% greater for diabetic individuals than for their nondiabetic counterparts. CONCLUSIONS: Younger diabetic individuals appear to have calcified plaque burden comparable to that of older individuals without diabetes. These findings call for future research to determine if EBT-CAC screening has an incremental value over the current CAD risk assessment of individuals with diabetes.     

Framingham risk score and severity of coronary artery disease

Objectives

Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide. Easy-to-perform and reliable parameters are needed to predict the presence and severity of CAD and to implement efficient diagnostic and therapeutic modalities. We aimed to examine whether the Framingham risk scoring system can be used for this purpose.

Methods

A total of 222 patients (96 women, 126 men; mean age, 59.1?±?11.9 years) who underwent coronary angiography were enrolled in the study. Presence of >?%50 stenosis in a coronary artery was assessed as critical CAD. The Framingham risk score (FRS) was calculated for each patient. CAD severity was assessed by the Gensini score. The relationship between the FRS and the Gensini score was analyzed by correlation and regression analyses.

Results

The mean Gensini score was 18.9?±?25.8, the median Gensini score was 7.5 (0–172), the mean FRS was 7.7?±?4.2, and the median FRS was 7 (0–21). Correlation analysis revealed a significant relationship between FRS and Gensini score (r?=?0.432, p?Conclusion Our work suggests that the FRS system is a simple and feasible method that can be used for prediction of CAD severity. As the sample size was small in our study, further large-scale studies are needed on this subject to draw solid conclusions.     

Incremental prognostic value of coronary artery calcium score versus CT angiography among symptomatic patients without known coronary artery disease

Objective

To evaluate the prognostic value and test characteristics of coronary artery calcium (CAC) score for the identification of obstructive coronary artery disease (CAD) in comparison with coronary computed tomography angiography (CCTA) among symptomatic patients.

Methods

Retrospective cohort study at two large hospitals, including all symptomatic patients without prior CAD who underwent both CCTA and CAC. Accuracy of CAC for the identification of ≥50% and ≥70% stenosis by CCTA was evaluated. Prognostic value of CAC and CCTA were compared for prediction of major adverse cardiovascular events (MACE, defined as non-fatal myocardial infarction, cardiovascular death, late coronary revascularization (>90 days), and unstable angina requiring hospitalization).

Results

Among 1145 included patients, the mean age was 55 ± 12 years and median follow up 2.4 (IQR: 1.5–3.5) years. Overall, 406 (35%) CCTA were normal, 454 (40%) had <50% stenosis, and 285 (25%) had ≥50% stenosis. The prevalence of ≥70% stenosis was 16%. Among 483 (42%) patients with CAC zero, 395 (82%) had normal CCTA, 81 (17%) <50% stenosis, and 7 (1.5%) ≥ 50% stenosis. 2 (0.4%) patients had ≥70% stenosis. For diagnosis of ≥50% stenosis, CAC had a sensitivity of 98% and specificity of 55%. The negative predictive value (NPV) for CAC was 99% for ≥50% stenosis and 99.6% for ≥70% stenosis by CCTA. There were no adverse events among the 7 patients with zero calcium and ≥50% CAD. For prediction of MACE, the c-statistic for clinical risk factors of 0.62 increased to 0.73 (p < 0.001) with CAC versus 0.77 (p = 0.02) with CCTA.

Conclusion

Among symptomatic patients with CAC zero, a 1–2% prevalence of potentially obstructive CAD occurs, although this finding was not associated with future coronary revascularization or adverse prognosis within 2 years.     

Association between C-reactive protein and coronary calcium score in coronary artery disease

Background

Both high-sensitivity C-reactive protein (hs-CRP) and spiral computed tomography coronary artery calcium score (CCS) are valid markers of cardiovascular risk. It is unknown whether hs-CRP is a marker of atherosclerotic burden or if it reflects a process leading to acute coronary events.

Methods and results

We studied the association between hs-CRP and CCS in 143 patients who were candidates for coronary artery bypass grafting (CABG). In our cross-sectional study, we found no significant association between hs-CRP and the CCS in bivariant (p = 0.162) and multivariant (p = 0.062) analyses. However, in patients who did not use statins, this association was significant and positive in the bivariant analysis (p = 0.001), but in the multivariant analysis it was negative and significant (p = 0.008).

Conclusion

High-sensitivity CRP was not correlated with CCS. The relationship between CRP and clinical events might not be related to atherosclerotic burden. Measures of inflammation, such as hs-CRP, and indices of atherosclerosis, such as CCS, are likely to provide distinct information regarding cardiovascular risk.     

Framingham risk score and prediction of lifetime risk for coronary heart disease

We investigated whether the Framingham risk score, which was designed to estimate the 10-year risk of coronary heart disease (CHD), differentiates lifetime risk for CHD. All subjects in the Framingham Heart Study examined from 1971 to 1996 who were free of CHD were included. Subjects were stratified into age- and gender-specific tertiles of Framingham risk score, and lifetime risk for CHD was estimated. We followed 2,716 men and 3,500 women; 939 developed CHD and 1,363 died free of CHD. At age 40 years, in risk score tertiles 1, 2, and 3, respectively, the lifetime risks for CHD were 38.4%, 41.7%, and 50.7% for men and 12.2%, 25.4%, and 33.2% for women. At age 80 years, risks were 16.4%, 17.4%, and 38.8% for men and 12.8%, 22.4%, and 27.4% for women. The Framingham risk score stratified lifetime risk well for women at all ages. It performed less well in younger men but improved at older ages as remaining life expectancy approached 10 years. Lifetime risks contrasted sharply with shorter term risks: at age 40 years, the 10-year risks of CHD in tertiles 1, 2, and 3, respectively, were 0%, 2.2%, and 11.6% for men and 0%, 0.7%, and 2.3% for women. The Framingham 10-year CHD risk prediction model discriminated short-term risk well for men and women. However, it may not identify subjects with low short-term but high lifetime risk for CHD, likely due to changes in risk factor status over time. Further work is needed to generate multivariate risk models that can reliably predict lifetime risk for CHD.     

Metabolic syndrome is associated with coronary artery calcium in asymptomatic white Brazilian men considered low-risk by Framingham risk score

The authors investigated whether the metabolic syndrome is associated with coronary artery calcium (CAC) independently of 10-year coronary heart disease risk assessment by Framingham risk scores (FRS) in asymptomatic white Brazilian men. In a group of 458 men (mean age 46+/-7 years), the 10-year coronary heart disease risk was 9%+/-8%, and the metabolic syndrome and CAC were present in 24% and 41% of the participants, respectively. Compared with those classified as low risk (<10% FRS; n=256), men with FRS of 10% or more had an odds ratio of 4.57 (95% confidence interval, 3.08-6.82; P<.0001) for the presence of any CAC. The prevalence of CAC increased monotonically with the increasing number of metabolic syndrome components (none=29%, 1 or 2=44%, and >or=3=51%, P=.002 for trend). The presence of the metabolic syndrome was associated with an increased risk of CAC: odds ratio, 1.94 (95% CI, 1.05-3.61); however, this finding was significant only in those individuals classified as low risk (FRS <10%). In conclusion, metabolic syndrome is associated with subclinical atherosclerosis in Brazilian participants considered at low risk according to FRS.     

钙化积分与冠状动脉多支病变介入术后预后的相关性

目的 研究冠状动脉钙化积分（CCS）与冠状动脉多支血管病变患者经皮冠状动脉介入治疗（PCI）后近、远期预后的关系.方法 入选145例冠状动脉多支血管病变的冠心病患者,在PCI治疗前均接受了多排螺旋CT （MDCT）检查并计算CCS.根据CCS水平将患者分为三组：CCS≤100、CCS=101～400和CCS＞400组.记录患者PCI操作相关并发症,随访记录患者PCI术后主要不良心血管事件（MACE）情况.结果 CCS＞400组患者Syntax积分[（23.5＆#177;8.8）比（17.9＆#177;8.5）,P＜0.001]、三支血管病变的比率（75.4％比56.3％,P=0.015）和PCI操作相关并发症发生率（21.5％比5.0％,P=0.005）均显著高于CCS≤400组患者.所有患者随访360～2542 d（中位数952 d）,Kaplan-Meier生存分析显示CCS≤100、CCS=101～400和CCS＞400组患者累积无事件生存率差异无统计学意义（84.6％比78.0％比64.6％,P=0.141）.但女性患者中累积无事件生存率差异有统计学意义（100.0％比75.0％比50.0％,Log rank 6.836,P=0.033）.结论 在冠状动脉多支血管病变患者中CCS与PCI预后有关,CCS＞400提示较高的PCI并发症发生率.女性患者CCS越高PCI预后越差.     

冠状动脉0钙化积分人群非钙化性斑块的发生率及其危险因素分析简

目的 利用计算机断层扫描（computerized tomography,CT）冠状动脉成像,研究冠状动脉0钙化积分人群非钙化性斑块的发生率及管腔狭窄程度,并分析其相关危险因素.方法 对968例冠状动脉0钙化积分患者的影像学资料和临床资料进行回顾性分析,所有患者均行64层螺旋CT冠状动脉钙化积分扫描及CT冠状动脉成像检查;采用单因素分析和Logistic回归分析冠状动脉非钙化性斑块形成的相关危险因素.结果 968例患者中,203例（21.0％）检出非钙化性斑块,斑块导致轻度狭窄124例（61.1％）、中度狭窄53例（26.1％）、重度狭窄26例（12.8％）.Logistic回归分析显示原发性高血压（高血压）（OR=3.994,P=0.010）、男性（OR=2.663,P=0.000）、吸烟史（OR=1.376,P=0.001）、甘油三酯增高（OR=3.536,P=0.000）、高密度脂蛋白胆固醇降低（OR=0.653,P=0.008）为冠状动脉非钙化性斑块形成的危险因素.糖尿病史、血清甘油三酯和高密度脂蛋白胆固醇浓度与斑块导致的管腔狭窄程度有关.结论 冠状动脉0钙化积分人群中有相当比例的人存在非钙化性斑块,高血压、高脂血症为非钙化性斑块形成的两大独立危险因素.     

Prediction of coronary heart disease: a comparison between the Copenhagen risk score and the Framingham risk score applied to a Dutch population

OBJECTIVES: To compare the estimation of coronary heart disease (CHD) risk by the Framingham risk score (FRS) and the Copenhagen risk score (CRS) using Dutch population data. DESIGN: Comparison of CHD risk estimates from FRS and CRS. CHD risk-estimations for each separate risk factor. SETTING: Urk, the Netherlands. SUBJECTS: A total of 408 fishermen from Urk, aged 30-65 years, without pre-existing cardiovascular disease. MAIN OUTCOME MEASURES: Absolute CHD risk estimates. RESULTS: The average 10-year risk for CHD was significantly different between the FRS (4.6%, SD 5.0) and the CRS (3.2%, SD 4.1). The correlation between the two estimates was 0.94 (P < 0.001). The Bland-Altman figure shows a large proportion of agreement, but with an increasing difference with increasing average risk. When examining the separate risk factors age, total cholesterol, HDL cholesterol and systolic blood pressure and smoking, there appear differences between the two risk functions. CONCLUSION: Using Dutch population data, differences were found for the calculation of CHD risk with the FRS and the CRS. Further research must be carried out to examine the validity of these risk functions in the Dutch population.     

Coronary artery calcium score, risk factors, and incident coronary heart disease events

BACKGROUND: Whether the absence of coronary artery calcium, or conversely the presence of high volumes of coronary artery calcium, may alter assessment of coronary heart disease risk based on traditional risk factors is uncertain. We sought to identify a potential threshold of coronary artery calcium for clinical use and examine the predictive power of coronary artery calcium in individuals categorized using conventional coronary heart disease risk assessment. METHODS: The study included 10,746 men and women (36.3%) with a mean age of 53.8+/-9.9 years who were either physician- or self-referred for electron beam tomography scanning to a preventive medical clinic. Coronary heart disease risk factors were elicited by use of a questionnaire. RESULTS: During a mean follow-up of 3.5 years, 81 primary events (coronary heart disease death or nonfatal myocardial infarction) occurred. Among individuals with a coronary artery calcium score of zero, the primary event rate was very low (0.4 events per 1000 person-years of observation). When participants were stratified by self-reported coronary heart disease risk factors (0-2, or 3-4), a coronary artery calcium score >or=100 was associated with substantially increased risk of coronary heart disease events within each level of stratification. In a subgroup of participants with available clinical data, similar results were found when participants were categorized by Framingham risk scores. CONCLUSIONS: Coronary artery calcium score can identify individuals at increased risk for coronary heart disease events who otherwise would be considered low-risk based on clinical assessment. A coronary artery calcium score of zero is associated with very low risk for coronary heart disease in the short to intermediate term ( approximately 3.5 years) regardless of the number of risk factors present.     

Relation of degree of physical activity to coronary artery calcium score in asymptomatic individuals with multiple metabolic risk factors

Lack of physical activity (PA) increases risk of coronary heart disease. Metabolic risk factors increase the risk of coronary heart disease and development of advanced coronary artery calcium (CAC). We hypothesized that, in a population with multiple metabolic risk factors (> or =2), the degree of PA would be inversely associated with the degree and prevalence of CAC. After excluding subjects who had known diabetes and coronary heart disease, we studied 779 asymptomatic patients referred for electron beam tomography. All patients had > or =2 of the following metabolic risk factors: blood pressure > 130/85 mm Hg, serum triglycerides >150 mg/dl, serum high-density lipoprotein < 40 and < 50 mg/dl in men and women, respectively, and body mass index >30 kg/m(2). Advanced CAC was defined as a calcium score >75th percentile based on gender and age. In the study, 37% patients were sedentary, 26% engaged in moderate-duration (< 30 minutes 1 to 2 times/week) PA, and 37% engaged in long-duration (> or =30 minutes > or =3 times/week) PA.The median CAC scores were 24 (sedentary), 18 (moderate PA), and 11 (long-duration PA; p <0.002). Advanced CAC was prevalent in 26% of sedentary patients, 24% of patients who performed moderate PA, and 16% of patients who engaged in long-duration PA (p <0.05). On logistic regression analysis, long-duration PA had an independent inverse association with advanced CAC. Thus, asymptomatic patients who have > or =2 metabolic risk factors and who regularly engage in long-duration PA have a lower prevalence of CAC than do those who are sedentary or participate in moderate-duration PA.     

The associated risk factors for coronary artery calcium in asymptomatic individuals with and without diabetes in rural Central Appalachia

Aim

To examine the risk factor of coronary artery calcium (CAC) in individuals with diabetes and those without diabetes in Central Appalachia.

The relationship between soluble CD40 ligand levels and Framingham coronary heart disease risk score in healthy volunteers

Elevated soluble CD40 ligand (sCD40L) levels are associated with an increased risk of cardiovascular events in patients with acute coronary syndromes and in middle-aged healthy women. However, the relationship between sCD40L and global risk assessment remains unclear. The present study was designed to examine the relationship between sCD40L and Framingham Coronary Heart Disease Risk Scores (FCRS) in healthy middle-aged men. The study population consisted of 400 active and retired male firefighters, with no previous history of cardiovascular disease, as part of the Firefighters and Their Endothelium (FATE) study. FCRS correlated poorly with sCD40L levels (p=0.14). Soluble CD40L concentrations correlated only with total (r=0.105; p=0.035) and LDL cholesterol (r=0.104; p=0.039), and CRP levels (r=0.11; p=0.03). Compared with participants with sCD40L levels <4.36 ng/mL (75th percentile), participants with sCD40L levels >4.36 ng/mL had higher total (p=0.016) and LDL cholesterol (p=0.018), CRP levels (p=0.034) and FCRS (p=0.012). Multivariate analysis revealed that CRP level was the only parameter that independently correlated with the sCD40L levels (p=0.032). This is the first study to evaluate the relationship between sCD40L levels and Framingham global risk assessment in a large cohort of otherwise healthy individuals. We demonstrate that sCD40L levels poorly correlate with both the individual components and the calculated FCRS. Long-term follow-up of the FATE study will shed light on whether the predictive value of sCD40L is independent of Framingham based global risk assessment.     

Relation of cardiovascular risk factors and angina status to obstructive coronary artery disease according to categorical coronary artery calcium score

Coronary artery calcium (CAC) is associated with the presence of coronary artery disease (CAD) and cardiovascular risk factors. However, the relation between cardiovascular risk factors and CAD has not yet been fully elucidated in patients with a zero or low coronary artery calcium score (CACS). The purpose of this study was to evaluate the relation of cardiovascular risk factors and angina status to obstructive CAD according to categorical CACS. A total of 753 patients were enrolled in this study. CAC scoring and coronary computed tomographic angiography (CCTA) were performed with dual-source 64-slice CT scanners. The number of patients with a CACS ≤10 and ≤100 were 358 and 528, respectively. Patients with a higher CACS were older and more frequently male, and had a greater frequency of hypertension, diabetes, and hypercholesterolemia. The prevalence of obstructive CAD increased with the CACS. Among patients with a CACS ≤100, age, male gender, diabetes, hypercholesterolemia, and typical angina pectoris were related to obstructive CAD. The presence of hypercholesterolemia was relatively strongly associated with obstructive CAD (OR 6.67, 95% CI 2.91–15.3, p < 0.001) on multivariate analysis. Among patients with a CACS ≤10, men, hypercholesterolemia, and typical angina pectoris were significantly more frequent in patients with than in those without obstructive CAD (p < 0.01). Our data suggest that neither the absence nor low of coronary calcium burden may reliably exclude obstructive CAD in typical symptomatic male patients with hypercholesterolemia. This result may be useful to interpret the relation of CACS to obstructive CAD.     

Obstructive coronary artery disease with a coronary artery calcium score of 0: A case report

Coronary artery calcium (CAC) scoring has emerged as a useful tool in identifying patients who may benefit from more aggressive risk factor modification and for prognostication. Although a CAC score of 0 is associated with a very low prevalence of obstructive epicardial coronary artery disease and low event rates, it can also provide a false sense of reassurance. We present a case of a 39-year-old woman with a CAC score of 0 obtained as part of a coronary computerized tomography angiography study that was ultimately found to have significant left anterior descending artery disease requiring percutaneous coronary intervention and a stent.     

Relation of aortic valve calcium to myocardial ischemic perfusion in individuals with a low coronary artery calcium score

The absence of coronary artery calcium (CAC) is associated with minimal atherosclerosis. Nonetheless, morbid and mortal cardiovascular events occur in patients with low CAC. This study attempts to identify whether calcific deposits outside the coronary arteries or traditional cardiovascular risk variables are associated with myocardial ischemia in patients with low CAC scores. From 1998 to 2006, a total of 605 patients with an Agatston CAC score of 0 to 10 were referred for stress echocardiography or myocardial perfusion imaging. There was a low rate (1.2%) of myocardial ischemia. Seven of 303 patients (2.3%) had ischemia on perfusion imaging. Zero of 302 stress echocardiograms were abnormal. Traditional risk-factor analysis did not predict the presence of ischemia. No differences in age, gender, or self-reported hyperlipidemia, diabetes mellitus, tobacco use, hypertension, or family history of premature heart disease were noted. Contrary to previous belief, patients with myocardial ischemia were not younger or female. Aortic valve calcium (AVC) was associated with ischemia (p = 0.02), with a >10-fold likelihood of having ischemia detected by MPS versus those without AVC (20.0% vs 1.7%). In conclusion, a CAC score <10 is associated with a low rate of myocardial ischemia. AVC may identify a subset of patients who may be at higher risk.     

Usefulness of the Framingham risk score and body mass index to predict early coronary artery calcium in young adults (Muscatine Study)

The value of a coronary artery disease prediction algorithm, the Framingham risk score (score), for detecting coronary artery calcium (CAC) was examined in 385 men and 472 women, aged 29 to 43 years. Scores were compared in subjects with and without CAC and were also used to predict presence of CAC. Receiver-operating characteristic curves were computed to compare different prediction models. The score model was compared with age only, natural logarithm of body mass index (lnBMI) only, and score plus lnBMI models. CAC was detected in 30% of men and 16% of women. The mean score was significantly higher in men and women with CAC. For every 2-point increase in the score, the odds of CAC increased by 30% in women and 20% in men. Significant associations between CAC status and risk factors were observed for age in women, and high- density lipoprotein cholesterol and blood pressure in men and women. The area under the receiver-operating characteristic curve for the score was 0.67 and 0.57 for women and men, respectively. When lnBMI was added to the score model, the area increased to 0.76 in women (lnBMI p <0.0001, score p <0.005). For men, the area increased from 0.57 to 0.67, and the score was no longer significant (p >0.60) in the model with lnBMI (p <0.0001). Score predicts CAC in asymptomatic young adults. Inclusion of lnBMI in the score model adds significantly to the prediction of CAC in women and men. The lnBMI model has a greater predictive value than the score in this young population.