High Coronary Artery Calcium Score Research Articles

Vascular smooth muscle cells sense calcium: a new paradigm in vascular calcification

Calcification of arteries is a complex and dynamic process frequently seen in atherosclerosis, diabetes, and chronic kidney disease. This phenomenon, now considered a distinct inflammatory arteriopathy, has important clinical significance because arterial calcification is associated with increased cardiovascular events and is a strong predictor of poor cardiovascular outcomes.1,2 Patients with high coronary artery calcification scores have a five- to seven-fold increase in the risk of a hard coronary event compared with patients with low calcium scores, and patients with chronic kidney disease and vascular calcification have a 20- to 30-fold increase in cardiovascular mortality.2 Arterial calcification is a pathological process involving the vascular media and adventitia.3 Medial vascular smooth muscle cells (VSMCs) lose their ability to express smooth muscle-specific markers and undergo phenotypic transformation to osteoblast-like cells. Perivascular adventitial cells, microvascular pericytes, and adventitial mesenchymal stem cells also have the potential to express osteoblastic transcription factors, suggesting that, in addition to VSMCs, other vascular cell types contribute to calcification. The course of vascular calcification shares many features with that of bone mineralization, except that whereas skeletal mineralization is a physiological and highly regulated process, vascular calcification is a pathological phenomenon associated with extraskeletal mineralization in the vascular wall.2,3 Passive calcium phosphate deposition, active cell-mediated processes, and inflammatory responses contribute to vascular calcification.4 … *Corresponding author. Tel: +1 613 562 5800; fax: +1 613 562 5487. E-mail address : rtouyz{at}uottawa.ca

Comprehensive evaluation of coronary arteries by multidetector-row cardiac computed tomography according to the glucose level of asymptomatic individuals

BackgroundEarly detection of atherosclerosis in individuals with diabetes is important because of high cardiovascular mortality in this population. We performed multidetector-row computed tomography (MDCT) in asymptomatic individuals to investigate the status of coronary artery stenosis and plaque characteristics depending on the glucose level. Methods and resultsThe plaque burden (number of diseased coronary segments), severity of stenosis, plaques characteristics, and coronary artery calcium score (CACS) were assessed by MDCT in 1043 asymptomatic individuals. Anthropometric parameters and metabolic profiles were also acquired. Twenty-one percents of subjects had plaques and 5% had significant stenosis. Mean (±S.D.) CACS of study population was 17±81. Subjects with impaired fasting glucose (IFG, n=215, 21%) or diabetes (n=112, 11%) had a greater plaque burden, more coronary stenosis (>50% of diameter stenosis) and higher CACS than normal subjects (all, p<0.01). Noncalcified and mixed plaques were observed more in subjects with diabetes (19%) and IFG (11%) than normal (7%). After adjustment for confounding factors, higher fasting glucose was strongly associated with significant coronary stenosis and a greater plaque burden. ConclusionsMore significant coronary stenosis and multivessel involvement, higher CACS, and greater plaque burden were observed in subjects with IFG or diabetes by MDCT, even they are asymptomatic. Proactive screening, irrespective of the imaging modalities used, in asymptomatic subjects with prediabetes and diabetes is helpful to identify those who have a higher cardiovascular morbidity and mortality. Further studies will guide us with respect to which imaging modality is more appropriate.

Abstract 3126: Coronary Artery Calcification as a Predictor of Subsequent Coronary Artery Disease Events

Coronary artery calcification (CAC) as measured by electron beam computed tomography (EBCT) can be used as an indicator of atherosclerotic burden. We have previously reported a cross sectional association between the presence of CAC and history of clinical coronary artery disease (CAD) in type 1 diabetes. In this analysis, we assessed the ability of CAC to predict the incidence of CAD events. Participants from the Pittsburgh Epidemiology of Diabetes Complications Study of childhood onset type 1 diabetes who underwent an EBCT screening (1996–98) and were free of clinical CAD were selected for study (n=236). Mean age at EBCT screening was 36.6 years and diabetes duration 28 years. CAC was calculated using the Agatston score and was used both as a continuous variable (after log transformation) and as a categorical variable. CAD was defined as non-fatal MI (n=4), ischemic ECG changes (Minnesota codes 1.3, 4.1, 4.2, 4.3, 5.1, 5.2, 5.3, 7.1) (n=9), hospitalized unstable angina (n=1), new onset angina leading to revascularization (n=2) or fatal CAD (n=4). Glucose disposal rate (eGDR-insulin sensitivity) was estimated by a regression equation derived from hyperinsulinemic euglycemic clamp studies with terms for waist to hip ratio, HbA 1c , and hypertension. During a mean follow-up of 7.4 years, 20 (8.5%) individuals had an incident event. Individuals who had an event were older, with a greater diabetes duration, systolic blood pressure, HbA 1c , and WBC count, a lower eGDR (all p-values &lt;0.05), and a higher CAC score (p&lt;0.0001). Thus, approximately 24% of persons with CAC ≥200 had a subsequent CAD event compared to only 3% of those with a zero score. In multivariable Cox proportional hazard models with backward elimination, a CAC score greater than zero was a significant predictor of CAD incidence (HR=4.07, 95% CI=1.38–11.96). Other significant predictors comprised diabetes duration (HR=1.07, 95% CI=1.01–1.14) and HbA 1c (HR=1.39, 95% CI=1.10–1.76). The area under the ROC curve increased from 0.720 to 0.784 with the inclusion of CAC score. In this cohort of individuals with type 1 diabetes, CAC is a significant predictor of subsequent CAD status and adds to the prediction beyond standard risk factors. Thus, CAC may be used as a screening tool for CAD risk in type 1 diabetes.

Abstract 2733: Association of Psychological Disorders and Structural Coronary Arterial Disease

Background : Growing numbers of American Veterans are diagnosed with psychological disorders and myocardial infarctions without known preexisting cardiac risk factors. Confronted with this information, we studied the association between psychological disorders and the presence of coronary artery calcium. High risk coronary calcification [Agatston method coronary artery calcium score (CAC) &gt;100] is associated with a striking increase in cardiovascular events (hazard ratio&gt;10) making it an excellent surrogate marker. Methods : From a database of VA patients who have undergone cardiac computed tomography, 483 were studied (age 59±12 years, 86% male). Regression analysis was utilized for comparison of CAC score for individuals with depression, anxiety, post-traumatic stress disorder (PTSD) and substance abuse.. Results : After adjustment for age, gender and cardiac risk factors, the odds ratio of CAC≥100 vs. CAC=0 was 1.24 (95% CI 1.02–2.08, p=0.044) for depression, 2.04 (95% CI 1.11– 6.17, p=0.027) for anxiety, 2.28 (95% CI 1.15–5.76, p=0.026) for PTSD and 2.61 (95% CI 1.14 – 6.03, p=0.022) for substance abuse as compared to normal cohort. Conclusion : Veterans with psychological disorders were found to have a significantly higher coronary artery calcification score than those without such disorders. These findings are independent of age, gender and other traditional cardiac risk factors.

Characterization of blood borne microparticles as markers of premature coronary calcification in newly menopausal women

While the risk for symptomatic atherosclerotic disease increases after menopause, currently recognized risk factors do not identify ongoing disease processes in low-risk women. This study tested the hypothesis that circulating cell-derived microparticles may reflect disease processes in women defined as low risk by the Framingham risk score. The concentration and phenotype of circulating microparticles were evaluated in a cross-sectional study of apparently healthy menopausal women, screened for enrollment into the Kronos Early Estrogen Prevention Study. Microparticles were evaluated by flow cytometry, and coronary artery calcification (CAC) was scored using 64-slice computed tomography scanners. The procoagulant activity of isolated microparticles was determined with a sensitive fluorescent thrombin generation assay. Chronological age, body mass index, serum lipids, systolic blood pressure (Framingham risk score < 10%, range 1-3%), and high-sensitivity C-reactive protein did not differ significantly among women with low (0 < 35; range, 0.3-32 Agatston units) or high (>50; range, 93-315 Agatston units) CAC compared with women without calcification. The total concentration and percentage of microparticles derived from platelets and endothelial cells were greatest in women with high CAC scores. The thrombin-generating capacity of the isolated microparticles correlated with phosphatidylserine expression, which also was greatest in women with high CAC scores. The percentages of microparticles expressing granulocyte and monocyte markers were not significantly different among groups. Therefore, the characterization of platelet and endothelial microparticles may identify early menopausal women with premature CAC who would not otherwise be identified by the usual risk factor analysis.

Accuracy of Multislice Computed Tomography Coronary Angiography

A PUBMED search was performed for peer-reviewed studies published in English from 2002 through August 2006. Accuracy parameters for detection of obstructive coronary artery disease by MSCT (multislice computed tomography) coronary angiography were analyzed on patient and segment basis. Pooled estimates of sensitivity (SN), specificity, positive predictive value, and negative predictive value (NPV) in patient-based analyses were 93%, 82%, 83%, and 92%, respectively. For 64/40-slice MSCT the respective accuracy estimates were 96%, 91%, 93%, and 96% and were better compared with 16-slice MSCT. Also, more segments were evaluated by 64-slice MSCT (96%) compared with 16-slice MSCT (86%). The SN and NPV of MSCT coronary angiography for patients with low coronary artery calcium (CAC) score were 92% and 99% compared with 77% and 89% for patients with high CAC score. The accuracy estimates for MSCT in studying coronary artery by-pass grafts and intracoronary stents showed a SN and NPV of 97% and 97% for graft occlusion or stenosis and only 71% and 93% respectively for in-stent restenosis. Diagnostic accuracy of MSCT coronary angiography has improved with the newer 64-slice versions. High CAC scores can affect the accuracy of MSCT coronary angiography. Although the accuracy of MSCT in evaluating native vessel and graft disease has improved significantly, its reliability in studying intracoronary stents remains uncertain.

THE EFFECTIVENESS OF ROSUVASTATIN IN HIGH RISK PATIENTS TREATMENT

C-reactive protein (CRP) or coronary artery calcium (CAC) score have been suggested to identify a higher risk subset of intermediate-risk individuals, who potentially could be considered for more aggressive therapy. In the Multi-Ethnic Study of Atherosclerosis (MESA), we estimated the proportion of intermediate-risk participants whose risk status might change based on additional testing using CRP and/or CAC score.Framingham 10-year CHD risk scores (FRS) were calculated and cross tabulations were used to determine the percent of individuals at intermediate-risk by FRS with a CRP >3 mg/L and/or CAC score >100 AU. Similar analyses were performed using the gender-specific 75th percentile for CRP and CAC.Of the 30% of participants (N = 1450) classified as intermediate-risk by FRS, 30% had a CRP >3 mg/L and 33% had a CAC score >100 AU. Among intermediate-risk women, 49% had a CRP >3 mg/L compared to 27% of intermediate-risk men (p < 0.0001) while the same percent of intermediate-risk women and men (33%) had a CAC score >100 AU. Eleven percent or less of men or women had both a high CRP and CAC score whether conventional or gender-specific cut points were used. When the percent of intermediate-risk individuals with an elevated CRP and/or CAC score in MESA were applied to NHANES III data, over a million intermediate-risk individuals would move to high risk status if CRP or CAC screening directed treatment strategies were uniformly adopted in the U.S.There were differences in the number of intermediate-risk individuals reclassified as high risk depending on the screening test used, the cut points selected, and the demographics of the individuals being screened. These data highlight current limitations of broadly using risk markers such as CRP and CAC score in an intermediate-risk population.

Relation of a Coronary Artery Calcium Score Higher Than 400 to Coronary Stenoses Detected Using Multidetector Computed Tomography and to Traditional Cardiovascular Risk Factors

Coronary artery calcium (CAC) is an excellent surrogate for atherosclerosis. However, this calcium is nonspecific for obstructive heart disease. This study sought to determine (1) the frequency of significant computed tomographic (CT) angiographic stenoses as a function of CAC scores, and (2) whether high CAC scores were associated with these stenoses independent of traditional risk factors. Subjects (n = 664) underwent Agatston CAC scoring and multidetector CT angiography using current 64-slice technology. Significant stenoses were defined as >60% diameter compromise. Self-reported risk factors and frequency of stenoses were analyzed as a function of CAC scores. The prevalence of risk factors increased significantly as CAC scores increased. Significant univariate associations included age (p <0.001), male gender (p <0.001), hypertension (p <0.001), and hyperlipidemia (p <0.001). There was also a significant association between CAC scores and the frequency of significant CT angiographic stenoses (p <0.001 for trend). The frequency of CT angiographic stenoses increased as CAC scores increased, with 7.9%, 8.3%, 14.5%, and 27.2% prevalences of significant stenoses in those with CAC scores of 1 to 100, 101 to 400, 401 to 1,000, and >1,000, respectively. Conversely, no significant lesions were found in those with no CAC. Multivariable logistic regression analysis controlling for traditional risk factors showed odds ratios for CAC score of 401 to 1,000 and >1,000 for having significant stenoses of 3.1 (95% confidence interval 1.6 to 6.0) and 6.9 (95% confidence interval 3.5 to 13.5), respectively. In conclusion, a CAC score >400 was significantly associated with multidetector CT angiographic stenoses independently of traditional risk factors.

Effect of Patient Visualization of Coronary Calcium by Electron Beam Computed Tomography on Changes in Beneficial Lifestyle Behaviors

Despite convincing data demonstrating the benefits of aspirin (ASA), exercise, and dietary changes for both primary and secondary prevention of coronary heart disease, they remain underused. In this study, we assess whether higher coronary artery calcium (CAC) scores determined by electron beam computed tomography (EBCT) are associated with beneficial lifestyle behaviors in asymptomatic individuals. A total of 980 asymptomatic patients referred for EBCT risk assessment by their primary physician were sent a survey questioning them about health behaviors. We evaluated long-term ASA utilization, exercise, and dietary changes based on CAC using multivariable analysis. The study population consisted of 980 individuals (78% men, mean age 60 +/- 8 years) who were followed for a mean of 3 +/- 2 years after an initial EBCT scan. Overall, ASA initiation was lowest (29%) among those with CAC = 0, and gradually increased with higher CAC scores (1 to 99, 55%; 100 to 399, 61%; > or =400, 63%; p <0.001 for trend). Similarly, dietary changes and exercise were lowest (33% and 44%, respectively) among those with CAC = 0 and gradually increased with higher CAC scores (1 to 99, 40%; 100 to 399, 58%; > or =400, 56%; p <0.001 for trend for dietary changes; and 1 to 99, 62%; 100 to 399, 63%; > or =400, 67%; p <0.001 for trend for exercise). In multivariable analysis, greater baseline CAC was strongly associated with initiation of ASA therapy, dietary changes, and increased exercise. In conclusion, in addition to risk stratification of asymptomatic individuals, determination of CAC may also improve utilization of ASA therapy and behavioral modification.

Serum Osteoprotegerin as a Screening Tool for Coronary Artery Calcification Score in Diabetic Pre-Dialysis Patients

Although cardiovascular disease is a principal cause of death in patients with chronic kidney disease (CKD), it is often asymptomatic in diabetic patients. The coronary artery calcification score (CACS) measured by multidetector computed tomography (MDCT) is useful for screening ischemic heart disease in the general population. We investigated which clinical parameters predict high CACS in predialysis diabetic nephropathy (DN). Participants were 85 patients with DN. Nobody had any history of coronary angioplasty or coronary bypass surgery. We measured blood counts, blood chemistry, bone alkaline phosphatase, intact-PTH, interleukin-6, osteoprotegerin (OPG), hemoglobin A1c, 25-hydroxyvitamin D (25(OH)D) and fetuin-A. CACS and bone mineral density (BMD) were measured by a single 16-slice MDCT and DEXA, respectively. The median value of CACS equaled 256 Agatston units (range 0-4494 units). Stepwise increase in CACS with CKD stage progression was observed (p<0.01 for trend). Simple regression analyses showed that Log (CACS+1) was positively correlated with age, systolic blood pressure, phosphorus and OPG. In addition, it was negatively correlated with nutritional parameters, such as body mass index, albumin, total-cholesterol and 25(OH)D. Fetuin-A and BMD had no impact on CACS. Multiple regression analyses showed that low albumin and high OPG were associated with high CACS. The sensitivity of OPG for detecting CACS>200 was 80%, when the cut-off value was 1.2 ng/mL. In conclusion, CACS increased with CKD stage progression in predialysis DN patients. Serum OPG was positively associated with high CACS and can be a useful screening tool for severe coronary calcification, whereas no association between fetuin-A and CACS was found.

Prognostic Value of Number and Site of Calcified Coronary Lesions Compared With the Total Score

This study sought to evaluate the long-term prognostic value of the number and sites of calcified coronary lesions and to compare the accuracy of number of calcified lesions with the extent of total calcium score. There is a strong relationship between mortality and total coronary artery calcium (CAC) score. It is not known whether the number of calcified lesions or their location influences outcome. A total of 14,759 asymptomatic patients were referred for evaluation of CAC scanning using electron beam tomography. Univariable and multivariable Cox proportional hazards models were developed to estimate time to all-cause mortality at, on average, 6.8 years (n = 281). Risk-adjusted annual mortality was 0.19% (95% confidence interval 0.18% to 0.21%) for patients without any calcified lesions. For patients with >20 lesions, annual risk-adjusted mortality exceeded 2% per year. Mortality rates were significantly higher for left main lesions as compared to other coronary arteries with annual mortality rates of 1.3%, 2.1%, 9.2%, and 13.6% for 1 to 2, 3 to 5, and > or =6 lesions, respectively (p < 0.0001). For left main CAC scores of 0 to 10, 11 to 100, 101 to 399, and 400 to 999, annual risk-adjusted mortality was 0.33%, 0.81%, 1.73%, and 7.71%, respectively (p < 0.0001). All 4 patients with a CAC score of > or =1,000 in the left main died during follow-up. However, patients with more frequent calcified lesions also had higher CAC scores. Specifically, > or =81% of patients with >10 calcified lesions also had a CAC score > or =100. With exception, for patients with CAC scores > or =1,000, annual mortality was dramatically higher at 3.0% to 4.5% for those with 1 to 5 calcified lesions as compared with 1.1% to 2.0% for those with 6 or more lesions (p < 0.0001). We report that mortality rates increased proportionally with the number of calcified lesions. Although predictive information is contained in the number of calcified lesions, its added statistical value is minimal. With exception, patients with frequent lesions in the left main or those with a few large calcified lesions have a particularly high mortality risk.

Is Chronic Kidney Disease Associated with Coronary Artery Stenosis or Calcification as Assessed by Multi-detector Row Computed Tomography?

The coronary artery calcification (CAC) score as determined by multi-detector row computed tomography (MDCT) is known to predict coronary artery disease (CAD). Chronic kidney disease (CKD) is also known to be a risk factor for CAD. Little is known about the relationship between CKD and the severity of coronary artery stenosis or CAC as determined by MDCT, a non-invasive method for screening. The subjects included 313 consecutive patients who underwent MDCT angiography. We quantified the number of significantly stenosed vessels in coronary vessel disease (VD) and CAC score using MDCT and measured body mass index (BMI), waist circumference and blood pressure. We also analyzed plasma levels of lipid profile, hemoglobin A1c, uric acid, and creatinine. Furthermore, we calculated the estimated glomerular filtration rate (eGFR), and defined CKD as GFR <60 mL/min/1.73 m(2). eGFR levels in the 3-VD group were significantly lower than those in patients without stenosed vessels. In the two classifications that were based on the CAC score [low (L, 0-444) and high (H, >or=445)] in our previous report, the H group was significantly associated with age, number of VD, incidence of hypertension and CKD. Multivariate logistic regression analysis revealed that the high CAC score group was significantly correlated with age (p=0.0023), CKD (p=0.0109) and number of VD (p=0.0470). CKD may contribute to the severity of CAD associated with the progression of CAC. Therefore, therapeutic intervention for CKD, in addition to the improvement of conventional risk factors, is needed to prevent CAD when MDCT is performed.

Abstract 2539: Relationship of Aortic Wall Thickness and Distensibility with Subclinical Measures of Cardiovascular Disease: The Multi-Ethnic Study of Atherosclerosis

Background: While increased carotid intima-media thickness (IMT) is considered an independent risk factor for cardiovascular disease (CVD), little is known about the relationship of aortic thickness (AWT) and aortic distensibility (AD) with CVD risk factors. We studied the association of these aortic parameters with other measures of subclinical CVD. Methods: The Multi-Ethnic Study of Atherosclerosis (MESA) includes 6,814 participants, aged 45– 85 years; white, African-American, Hispanic, and Chinese. AD and AWT were measured by MRI. Average and maximum AWT of the proximal descending thoracic aorta were used as two measures of AWT. AD was calculated as the difference in aortic cross-sectional area indexed by diastolic cross-sectional area and average pulse pressure. IMT of the common and internal carotid arteries were determined by high-resolution B-mode ultrasonography and LV mass was determined by MRI. Phantom-adjusted Agatston calcium score from CT images was used to define coronary artery calcification (CAC). Results: In univariable analyses, higher carotid IMT, ankle-brachial index (ABI) &lt;0.9, CAC score, LV mass, and presence of coronary calcium were associated with lower AD and higher AWT (table ). However, in multivariable analyses, the only measures of subclinical CVD that had significant associations with both AD and AWT were LV mass and carotid IMT, while ABI was associated with only AWT. After adding age to the models, CAC score was no longer associated with either AD or AWT. The relationship between CAC score and AD varied by ethnicity; higher CAC score was associated with higher AD only in African Americans. Conclusions: AD and AWT are related to carotid IMT and LV mass, even after controlling for traditional risk factors. The associations of AD and AWT with CAC appears to be mainly due to their relationship with conventional risk factors, particularly age. Overall, AWT and AD may have closer relationship with LV mass than with subclinical atherosclerosis.

Coronary artery calcium score: è cambiato qualcosa?

Calcium deposition along the coronary artery walls is a surrogate biomarker for atherosclerosis, and its presence in the coronary arteries could reflect the severity of coronary artery disease (CAD) High coronary artery calcium score (CACS) correlates with advanced disease and a higher likelihood of coronary stenoses. Many studies have supported the role of CACS as a screening tool for CAD. Historically, CACS was introduced with electron beam computed tomography (EBCT), but in the last 30 years, many changes have occurred in CT, where the development of multidetector spiral technology has made reliable the noninvasive study of the heart and coronary arteries. Correlation studies with intravascular ultrasound (IVUS) and histology have demonstrated the capability of multidetector CT (MDCT) to provide information useful for characterising atherosclerotic plaque in a noninvasive manner. This has shifted the interest from heavily calcified deposits to plaque with a low-density core and small, superficial calcified nodules, features more frequently present in atherosclerotic plaque prone to rupture and responsible for acute coronary events (culprit lesions). The purpose of this review article is to summarise the recent evolution and revolution in the field of CT, strengthen the importance of a coronary CT study not limited to CACS evaluation and CAD grading but also used to obtain information about plaque composition, and to improve stratification of the patient at risk for acute coronary events.

Detection of coronary and peripheral artery calcification in patients with chronic kidney disease stages 3 and 4, with and without diabetes

The purpose of this study was to describe the prevalence and extent of coronary artery calcification (CAC) in subjects with chronic kidney disease (CKD) stages 3 and 4 comparing those with and without diabetes. We also wished to determine if the presence of peripheral artery calcification (PAC) would assist in identifying patients positive for CAC. CAC was detected by multi-slice computed tomography and PAC was detected by plain foot radiography. Study population was 112 patients, 54 with diabetes and 58 without, all asymptomatic for heart disease. Demographic and laboratory data were collected and analysed. The prevalence of CAC in CKD patients was 76 and 46.5% with and without diabetes, respectively. Patients with diabetes had higher CAC scores with more vessels affected, and in the presence of diabetes men and women had the same risk for CAC. In patients with diabetes, age was the unique explanatory variable for detecting the presence of CAC, while age and smoking history predicted severity. In patients without diabetes, age, male gender, body mass index, estimated glomerular filtration rate and serum phosphate levels predicted the presence of CAC, while parathyroid hormone predicted severity. Prevalence of PAC was 63 and 12% in subjects with and without diabetes. PAC detected by foot radiography was not an adequate alternative-screening marker for identifying patients with CAC. CAC is common in CKD stages 3 and 4 patients, especially in men and women with diabetes.

Severe coronary artery calcifications are associated with ischemia in patients undergoing medical therapy

The role of coronary artery calcification (CAC) detection in individuals undergoing medical therapy is controversial. These patients frequently exhibit an artificially low clinical suspicion for obstructive heart disease. Whether detection of CAC adds value to their assessment is unknown. We conducted a cross-sectional analysis of 703 adequately treated individuals who had CAC scoring with electron beam computed tomography and myocardial perfusion imaging within 6 months. We assessed the association of risk factor analysis and CAC scoring with myocardial perfusion imaging abnormalities. Univariate associations between ischemia and male gender, low high-density lipoprotein, high body mass index, diabetes, and CAC score were noted. Despite reasonable control of blood pressure and low-density lipoprotein, the prevalence of inducible ischemia was 0.8%, 4.8%, 5.7%, 8.0%, and 15.1% across CAC scores of 0 to 10, 11 to 100, 101 to 400, 401 to 1000, and greater than 1000, respectively (P < .001 for trend). Logistic regression analysis demonstrated that, after adjustment for risk factors, the odds of ischemia was 3.0 (95% confidence interval, 1.5-5.7) in individuals with CAC scores greater than 400 compared with those with CAC scores of 400 or less. The presence of a CAC score greater than 400 is associated with ischemia in a population receiving good medical therapy. The detection of significant CAC in these individuals warrants additional evaluation for ischemia.

The impact of the menopause on coronary artery calcification examined by multislice computed tomography scanning

Background and aimsTo examine whether there is a difference in coronary artery calcification (CAC) scores between males and females aged above 50years. Methods and resultsA total of 479 subjects aged between 40 and 70years with no clinical or family history of cardiovascular disease (CVD) were enrolled for this study. All subjects were assessed by multislice CT scanning (MCTS), and the CAC scores obtained were assigned to one of four quartiles for further assessment and comparison. The main outcome evaluated was the percentage of high CAC scores and mean CAC scores, comparing males and females of different age groups.This study found that the percentage of high CAC scores increased markedly from 5% (40–49 age group) to 21.2% (50–59 age group) among females. The increase was significantly less when comparing males from different age groups (from 25% in the 40–49 age group to 31.2% in the 50–59 age group). Females had higher odds ratios (ORs) postmenopausally (4.3 in the 50–59 age group) than males in the same age group (1.6). ConclusionsThese initial findings seem to indicate that above 50years of age, CAC is more dependent on age in females than in males, which might be due to the effect of the menopause.

Association of pulse wave velocity with vascular and valvular calcification in hemodialysis patients

The recent Kidney Disease: Improving Quality Outcomes (KDIGO) recommendations called for an investigation of the relationship between various radiological methods to assess cardiovascular calcification and measures of arterial stiffness. Accordingly, in 131 adult maintenance hemodialysis patients, we investigated the association of aortic pulse wave velocity (PWV) with calcification of cardiac valves on echocardiography, coronary artery, and thoracic aorta calcium on computed tomography and a calcification score of the abdominal aorta obtained on a plain abdominal X-ray. All tests were performed within a week. Mean PWV increased as the severity of coronary artery, thoracic, and abdominal aorta calcium scores increased (each P<0.05). No trend was present for number of valves with calcification. After multivariable adjustment, abdominal aorta X-ray calcium scores remained associated with PWV (P=0.004), whereas the association of PWV with thoracic aorta and coronary artery calcium scores became marginal (P=0.308 and P=0.083, respectively). No association was found between number of calcified valves and PWV. This study demonstrates a strong association between abdominal aorta calcification on plain X-ray and PWV and a borderline association with thoracic aorta and coronary artery calcification. Sudden death and congestive heart failure, two frequent causes of death in hemodialysis, are likely caused by increased arterial stiffness that can be closely predicted by the presence of aortic calcification on plain X-rays.

Clinical Outcomes After Both Coronary Calcium Scanning and Exercise Myocardial Perfusion Scintigraphy

The purpose of this work was to assess the prognosis in patients undergoing both coronary artery calcium (CAC) scanning and exercise myocardial perfusion scintigraphy (MPS). Whereas the prognostic effectiveness of MPS is well established, recent studies indicate that quantification of CAC also predicts cardiac outcomes. However, prognostic information is not yet available upon which to guide the management of patients who have had both tests. We assessed the frequency of cardiac death and myocardial infarction over a mean follow-up of 32 +/- 16 months in 1,153 patients undergoing both CAC scanning and MPS. Results were compared with those from a referent cohort of 9,308 patients who had earlier undergone MPS only. The frequency of myocardial ischemia rose with increasing CAC scores (p < 0.001), but ischemia was present in only 64 patients. Among the 1,089 nonischemic patients, of which only 3 (0.3%) underwent early revascularization, the annualized cardiac event rate was <1% in all CAC subgroups, including those with CAC scores >1,000. Kaplan-Meier analysis revealed similarly low cardiac event rates among nonischemic patients with CAC scores >1,000 and nonischemic patients with Bayesian coronary artery disease likelihood > or =85%. Late myocardial revascularization rates were also similar in these 2 groups. Among patients with nonischemic MPS studies, high CAC scores do not confer an increased risk for cardiac events. Thus, although patients with high CAC scores may be considered for intensive medical therapy to prevent future coronary artery disease events, a normal MPS study in such patients suggests no need for more aggressive interventions.

Prevalence of the metabolic syndrome is increased in rheumatoid arthritis and is associated with coronary atherosclerosis

Patients with rheumatoid arthritis (RA) have accelerated atherosclerosis. The metabolic syndrome, a cluster of cardiovascular risk factors, identifies cardiovascular risk. We tested the hypotheses that patients with RA have a higher prevalence of the metabolic syndrome, particularly the WHO-defined syndrome that requires insulin resistance, and that this is associated with coronary atherosclerosis. The prevalence of the metabolic syndrome was determined using the modified WHO and NCEP III criteria in 154 patients with RA (88 with early RA and 66 with long-standing RA) and 85 control subjects. Coronary-artery atherosclerosis was detected by electron beam computed tomography. The WHO-defined metabolic syndrome was present in 42% of patients with long-standing RA, 31% with early RA and 11% of controls ( P < 0.001); the NCEP-defined metabolic syndrome was present in 42% of patients with long-standing RA, 30% with early RA and 22% of controls ( P = 0.03). Patients with the WHO-defined metabolic syndrome had an increased risk of having higher coronary-artery calcification scores, independent of age and sex (OR = 2.02, 95% CI: 1.03–3.97, P = 0.04). In conclusion, patients with RA have a higher prevalence of the metabolic syndrome than control subjects. Inflammation-associated metabolic syndrome is a mechanism that may contribute to increased coronary-artery atherosclerosis in RA.