Multidetector row CT in assessment of coronary artery calcification on hemodialisis

Vascular calcification is a strong predictor of cardiovascular and all-cause mortality. Coronary artery calcification is more frequent, more extensive and progresses more rapidly in CKD than in general population. They are also considered a marker of coronary heart disease, with high prevalence and functional significance. It suggests that detection and surveillance may be worthwhile in general clinical practice. New non-invasive image techniques, like Multi-detector row CT, a type of spiral scanner, assess density and volume of calcification at multiple sites and allow quantitative scoring of vascular calcification using calcium scores analogous to those from electron-beam CT. We have assessed and quantified coronary artery calcification with 16 multidetector row CT in 44 patients on hemodialysis and their relationship with several cardiovascular risk factors. Coronary artery calcification prevalence was of 84 % with mean calcium score of 1580 +/- 2010 ( r 0-9844) with calcium score > 400 in 66% of patients. It was usually multiple, affecting more than two vessels in more than 50%. In all but one patient, left anterior descending artery was involved with higher calcium score level at right coronary artery. Advanced age, male, diabetes, smoking, more morbidity, cerebrovascular disease previous, and calcium-binders phosphate and analogous vitamin D treatment would seem to be associated with coronary artery calcification. Coronary artery calcification is very frequent and extensive, usually multiple and associated to modifiable risk factors in hemodialysis patients. Multi-detector-row CT seems an effective, suitable, readily applicable method to assess and quantify coronary artery calcification.     

Screening patients for subclinical atherosclerosis with non-contrast cardiac CT

Accurate risk assessment may be helpful in decreasing cardiovascular events through more appropriate targeting of preventive measures. Traditional risk assessment may be refined with the selective use of coronary artery calcium score (CACS) or other methods of subclinical atherosclerosis measurement. This article reviews information pertaining to the clinical use of CACS for assessing coronary atherosclerosis as a useful predictor of coronary artery disease (CAD) in certain population of patients. Coronary calcification is a marker of atherosclerosis that can be quantified with the use of cardiac CT and it is proportional to the extent and severity of atherosclerotic disease. The published studies demonstrate a high sensitivity of CACS for the presence of coronary artery disease but a much lower specificity for obstructive CAD depending on the magnitude of the CACS. Several large clinical trials have found clear, incremental predictive value of CACS over the Framingham risk score when used in asymptomatic patients. However, early detection of CAD by Electron Beam Tomography (EBT) screening has not convincingly demonstrated a reduction in mortality and morbidity. Nevertheless, relevant prognostic information obtained may be useful to initiate or intensify appropriate treatment strategies to slow the progression of existing atherosclerotic vascular disease. Current data suggest intermediate-risk patients may benefit most from further risk stratification with cardiac CT, as CAC testing is effective at identifying increased risk and in one study motivating effective behavioral changes. Randomized clinical trials will help determine if selective use of cardiac CT in the intermediate-risk patient would lead to more appropriate use of pharmacologic therapy and improved clinical outcomes.     

Aortic calcification is associated with coronary artery calcification and is a potential surrogate marker for ischemic heart disease risk: A cross-sectional study

Coronary artery calcification, an established marker of atherosclerotic plaque burden associated with increased risk of coronary artery disease, is routinely evaluated using electron beam computerized tomography or multidetector computed tomography (CT). However, aortic calcification, which is also a risk factor for adverse cardiac events, is not frequently assessed, despite being easily detected via standard chest radiography. We therefore sought to clarify the association between aortic calcification and significant coronary artery calcification to determine the feasibility of performing chest radiography to evaluate the risk of future cardiovascular events.Data from 682 consecutive patients who underwent cardiac CT scanning at our institution from May to September 2012 were included in this cross-sectional analysis. Electrocardiographic-gated CT was used to qualitatively evaluate calcification in 6 aortic segments. Cardiac contrast-ehnanced CT was performed to identify significant calcification of the coronary artery. Calcification was quantified by calculating the Agatston score, and the relationship between significant coronary artery calcification and calcification at each aortic site was evaluated.Among the aortic sites, calcification was most commonly observed in the aortic arch (77.4% of patients). Significant coronary artery calcification was observed in 267 patients (39.1%). Calcification in the ascending aorta, aortic arch, descending aorta, abdominal aorta, and aortic valve were significantly associated with the presence of coronary artery calcification after adjustment for cardiovascular risk factors and statin use (odds ratios [95% confidence intervals] 4.21 [2.55, 6.93], 1.65 [1.01, 2.69], 2.14 [1.36, 3.36], 2.87 [1.83, 4.50], and 3.32 [2.02, 5.46], respectively). Mitral valve calcification was weakly but nonsignificantly associated with coronary artery calcification (odds ratio 1.84 [95% confidence interval 0.94, 3.62]). Calcification of each aortic segment assessed was significantly associated with Agatston score ≥ 100.Aortic calcification was associated with coronary artery calcification. Calcification of the aortic arch, which can be readily detected by routine chest radiography, may be associated with coronary artery calcification and its assessment should therefore be considered to identify patients at increased risk of cardiovascular events. Further studies are warranted to confirm these findings.     

血透患者冠状动脉钙化多层螺旋CT评价及与心血管事件的关系

目的 通过对血液透析患者进行多层螺旋CT冠状动脉钙化评分,分析其与心血管事件发生的关系.方法 29例初始血液透析患者(透析龄<6个月)接受冠状动脉多层螺旋CT钙化评价及相关因素检测,随访评价心血管事件;随访时间为18个月.结果 所有29例患者多层螺旋CT冠状动脉扫描:62.07%(18/29)的患者存在冠状动脉钙化,平均钙化积分为482.41±739.97;18个月随访期内,发生心血管事件23例次,其中冠状动脉钙化组22例次,无冠状动脉钙化组仅1例次(P=0.001);心血管事件发生与冠状动脉钙化相关(Spearman's Rho=0.882,P<0.0005);多元逐步回归分析表明,冠状动脉钙化与年龄和高血磷有关(P=0.013,P=0.043),其中,C反应蛋白、血钙、全段甲状旁腺激素、胆固醇、甘油三酯、高密度脂蛋白、低密度脂蛋白、体重指数、收缩压、舒张压未能进入回归方程(P>0.05);随访期内,因心血管事件死亡6例,占15.79%,其中冠状动脉钙化组5例,无冠状动脉钙化组1例;Kaplan-Meier生存分析显示,无心血管事件生存率两组无统计学差异(P=0.2150).结论 血液透析患者冠状动脉钙化多层螺旋CT评分有助于心血管事件发生危险度的评价.     

The association between coronary artery calcification and mean platelet volume in the general population

Patients with coronary artery calcification have an increased risk of coronary vascular events and mortality. Coronary artery calcification can be quantified using the coronary calcium score (CCS) from multi-detected row computed tomography (MDCT), and the score is proportionally related to the severity of atherosclerotic disease. Mean platelet volume (MPV) is gaining interest as a new independent cardiovascular risk factor. Accordingly, the aim of our study was to evaluate the relationship between CCS and MPV in the general population. A total of 2116 individuals were enrolled from a health promotion center between July 2007 and June 2010. Among them, 259 subjects were included in the final analysis. MDCT was used to measure CCS and CCS?>?1 was defined as the presence of coronary calcification. The MPV value was significantly higher in the coronary artery calcification group than in the control group. Multivariate analyses showed that MPV was positively associated with coronary calcification (OR, 1.61; 95% CI 1.02–2.55). In summary, there was a significant association between coronary artery calcification and MPV in the general population. Therefore, the detection of elevated MPV should alert clinicians to the coexistence of multiple underlying CVD risk factors warranting early evaluation and treatment.     

The association between coronary artery calcification and mean platelet volume in the general population

Patients with coronary artery calcification have an increased risk of coronary vascular events and mortality. Coronary artery calcification can be quantified using the coronary calcium score (CCS) from multi-detected row computed tomography (MDCT), and the score is proportionally related to the severity of atherosclerotic disease. Mean platelet volume (MPV) is gaining interest as a new independent cardiovascular risk factor. Accordingly, the aim of our study was to evaluate the relationship between CCS and MPV in the general population. A total of 2116 individuals were enrolled from a health promotion center between July 2007 and June 2010. Among them, 259 subjects were included in the final analysis. MDCT was used to measure CCS and CCS?>?1 was defined as the presence of coronary calcification. The MPV value was significantly higher in the coronary artery calcification group than in the control group. Multivariate analyses showed that MPV was positively associated with coronary calcification (OR, 1.61; 95% CI 1.02-2.55). In summary, there was a significant association between coronary artery calcification and MPV in the general population. Therefore, the detection of elevated MPV should alert clinicians to the coexistence of multiple underlying CVD risk factors warranting early evaluation and treatment.     

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.     

Multislice computed tomography angiography in the diagnosis of coronary artery disease

Multislice CT angiography represents one of the most exciting technological revolutions in cardiac imaging and it has been increasingly used in the diagnosis of coronary artery disease. Rapid improvements in multislice CT scanners over the last decade have allowed this technique to become a potentially effective alternative to invasive coronary angiography in patients with suspected coronary artery disease. High diagnostic value has been achieved with multislice CT angiography with use of 64- and more slice CT scanners. In addition, multislice CT angiography shows accurate detection and analysis of coronary calcium, characterization of coronary plaques, as well as prediction of the disease progression and major cardiac events. Thus, patients can benefit from multislice CT angiography that provides a rapid and accurate diagnosis while avoiding unnecessary invasive coronary angiography procedures. The aim of this article is present an overview of the clinical applications of multislice CT angiography in coronary artery disease with a focus on the diagnostic accuracy of coronary artery disease; prognostic value of coronary artery disease with regard to the prediction of major cardiac events; detection and quantification of coronary calcium and characterization of coronary plaques. Limitations of multislice CT angiography in coronary artery disease are also briefly discussed, and future directions are highlighted.     

Determination of Pericardial Adipose Tissue Increases the Prognostic Accuracy of Coronary Artery Calcification for Future Cardiovascular Events

Objectives: Pericardial adipose tissue (PAT) is associated with coronary artery plaque accumulation and the incidence of coronary heart disease. We evaluated the possible incremental prognostic value of PAT for future cardiovascular events. Methods: 145 patients (94 males, age 60 ± 10 years) with stable coronary artery disease underwent coronary artery calcification (CAC) scanning in a multislice CT scanner, and the volume of pericardial fat was measured. Mean observation time was 5.4 years. Results: 34 patients experienced a severe cardiac event. They had a significantly higher CAC score (1,708 ± 2,269 vs. 538 ± 1,150, p < 0.01), and the CAC score was highly correlated with the relative risk of a future cardiac event: 2.4 (1.8-3.7; p = 0.01) for scores >400, 3.5 (1.9-5.4; p = 0.007) for scores >800 and 5.9 (3.7-7.8; p = 0.005) for scores >1,600. When additionally a PAT volume >200 cm(3) was determined, there was a significant increase in the event rate and relative risk. We calculated a relative risk of 2.9 (1.9-4.2; p = 0.01) for scores >400, 4.0 (2.1-5.0; p = 0.006) for scores >800 and 7.1 (4.1-10.2; p = 0.005) for scores >1,600. Conclusions: The additional determination of PAT increases the predictive power of CAC for future cardiovascular events. PAT might therefore be used as a further parameter for risk stratification.     

Cardiac calcification in adult hemodialysis patients. A link between end-stage renal disease and cardiovascular disease?

OBJECTIVES: We sought to determine clinical and laboratory correlates of calcification of the coronary arteries (CAs), aorta and mitral and aortic valves in adult subjects with end-stage renal disease (ESRD) receiving hemodialysis. BACKGROUND: Vascular calcification is known to be a risk factor for ischemic heart disease in non-uremic individuals. Patients with ESRD experience accelerated vascular calcification, due at least in part to dysregulation of mineral metabolism. Clinical correlates of the extent of calcification in ESRD have not been identified. Moreover, the clinical relevance of calcification as measured by electron-beam tomography (EBT) has not been determined in the ESRD population. METHODS: We conducted a cross-sectional analysis of 205 maintenance hemodialysis patients who received baseline EBT for evaluation of vascular and valvular calcification. We compared subjects with and without clinical evidence of atherosclerotic vascular disease and determined correlates of the extent of vascular and valvular calcification using multivariable linear regression and proportional odds logistic regression analyses. RESULTS: The median coronary artery calcium score was 595 (interquartile range, 76 to 1,600), values consistent with a high risk of obstructive coronary artery disease in the general population. The CA calcium scores were directly related to the prevalence of myocardial infarction (p < 0.0001) and angina (p < 0.0001), and the aortic calcium scores were directly related to the prevalence of claudication (p = 0.001) and aortic aneurysm (p = 0.02). The extent of coronary calcification was more pronounced with older age, male gender, white race, diabetes, longer dialysis vintage and higher serum concentrations of calcium and phosphorus. Total cholesterol (and high-density lipoprotein and low-density lipoprotein subfractions), triglycerides, hemoglobin and albumin were not significantly related to the extent of CA calcification. Only dialysis vintage was significantly associated with the prevalence of valvular calcification. CONCLUSIONS: Coronary artery calcification is common, severe and significantly associated with ischemic cardiovascular disease in adult ESRD patients. The dysregulation of mineral metabolism in ESRD may influence vascular calcification risk.     

Imaging of calcified coronary arteries with multislice computed tomography

Reliable noninvasive detection of coronary artery disease is a prime goal in clinical cardiology. The aim of this study was to investigate the accuracy of multislice computed tomography in detecting coronary artery disease in correlation to the calcium score. Fifty patients with 61 stenoses > 50% and 41 occlusions underwent multislice computed tomography and conventional coronary angiography. Calcium scoring was calculated for the total coronary artery territory and patients were divided into 3 groups based on this score. Multislice computed tomography visualized 89% (365/500) of all coronary segments. The sensitivity and specificity for detection of stenoses > 50% or occlusion was 47%-92%, and 97%-100% for the calcium score. Forty of 500 segments were underestimated by multislice computed tomography, of which 39 were in the group with a calcium score > 400. Multislice computed tomography allows noninvasive angiographic evaluation of coronary artery disease with high diagnostic accuracy. However, the method strongly depends on the degree of vascular calcification and underestimates the degree of stenosis according to the calcium score. This new technology holds promise for noninvasive risk assessment in patients with known or suspected coronary artery disease.     

Cardiac imaging using multislice computed tomography scanners: technical considerations

Conventional coronary angiography is currently the gold standard in the detection and diagnosis of coronary artery disease. This modality, however, is invasive in nature. Hence, there is a need for noninvasive imaging techniques to provide comprehensive assessment of coronary artery disease, especially in stable patients at low to moderate risk of disease. In recent years, a number of noninvasive modalities have found wide applications in cardiac imaging. Most recent investigations have used magnetic resonance imaging, multislice computed tomography and electron-beam computed tomography scanners. This review discusses the clinical challenges existing in the field of cardiac imaging and focuses on the technical advancements of multislice computed tomography scanners that have made them a very attractive noninvasive option for the detection and diagnosis of coronary artery disease.     

Current Role of Cardiac Computed Tomography

The introduction of recent generations of multidetector computed tomography scanners has brought about substantial improvements in spatial and especially temporal resolution which have made imaging of the heart and, under certain conditions, visualization of the coronary arteries possible. Non-enhanced scans allow visualization of cardiac and coronary artery calcification. After intravenous injection of contrast agent, it is possible to visualize cardiac chambers and to analyze the coronary artery lumen.Morphological imaging of the heart, for example in the context of congenital heart disease, is possible by computed tomography (CT) and can, in some very selected cases, be clinically useful as an adjunct to echocardiography or magnetic resonance imaging. Functional imaging allows to analyze left and right ventricular function by CT.CT plays a more prominent clinical role in the context of coronary artery visualization. Coronary calcifications are indicative of coronary atherosclerosis and the presence and amount of coronary artery calcium have a strong predictive value concerning future cardiovascular events, even in asymptomatic individuals. It can potentially be used for refined risk stratification. Contrast-enhanced "CT coronary angiography" has become quite reliable under certain conditions (e.g., a low heart rate). The negative predictive value to rule out coronary artery stenoses has been found to be high in several studies. Therefore, clinical utility to rule out significant coronary artery stenoses in patients who are symptomatic, but have a low to intermediate pretest likelihood of disease is assumed. Ideally, "negative" coronary angiograms would be avoided by using coronary CT angiography. Large-scale trials that would pinpoint specific patient groups to benefit from "CT coronary angiography" are currently lacking.     

冠状动脉钙化积分预测老年冠心病的相关研究

目的进一步探讨预测老年冠心病的新指标,预防心血管事件的发生。方法对≥60岁老年人66例(冠心病48例,非冠心病18例)进行多层螺旋CT(MSCT)冠状动脉扫描和计算机自动测定冠状动脉钙化积分(CACS),对CACS结果进行分析。结果老年冠心病组的CACS明显高于非冠心病组(P<0·01)。3支血管钙化者CACS明显高于1支及2支血管钙化者,且钙化发生在任意血管段都有明确意义(P<0·01,P<0·05)。结论CACS优于传统危险因子,可作为预测冠心病的新指标之一。     

Indian Asian men have less peripheral arterial disease than European men for equivalent levels of coronary disease

OBJECTIVES: Indian Asians have high rates of heart disease and stroke, but risks of peripheral arterial disease appear to be low. This paradox, and reasons for it, have not been explored. We compared ethnic differences in peripheral arterial disease for a given level of coronary disease. METHODS: We studied 83 European and 84 Indian Asian men with a range of coronary disease. Extent of coronary atheroma was quantified by coronary artery calcification score on multislice CT. Femoral intima-media thickness (IMT) was measured by ultrasound. RESULTS: Femoral IMT was 1.58, 2.06, 2.12, and 2.69 mm in Europeans, and 0.61, 1.41, 1.81 and 2.29 in Indian Asians by increasing categories of coronary atheroma (p=0.003 for ethnic difference, adjusted for age and lumen diameter). Adjustment for smoking and systolic blood pressure, the only risk factors adversely distributed in Europeans, only partly accounted for this ethnic difference (p=0.05). Other risk factors, including lipids, obesity, insulin and glycaemic status, more adversely distributed in Indian Asians, could not account for ethnic differences. Prevalence of abnormal ankle brachial index and lower limb atherosclerotic plaque was also greater in Europeans. CONCLUSIONS: For a given level of coronary disease, Indian Asians have less lower limb atherosclerosis than Europeans, unexplained by established risk factors. Further study of these populations would help tease out relative contributions of risk factors to atherosclerosis in different vessel beds.     

Coronary CT angiography: Diagnostic value and clinical challenges

Coronary computed tomography (CT) angiography has been increasingly used in the diagnosis of coronary artery disease due to improved spatial and temporal resolution with high diagnostic value being reported when compared to invasive coronary angiography. Diagnostic performance of coronary CT angiography has been significantly improved with the technological developments in multislice CT scanners from the early generation of 4-slice CT to the latest 320- slice CT scanners. Despite the promising diagnostic value, coronary CT angiography is still limited in some areas, such as inferior temporal resolution, motion-related artifacts and high false positive results due to severe calcification. The aim of this review is to present an overview of the technical developments of multislice CT and diagnostic value of coronary CT angiography in coronary artery disease based on different generations of multislice CT scanners. Prognostic value of coronary CT angiography in coronary artery disease is also discussed, while limitations and challenges of coronary CT angiography are highlighted.     

Detection of coronary calcifications by electron beam tomography and multislice spiral CT: clinical relevance

Coronary calcifications can be detected and quantified using electron beam tomography (EBT) or newer generation multi-slice spiral CT (MSCT) scanners. An abundance of data has been acquired by EBT. It could be shown that the amount of coronary calcium correlates to the coronary plaque burden. The detection of coronary calcium with CT imaging methods therefore provides a unique opportunity to detect and quantify coronary atherosclerosis in a subclinical stage. Consequently, the presence and amount of coronary calcium has been shown to be indicative for an increased coronary event risk in symptomatic and asymptomatic individuals. Several clinical studies found a predictive value that was superior to conventional risk factors. Clinically, the use of coronary calcification assessment may therefore be beneficial in patients who, based on traditional risk factors, seem to be at "intermediate risk" for coronary events (10-year event risk 10-20%) in order to decide on the aggressiveness of risk factor modification. The role of coronary calcium quantification to monitor the progression of disease has not been clarified yet. Large, ongoing trials will provide further data as to the relative merit of coronary calcium assessment for risk stratification and will help to more clearly define its clinical role. The relationship between coronary calcium and coronary stenoses is more complex. While the absence of coronary calcifications makes significant coronary stenoses unlikely, even large amounts of coronary calcium do not necessarily indicate the presence of coronary artery stenoses. Pronounced coronary calcifications as an isolated finding should therefore not be the motivation for invasive diagnostic procedures in the absence of other evidence of ischemic heart disease.     

Nichtinvasive Darstellung koronarer Plaques mittels kontrastgestützter kardialer Computertomographie

Recent technical advances in both multislice spiral computed tomography (MSCT) and electron-beam computed tomography (EBT) renewed the clinicians' interest in the potentials of CT-based, contrast-enhanced, noninvasive coronary angiography. Despite the fact that invasive, selective coronary angiography remains the "gold standard", cardiac CT lumenography permits visualization of flow-limiting coronary stenosis with a sensitivity and specificity of about 90%. The method is, nevertheless, limited by imaging artifacts which are due to extensive coronary calcifications, or, especially in the right coronary and circumflex artery, to rapid coronary motion. Moreover, the clinical value for the exclusion of obstructive coronary artery disease is not yet established, and further prospective studies are required.On the other hand, cardiac CT permits reliable estimation of coronary calcification and quantification of overall coronary plaque burden and thereby allows risk assessment to predict the individual cardiovascular risk. Diagnostic accuracy may be enhanced by combining assessment of calcified plaque burden and contrast imaging. The newer MSCT technology also allows for differentiation of coronary lesion configuration, especially of noncalcified plaques. However, very few data are currently available on this aspect, and the future clinical relevance of this promising technique remains to be proven. The purpose of this article is to describe the principles and potentials of contrast-enhanced coronary CT imaging and to summarize the practical limitations with the currently available scanning equipment.     

Incidence and clinical relevance of coronary calcification detected by electron beam computed tomography in heart transplant recipients.

BACKGROUND: Patients treated by cardiac transplantation who survive beyond one year are at significant risk from fatal coronary artery disease. The development of coronary artery calcification in these patients is discussed and methods available to detect it are reviewed. OBJECTIVES: To assess the clinical importance of coronary artery calcium in heart transplant recipients. METHODS: In a cohort of 102 cardiac transplant recipients, electron beam computed tomography was used to measure calcium in the coronary arterial wall 63 days to 9.1 years (median 4.6 years) after transplantation. The results were compared with angiographic findings and with conventional coronary disease risk factors. The patients were followed for a mean of 2.12 years (1.2-4.02 years) to assess the relationship between these findings and future cardiac events. RESULTS: Forty-one (40.2%) had a stenosis of > 24% in one or more major coronary artery at angiography. Forty-six (45%) had a coronary calcium score > 0. The absence of calcium had a negative predictive value with respect to angiographic disease in any vessels of 87.5%. Logistic regression revealed that dyslipidaemia, systemic hypertension and organ ischaemic time were significant predictors of calcification. At follow-up, both an abnormal coronary angiogram and coronary calcium were found to be the only significant predictors of late events. Multivariate analysis suggested that the detection of coronary calcium did not offer any additional predictive information over that provided by the angiogram itself. CONCLUSION: Electron beam computed tomography is well suited to the assessment of calcium in the coronary arteries of heart transplant recipients, although the mechanisms of this calcification remain poorly understood. Calcium is detected more frequently than would be suggested by studies using intravascular ultrasound. It is associated with the presence of angiographic disease, and with some conventional risk factors for coronary disease. At follow-up the presence of coronary calcium was associated with an adverse clinical outcome, as it is in conventional ischaemic heart disease.     

Potential use of Ca++ scanning to determine the need for and intensity of lipid-lowering therapy in asymptomatic adults

Deficiencies in traditional cardiovascular risk-factor assessment in asymptomatic individuals have led to the use of electron beam computed tomography (CT) scanning as a screening test for coronary artery disease. This novel approach is based on a secure pathologic foundation: the risk of coronary disease events is proportional to the severity and extent of underlying coronary atherosclerosis, and in middle-aged and elderly adults, calcified plaque is closely related to total plaque. Electron beam CT measures coronary calcium quickly, easily, accurately, and with a high degree of reproducibility. Coronary calcium is three to nine times higher in persons with fatal or nonfatal myocardial infarction than in age-matched controls, and four observational outcomes studies have demonstrated that the electron beam CT-derived coronary calcium score predicts fatal and nonfatal myocardial infarction. In symptomatic persons undergoing cardiac catheterization, electron beam CT is more closely associated with the severity of coronary atherosclerosis than are standard coronary risk factors. Preliminary evidence in asymptomatic persons indicates that the coronary calcium score also predicts coronary disease events more accurately than standard risk factors.