Coronary Artery Calcium Scoring in Cardiovascular Risk Assessment

Identification of patients at risk of future coronary artery disease (CAD) events traditionally relies on scoring tools that take demographic and clinical characteristics into account (e.g., the Framingham risk score in the United States and the Heart Score in Europe). Although these scoring tools have been shown to have a good predictive value, they may still fail to recognize a proportion of patients with coronary atherosclerosis at risk for future CAD events. In order to improve risk stratification, direct visualization of subclinical atherosclerosis has been advocated. Electron‐beam computed tomography and multislice computed tomography provide a direct estimation of coronary calcium, a marker of coronary atherosclerosis. A large amount of data is available supporting the clinical value of the noninvasive assessment of coronary artery calcium score (CACS) with these techniques and its incremental prognostic information over traditional risk stratification. Aim of this review is to provide an overview of the literature regarding the prognostic value of CACS assessment. In addition, potential other applications of CACS assessment as well as the limitations of the technique are discussed.     

Coronary artery calcium scoring: an evidence-based guide for primary care physicians

Primary care physicians often must decide whether statin therapy would be appropriate (in addition to lifestyle modification) for managing asymptomatic individuals with borderline or intermediate risk for developing atherosclerotic cardiovascular disease (ASCVD), as assessed on the basis of traditional risk factors. In appropriate subjects, a simple, noninvasive measurement of coronary artery calcium can help clarify risk. Coronary atherosclerosis is a chronic inflammatory disease, with atherosclerotic plaque formation involving intimal inflammation and repeated cycles of erosion and fibrosis, healing and calcification. Atherosclerotic plaque formation represents the prognostic link between risk factors and future clinical events. The presence of coronary artery calcification is almost exclusively an indication of coronary artery disease, except in certain metabolic conditions. Coronary artery calcification can be detected and quantified in a matter of seconds by noncontrast electrocardiogram-gated low-dose X-ray computed tomography (coronary artery calcium scoring [CACS]). Since the publication of the seminal work by Dr. Arthur Agatston in 1990, a wealth of CACS-based prognostic data has been reported. In addition, recent guidelines from various professional societies conclude that CACS may be considered as a tool for reclassifying risk for atherosclerotic cardiovascular disease in patients otherwise assessed to have intermediate risk, so as to more accurately inform decisions about possible statin therapy in addition to lifestyle modification as primary preventive therapy. In this review, we provide an overview of CACS, from acquisition to interpretation, and summarize the scientific evidence for and the appropriate use of CACS as put forth in current clinical guidelines.     

Challenges in Utilizing CT Coronary Angiography and CT Calcium Scoring to Determine Aeromedical Fitness for Aicrew: A Tale of 3 CTs

The management of coronary artery disease (CAD) in aviators remains as one of the dominant preoccupation in determining vocational fitness. With the emerging awareness and accessibility of non-invasive modalities for assessing CAD, there is an increasing likelihood that aircrew may have undergone some form of functional or anatomic assessment of the coronary circulation, prior to their presentation to the aviation medical examination office. In particular, computer tomographic coronary angiography (CTCA) and CT coronary artery calcium scoring (CACS) had gained significant traction in recent years, as novel scanning algorithms had enabled faster, safer and more affordable imaging. However, the utilization of CTCA and CACS are not without challenges. Against this backdrop, this paper presents three clinical vignettes of aviators who presented to our cardiac department for specialist evaluation and the eventual aeromedical dispositions. The paper also discusses the evolving opportunities and issues in the application of CTCA and CACS findings to aeromedical risk assessment in aviators.     

Diagnostic value of coronary artery calcium scoring in low-intermediate risk patients evaluated in the emergency department for acute coronary syndrome

Early and accurate triage of patients with possible ischemic chest pain remains challenging in the emergency department because current risk stratification techniques have significant cost and limited availability. The aim of this study was to determine the diagnostic value of the coronary artery calcium score (CACS) for the detection of obstructive coronary artery disease (CAD) in low- to intermediate-risk patients evaluated in the emergency department for suspected acute coronary syndromes. A total of 225 patients presenting to the emergency department with acute chest pain and Thrombolysis In Myocardial Infarction (TIMI) scores <4 who underwent non-contrast- and contrast-enhanced coronary computed tomographic angiography were included. CACS was calculated from the noncontrast scan using the Agatston method. The prevalence of obstructive CAD (defined from the contrast scan as ≥ 50% maximal reduction in luminal diameter in any segment) was 9% and increased significantly with higher scores (p <0.01 for trend). CACS of 0 were observed in 133 patients (59%), of whom only 2 (1.5%) had obstructive CAD. The diagnostic accuracy of CACS to detect obstructive CAD was good, with an area under the receiver-operating characteristic curve of 0.88 and a negative predictive value of 99% for a CACS of 0. In a multivariate model, CACS was independently associated with obstructive CAD (odds ratio 7.01, p = 0.02) and provided additional diagnostic value over traditional CAD risk factors. In conclusion, CACS appears to be an effective initial tool for risk stratification of low- to intermediate-risk patients with possible acute coronary syndromes, on the basis of its high negative predictive value and additive diagnostic value.     

双源CT心周脂肪定量与冠状动脉粥样硬化病变程度的相关性

目的 分析心周脂肪体积与心血管危险因素、冠心病的发生和冠状动脉狭窄程度之间的关系.方法 221例同期行64排双源CT和经皮冠状动脉造影检查的患者入选,进行腰围、体质指数和空腹血生物化学指标测定.使用64排双源CT测定心周脂肪体积,通过经皮冠状动脉造影检查明确患者的冠心病诊断和冠状动脉病变支数,并采用Gensini积分量化冠状动脉狭窄的严重程度.结果 入选患者男性占71.04%.男性心周脂肪体积明显大于女性(241.44±78.08 cm~3比216.46±64.36 cm~3,P=0.025).年龄≥70岁的患者心周脂肪体积明显大于年龄<70岁的同性别患者(P<0.05).冠心病患者的心周脂肪体积明显大于非冠心病患者(242.10±75.80 cm~3比189.23±52.26 cm~3,P<0.001).Logistic回归分析显示心周脂肪体积(OR=1.11,P<0.001)和体质指数(OR=1.01,P=0.001)是影响冠心病发生的独立危险因子.心周脂肪体积随着冠状动脉病变支数的增加而增加,并且与Gensini积分呈正相关.结论 64排双源CT可对心周脂肪组织进行准确定量,心周脂肪体积与心血管危险因素和冠心痛的发生以及冠状动脉病变程度存在较强的相关性,可作为一个新的评估冠心病风险和病变程度的指标.     

Cardiovascular imaging for the assessment of atherosclerotic disease: Implications for cardiac risk stratification

Cardiovascular imaging is applied in daily clinical practice to the diagnostic and prognostic assessment of patients with suspected or known coronary artery disease (CAD). Imaging allows the clinician to non-invasively assess and risk-stratify patients to enable proper management and prevention of CAD, myocardial infarction, acute coronary syndromes, and angina. Radionuclide cardiac stress imaging, echocardiography and, increasingly, cardiac CT and cardiac magnetic resonance techniques play important roles in the diagnosis of coronary atherosclerotic disease, which is the leading cause of mortality for adults in the United States. While many guidelines are in place for the proper treatment of patients with and at risk for CAD, the risk stratification and treatment of patients ultimately is based on clinical judgment of the risk of a cardiac event. Cardiovascular imaging of atherosclerotic coronary disease is at the foundation of this all-important clinical decision.     

Menor Prevalência e Extensão da Aterosclerose Coronária na Doença de Chagas Crônica por Angiotomografia Coronária

BackgroundIn Chagas’ disease endemic regions, there has been for many years a recurrent empirical observation that coronary artery disease (CAD) is uncommon in patients with Chagas’ disease. Previous pathological and invasive coronary angiography studies led to controversial results.ObjectiveWe sought to investigate whether CAD is less prevalent and less severe in patients with chronic Chagas’ disease when compared with a matched population with a similar CAD risk profile.MethodsA total of 86 participants, 43 consecutive patients with chronic Chagas’ disease and 43 asymptomatic individuals, without any prior history of cardiac disease or known CAD (control group), were included. Patients and controls were matched according to gender, age, and Framingham risk score. All participants underwent coronary calcium scoring and coronary computed tomography angiography on a 320-row detector scanner. Statistical significance level adopted was p < 0.05.ResultsThe coronary artery calcium score (CACS) was significantly lower in patients with Chagas’ disease than in controls (p<0.05). The presence of coronary atherosclerotic plaques was significantly less frequent in patients with Chagas’ disease than in controls (20.9% versus 41.9%, p=0.037). After adjustment for the Framingham score, the odds ratio for the presence of any coronary artery calcium (CAC) in Chagas patients was 0.26 (95%CI: 0.07-0.99, p=0.048). The pattern is similar for CACS > 10 (OR: 0.11, 95%CI: 0.01-0.87, p=0.04) and for the presence of any stenosis (OR: 0.06, 95%CI: 0.01-0.47, p=0.001). Propensity score matching also indicated an effect of Chagas disease on the CACS (-21.6 points in the absolute score and 25% less of patients with CACS >10, p=0.015).ConclusionsCAD is less prevalent and less severe in patients with chronic Chagas’ disease when compared with a matched population with a similar CAD risk profile. (Arq Bras Cardiol. 2020; 115(6):1051-1060)     

Complementary results of computed tomography and magnetic resonance imaging of the heart and coronary arteries: a review and future outlook

MR and CT imaging are emerging as promising complementary imaging modalities in the primary diagnosis of CAD and for the detection of subclinical atherosclerotic disease. For the detection or exclusion of significant CAD, both cardiac CT (including coronary calcium screening and non-invasive coronary angiography), and cardiac MRI (using stress function and stress perfusion imaging) are becoming widely available for routine clinical evaluation. Their high negative predictive value, especially when combining two or more of these modalities, allows the exclusion of significant CAD with high certainty, provided that patients are selected appropriately. The primary goal of current investigations using this combined imaging approach is to reduce the number of unnecessary diagnostic coronary catheterizations, and not to replace cardiac catheterization altogether. For the diagnosis of obstructive coronary atherosclerosis and for screening for subclinical disease, CT and MRI have shown potential to directly image the atherosclerotic lesion, measure atherosclerotic burden, and characterize the plaque components. The information obtained may be used to assess progression and regression of atherosclerosis and may open new areas for diagnosis, prevention, and treatment of coronary atherosclerosis. Further clinical investigation is needed to define the technical requirements for optimal imaging, develop accurate quantitative image analysis techniques, outline criteria for image interpretation, and define the clinical indications for both MR or CT imaging. Additional studies are also needed to address the cost effectiveness of such a combined approach versus other currently available imaging modalities.     

Role of Coronary Artery Calcium Score and Coronary CT Angiography in the Diagnosis and Risk Stratification of Individuals with Suspected Coronary Artery Disease

Coronary heart disease is the leading cause of death worldwide, and has traditionally been assessed through a patient’s cardiovascular risk profile that is comprised of a combination of genetic, social, physiologic, and environmental factors. A growing discordance is being recognized in the ability of current risk estimation tools to predict outcomes versus that of actual measured outcomes. Exciting new improvements in technology have made noninvasive imaging modalities of the heart—in particular, coronary artery calcium score (CACS) and coronary computed tomography (CT) angiography—an increasingly important component in the diagnosis of ischemic heart disease. The CACS has been found to be a marker of vascular injury that correlates closely with overall atherosclerotic burden, whereas coronary CT angiography permits detection of noncalcified plaque coronary artery stenosis severity. A growing body of literature has developed detailing the valuable prognostic utility of these tests in the management of patients and how they may 1 day be used to complement current risk prediction models.     

Doença coronária não obstrutiva documentada por tomografia computorizada cardíaca: contraste entre a carga aterosclerótica e o risco cardiovascular

Cardiac computed tomography (CT) documents the presence of coronary artery disease, regardless of the degree of stenosis. The prognostic value of non-obstructive coronary artery disease documented by cardiac CT has recently been validated. However, there are still no clear guidelines on the management of such patients, particularly concerning initiation of more aggressive pharmacological measures for primary prevention. The approach to these patients remains controversial, especially in cases in which there is a discrepancy between cardiovascular risk and the atherosclerotic burden as documented by cardiac CT.The authors describe the case of a patient with a discrepancy between the extent of documented coronary atherosclerosis and that estimated according to pretest probability and cardiovascular risk scores. As this individual had more severe coronary atherosclerosis than expected (calcium score above the 90th percentile and non-obstructive coronary artery disease on cardiac CT) but was a competitive athlete and otherwise asymptomatic and without risk factors or cardiovascular history, with a very low estimated cardiovascular risk, it was difficult to decide on the risks and benefits of pharmacological primary prevention.     

The association between extracoronary calcification and coronary artery disease in patients with type 2 diabetes mellitus

Cardiovascular complications are the major cause of diabetes-associated morbidity and mortality. However, not all patients with diabetes are at increased risk for cardiovascular disease (CVD). Coronary artery calcification was found to be a powerful predictor of coronary artery disease (CAD). The presence of extracoronary cardiac calcification as a useful predictor of CAD is not yet established, especially in type 2 diabetes mellitus (T2DM). The aim of this study was to evaluate the relation between extracoronary calcification and extent of CAD in a group of T2DM patients who were scheduled for computed tomographic coronary angiography (CTCA). We prospectively studied 380 patients (151 had T2DM) under the age of 60 years who were scheduled for CTCA because of suspected CAD. Severity of CAD was assessed by Gensini score. Coronary artery calcium score (CACS) as well as calcium score in the aortic valve, mitral annulus, ascending aorta, and descending aorta were measured by a 256-row multidetector computed tomography scanner with dedicated software for calcium calculation. Patients with known CAD were excluded. Diabetic and nondiabetic patients had comparable age and gender distribution. However, the diabetic group had higher Gensini score, CACS, and extracoronary calcium score (ECCS). Logistic regression analyses identified male gender and ECCS as significant predictors for the presence of CAD in diabetic patients. Age, smoking, and ECCS were the significant predictors of CAD in nondiabetic patients. Type 2 diabetic patients had increased coronary and extracoronary calcification. ECCS was found to be a significant predictor of CAD in diabetic and nondiabetic patients only when CACS was not taken into account.     

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。     

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.     

Coronary risk assessment using traditional risk factors with CT coronary artery calcium scoring in clinical practice

As coronary artery calcium (CAC) is atherosclerosis and not just a marker of cardiovascular (CV) disease, measurement of a patient's coronary artery calcium score (CACS) is a strong predictor of risk. Clinically performed in asymptomatic patients, the CACS, along with several CV risk factors, namely age, sex, ethnicity, diabetes, tobacco use, family history, cholesterol level, blood pressure, and use of cholesterol or hypertensive medications, provide a predictive model of 10 year risk for CV events. A smartphone “App” makes this quick to obtain and use. This helps the clinician in making recommendations for both lifestyle changes and statin therapy. Those patients in which the most benefit occur from measurement of a CACS are those at an intermediate CV risk. Measurement of the CACS has become an integral part of the clinician's assessment of a patient's CV risk and for guiding preventative therapies.     

MRI versus CT for the detection of coronary artery disease: Current state and future promises

CT and MR are two noninvasive imaging techniques that are capable of detecting different aspects of coronary artery disease (CAD). Both techniques can directly and noninvasively visualize the coronary artery tree, allowing detection of atherosclerotic plaques, coronary stenosis, or occlusion. In addition to direct anatomic visualization, MR also allows assessment of stress-induced ischemia. Both dobutamine stress and dipyridamole or adenosine perfusion MR can be used for this purpose with high sensitivity and specificity. Both MR and multidetector CT can also reveal the functional consequences of CAD, that is, reduced regional and global cardiac function, as well as the presence of myocardial infarction. Finally, there is promise that in the future, both techniques may predict individual risk of unstable CAD by identifying vulnerable plaques that are prone to rupture.     

联合踝臂指数和钙化积分判定老年冠脉3支病变的价值

目的 探讨联合应用踝臂指数（ankle-brachial index,ABI）和钙化积分(coronary artery calcium score,CACS)提高判定冠状动脉3支病变的价值。方法 选择连续96例行冠脉造影的老年患者,分别予ABI检测和64排CT检测CACS。结果 ABI<0.9、CACS>400判定冠脉3支病变敏感度分别为58％、64％,特异度分别为87％、86％,联合使用敏感度显著提高（85％）,特异度未明显降低（83％）。结论 ABI<0.9、CACS>400一定程度上能够判定老年人冠脉3支病变,联合使用判定价值更大。     

Ultrasound Imaging of Carotid Intima-Media Thickness: an Office-Based Tool to Assist Physicians in Cardiovascular Risk Assessment

Traditional coronary heart disease risk prediction schemes such as the Framingham Risk Score, although useful, do not adequately identify all individuals who experience an adverse coronary heart disease event. Therefore, additional tools, including biomarkers, genetic markers, and imaging markers, are being evaluated for their value in improving cardiovascular risk assessment. Of the two accepted imaging markers of atherosclerosis, namely coronary artery calcium score (CACS) measured by CT scan and carotid intima-media thickness (CIMT) measured by ultrasound, CIMT has the potential to be widely adopted as a clinical tool for physician offices. Ultrasound-based CIMT measurement is safe but has several challenges, including reproducibility and operator-dependency. We review and present data with respect to the added value of CIMT and information about plaque presence or absence in improving coronary heart disease risk prediction and further provide information related to adequate scanning protocols. New developments in the area of automated CIMT measurement, three-dimensional, ultrasound-based plaque volume estimation are promising and have the potential to create a quantum leap in our ability to measure, characterize, and monitor carotid atherosclerosis and in turn prediction of cardiovascular disease risk.     

Coronary atherosclerotic burden in veteran male recreational athletes with low to intermediate cardiovascular risk

IntroductionAlthough there is evidence that a significant proportion of veteran athletes have coronary atherosclerotic disease (CAD), its prevalence in recreational athletes with low to intermediate cardiovascular (CV) risk is not established. This study aimed to characterize the coronary atherosclerotic burden in veteran male recreational athletes with low to intermediate CV risk.MethodsAsymptomatic male athletes aged ≥40 years with low to intermediate risk, who exercised >4 hours/week for >5 years, underwent cardiac computed tomography (CT) for coronary artery calcium (CAC) scoring and CT angiography. High coronary atherosclerotic burden was defined as at least one of the following: CAC score >100; CAC score ≥75th percentile; obstructive CAD; disease involving the left main, three vessels or two vessels including the proximal left anterior descending artery; segment involvement score >5; or CT Leaman score ≥5. Athletes were categorized by tertiles of exercise volume, calculated by metabolic equivalent of task (MET) scores.ResultsA total of 105 athletes were included, all with SCORE <4%, mainly engaged in high-dynamic sports. Median exercise volume was 66 (44-103) METs/hour/week, with 8±5 hours training/week and 17±10 years of exercise. A high coronary atherosclerotic burden was present in 27 (25.7%) athletes. Ten (9.5%) athletes had CAC score >100, 13 (12.4%) had CAC score ≥75th percentile and six (5.7%) had obstructive lesions. The extent and severity of coronary plaques did not differ according to exercise volume.ConclusionsThe prevalence of subclinical CAD detected by cardiac CT in veteran male recreational athletes with low to intermediate CV risk was high. Up to a quarter of our cohort had a high coronary atherosclerotic burden.     

Coronary artery calcification and risk factors for atherosclerosis in patients with venous thromboembolism

BACKGROUND: Venous thromboembolism (VTE) and atherosclerosis may be associated and may share common risk factors. We conducted a retrospective case-control study to investigate the association between VTE and coronary atherosclerotic disease (CAD) by means of measuring coronary artery calcification and evaluating clinical risk factors. METHODS: From 385 consecutive patients suspected of VTE, we randomly selected 89 cases with idiopathic VTE and 89 controls without VTE, frequency matched on gender and age. Risk factors for atherosclerosis were noted for both groups. Coronary artery calcification was quantified on pulmonary computed tomography (CT) angiographic images. The coronary artery calcification and risk factors were compared between the case and control groups. The associations between VTE and the presence of coronary artery calcium and risk factors were assessed with logistic regression analysis. RESULTS: A higher prevalence of coronary artery calcium was found in the case group (51.7%) than in the control group (28.1%) (p=0.001). The presence of coronary artery calcium was significantly associated with VTE with an odds ratio of 4.3 (95% confidence interval, 1.9-10.1) in a multivariable model. Diabetes mellitus and hypertension were also significantly associated with VTE. CONCLUSION: A significant association between VTE and CAD suggests that CAD is an independent risk factor for VTE. Diabetes and hypertension are also independent risk factors for VTE.     

Prognostication of cardiac CT angiography

The rapidly emerging technique of cardiac computed tomography angiography (CTA) has enabled the anatomical assessment of coronary artery disease. CTA has very good diagnostic accuracy with the ability to detect nonobstructive from obstructive coronary artery disease and provides information on the presence of coronary artery calcification as well as on left ventricular function. Over the last few years, many prognostic studies have reviewed the outcome benefit of different scoring indices in predicting hard cardiac events. The following article will review the most recent literature available on the use of CTA in measuring luminal stenoses, identifying high-risk obstructive CAD, calcium plaque score, and LV function all in different models with their impact on the estimation of clinical risk. More recent data from a large multicenter registry supports the incremental benefit of CAD severity and LVEF as independent predictors of prognosis. Future directions and emerging applications such as the utility of CTA combined with perfusion analysis may lead to a new anatomical-functional diagnostic test that may provide optimal noninvasive assessment of coronary artery anatomy and be superior to invasive coronary angiography.