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An important advantage of computed tomography coronary angiography (CCTA) is its ability to visualize the presence and severity of atherosclerotic plaque, rather than just assessing coronary artery stenoses. Until recently, assessment of plaque subtypes on CCTA relied on visual assessment of the extent of calcified/non-calcified plaque, or visually identifying high-risk plaque characteristics. Recent software developments facilitate the quantitative assessment of plaque volume or burden on CCTA, and the identification of subtypes of plaque based on their attenuation density. These techniques have shown promise in single and multicenter studies, demonstrating that the amount and type of plaque are associated with subsequent cardiac events. However, there are a number of limitations to the application of these techniques, including the limitations imposed by the spatial resolution of current CT scanners, challenges from variations between reconstruction algorithms, and the additional time to perform these assessments. At present, these are a valuable research technique, but not yet part of routine clinical practice. Future advances that improve CT resolution, standardize acquisition techniques and reconstruction algorithms and automate image analysis will improve the clinical utility of these techniques. This review will discuss the technical aspects of quantitative plaque analysis and present pro and con arguments for the routine use of quantitative plaque analysis on CCTA., Competing Interests: Declaration of competing interest JPE Equity and Consultant, Cleerly Healthcare Inc. The other authors have no conflicts of interest., (Copyright © 2021 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Coronary computed tomographic angiography (CCTA) provides a wealth of clinically meaningful information beyond anatomic stenosis alone, including the presence or absence of nonobstructive atherosclerosis and high-risk plaque features as precursors for incident coronary events. There is, however, no uniform agreement on how to identify and quantify these features or their use in evidence-based clinical decision-making. This statement from the Society of Cardiovascular Computed Tomography and North American Society of Cardiovascular Imaging addresses this gap and provides a comprehensive review of the available evidence on imaging of coronary atherosclerosis. In this statement, we provide standardized definitions for high-risk plaque (HRP) features and distill the evidence on the effectiveness of risk stratification into usable practice points. This statement outlines how this information should be communicated to referring physicians and patients by identifying critical elements to include in a structured CCTA report - the presence and severity of atherosclerotic plaque (descriptive statements, CAD-RADS™ categories), the segment involvement score, HRP features (e.g., low attenuation plaque, positive remodeling), and the coronary artery calcium score (when performed). Rigorous documentation of atherosclerosis on CCTA provides a vital opportunity to make recommendations for preventive care and to initiate and guide an effective care strategy for at-risk patients., (Copyright © 2020. Published by Elsevier Inc.)

This expert consensus statement from the Society of Cardiovascular Computed Tomography (SCCT) provides an evidence synthesis on the use of computed tomography (CT) imaging for diagnosis and risk stratification of coronary artery disease in women. From large patient and population cohorts of asymptomatic women, detection of any coronary artery calcium that identifies females with a 10-year atherosclerotic cardiovascular disease risk of >7.5% may more effectively triage women who may benefit from pharmacologic therapy. In addition to accurate detection of obstructive coronary artery disease (CAD), CT angiography (CTA) identifies nonobstructive atherosclerotic plaque extent and composition which is otherwise not detected by alternative stress testing modalities. Moreover, CTA has superior risk stratification when compared to stress testing in symptomatic women with stable chest pain (or equivalent) symptoms. For the evaluation of symptomatic women both in the emergency department and the outpatient setting, there is abundant evidence from large observational registries and multi-center randomized trials, that CT imaging is an effective procedure. Although radiation doses are far less for CT when compared to nuclear imaging, radiation dose reduction strategies should be applied in all women undergoing CT imaging. Effective and appropriate use of CT imaging can provide the means for improved detection of at-risk women and thereby focus preventive management resulting in long-term risk reduction and improved clinical outcomes., (Copyright © 2018 Society of Cardiovascular Computed Tomography. All rights reserved.)

Objectives: The aim of this study was to assess the relationship of the extent of atherosclerosis on coronary computed tomographic angiography to the extent of secondhand tobacco smoke (SHTS) exposure in asymptomatic never smokers., Background: A dose-related association between SHTS and coronary artery calcium has been reported, but the total extent of atherosclerosis has not been investigated., Methods: A total of 268 never smokers, ages 40 to 80 years, completed a questionnaire assessing risk factors and extent of lifetime SHTS exposure, providing a total SHTS exposure score. Ordinal coronary artery calcium scores were derived from low-dose nongated computed tomographic scans, followed by computed tomographic angiography. Analyses of the prevalence, extent, and plaque characteristics of atherosclerosis were performed, and the independent contribution of SHTS, adjusted for other documented risk factors, was determined., Results: Coronary atherosclerosis was noted in 48% and was more frequent with low to moderate and high versus minimal SHTS exposure (48% and 69% vs. 25%; p < 0.0001). Adjusted odds ratios for any atherosclerosis were 2.1 (95% confidence interval: 1.0 to 4.4; p = 0.05) for low to moderate and 3.5 (95% confidence interval: 1.4 to 8.5; p = 0.01) for high exposure versus minimal SHTS exposure and were not significant for standard risk factors of diabetes (p = 0.56), hyperlipidemia (p = 0.11), hypertension (p = 0.65), and renal disease (p = 0.24). With increasing SHTS exposure, the percentage of major vessel (14%, 41%, and 45%; p = 0.0013) with any plaque or stenosis increased, as did the number with 5 or more involved segments (0%, 39%, and 61%; p = 0.0001). Also the average number of involved segments increased (0.82, 1.98, and 3.49; p < 0.0001), with calcified plaques alone (0.25, 0.77, and 1.52; p < 0.0001), with calcified and partially calcified plaques (0.28, 0.82, and 1.58; p < 0.001), but not with noncalcified plaques alone (p = 0.11)., Conclusions: The presence and extent of atherosclerosis were associated with the extent of SHTS exposure even when adjusted for other risk factors, further demonstrating the causal relationship of SHTS exposure and coronary disease., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

This expert consensus statement summarizes the available data regarding the prognostic value of CAC in the asymptomatic population and its ability to refine individual risk prediction, addresses the limitations identified in the current traditional risk factor-based treatment strategies recommended by the 2013 ACC/AHA Prevention guidelines including use of the Pooled Cohort Equations (PCE), and the US Preventive Services Task Force (USPSTF) Recommendation Statement for Statin Use for the Primary Prevention of Cardiovascular Disease in Adults. It provides CAC based treatment recommendations both within the context of the shared decision making model espoused by the 2013 ACC/AHA Prevention guidelines and independent of these guidelines., (Copyright © 2017 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Objective: This study was designed to evaluate the severity of subclinical atherosclerosis in patients with asymptomatic impaired fasting glucose (IFG) compared to those with diabetes mellitus (DM) and normal fasting glucose (NFG), as measured by coronary computed tomographic angiography (CCTA)., Design: Subjects were divided into three groups: NFG (<100 mg/dL), IFG (100-125 mg/dL) and DM. Coronary artery calcium on non-contrast CT and plaque analysis on CCTA were performed., Setting: University hospital, single centre., Participants: 216 asymptomatic participants prospectively underwent CCTA for the evaluation of coronary artery disease (CAD)., Primary and Secondary Outcome Measures: Atherosclerotic plaque burden in IFG compared to NFG patients., Results: 2664 segments were analysed in 120 NFG, 44 IFG and 52 DM participants. The mean calcium scores were 178±395, 259±510 and 414±836 for NFG, IFG and DM, respectively (p=0·037). The mean plaque burdens in the NFG, IFG and DM groups were 0.31±0.45, 0.50±0.69 and 0.68±0.69, respectively (p=0·0007). A greater proportion of patients with DM (19/52, 36.5%) and IFG (13/44, 29.5%) had obstructive CAD compared to those with NFG (16/120, 13.3%) (p=0.0015). The number of segments with severe disease was significantly higher in the DM (60/637, 9.4%) and IFG (42/539, 7.8%) groups compared to that in the NFG group (34/1488, 2.3%) (p=0.0001)., Conclusions: (1) IFG and DM have significantly higher, but comparable, calcium scores, plaque burden and obstructive CAD compared to NFG in asymptomatic individuals. (2) Pending corroboration by other reports, more intensive efforts may be devoted to the evaluation and treatment of patients with IFG., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Risk stratification in patients with stable ischemic heart disease is essential to guide treatment decisions. In this regard, whether coronary anatomy, physiology, or plaque morphology is the best determinant of prognosis (and driver an effective therapeutic risk reduction) remains one of the greatest ongoing debates in cardiology. In the present report, we review the evidence for each of these characteristics and explore potential algorithms that may enable a practical diagnostic and therapeutic strategy for the management of patients with stable ischemic heart disease., (© 2016 American Heart Association, Inc.)

Background: The incremental prognostic value of the plaque features in coronary computed tomographic angiography (CTA) has not been well assessed. This study was designed to determine whether CTA high-risk plaques have prognostic value incremental to the Framingham risk score (FRS) and the severity of luminal obstruction., Methods: A total of 628 newly symptomatic patients without known coronary artery disease underwent CTA. They were followed for a median of 677 days during which there were 26 cardiac events, including cardiac death, acute myocardial infarction, and hospitalization for unstable angina. Incremental prognostic value of adding plaque characteristics to the number of diseased vessels and the FRS was evaluated using 3 Cox models and net reclassification indexes., Results: The discrimination index was significantly increased by adding the number of diseased vessels to the FRS (change in c-statistic from 65.8% to 78.6%, p=0.028) but not significantly by further adding plaque characteristics (change in c-statistic from 78.6% to 80.0%, p=0.812). However, improved model-fitting by adding plaque characteristics into the linear combination with risk score and the number of diseased vessels (p=0.007 from likelihood ratio test) and the lowest value of Akaike's information criteria of that model indicated that plaque characteristics improved both predictive accuracy and discrimination perspective. More subjects reclassified by plaque characteristics were moved to directions consistent with their subsequent cardiac event status than in an inconsistent direction., Conclusions: Evaluation of CTA plaque characteristics may provide incremental prognostic value to the number of diseased vessels and the FRS., (Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

Objective: To compare Agatston with Ordinal Scores for the extent of coronary artery calcification (coronary artery calcium) using nongated low-dose computed tomography (CT) scans., Materials and Methods: A total of 631 asymptomatic participants had CT scans from 2010 to 2013. Their Ordinal and Agatston Score were classified into categories., Results: The Ordinal Score Categories showed excellent agreement (weighted kappa of 0.83; 95% confidence interval: 0.79-0.88) with the Agatston Score Categories., Conclusions: The use of the Ordinal Score is readily obtained on low-dose CT scans that are used for CT screening for lung cancer and these scores are useful for risk stratification of coronary artery disease., (Copyright © 2015. Published by Elsevier Inc.)

There is a common misperception in the cardiology community that most acute coronary events arise from ruptures of mildly stenotic plaques. This notion has emanated from multiple studies that had measured the degree of angiographic luminal narrowing in culprit plaques months to years before myocardial infarction. However, angiographic studies within 3 months before myocardial infarction, immediately after myocardial infarction with thrombus aspiration or fibrinolytic therapy, and postmortem pathological observations have all shown that culprit plaques in acute myocardial infarction are severely stenotic. Serial angiographic studies also have demonstrated a sudden rapid lesion progression before most cases of acute coronary syndromes. The possible mechanisms for such rapid plaque progression and consequent luminal obstruction include recurrent plaque rupture and healing and intraplaque neovascularization and hemorrhage with deposition of erythrocyte-derived free cholesterol. Moreover, recent intravascular and noninvasive imaging studies have demonstrated that plaques which result in coronary events have larger plaque volume and necrotic core size with greater positive vessel remodeling compared with plaques, which remain asymptomatic during several years follow-up, although these large atheromatous vulnerable plaques may angiographically seem mild. As such, it is these vulnerable plaques which are more prone to rapid plaque progression or are those in which plaque progression is more likely to become clinically evident. Therefore, in addition to characterizing plaque morphology, inflammatory activity, and severity, detection of the rate of plaque progression might identify vulnerable plaques with an increased potential for adverse outcomes., (© 2015 American Heart Association, Inc.)

Background: Previous studies have shown that vascular dysfunction measured by digital thermal monitoring (DTM) during an arm-cuff reactive hyperemia procedure correlates with the severity of coronary artery disease measured by coronary artery calcium in asymptomatic patients. Current study investigates the correlation between DTM and abnormal myocardial perfusion imaging (MPI)., Methods: About 116 consecutive patients with chest discomfort, age 57 +/- 10 years, underwent MPI, DTM and Framingham Risk Score (FRS) assessment. Fingertip temperature rebound (TR), DTM index of vascular reactivity, was assessed after a 2-minute arm-cuff reactive hyperemia test. The extent of myocardial perfusion defect was measured by summed stress score (SSS)., Results: TR decreased from SSS < 4 (1.61 +/- 0.15) to 4 < or = SSS < or = 8 (0.5 +/- 0.22) to 9 < or = SSS < or = 13 (0.26 +/- 0.15) to SSS > 13 (-0.37 +/- 0.19) (P = .0001). After adjusting for cardiac risk factors, the odds ratio of the lowest versus two upper tertiles of TR was 3.93 for SSS > or = 4 and 9.65 for SSS > or = 8 compared to SSS < 4. TR correlated well with SSS (r = -0.88, P = .0001). Addition of TR to FRS increased the area under the ROC curve to predict abnormal MPI, SSS > or = 4, from 0.65 to 0.84 (P < .05)., Conclusion: Vascular dysfunction measured by DTM is associated with the extent of myocardial perfusion defect independent of age, gender, and cardiac risk factors.

Background: Digital thermal monitoring (DTM) of vascular function was shown to correlate with the presence of known coronary artery disease (CAD)., Objective: We evaluated whether DTM can identify at-risk, asymptomatic patients with significant coronary artery calcium (CAC) or increased Framingham risk score (FRS)., Methods: Two hundred thirty-three consecutive asymptomatic subjects (58 +/- 11 years; 62% men) without known CAD underwent DTM, CAC, and FRS calculation. DTM measurements were obtained during and after a 5-minute suprasystolic arm-cuff occlusion. After cuff-deflation temperature rebound (TR) and area under the temperature curve (AUC) were measured and correlated with FRS and CAC., Results: TR was lower in patients with FRS > 20% and CAC >or= 100 as compared with FRS < 10% and CAC < 10, respectively (P < 0.05). After adjustment for age, sex, and traditional cardiac risk factors, the odds ratio of the lowest compared with the upper 2 tertiles of TR was 3.96 for FRS >or= 20% and 2.37 for CAC >or= 100 compared with low-risk cohorts. The area under the receiver operating characteristic (ROC) curve to predict CAC >or= 100 increased significantly from 0.66 for FRS to 0.79 for TR to 0.89 for TR + FRS., Conclusions: Vascular dysfunction measured by DTM strongly correlates with FRS and CAC independent of age, sex, and traditional cardiac risk factors and was superior to FRS for the prediction of significant CAC.

Objective: It is thought that emphysema patients are at a higher risk of coronary artery disease. The present study is one of very few that evaluated the prevalence of significant coronary artery disease in emphysema patients using coronary artery calcification measured by electron beam computed tomography., Methods: A retrospective chart review evaluated 1720 consecutive patients, some of whom were self-referred. All patients had both heart and lungs imaged with electron beam computed tomography when they were seen at the Inner Imaging Center, a cardiac imaging center affiliated with the Beth Israel Hospital in New York, New York. Multiple logistic regression was performed to determine which factors were independently associated with coronary artery calcification., Results: Age, sex, hypertension and smoking were the risk factors independently associated with coronary artery calcification in the population studied. The emphysema group was significantly higher on measures of smoking and hypertension compared with the control group. Comparison of scores between the two groups using different categories for coronary artery calcification scores did not show a statistically significant difference using chi(2) analysis (P=0.088). However, there was a significant difference between dichotomized coronary artery calcification scores of lower than 100 and 100 or higher in patients with and without emphysema, respectively (P=0.013). Coexisting smoking and hypertension may contribute to the higher incidence of coronary artery calcification in emphysema patients. Symptoms of chest pain and shortness of breath were not different between the emphysema and control groups., Conclusion: Emphysema patients have a higher prevalence of significant coronary artery calcification, defined as a coronary artery calcification score higher than 100.

Objectives: This investigation was designed to determine the relationship between National Cholesterol Education Program (NCEP) ATP-II lipid guidelines and subclinical atherosclerosis, defined by electron beam tomography (EBT) calcified coronary plaque, in asymptomatic women., Background: NCEP guidelines are used to identify women at increased risk for coronary artery disease (CAD) on the basis of low density lipoprotein cholesterol (LDLC) and high density lipoprotein cholesterol (HDLC) values. The relationship of the guidelines to subclinical atherosclerosis is unknown., Methods: A total of 304 asymptomatic women underwent lipid and EBT evaluation and were classified as: 1) NCEP higher risk, with LDLC > or =130 mg/dl and/or HDLC <35 mg/dl, or lower risk with LDLC <130 mg/dl and HDLC > or =35 mg/dl; and 2) EBT+ if any calcified plaque was noted or EBT- if there was no calcified plaque., Results: Forty-two percent of patients were EBT+, with a mean score of 227 and percentile of 73%; 58% were EBT-. Women who were EBT+ had significantly higher total cholesterol, LDLC and triglycerides than EBT- women, but only with ages < or =55 years; women >55 years demonstrated no differences. NCEP higher risk women made up 53.5% of the EBT+ and 37.7% of the EBT- groups; NCEP lower risk women accounted for 46.5% of the EBT+ and 62.3% of the EBT- groups. Assuming a higher risk in subjects with EBT-defined subclinical CAD than in those without, only 58.6% of the total group would be correctly identified by NCEP guidelines as either higher or lower risk, with correct identification of 65.5% of the younger and 52.2% of the older women. There was no correlation between either calcium percentile or score and any lipid measurement., Conclusions: This study demonstrates the shortcomings of employing NCEP guidelines to identify asymptomatic women with subclinical CAD, particularly women >55 years, and suggests increased utilization of EBT for primary prevention in the female population.

This study was designed to determine whether the National Cholesterol Education Program (NCEP) lipid guidelines accurately identify subclinical atherosclerosis and whether low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels are related to the extent and prematurity of coronary artery disease (CAD) as determined by electron beam tomography (EBT). Out of personal concern for CAD risk, 930 consecutive asymptomatic subjects, without clinical CAD and on no lipid-lowering agents, underwent EBT. Calcium score and percentile were correlated with total cholesterol (TC), LDL-C, HDL-C, triglycerides, and demographic parameters. A calcium score of > 0 (EBT+) was found in 55% of patients; 45% of patients had a 0 score (EBT-). Mean age (58.0 +/- 10.5 vs 49.3 +/- 9.7 years, p = 0.0001), TC (218 +/- 39 vs 211 +/- 41 mg/dl, p = 0.006), LDL-C (136 +/- 36 vs 127 +/- 27 mg/dl, p = 0.005), and TC/HDL-C (4.6 +/- 1.4 vs 4.2 +/- 1.5, p = 0.0001) were significantly higher and HDL-C (52.2 +/- 17.6 vs 55.4 +/- 19.3 mg/dl, p = 0.008) lower in the EBT+ compared with EBT- group. In the EBT+ group, 75.1% of subjects had LDL-C < 160 mg/dl and would not be advised to use lipid-lowering medications according to NCEP guidelines. In subjects with LDL-C < 160 mg/dl, 51.8% of subjects were EBT+, as were 46.1% of those with LDL-C < 100 mg/dl. There were no significant differences in the calcium scores throughout the entire range of all lipid parameters; calcium percentiles were virtually identical within lipid value subgroups. We conclude that asymptomatic patients with EBT-defined subclinical atherosclerosis are not reliably identified by NCEP guidelines, and TC, LDL-C, HDL-C, TC/HDL-C, and triglyceride levels do not correlate with either the extent or prematurity of calcified plaque burden.