Traditional clinical risk assessment tools do not accurately predict coronary atherosclerotic plaque burden: a CT angiography study. AJR Am J Roentgenol. 2009;192:235-243. [PMID: 19098205 DOI: 10.2214/ajr.08.1056]

Reduced radiation dose and volume of contrast medium in heart rate-based, one-stop computed tomography angiography of coronary, carotid and cerebrovascular arteries

BACKGROUND

Computed tomography angiography (CTA) is a reliable, non-invasive screening method for diagnosing panvascular disease. By using low contrast agent volume, CTA imaging enables one-stop multi-organ scanning, thereby minimizing the potential risk of contrast-induced nephropathy in patients with impaired renal function.

PURPOSE

To evaluate the feasibility of one-stop CTA following a heart rate (HR)-based protocol using a low volume of contrast medium (CM) for examination of the coronary, carotid and cerebrovascular arteries.

MATERIAL AND METHODS

Sixty patients undergoing coronary carotid, and cerebrovascular CTA after a single injection of CM were recruited and randomly divided into two groups. Group A (n = 30) underwent CTA following a traditional protocol. The timing of the scans in Group B (n = 30) was determined according to the patient's HR.

RESULTS

The CT values for the thoracic aorta (432.2 ± 104.28 HU), anterior cerebral artery (303.96 ± 99.29 HU), and right coronary artery (366.70 ± 85.10 HU) in Group A did not differ significantly from those in Group B (445.80 ± 106.13, 293.73 ± 75.25 and 344.13 ± 111.04 HU, respectively). The qualities of most of the scanned images for both groups were scored as 3 or 4 (on a five-point scale). The radiation dose and the volume of CM were significantly higher in Group A (303.05 ± 110.95 mGy) (100 mL) than in Group B (239.46 ± 101.12 mGy) (50 mL).

CONCLUSION

The radiation dose and volume of CM were significantly reduced in CTA following the HR-based protocol. The personalized administration of CM also simplified the scanning process.

Predictive value of HDL function in patients with coronary artery disease: relationship with coronary plaque characteristics and clinical events

BACKGROUND

HDL is endowed with several metabolic, vascular, and immunoinflammatory protective functions. Among them, a key property is to promote reverse cholesterol transport from cells back to the liver. The aim of this study was to estimate the association of scavenger receptor class B type I (SR-BI)- and ATP binding cassette transporter A1 (ABCA1)-mediated cholesterol efflux (the two major routes for cholesterol efflux to HDL) with the presence, extent, and severity of coronary artery disease (CAD), vascular wall remodelling processes, coronary plaque characteristics, and the incidence of myocardial infarction in the different subgroups of patients from the CAPIRE study.

METHODS

Patients (n = 525) from the CAPIRE study were divided into two groups: low-risk factors (RF), with 0-1 RF (n = 263), and multiple-RF, with ≥2 RFs; within each group, subjects were classified as no-CAD or CAD based on the segment involvement score (SIS) evaluated by coronary computed tomography angiography (SIS = 0 and SIS > 5, respectively). SR-BI- and ABCA1-mediated cholesterol efflux were measured using the plasma of all patients.

RESULTS

SR-BI-mediated cholesterol efflux was significantly reduced in patients with CAD in both the low-RF and multiple-RF groups, whereas ABCA1-mediated cholesterol efflux was similar among all groups. In CAD patients, multivariable analysis showed that SR-BI-mediated cholesterol efflux <25^th percentile predicted cardiovascular outcome (odds ratio 4.1; 95% CI: 1.3-13.7; p = .019), whereas ABCA-1-mediated cholesterol efflux and HDL-C levels significantly did not. Despite this finding, reduced SR-BI-mediated cholesterol efflux was not associated with changes in high-risk plaque features or changes in the prevalence of elevated total, non-calcified, and low-attenuation plaque volume.

CONCLUSION

SR-BI-mediated cholesterol efflux capacity is lower in patients with diffuse coronary atherosclerosis. In addition, a lower SR-BI-mediated cholesterol efflux capacity is associated with the worst clinical outcomes in patients with CAD, independently of atherosclerotic plaque features. Key MessagesIncreased cholesterol efflux capacity, an estimate of HDL function, is associated with a reduced CVD risk, regardless of HDL-C levels.HDL-C levels are significantly lower in patients with CAD.Lower SR-BI-mediated cholesterol efflux capacity is observed in patients with diffuse coronary atherosclerosis and is associated with the worst clinical outcomes in patients with CAD, independently of atherosclerotic plaque features.

The Potential Mediating Effects of Inflammation on the Association Between Type D Personality and Coronary Plaque Vulnerability in Patients With Coronary Artery Disease: An Optical Coherence Tomography Study

OBJECTIVE

Type D personality involves the interaction between negative affectivity with social inhibition and has been associated with an increased risk of coronary artery disease (CAD) progression and coronary plaque vulnerability. However, the underlying mechanisms in the relationship between type D personality and coronary plaque vulnerability remain indeterminate. The present study examined the potential mediating effects of inflammation biomarkers on the association between type D personality and coronary plaque vulnerability in patients with CAD.

METHODS

A total of 347 patients (mean [standard deviation] age = 56.6 [11.2] years; 29.3% women) with CAD who had culprit coronary plaques were examined for type D personality. The inflammation biomarkers (high-sensitivity C-reactive protein, interleukin 6 [IL-6], and tumor necrosis factor α [TNF-α]) were evaluated. Each individual inflammation biomarker was standardized using z scores to calculate inflammation standardized sumscores. Plaque vulnerability of culprit lesions was measured in vivo using optical coherence tomography.

RESULTS

The presence of type D personality (38%) was associated with TNF-α, IL-6, and inflammation standardized sumscores (t = 2.74, Cohen d = 0.32, p = .006; t = 4.03, Cohen d = 0.44, p ≤. 001; t = 4.16, Cohen d = 0.11, p = .001, respectively). In addition, the standardized inflammation sumscore was a mediator of the relationship between type D personality and lipid-rich plaques (effect sizes = 0.12, 95% confidence interval = 0.007-0.286, p = .064) and plaque rupture vulnerability (effect sizes = 0.16, 95% confidence interval = 0.043-0.365, p = .024). Analysis of continuous type D scores revealed that TNF-α, IL-6, and inflammation standardized sumscores also mediate the relationship between the primary effect of negative affectivity and plaque vulnerability.

CONCLUSIONS

Inflammation activation is a potential mediator of the association between type D personality and plaque vulnerability. The negative affectivity component of type D personality might be particularly relevant to the inflammatory aspects of plaque vulnerability.

Value of Coronary Calcium Scoring in Symptomatic and Asymptomatic Coronary Artery Disease Patients

AIM AND OBJECTIVE

The study aimed to estimate the relationship between Coronary Calcium Scoring (CCS) and the presence of different degrees of obstructive coronary artery disease (CAD) to avoid unnecessary examinations and hence unnecessary radiation exposure and contrast injection.

BACKGROUND

Coronary Calcium Scoring (CCS) is a test that uses x-ray equipment to produce pictures of the coronary arteries to determine the degree of its narrowing by the build-up of calcified plaques. Despite the lack of definitive data linking ionizing radiation with cancer, the American Heart Association supports widely that practitioners of Computed tomography Coronary Angiography (CTCA) should keep "patient radiation doses as low as reasonably achievable but consistent with obtaining the desired medical information".

METHODS

Data obtained from 275 CTCA examinations were reviewed. Radiation effective doses were estimated for both CCS and CTCA, and measures to keep them as low as possible were presented. CCS and Framingham risk estimates were compared to obtain the final results of CTCA to detect sensitivity and specificity of each one in detecting obstructive lesions.

RESULTS

CCS is a strong discriminator for obstructive CAD with high sensitivity and specificity and correlates well with the degree of obstruction even more than Framingham risk estimate, which has high sensitivity and low specificity.

CONCLUSION

CCS helps to reduce the effective radiation dose if properly evaluated to skip unnecessary CTCA if obstructive lesions are unlikely, and this as a test does not use contrast material, thus harmful effect on the kidney will be avoided as most of the coronary atherosclerotic patients have renal problems.

Lipid profile as a strong indicator of coronary plaques: noninvasive assessment by multislice computerized tomography

BACKGROUND

Most acute coronary syndrome disorders occur as a consequence of atherosclerotic plaque rupture. Lipids are involved in atherosclerotic plaque buildup. Advances in image quality of coronary computed tomography have enabled improved characterization of coronary plaques. The aim of our study was to evaluate the association between lipid profile and coronary plaque presence in general and soft plaques in particular.

METHODS

In this cross-sectional survey, 258 consecutive patients presenting with chest pain either or both with low-to-moderate risk for coronary artery disease, were included. All patients were tested for lipid profile prior to cardiac imaging on a 64-slice computer tomography. Multivariate logistic regression models were used to assess the odds ratios (ORs) and 95% confidence interval (CI) for the relationship between blood lipid levels and prevalence of coronary plaques.

RESULTS

Age, total cholesterol levels, hypertension, hyperlipidemia (dichotomous) and risk factor index, all were independently associated with prevalence all kind of plaques, especially with soft plaques. No significant relationships were detected among BMI, current smoking, diabetes or triglycerides levels. In a multivariate logistic regression, hyperlipidemia was associated with presence of coronary plaque risk with adjusted OR of 2.28 (95% CI 1.30-4.01), total cholesterol with adjusted OR = 1.05 (95% CI 1.01-1.06), and risk factor index (1-6) with adjusted OR = 2.23 (95% CI 1.40-3.55).

CONCLUSION

Hyperlipidemia is strongly associated with prevalence of coronary plaques (P < 0.001) in individuals with low-to-intermediate risk for coronary artery disease, based on cardiac CT. Cardiac CT may serve as a noninvasive alternative for the early diagnosis of CAD in such individuals.

Fragmented QRS complex is an independent predictor of plaque burden in patients at intermediate risk of coronary artery disease

OBJECTIVE

We aimed to evaluate the relationship between fragmented QRS complex and plaque burden in patients presented with typical chest pain and deemed to have intermediate pretest probability of CAD using coronary computed tomography angiography (CCTA).

METHODS

We studied electrocardiograms (ECGs) obtained from 172 subjects (47.5 ± 9.5 years, 125 were men) presented with chest pain and had intermediate pretest probability for CAD. The presence was found and evaluation of CAD was performed with CCTA.

RESULTS

Seventy four (43%) of the study cohort had CCTA-documented CAD. Meanwhile the frequency of fQRS in our cohort was (57%). 70 (71.4%) patients with fQRS had CAD compared with only 4 (5.4%) patients without fQRS (p < 0.001). The number of leads with fQRs was correlated with the calcium score (p < 0.005), segment stenosis score, segment involvement score, total plaque score (TPS), and E/e ratio (p < 0.001, for all). Multivariate analysis demonstrated that fQRS was a strong independent predictor for CAD (or = 2.15, p < 0.001). ROC analysis showed that the number of leads ≥3 was the optimal number for predicting CAD (AUC = 0.89, sensitivity 88%, and specificity 83%, p < 0.001).

CONCLUSION

Fragmented QRS was seen more often in patients with high plaque burden. We suggest that fQRS might provide a useful noninvasive prognosticator for subjects with intermediate pretest probability of CAD for further investigation.

Scoring of Coronary Artery Disease Characteristics on Coronary CT Angiograms by Using Machine Learning

Background Coronary CT angiography contains prognostic information but the best method to extract these data remains unknown. Purpose To use machine learning to develop a model of vessel features to discriminate between patients with and without subsequent death or cardiovascular events. Performance was compared with that of conventional scores. Materials and Methods Coronary CT angiography was analyzed by radiologists into four features for each of 16 coronary segments. Four machine learning model types were explored. Five conventional vessel scores were computed for comparison including the Coronary Artery Disease Reporting and Data System (CAD-RADS) score. The National Death Index was retrospectively queried from January 2004 through December 2015. Outcomes were all-cause mortality, coronary heart disease deaths, and coronary deaths or nonfatal myocardial infarctions. Score performance was assessed by using area under the receiver operating characteristic curve (AUC). Results Between February 2004 and November 2009, 6892 patients (4452 men [mean age ± standard deviation, 51 years ± 11] and 2440 women [mean age, 57 years ± 12]) underwent coronary CT angiography (median follow-up, 9.0 years; interquartile range, 8.2-9.8 years). There were 380 deaths of all causes, 70 patients died of coronary artery disease, and 43 patients reported nonfatal myocardial infarctions. For all-cause mortality, the AUC was 0.77 (95% confidence interval: 0.76, 0.77) for machine learning (k-nearest neighbors) versus 0.72 (95% confidence interval: 0.72, 0.72) for CAD-RADS (P < .001). For coronary artery heart disease deaths, AUC was 0.85 (95% confidence interval: 0.84, 0.85) for machine learning versus 0.79 (95% confidence interval: 0.78, 0.80) for CAD-RADS (P < .001). When deciding whether to start statins, if the choice is made to tolerate treating 45 patients to be sure to include one patient who will later die of coronary disease, the use of the machine learning score ensures that 93% of patients with events will be administered the drug; if CAD-RADS is used, only 69% will be treated. Conclusion Compared with Coronary Artery Disease Reporting and Data System and other scores, machine learning methods better discriminated patients who subsequently experienced an adverse event from those who did not. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Schoepf and Tesche in this issue.

Sexual Dimorphism of Coronary Artery Disease in a Low- and Intermediate-Risk Asymptomatic Population: Association with Coronary Vessel Wall Thickness at MRI in Women

Purpose

To demonstrate the association between coronary vessel wall thickness (VWT) measured at MRI and coronary artery disease (CAD) risk in asymptomatic groups at low and intermediate risk on the basis of Framingham score.

Materials and Methods

A total of 131 asymptomatic adults were prospectively enrolled. All participants underwent CT angiography for scoring CAD, and coronary VWT was measured at 3.0-T MRI. Nonlinear single and multivariable regression analyses with consideration for interaction with sex were performed to investigate the association of traditional atherosclerotic risk factors and VWT with CT angiography-based CAD scores.

Results

The analysis included 62 women and 62 men with low or intermediate Framingham score of less than 20%. Age (mean age, 45.0 years ± 14.5 [standard deviation]) and body mass index were not different between the groups. Age, sex, and VWT were individually significantly associated with all CT angiography-based CAD scores (P < .05). Additionally, sex was a significant effect modifier of the associations with all CAD scores. In men, age was the only statistically significant independent risk factor of CAD; in women, VWT was the only statistically significant independent surrogate associated with increased CAD scores (P < .05).

Conclusion

In asymptomatic women, VWT MRI was the primary independent surrogate of CAD, whereas age was the strongest risk factor in men. This study suggests that VWT may be used as a CAD surrogate in women at low or intermediate risk of CAD. Further longitudinal studies are required to determine the potential implication and use of this MRI technique for the preventative management of CAD in women.© RSNA, 2019.

Automatic Coronary Wall and Atherosclerotic Plaque Segmentation from 3D Coronary CT Angiography

Coronary plaque burden measured by coronary computerized tomography angiography (CCTA), independent of stenosis, is a significant independent predictor of coronary heart disease (CHD) events and mortality. Hence, it is essential to develop comprehensive CCTA plaque quantification beyond existing subjective plaque volume or stenosis scoring methods. The purpose of this study is to develop a framework for automated 3D segmentation of CCTA vessel wall and quantification of atherosclerotic plaque, independent of the amount of stenosis, along with overcoming challenges caused by poor contrast, motion artifacts, severe stenosis, and degradation of image quality. Vesselness, region growing, and two sequential level sets are employed for segmenting the inner and outer wall to prevent artifact-defective segmentation. Lumen and vessel boundaries are joined to create the coronary wall. Curved multiplanar reformation is used to straighten the segmented lumen and wall using lumen centerline. In-vivo evaluation included CCTA stenotic and non-stenotic plaques from 41 asymptomatic subjects with 122 plaques of different characteristics against the individual and consensus of expert readers. Results demonstrate that the framework segmentation performed robustly by providing a reliable working platform for accelerated, objective, and reproducible atherosclerotic plaque characterization beyond subjective assessment of stenosis; can be potentially applicable for monitoring response to therapy.

Personalized Statin Therapy and Coronary Atherosclerotic Plaque Burden in Asymptomatic Low/Intermediate-Risk Individuals

BACKGROUND

Current guidelines for the primary prevention of atherosclerotic cardiovascular disease are based on the estimation of a predicted 10-year cardiovascular disease risk and the average relative risk reduction estimates from statin trials. In the clinical setting, however, decision-making is better informed by the expected benefit for the individual patient, which is typically lacking. Consequently, a personalized statin benefit approach based on absolute risk reduction over 10 years (ARR10 benefit threshold ≥2.3%) has been proposed as a novel approach. However, how this benefit threshold relates with coronary plaque burden in asymptomatic individuals with low/intermediate cardiovascular disease risk is unknown.

AIMS

In this study, we compared the predicted ARR10 obtained in each individual with plaque burden detected by coronary computed tomography angiography.

METHODS AND RESULTS

Plaque burden (segment volume score, segment stenosis score, and segment involvement score) was assessed in prospectively recruited asymptomatic subjects (n = 70; 52% male; median age 56 years [interquartile range 51-64 years]) with low/intermediate Framingham risk score (< 20%). The expected ARR10 with statin in the entire cohort was 2.7% (1.5-4.6%) with a corresponding number needed to treat over 10 years of 36 (22-63). In subjects with an ARR10 benefit threshold ≥2.3% (vs. < 2.3%), plaque burden was significantly higher (p = 0.02).

CONCLUSION

These findings suggest that individuals with higher coronary plaque burden are more likely to get greater benefit from statin therapy even among asymptomatic individuals with low cardiovascular risk.

Thyrotropin and free thyroxine levels and coronary artery disease: cross-sectional analysis of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Data on the association between subclinical thyroid dysfunction and coronary artery disease (CAD) is scarce. We aimed to analyze the association between thyroid function and CAD using baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). We included subjects with normal thyroid function (0.4-4.0 mIU/L, and normal free thyroxine, FT4, or 0.8 to 1.9 ng/dL), subclinical hypothyroidism (SCHypo; TSH>4.0 mIU/L and normal FT4), and subclinical hyperthyroidism (SCHyper; TSH<0.4 mIU/L and normal FT4) evaluated by coronary computed tomography angiography. We excluded individuals using medications that interfere in thyroid function or with past medical history of cardiovascular disease. Logistic regression models evaluated the presence of CAD, segment involvement score (SIS) >4, and segment severity score (SSS) >4 of coronary arteries as the dependent variables, and quintiles of TSH and FT4 as the independent variables, adjusted for demographical data and cardiovascular risk factors. We included 767 subjects, median age 58 years (IQR=55-63), 378 (49.3%) women, 697 euthyroid (90.9%), 57 (7.4%) with SCHypo, and 13 (1.7%) with SCHyper. No association between TSH and FT4 quintiles and CAD prevalence was noted. Similarly, no association between TSH levels and the extent or severity of CAD, represented by SIS>4 and SSS>4 were seen. Restricting analysis to euthyroid subjects did not alter the results. TSH levels were not significantly associated with the presence, extent, or severity of CAD in a middle-aged healthy population.

Obesity, metabolic syndrome and cardiovascular prognosis: from the Partners coronary computed tomography angiography registry

Objective

To investigate the relationship among body mass index (BMI), cardiometabolic risk and coronary artery disease (CAD) among patients undergoing coronary computed tomography angiography (CTA).

Methods

Retrospective cohort study of 1118 patients, who underwent coronary CTA at two centers from September 2004 to October 2011. Coronary CTA were categorized as normal, nonobstructive CAD (<50%), or obstructive CAD (≥50%) in addition to segment involvement (SIS) and stenosis scores. Extensive CAD was defined as SIS > 4. Association of BMI with cardiovascular prognosis was evaluated using multivariable fractional polynomial models.

Results

Mean age of the cohort was 57 ± 13 years with median follow-up of 3.2 years. Increasing BMI was associated with MetS (OR 1.28 per 1 kg/m², p < 0.001) and burden of CAD on a univariable basis, but not after multivariable adjustment. Prognosis demonstrated a J-shaped relationship with BMI. For BMI from 20–39.9 kg/m², after adjustment for age, gender, and smoking, MetS (HR 2.23, p = 0.009) was more strongly associated with adverse events.

Conclusions

Compared to normal BMI, there was an increased burden of CAD for BMI > 25 kg/m². Within each BMI category, metabolically unhealthy patients had greater extent of CAD, as measured by CCTA, compared to metabolically healthy patients.

T-cell Activation and E-selectin Are Associated With Coronary Plaque in HIV-infected Young Adults

We evaluated immune activation and coronary artery plaque in young adults with human immunodeficiency virus acquired in early life (n = 31). Coronary plaque was positively associated with lipids, immune activation marker %CD8+CD38+DR+ and E-selectin, a marker of endothelial inflammation. Immune activation and endothelial inflammation may drive coronary plaque formation during the early stages of atherosclerosis in the context of chronic human immunodeficiency virus.

Cohort profile of BIOMArCS: the BIOMarker study to identify the Acute risk of a Coronary Syndrome-a prospective multicentre biomarker study conducted in the Netherlands

PURPOSE

Progression of stable coronary artery disease (CAD) towards acute coronary syndrome (ACS) is a dynamic and heterogeneous process with many intertwined constituents, in which a plaque destabilising sequence could lead to ACS within short time frames. Current CAD risk assessment models, however, are not designed to identify increased vulnerability for the occurrence of coronary events within a precise, short time frame at the individual patient level. The BIOMarker study to identify the Acute risk of a Coronary Syndrome (BIOMArCS) was designed to evaluate whether repeated measurements of multiple biomarkers can predict such 'vulnerable periods'.

PARTICIPANTS

BIOMArCS is a multicentre, prospective, observational study of 844 patients presenting with ACS, either with or without ST-elevation and at least one additional cardiovascular risk factor.

METHODS AND ANALYSIS

We hypothesised that patterns of circulating biomarkers that reflect the various pathophysiological components of CAD, such as distorted lipid metabolism, vascular inflammation, endothelial dysfunction, increased thrombogenicity and ischaemia, diverge in the days to weeks before a coronary event. Divergent biomarker patterns, identified by serial biomarker measurements during 1-year follow-up might then indicate 'vulnerable periods' during which patients with CAD are at high short-term risk of developing an ACS. Venepuncture was performed every fortnight during the first half-year and monthly thereafter. As prespecified, patient enrolment was terminated after the primary end point of cardiovascular death or hospital admission for non-fatal ACS had occurred in 50 patients. A case-cohort design will explore differences in temporal patterns of circulating biomarkers prior to the repeat ACS.

FUTURE PLANS AND DISSEMINATION

Follow-up and event adjudication have been completed. Prespecified biomarker analyses are currently being performed and dissemination through peer-reviewed publications and conference presentations is expected from the third quarter of 2016. Should identification of a 'vulnerable period' prove to be feasible, then future research could focus on event reduction through pharmacological or mechanical intervention during such periods of high risk for ACS.

TRIAL REGISTRATION NUMBER

NTR1698 and NTR1106.

Clinical Utility and Future Applications of PET/CT and PET/CMR in Cardiology

Over the past several years, there have been major advances in cardiovascular positron emission tomography (PET) in combination with either computed tomography (CT) or, more recently, cardiovascular magnetic resonance (CMR). These multi-modality approaches have significant potential to leverage the strengths of each modality to improve the characterization of a variety of cardiovascular diseases and to predict clinical outcomes. This review will discuss current developments and potential future uses of PET/CT and PET/CMR for cardiovascular applications, which promise to add significant incremental benefits to the data provided by each modality alone.

Usefulness of High-Sensitivity Cardiac Troponin T for the Identification of Outlier Patients With Diffuse Coronary Atherosclerosis and Low-Risk Factors

Novel high-sensitivity assay can detect very low levels of circulating cardiac troponin (hs-cTnT) in apparently healthy subjects. Within normal range, higher levels are associated with coronary artery disease (CAD) and cardiac abnormalities commonly associated to traditional risk factors (RFs) for CAD. Therefore, we investigated the relation between circulating hs-cTnT and CAD in patients with a spectrum of RF burden aiming to assess the added value of hs-cTnT to identify "outlier" patients with CAD despite a low RF burden. Hs-cTnT was measured in 525 stable patients without previous diagnosis of ischemic heart disease with 0 to 1 RF, excluded diabetes, (low-RF group, n = 263) or ≥2 RFs (multiple-RF group, n = 262) and without CAD (segment involvement score = 0) or diffuse CAD (segment involvement score >5) at coronary computed tomography angiography. Outlier patients with diffuse CAD despite low-RF burden had similar extent, severity, and plaque composition than patients with multiple RFs. Overall, hs-cTnT was measurable in 81% of patients with median value of 6.0 ng/L. In both groups, hs-cTnT concentration was higher in patients with CAD than in patients with normal coronary arteries (p <0.0001). Hs-cTnT was more accurate to detect patients with CAD in the low-RF group than in the multiple-RF group (p = 0.04). In multivariate analysis, higher level of hs-cTnT (>6 ng/L) was independently associated with CAD in low-RF group only. Despite very low circulating concentrations, hs-cTnT may identify with a good accuracy the outlier patients with diffuse CAD despite low-RF burden.

The presence of remodeled and mixed atherosclerotic plaques at coronary ct angiography predicts major cardiac adverse events - The CAFÉ-PIE Study

BACKGROUND

It is still unclear how to exploit information made available by coronary computed tomography angiography (CCTA) on coronary artery disease (CAD) features in order to better predicting major adverse cardiac events (MACEs). Aim of this study was to validate the prognostic role of a comprehensive and simplified CT-derived score in patients evaluated for suspected CAD.

METHODS

A prospective registry included 477 consecutive symptomatic patients without known CAD who underwent clinically-indicated CCTA. All patients were followed-up for MACE occurrence for a period of 49±15-month.

RESULTS

The mean CT Score was 10.5±10.8, with a MACE rate of 11.3%. There was a stepwise relationship between MACE rate during follow-up and CT Score values. MACEs were 1.9% in patients with CT Score<10 (reference group), 16.6% in those with CT Score 10-20 (OR 9.9, 95% C.I. 3.5-27.8 vs. reference group, p<0.001), 24.5% in those with CT Score 21-30 (OR 16.6, 95% C.I. 6.1-45.0 vs. reference group, p<0.001), and 47.4% in those with CT Score>30 (OR 46.1, 95% C.I. 13.0-162.9 vs. reference group, p<0.001) (p for trend <0.001). At ROC curve analysis, CT Score was the best predictor of MACE (AUC: 0.81, CI 95%: 0.78-0.84) as compared to Diamond and Forrester score (p<0.001), segment stenosis score (p<0.05) and segment involved score (p<.0.01).

CONCLUSIONS

The use of an integrated score obtained with CCTA and based on the presence of remodeled and mixed atherosclerotic coronary plaques may improve MACE prediction in symptomatic patients at intermediate risk outweighing that provided by standard clinical and CCTA scores.

Coronary atherosclerosis in outlier subjects at the opposite extremes of traditional risk factors: Rationale and preliminary results of the Coronary Atherosclerosis in outlier subjects: Protective and novel Individual Risk factors Evaluation (CAPIRE) study

Although it is generally accepted that cardiac ischemic events develop when coronary atherosclerosis (coronary artery disease [CAD]) has reached a critical threshold, this is true only to a first approximation. Indeed, there are patients with severe CAD who do not develop ischemic events; conversely, at the other extreme, individuals with minimal CAD may do. Similar exceptions to this paradigm include patients with diffuse CAD with a low risk factor (RF) profile and others with multiple RFs who develop only mild or no CAD. Therefore, the CAPIRE project was designed to investigate whether the specific study of these extreme outlier populations could provide clues for identification of yet unknown risk or protective factors for CAD and ischemic events. In the CAPIRE study, 481 subjects without previous symptoms or history of ischemic heart disease and normal left ventricular systolic function undergoing coronary computed tomography angiography have been selected based on coronary computed tomography angiography findings and cardiovascular RF profile. Therefore, in the whole population, 2 extreme outlier populations have been identified: (1) subjects with no CAD despite multiple RFs, and (2) at the opposite extreme, subjects with diffuse CAD despite a low-risk profile. Each subject has been characterized by clinical, anatomical imaging variables of CAD and baseline circulating biomarkers. Blood samples were collected and stored in a biological bank for further advanced investigations. The project is designed as a prospective, observational, international multicenter study with an initial cross-sectional analysis of clinical, imaging, and biomolecular variables in the selected groups and a longitudinal 5-year follow-up.

Noninvasive Imaging of Atherosclerotic Plaque Progression: Status of Coronary Computed Tomography Angiography

The process of coronary artery disease progression is infrequently visualized. Intravascular ultrasound has been used to gain important insights but is invasive and therefore limited to high-risk patients. For low-to-moderate risk patients, noninvasive methods may be useful to quantitatively monitor plaque progression or regression and to understand and personalize atherosclerosis therapy. This review discusses the potential for coronary computed tomography angiography to evaluate the extent and subtypes of coronary plaque. Computed tomographic technology is evolving and image quality of the method approaches the level required for plaque progression monitoring. Methods to quantify plaque on computed tomography angiography are reviewed as well as a discussion of their use in clinical trials. Limitations of coronary computed tomography angiography compared with competing modalities include limited evaluation of plaque subcomponents and incomplete knowledge of the value of the method especially in patients with low-to-moderate cardiovascular risk.

Age and sex relationship with flow-mediated dilation in healthy children and adolescents

Flow-mediated dilation (FMD) is a noninvasive technique used to measure conduit artery vascular function. Limited information is available on normative FMD values in healthy children and adolescents. The objective of this study was to assess relationships between age and sex with FMD across childhood and adolescence. Nine hundred and seventy-eight asymptomatic children (12 ± 3 yr, range 6-18 yr, 530 male) underwent ultrasonic brachial artery assessment before and after 5 min of forearm ischemia. Sex differences in FMD and baseline artery diameter were assessed using mixed linear models. Baseline artery diameter was smaller in females than males [2.96 mm (95% CI: 2.92-3.00) vs. 3.24 mm (3.19-3.28), P < 0.001] and increased with age across the cohort (P < 0.001). Diameter increased between ages 6 and 17 yr in males [from 2.81 mm (2.63, 3.00) to 3.91 mm (3.68, 4.14)] but plateaued at age 12 yr in females. Males had a lower FMD [7.62% (7.33-7.91) vs. 8.31% (7.95-8.66), P = 0.024], specifically at ages 17 and 18 yr. There was a significant effect of age on FMD (P = 0.023), with a reduction in FMD apparent postpuberty in males. In conclusion, the brachial artery increases structurally with age in both sexes; however, there are sex differences in the timing and rate of growth, in line with typical sex-specific adolescent growth patterns. Males have a lower FMD than females, and FMD appears to decline with age; however, these findings are driven by reductions in FMD as males near maturity. The use of age- and sex-specific FMD data may therefore not be pertinent in childhood and adolescence.

Arterial structure and function in vascular ageing: are you as old as your arteries?

Advancing age may be the most potent independent predictor of future cardiovascular events, a relationship that is not fully explained by time-related changes in traditional cardiovascular risk factors. Since some arteries exhibit differential susceptibility to atherosclerosis, generalisations regarding the impact of ageing in humans may be overly simplistic, whereas in vivo assessment of arterial function and health provide direct insight. Coronary and peripheral (conduit, resistance and skin) arteries demonstrate a gradual, age-related impairment in vascular function that is likely to be related to a reduction in endothelium-derived nitric oxide bioavailability and/or increased production of vasoconstrictors (e.g. endothelin-1). Increased exposure and impaired ability for defence mechanisms to resist oxidative stress and inflammation, but also cellular senescence processes, may contribute to age-related changes in vascular function and health. Arteries also undergo structural changes as they age. Gradual thickening of the arterial wall, changes in wall content (i.e. less elastin, advanced glycation end-products) and increase in conduit artery diameter are observed with older age and occur similarly in central and peripheral arteries. These changes in structure have important interactive effects on artery function, with increases in small and large arterial stiffness representing a characteristic change with older age. Importantly, direct measures of arterial function and structure predict future cardiovascular events, independent of age or other cardiovascular risk factors. Taken together, and given the differential susceptibility of arteries to atherosclerosis in humans, direct measurement of arterial function and health may help to distinguish between biological and chronological age-related change in arterial health in humans.

Prognostic value of heart valve calcifications for cardiovascular events in a lung cancer screening population

To assess the prognostic value of aortic valve and mitral valve/annulus calcifications for cardiovascular events in heavily smoking men without a history of cardiovascular disease. Heavily smoking men without a cardiovascular disease history who underwent non-contrast-enhanced low-radiation-dose chest CT for lung cancer screening were included. Non-imaging predictors (age, smoking status and pack-years) were collected and imaging-predictors (calcium volume of the coronary arteries, aorta, aortic valve and mitral valve/annulus) were obtained. The outcome was the occurrence of cardiovascular events. Multivariable Cox proportional-hazards regression was used to calculate hazard-ratios (HRs) with 95% confidence interval (CI). Subsequently, concordance-statistics were calculated. In total 3111 individuals were included, of whom 186 (6.0%) developed a cardiovascular event during a follow-up of 2.9 (Q1-Q3, 2.7-3.3) years. If aortic (n = 657) or mitral (n = 85) annulus/valve calcifications were present, cardiovascular event incidence increased to 9.0% (n = 59) or 12.9% (n = 11), respectively. HRs of aortic and mitral valve/annulus calcium volume for cardiovascular events were 1.46 (95% CI, 1.09-1.84) and 2.74 (95% CI, 0.92-4.56) per 500 mm(3). The c-statistic of a basic model including age, pack-years, current smoking status, coronary and aorta calcium volume was 0.68 (95% CI, 0.63-0.72), which did not change after adding heart valve calcium volume. Aortic valve calcifications are predictors of future cardiovascular events. However, there was no added prognostic value beyond age, number of pack-years, current smoking status, coronary and aorta calcium volume for short term cardiovascular events.

Accuracy of statin assignment using the 2013 AHA/ACC Cholesterol Guideline versus the 2001 NCEP ATP III guideline: correlation with atherosclerotic plaque imaging

BACKGROUND

Accurate assignment of statin therapy is a major public health issue.

OBJECTIVES

The American Heart Association and the American College of Cardiology released a new guideline on the assessment of cardiovascular risk (GACR) to replace the 2001 National Cholesterol Education Program (NCEP) Adult Treatment Panel III recommendations. The aim of this study was to determine which method more accurately assigns statins to patients with features of coronary imaging known to have predictive value for cardiovascular events and whether more patients would be assigned to statins under the new method.

METHODS

The burden of coronary atherosclerosis on computed tomography angiography was measured in several ways on the basis of a 16-segment model. Whether to assign a given patient to statin therapy was compared between the NCEP and GACR guidelines.

RESULTS

A total of 3,076 subjects were studied (65.3% men, mean age 55.4 ± 10.3 years, mean age of women 58.9 ± 10.3 years). The probability of prescribing statins rose sharply with increasing plaque burden under the GACR compared with the NCEP guideline. Under the NCEP guideline, 59% of patients with ≥50% stenosis of the left main coronary artery and 40% of patients with ≥50% stenosis of other branches would not have been treated. The comparable results for the GACR were 19% and 10%. The use of low-density lipoprotein targets seriously degraded the accuracy of the NCEP guideline for statin assignment. The proportion of patients assigned to statin therapy was 15% higher under the GACR.

CONCLUSIONS

The new American Heart Association/American College of Cardiology guideline matches statin assignment to total plaque burden better than the older guidelines, with only a modest increase in the number of patients who were assigned statins.

Carotid intima media thickness and coronary atherosclerosis linkage in symptomatic intermediate risk patients evaluated by coronary computed tomography angiography

BACKGROUND

There is a growing evidence that carotid intima media thickness (CIMT) is associated with coronary artery disease (CAD) and it should be used as a predictor of atherosclerotic burden of coronary arteries. However, these studies have been performed by using invasive coronary angiography (ICA) and in high-risk patients for CAD. The purpose of this study was to evaluate the correlation between CIMT by ultrasound and coronary atherosclerosis in symptomatic intermediate risk patients by coronary computed tomography angiography (CCTA).

METHODS

We enrolled 204 consecutive symptomatic patients (mean age: 61±10; men: 118) and intermediate risk for CAD. All patients underwent CIMT ultrasound evaluation and CCTA. Coronary artery calcium score (CACS), characteristics of plaques, severity of CAD, segment involvement score (SIS) and Gensini's score were assessed and compared with CIMT values.

RESULTS

CIMT has been proved as an independent predictor of a number of coronary artery plaques, overall number of mixed and remodeled plaques, presence of obstructive CAD, high SIS and Gensini's score (HR 1.2, CI 1.05-1.42, p 0.01; HR 1.2, CI 1.01-1.41, p 0.03; HR 9.0, CI 1.37-59.7, p 0.02; HR 21.0, CI 2.40-184, p<0.01; HR 1.2, CI 1.08-1.42, p<0.01; HR 1.2, CI 1.08-1.42, p<0.01, respectively). A cut-off value>1.3 was associated with a better positive and negative predictive value (100% and 69%) to predict the combined endpoint of presence and mixed and/or remodeled coronary artery plaques.

CONCLUSIONS

CIMT is an independent predictor of coronary atherosclerotic burden as detected by CCTA in symptomatic intermediate risk patients.

Feasibility of low-dose contrast medium high pitch CT angiography for the combined evaluation of coronary, head and neck arteries

Purpose

To evaluate the image quality and radiation dose of combined heart, head, and neck CT angiography (CTA) using prospectively electrocardiography (ECG)-triggered high-pitch spiral scan protocol, compared with single coronary CTA.

Materials and Methods

151 consecutive patients were prospectively included and randomly divided into three groups. Group 1 (n = 47) underwent combined heart, neck, and head CTA using prospectively ECG-triggered high-pitch spiral (Flash) scan protocol with a single-phase intravenous injection of iodinated contrast and saline flush; Group 2 (n = 51) underwent single coronary CTA with Flash scan protocol; and Group 3 (n = 53) underwent single coronary CTA with prospective sequence scan protocol. All patients were examined on a dual source CT (Definition FLASH). The image quality was determined for each CT study.

Results

Patients of scanning protocol Group 1, 2, and 3 showed no significant differences in age, sex, heart rates, and BMI. Evaluation of coronary artery image quality showed comparable results in the three scanning protocol groups on a per patient-based analysis. In group 1, image quality was found to be sufficient to be diagnostic in all arterial segments of carotid arteries. The mean dose-length product (DLP) for group 1 was 256.3±24.5 mGy×cm and was significantly higher in comparison with group 2 (93.4±19.9 mGy×cm; p < 0.001). However, there was no significant difference of DLP between group 1 and group 3 (254.1±69.9 mGy×cm).

Conclusions

The combined heart, neck, and head arteries scan using prospectively electrocardiography (ECG)-triggered high-pitch spiral scan protocol in 1 single examination resulted in an excellent opacification of the aorta, the carotid arteries, and the coronary arteries and provided a good image quality with low radiation dose.

Calcium score, coronary artery disease extent and severity, and clinical outcomes among low Framingham risk patients with low vs high lifetime risk: results from the CONFIRM registry

BACKGROUND

Short-term risk scores, such as the Framingham risk score (FRS), frequently classify younger patients as low risk despite the presence of uncontrolled cardiovascular risk factors. Among patients with low FRS, estimation of lifetime risk is associated with significant differences in coronary arterial calcium scores (CACS); however, the relationship of lifetime risk to coronary atherosclerosis on coronary CT angiography (CCTA) and prognosis has not been studied.

METHODS AND RESULTS

We evaluated asymptomatic 20-60-year-old patients without diabetes or known coronary artery disease (CAD) within an international CT registry who underwent ≥64-slice CCTA. Patients with low FRS (<10%) were stratified as low (<39%) or high (≥39%) lifetime CAD risk, and compared for the presence and severity of CAD and prognosis for death, myocardial infarction, and late coronary revascularization (>90 days post CCTA). 1,863 patients of mean age of 47 years were included, with 48% of the low FRS patients at high lifetime risk. Median follow-up was 2.0 years. Comparing low-to-high lifetime risk, respectively, the prevalence of any CAD was 32% vs 41% (P < .001) and ≥50% stenosis was 7.4% vs 9.6% (P = .09). For those with CAD, subjects at low vs high lifetime risk had lower CACS (median 12 [IQR 0-94] vs 38 [IQR 0.05-144], P = .02) and less purely calcified plaque, 35% vs 45% (P < .001). Prognosis did not differ due to low number of events.

CONCLUSION

Assessment of lifetime risk among patients at low FRS identified those with the increase in CAD prevalence and severity and a higher proportion of calcified plaque.

Cardiometabolic risk is associated with atherosclerotic burden and prognosis: results from the partners coronary computed tomography angiography registry

OBJECTIVE

Our purpose was to evaluate coronary artery disease (CAD) prevalence and prognosis according to cardiometabolic (CM) risk.

RESEARCH DESIGN AND METHODS

Registry of all patients without prior CAD referred for coronary computed tomography angiography (CCTA). Patients were stratified by groups of increasing CM risk factors (hypertension, low HDL, hypertriglyceridemia, obesity, and dysglycemia) as follows: patients without type 2 diabetes mellitus (T2DM) with fewer than three or with three or more CM risk factors, patients with T2DM not requiring insulin, or those with T2DM requiring insulin. Patients were followed for a primary end point of major adverse cardiovascular events (MACE) composed of unstable angina, late coronary revascularization, myocardial infarction (MI), and cardiovascular mortality.

RESULTS

Among 1,118 patients (mean age 57 ± 13 years) followed for a mean 3.1 years, there were 21 (1.9%) cardiovascular deaths and 13 (1.2%) MIs. There was a stepwise increase in the prevalence of obstructive CAD with increasing CM risk, from 15% in those without diabetes and fewer than three CM risk factors to as high as 46% in patients with T2DM requiring insulin (P < 0.001). Insulin exposure was associated with the highest adjusted hazard of MACE (hazard ratio 3.29 [95% CI 1.28-8.45], P = 0.01), whereas both T2DM without insulin (1.35, P = 0.3) and three or more CM risk factors without T2DM (1.48, P = 0.3) were associated with a similar rate of MACE.

CONCLUSIONS

Patients without diabetes who have multiple metabolic risk factors have a similar prognosis and burden of CAD as those with T2DM not requiring insulin. Among patients with diabetes, the need for insulin therapy is associated with greater burden of CAD as well as worse prognosis.

Association between postprandial triglycerides and coronary artery disease detected by coronary computed tomography angiography

BACKGROUND

Studies have demonstrated the association of severe anatomical coronary artery disease (CAD) with postprandial triglycerides (TG) concentrations. Nevertheless the relationship between less severe atherosclerosis plaque burden and postprandial TG is less established.

OBJECTIVE

to study the relationship between postprandial TG and CAD detected by coronary computed tomographic angiography (CTA).

MATERIAL AND METHODS

130 patients who underwent an oral fat tolerance test were enrolled (85 with CAD detected by CTA and 45 without). Postprandial lipemia was studied by measuring TG from T0h to T6h with 2-h intervals, and analyzed the TG change over time using a longitudinal multivariable linear mixed effects model with the log normal of the TG as the primary outcome.

RESULTS

The majority of individuals with CAD had non-obstructive disease (63.3%) Patients with CAD had a slower clearance of postprandial TG change from 4 h to 6 h (p<0.05) compared to patients without CAD. These results remained significant after adjustment for fasting TG and glucose, age, gender, body mass index, and waist circumference. However, those differences did not reach statistical significance after adjustment for fasting HDL-C.

CONCLUSION

Patients with mild (<25% lumen obstruction) and moderate CAD (25-50% lumen obstruction) detected by coronary CTA had an impaired postprandial metabolism, with a delayed TG clearance, when compared to individuals with no CAD. This difference was partially explained by the lower HDL-C. Thus, though postprandial TG may contribute to the development of CAD, this association is partially related to low HDL-C.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Assessment of sex differences in plaque morphology by coronary computed tomography angiography--are men and women the same?

PURPOSE

The objective of this study was to assess whether sex differences exist in plaque burden and plaque subtype as assessed by coronary computed tomography angiography (CCTA).

METHODS

The study cohort included 937 consecutive patients who underwent CCTA between 2008 and 2010. Stenosis was quantified using the Society of Cardiovascular Computed Tomography stenosis grading scale and a total stenosis score (TSS) was generated. Plaque morphology (PM) was reported as predominantly calcified (CP), noncalcified (NCP), or mixed (MP) plaque, and CP, NCP, and MP percentages were calculated.

RESULTS

On multivariate analysis, men were significantly more likely to have plaque (65.9% of men vs. 44.6% of women, p<0.001), at least one segment with ≥50% stenosis (22.7% of men vs. 10.3% of women, p<0.001) and higher TSS (mean score=2.81 for men vs. 1.58 for women, p<0.001). Sex was the strongest predictor in all models (odds ratio [OR]=2.55, 95% confidence interval [CI] 1.78-3.67, p<0.001 for any plaque; OR=2.48, 95% CI 1.48-4.16, p<0.01 for segments with ≥50% stenosis; β=1.46, 95% CI 0.69-2.22, p<0.001 for TSS). Among patients with coronary plaque present, no significant sex differences in PM were found.

CONCLUSIONS

Sex was the strongest risk factor for the presence and extent of plaque. Significant sex differences in PM did not exist.

Coronary artery calcium score: a review

Context

Coronary artery disease (CAD) is the foremost cause of death in many countries and hence, its early diagnosis is usually concerned as a major healthcare priority. Coronary artery calcium scoring (CACS) using either electron beam computed tomography (EBCT) or multislice computed tomography (MSCT) has been applied for more than 20 years to provide an early CAD diagnosis in clinical routine practice. Moreover, its association with other body organs has been a matter of vast research.

Evidence Acquisition

In this review article, techniques of CACS using EBCT and MSCT scanners as well as clinical and research indications of CACS are searched from PubMed, ISI Web of Science, Google Scholar and Scopus databases in a time period between late 1970s through July 2013 and following appropriate selection, dealt with. Moreover, the previous and ongoing research subjects and their results are discussed.

Results

The CACS is vastly applied in early detection of CAD and in many other research fields.

Conclusions

CACS has remarkably changed the screening techniques to detect CAD earlier than before and is generally accepted as a standard of reference for determination of risk of further cardiac events.

Accuracy and predictive value of coronary computed tomography angiography for the detection of obstructive coronary heart disease in patients with an Agatston calcium score above 400

PURPOSE

We assessed the accuracy of coronary computed tomography angiography (CTA) in patients with an Agatston calcium score (ACS) of greater than 400 by comparing it with invasive coronary angiography (ICA), and we evaluated the predictive value of CTA for obstructive coronary heart disease (CHD) compared with traditional clinical risk assessment.

METHODS

A total of 253 patients who had an ACS of greater than 400 were enrolled in this study. The degree of coronary stenosis was visually and quantitatively estimated by postprocessing imaging using 15-segment coronary models. All patients underwent ICA after a mean (SD) of 34 (24) days, and the degree of coronary stenosis was compared with the results of CTA.

RESULTS

Computed tomography angiography accurately diagnosed significant stenosis in 204 (99.0%) of 206 patients and in 649 (83.5%) of 777 segments. When the patients were considered based on their ACS (group A, 400 < ACS ≤ 1000, vs group B, ACS > 1000), group B showed lower specificity (9.1% vs 41.7%) and poorer agreement (k = 0.149 vs 0.495) than for ICA. By segment-based analysis, the agreement between CTA and ICA was good (k = 0.729), and there was no significant difference between groups A (k = 0.728) and B (k = 0.727). Computed tomography angiography was the most powerful predictor (odds ratio = 52.645, P < 0.001), whereas the 10-year CHD risk and pretest probability were not significantly correlated with obstructive CHD.

CONCLUSIONS

Despite good overall diagnostic accuracy, coronary CTA in this group of patients was limited by low specificity. However, CTA was a better predictor of obstructive CHD compared with clinical predictors, and it avoided unnecessary ICA, even in patients with extensive coronary artery calcification.

Evaluation of framingham and systematic coronary risk evaluation scores by coronary computed tomographic angiography in asymptomatic adults

Recently, coronary computed tomographic angiography (CCTA) was introduced as a tool for the early detection of coronary atherosclerosis. However, a disagreement exists regarding the accuracy of CCTA for the prediction of future cardiovascular risk compared to conventional clinical risks scores (e.g., Framingham and Systematic Coronary Risk Evaluation [SCORE] scores). The aim of the present study was to compare these 2 methods in asymptomatic Israeli subjects. CCTA was performed in 190 asymptomatic patients with ≥1 atherogenic risk factor as the primary screening tool for the presence of cardiovascular disease. The calcium score (CS) was measured in these subjects as a part of CCTA. In addition, the Framingham and SCORE scores were calculated, and statistical analysis using regression models was performed. The study included 190 subjects (84% men). The mean age was 55 ± 9.7 years. A significant correlation with the CS and plaque severity detected by CCTA was found when comparing the risk factors calculated by the SCORE and Framingham scores. A SCORE calculation of >2 versus <2 was related to a greater incidence of a CS >100 (42.9% vs 21.9; odds ratio [OR] 2.68, p = 0.001). When comparing high-risk (>4) and low-risk (<4) SCORE scores, the risk of atherosclerosis per CCTA was 50% versus 27.1% respectively (OR 2.7, p = 0.001). A high-risk Framingham (>20) versus low-risk Framingham (<20) score was related to a greater incidence of CS >100 (53.3% vs 28.6%; OR 3.18, p = 0.001). A high-risk versus low-risk SCORE score was related to greater plaque severity (79.2% vs 59.4%, respectively; OR 2.6, p = 0.001). A high-risk versus low-risk Framingham score was also related to greater plaque severity (93.3% vs 59%, respectively; OR 3.18, p = 0.001). The variables best predicting the severity of artery stenosis were age, gender, diabetes, and hypertension. In conclusion, the results of the present study indicate that the results of the Framingham and SCORE scores compared to those obtained using CCTA are good predictors of coronary artery disease. The use of these clinical scores seems important in identifying patients at risk of coronary atherosclerosis and treating them properly before the development of symptoms and also to help prevent the use of unnecessary invasive procedures.

Characterization of culprit lesions in acute coronary syndromes compared with stable angina pectoris by dual-source computed tomography

To identify the characterization of culprit lesions in acute coronary syndrome (ACS) compared with stable angina pectoris (SAP) by dual-source computed tomography (DSCT). 65 patients with ACS and 75 controls with SAP and a similar atherosclerotic risk profile were studied. Computed tomography (CT) coronary angiography was performed using a DSCT scanner before invasive catheterization. Using DSCT and quantitative coronary angiography (QCA), lesion characteristics [luminal cross-section area (L-CSA), vascular cross-section area (V-CSA), plaque area and degree of stenosis) were detected. Plaque types, mean and minimum CT density (Hounsfield Unit; HU), remodeling index, and presence of "spotty" calcifications were analyzed using DSCT. A good correlation was observed between DSCT and QCA for all lesion characteristics (P < 0.05). Culprit lesions in ACS had much larger V-CSA (20.5 ± 6.0 vs. 14.8 ± 4.8 mm(2)), plaque area (15.3 ± 5.0 vs. 11.1 ± 3.3 mm(2)) and remodeling index (1.3 ± 0.2 vs. 1.0 ± 0.4) than stable lesions in SAP (P < 0.05). The prevalence of non-calcified/calcified/mixed plaque was 30/0/35 in ACS versus 25/15/35 stable lesions in SAP (P < 0.01). The proportion of "spotty" calcified plaques was 21.5 % in culprit lesions (14 of 65) versus 1.3 % in SAP (1 of 75). The mean/minimum HU of culprit lesions was 88.6 ± 43.2/154.2 ± 98.7 in ACS versus 45.9 ± 34.7/98.2 ± 76.8 in SAP (both P < 0.01). DSCT is a feasible means of detecting coronary stenosis with good accuracy compared with QCA. Culprit lesions in ACS display a greater proportion of non-calcified material with lower CT attenuation, "spotty" calcifications and higher remodeling index compared with SAP lesions.

Coronary artery calcium score: Re-evaluation of its predictive value for coronary artery disease

Coronary artery disease is the leading cause of death in advanced countries and its prevalence is increasing among the developing countries. Cardiac computed tomography (CT) has been increasingly used in the diagnosis of coronary artery disease due to its rapid improvements in multislice CT scanners over the last decade, and this less-invasive technique has become a potentially effective alternative to invasive coronary angiography. Quantifying the amount of coronary artery calcium with cardiac CT has been widely accepted as a reliable non-invasive technique for predicting risk of future cardiovascular events. However, the main question that remains uncertain is whether routine, widespread coronary artery calcium scoring in an individual patient will result in an overall improvement in quality of care and clinical outcomes. In this commentary, we discuss a current issue of the clinical value of coronary artery calcium scoring with regard to its value of predicting adverse cardiac events. We also discuss the applications of coronary artery calcium scores in patients with different risk groups.

Relation of aortic calcification, wall thickness, and distensibility with severity of coronary artery disease: evaluation with coronary CT angiography

BACKGROUND

Three known risk factors for aortic atherosclerosis predict the severity of coronary artery disease (CAD): aortic calcification (AC), aortic wall thickness (AWT), and aortic distensibility (AD).

PURPOSE

To determine the relationship of AC, AWT, and AD with the severity of CAD.

MATERIAL AND METHODS

A total of 104 patients who underwent both coronary CT angiography (CCTA) and invasive coronary angiography were enrolled. The severity of CAD was assessed by three methods: the segment involvement score (SIS), the segment stenosis score (SSS), and the modified Gensini score (mG). We quantified AC using the Agatston method on low-dose ungated chest CT (LDCT). We measured AWT at the thickest portion of the descending thoracic aorta on CCTA. AD was calculated as the difference between the maximum and minimum areas of the ascending aorta and the pulse pressure. The relationships between the severity of CAD and the three aortic factors were assessed.

RESULTS

The AC and AWT of the thoracic aorta were significantly higher in the occlusive CAD (OCAD) group (1984.21 ± 2986.10 vs. 733.00 ± 1648.71, P = 0.01; 4.13 ± 1.48 vs. 3.40 ± 1.01, P = 0.22). Patients with OCAD had more than one epicardial coronary artery with >50% luminal stenosis. The AC (r = 0.453 with SIS; r = 0.454 with SSS; r = 0.427 with mG) and the AWT (r = 0.279 with SIS; r = 0.324 with SSS; r = 0.304 with mG) were significantly correlated with all three methods, and the AD was negatively correlated with the SIS (r = - 0.221, P < 0.05, respectively) in the unadjusted model. After adjustment for cardiovascular risk factors, only the correlations between AC and all three methods assessing CAD remained significant.

CONCLUSION

There are significant relationships between AC, AWT and AD and severity of CAD. In particular, AC measured on LDCT is the most consistent predictor of severity of CAD.

Assessing coronary disease in symptomatic women by the Morise score

BACKGROUND

Early identification of coronary artery disease (CAD) among symptomatic women is critical given their worse outcomes as compared to men. We evaluated the value of the Morise score, a simple clinical risk score, for the assessment for CAD as determined by computed tomography coronary angiography (CTCA) and compared it to the Diamond-Forrester risk assessment.

METHODS

One hundred forty women (mean age, 64±11 years) with chest pain syndromes and no known CAD referred for CTCA were analyzed. Patients were risk stratified for likelihood of CAD by Morise and Diamond-Forrester scores. The presence and degree of CAD were determined by CTCA and classified as normal, nonobstructive (<50% stenosis), or obstructive (>50% stenosis). Total coronary calcium was calculated based on Agatston scores.

RESULTS

When risk was assessed by Morise vs. Diamond-Forrester, 5% vs. 7% of women were stratified as low, 41% vs. 82% as intermediate, and 54% vs. 11% as high risk for CAD, respectively. CAD was present in 95 (68%) patients; 22 (16%) had obstructive CAD, and 73 (52%) had nonobstructive CAD. Morise scores significantly correlated with calcium scores (p<0.001) as well as the presence and degree of CAD (p<0.0001). Morise scores also demonstrated significantly higher accuracy (66% vs. 48%, p<0.005) and higher sensitivity (56% vs. 16%, p<0.001) but lower specificity (82% vs. 97%, p<0.05) when compared to Diamond-Forrester risk assessment.

CONCLUSIONS

The Morise score performed better than Diamond-Forrester for CAD risk assessment, which highlights the importance and power of a simple history and physical examination in determining women at risk for CAD.

Automated tracing of the adventitial contour of aortoiliac and peripheral arterial walls in CT angiography (CTA) to allow calculation of non-calcified plaque burden

Aortoiliac and lower extremity arterial atherosclerotic plaque burden is a risk factor for the development of visceral and peripheral ischemic and aneurismal vascular disease. While prior research allows automated quantification of calcified plaque in these body regions using CT angiograms, no automated method exists to quantify soft plaque. We developed an automatic algorithm that defines the outer wall contour and wall thickness of vessels to quantify non-calcified plaque in CT angiograms of the chest, abdomen, pelvis, and lower extremities. The algorithm encodes the search space as a constrained graph and calculates the outer wall contour by deriving a minimum cost path through the graph, following the visible outer wall contour while minimizing path tortuosity. Our algorithm was statistically equivalent to a reference standard made by two reviewers. Absolute error was 1.9 ± 2.3% compared to the inter-observer variability of 3.9 ± 3.6%. Wall thickness in vessels with atherosclerosis was 3.4 ± 1.6 mm compared to 1.2 ± 0.4 mm in normal vessels. The algorithm shows promise as a tool for quantification of non-calcified plaque in CT angiography. When combined with previous research, our method has the potential to quantify both non-calcified and calcified plaque in all clinically significant systemic arteries, from the thoracic aorta to the arteries of the calf, over a wide range of diameters. This algorithm has the potential to enable risk stratification of patients and facilitate investigations into the relationships between asymptomatic atherosclerosis and a variety of behavioral, physiologic, pathologic, and genotypic conditions.

Arterial stiffness contributes to coronary artery disease risk prediction beyond the traditional risk score (RAMA-EGAT score)

Objectives

The traditional risk score (RAMA-EGAT) has been shown to be an accurate scoring system for predicting coronary artery disease (CAD). Arterial stiffness measured by the cardio–ankle vascular index (CAVI) is known to be a marker of atherosclerotic burden. A study was undertaken to determine whether CAVI improves the prediction of CAD beyond the RAMA-EGAT score.

Design

Cross-sectional study.

Patients

Patients with a moderate to high risk for CAD by the RAMA-EGAT score were enrolled between November 2005 and March 2006. 64-slice multidetector CT coronary angiography was used to evaluate the coronary artery calcium score and coronary stenosis. Arterial stiffness was assessed by CAVI.

Results

1391 patients of median age 59 years (range 31–88) were enrolled in the study, 635 (45.7%) men and 756 (54.3%) women. Of the 1391 patients, 346 (24.87%) had coronary stenosis. There was a correlation between CAVI and the prevalence of coronary stenosis after adjusting for traditional CAD risk factors (OR 3.29). In addition, adding CAVI into the RAMA-EGAT score (modified RAMA-EGAT score) improved the prediction of CAD incidence, increasing C-statistics from 0.72 to 0.85 and resulting in a net reclassification improvement of 27.7% (p<0.0001).

Conclusion

CAVI is an independent risk predictor for CAD. The addition of CAVI to the RAMA-EGAT score significantly improves the diagnostic yield of CAD.

Evaluation of the appropriateness criteria for coronary computed tomography angiography in an academic medical center in a developing country: comparison of the 2006 and 2010 criteria

BACKGROUND

The aims of this study are to analyze the risk profile and evaluate the appropriateness of patient referral to coronary CT angiography in a new MSCT laboratory in an academic medical center in a developing country.

METHODS AND RESULTS

The study population consisted of 100 consecutive patients (mean age 53 ± 13 years, 83% males) who were referred to the new 64 slice MSCT laboratory at the American University of Beirut between July 2008 and July 2009. 52% of patients had chest pain and 48% were asymptomatic. By the 2006 ACCF criteria, only 8% of the referrals fitted the "Appropriate" criteria, 49% were "Inappropriate", and 43% were "Uncertain". The percentage of "Appropriate" indications increased from 8% by the 2006 criteria to 38% by the 2010 ACCF criteria. Framingham risk score (FRS) calculation showed a substantial percentage (46%) of patients to be at low risk, with 32% being at intermediate risk, and 22% at high risk. The prevalence of high calcium score (>400) (0% vs 22%, vs 27%, P < .001) and of obstructive CAD (4% vs 23% vs 40%, P < .001) increased steadily across the low, intermediate, and high FRS groups, respectively.

CONCLUSIONS

There was a significant increase in the percentage of "Appropriate" indications for MSCT when comparing the 2010 to the 2006 ACCF appropriateness criteria. However, in spite of that, there was still significant deviation from the ACCF appropriateness criteria among patients referred for coronary CT angiography in this new MSCT laboratory in a developing country.

Coronary CT angiography: how should physicians use it wisely and when do physicians request it appropriately?

Coronary CT angiography has been increasingly used in the diagnosis of coronary artery disease due to rapid technological developments, which are reflected in the improved spatial and temporal resolution of the images. High diagnostic accuracy has been achieved with 64- and more slice CT scanners and in selected patients, coronary CT angiography is regarded as a reliable alternative to invasive coronary angiography. Although the tremendous contributions of coronary CT angiography to cardiac imaging are acknowledged, appropriate use of cardiac CT as the first line technique by physicians has not been well established. Optimal selection of cardiac CT is essential to ensure acquisition of valuable diagnostic information and avoid unnecessary invasive procedures. This is of paramount importance since cardiac CT not only involves patient risk assessment, prediction of major cardiac events, but also impacts physician decision-making on patient management. Applications of CT in cardiac imaging include coronary artery calcium scoring for predicting the patient risk of developing major cardiac events, followed by coronary CT angiography which is commonly used to determine the diagnostic and prognostic accuracy in the coronary artery disease. This review presents an overview of the applications of CT in cardiac imaging in terms of coronary calcium scoring and coronary CT angiography. Judicious use of both cardiac CT tools will be discussed with regard to their value in different patient risk groups with the aim of identifying the appropriate criteria for choosing a cardiac CT modality. An effective diagnostic pathway is finally recommended to physicians for appropriate selection of cardiac CT in clinical practice.