零钙化积分冠状动脉CTA表现分析

目的 分析零冠状动脉钙化积分(CACS)患者64层冠状动脉CTA(CTCA)表现,并评估诊断准确率。 方法 对328例零CACS的疑似冠心病患者,分析CTCA表现,包括有无狭窄、斑块形态、位置和狭窄程度。其中69例有传统冠状动脉造影结果,计算零CACS患者CTCA诊断狭窄≥70%的敏感度、特异度、准确度、阳性预测值和阴性预测值。 结果 328例零CACS患者,CTCA示37例(37/328,11.28%)存在不同程度的狭窄和斑块,无或轻度狭窄26例(26/37,70.27%),中度狭窄8例(8/37,21.62%),重度狭窄3例(3/37,8.11%)。54个狭窄斑块包括软斑块39个(39/54,72.22%)、混合斑块8个(8/54,14.81%)及7个钙化斑块(7/54,12.96%)。基于病例(69例)和基于冠状动脉节段(997个节段)CTCA诊断狭窄≥70%的敏感度、特异度、准确率、阳性预测值和阴性预测值分别为97.14%(34/35)、94.12%(32/34)、95.65%(66/69)、94.44%(34/36)、96.97%(32/33)和94.23%(49/52)、99.58%(941/945)、99.30%(990/997)、92.45%(49/53)、99.68%(941/944)。 结论 CTCA可显示零CACS患者冠状动脉的不同程度狭窄和斑块,且诊断准确度较高。     

The composition and extent of coronary artery plaque detected by multislice computed tomographic angiography provides incremental prognostic value in patients with suspected coronary artery disease

Multislice computed tomographic coronary angiography (CTCA) provides accurate noninvasive assessment of coronary artery disease (CAD). However, data on the prognostic value of CTCA in patients with suspected CAD are only beginning to emerge. The aim of the study was to assess the prognostic value of CTCA in patients with suspected CAD. Patients (males = 259, females = 235; mean age 58.2 ± 9.8 years) with suspected CAD who underwent 16- or 64-slice CTCA were followed for 1,308 ± 318 days for cardiac death, nonfatal myocaridal infarction (MI) and late (>90 days after CTCA) revascularization. Patient outcomes were related to clinical and CTCA data. Cox proportional-hazards model was applied in stepwise forward fashion to identify outcome predictors. Coronary artery plaque was found in 340 patients. Cardiac events occurred in 40 patients including cardiac death (n = 9), nonfatal MI (n = 8) and late revascularization (n = 23). A multivariable analysis identified the following independent predictors for adverse cardiac events: obstructive plaque in a proximal coronary artery segment (hazard ratio (HR) 2.73; 95% confidence interval (CI): 1.35–5.54; P = 0.005), the number of segments with noncalcified plaque(s) (HR 1.53 per segment; 95%CI: 1.21–1.92; P < 0.001), the number of segments with mixed plaque(s) (HR 1.56 per segment; 95%CI: 1.27–1.92; P < 0.001) and the number of segments with calcified plaque(s) (HR 1.21 per segment; 95%CI: 1.07–1.37; P = 0.002). In patients with suspected CAD, both the extent and composition of atherosclerotic plaque as determined by CTCA are prognostic of subsequent cardiac events.     

The absence of coronary artery calcification does not rule out the presence of significant coronary artery disease in Asian patients with acute chest pain

The absence of coronary artery calcification (CAC) has been used to as an indication to rule out significant coronary artery disease (CAD). However, diagnostic usefulness of ‘zero calcium score criteria’ as a decision-making strategy to rule out significant CAD as the etiology of acute chest pain has not been studied in depth, especially in Asian ethnicity. We prospectively enrolled 136 Korean patients (58% men, 56 ± 13 years) who presented to the emergency department (ED) with acute chest pain and non-diagnostic ECG. All patients underwent 64-slice CT for calcium scoring and coronary CT angiography (cCTA). We investigated the association of CAC with the presence of ≥50% CAD on cCTA and with a final diagnosis of an acute coronary syndrome (ACS). Ninety-two patients out of 136 (68%) did not show detectable CAC, and 14 out of these 92 without CAC (15%) had ≥50% CAD on cCTA. Sensitivity, specificity, positive predictive value and negative predictive value of zero calcium score criteria for the detection of ≥50% CAD were 0.66 (95% confidence interval, 0.50–0.80), 0.83 (0.74–0.90), 0.64 (0.48–0.77), 0.85 (0.75–0.91), respectively. Patients who had ≥50% CAD without detectable CAC were younger (P = 0.001), and had a higher prevalence of smoking (P = 0.048) as compared to patients with a degree of CAC. Most of the patients with ≥50% CAD of non-calcified plaque were younger than 60 years of age (79%, 11/14), however, 3 of them were older than 60 years of age. Forty-five patients (33%) were subsequently diagnosed as having ACS, and 38% (17/45) of them had no CAC. Zero calcium score did not necessarily guarantee the absence of significant CAD, even in patients older than 60 years, in Asian ethnicity presenting to the ED with chest pain.     

Guided review by frequent itemset mining: additional evidence for plaque detection

Purpose  A guided review process to support manual coronary plaque detection in computed tomography coronary angiography (CTCA) data sets is proposed. The method learns the spatial plaque distribution patterns by using the frequent itemset mining algorithm and uses this knowledge to predict potentially missed plaques during detection. Materials and methods  Plaque distribution patterns from 252 manually labeled patients who underwent CTCA were included. For various cross-validations a labeling with missing plaques was created from the initial manual ground truth labeling. Frequent itemset mining was used to learn the spatial plaque distribution patterns in form of association rules from a training set. These rules were then applied on a testing set to search for segments in the coronary tree showing evidence of containing unlabeled plaques. The segments with potentially missed plaques were finally reviewed for the existence of plaques. The proposed guided review was compared to a weighted random approach that considered only the probability of occurrence for a plaque in a specific segment and not its spatial correlation to other plaques. Results  Guided review by frequent itemset mining performed significantly better (p < 0.001) than the reference weighted random approach in predicting coronary segments with initially missed plaques. Up to 47% of the initially removed plaques were refound by only reviewing 4.4% of all possible segments. Conclusions  The spatial distribution patterns of atherosclerosis in coronary arteries can be used to predict potentially missed plaques by a guided review with frequent itemset mining. It shows potential to reduce the intra- and inter-observer variability.     

Accuracy of quantitative coronary angiography with computed tomography and its dependency on plaque composition

Objective: To determine the impact of plaque composition on accuracy of quantitative 64-slice computed tomography coronary angiography (CTCA). Methods: The institutional review board approved this study; written informed consent was obtained from all patients. One hundred consecutive patients (42 women, mean age 64.6 ± 9.4 years, age range 39–87 years) underwent CTCA and invasive quantitative coronary angiography (QCA) to determine (a) the diagnostic accuracy of CTCA for the detection of significant stenosis (diameter reduction of ≥50%), and (b) the accuracy of stenosis grading. In CTCA stenosis severity was graded in 10% steps and evaluated separately for calcified and non-calcified coronary lesions using Pearson-linear-regression analysis, Bland/Altman-analysis (BA), and Mann-Whitney-U-test. Results: In 60/100 patients 139 significant coronary artery stenoses were identified with QCA. On a per-segment analysis, sensitivity of CTCA was 75.5%, and specificity was 96.6% (positive predictive value: 72.9%, negative predictive value: 97.0%). Quantification of stenosis grading correlated moderately between methods (r = 0.60; P < 0.001), with an overestimation by CTCA of 5.5% (BA limits-of-agreement −29 to 39%). BA limits-of-agreement were greater in calcified lesions (−29.2 to 45.6%; mean error 8.2%) than in non-calcified lesions (−25.9 to 30.2%; mean error 2.2%) and differed significantly (P < 0.05). Conclusions: Diagnostic accuracy of CTCA is high, however agreement for quantitative lesion severity assessment between CTCA and QCA is moderate for calcified but superior for non-calcified lesions.     

健康体检中多层螺旋CT冠脉成像的初步观察

目的探讨健康体检中多层螺旋CT冠脉成像(CTCA)对冠脉病变的价值。方法对随机抽取的289例健康体检时进行CTCA的病例作冠脉钙化(CAC)的定性分析,然后分别对CAC阴性者和CAC阳性者的冠脉狭窄情况进行统计分析。结果 289名受检者中77例为CAC阳性,占26.64%;212例为CAC阴性,占73.36%。在CAC阳性者中检出冠脉狭窄57例,占74.03%;CAC阴性者中检出冠脉狭窄21例,占9.91%。结论在健康体检时行胸部CT检查发现CAC阳性者,均应做CTCA检查;对CAC阴性者,如有高血糖、高血压、高血脂、吸烟者或有胸闷史者,也应做CTCA检查,以明确有无非钙化斑块的存在,避免非钙化斑块的漏诊。     

Association of abdominal aortic calcium with coronary artery calcium and obstructive coronary artery disease: a pilot study

This study sought to determine the association of abdominal aortic calcium (AAC) with coronary artery calcium (CAC) and obstructive coronary artery disease (CAD). We included 58 patients (mean age 54.4 years, 40% males) without known CAD who underwent a non-contrast abdominal computed tomography (CT) scan and 64-slice coronary computed tomography angiography (CCTA) within 2 years. A total AAC score using Agatston method was calculated in the abdominal aorta from the takeoff of the celiac artery to the aortic bifurcation. A total of 43/58 patients had AAC. Patients with AAC were older with no differences in other baseline characteristics. None of the patients with a zero AAC score had obstructive CAD. Thus, an AAC score of zero had a 100% negative predictive value (NPV) and 23% positive predictive value (PPV) for the detection of obstructive CAD and an 80% NPV and 79% PPV for detection of any coronary plaque. Using multivariate linear regression, AAC score was an independent predictor of CAC score after adjusting for age (P < 0.001). In our analysis, AAC score correlates with CAC score and has a high NPV to rule out CAD. The absence of AAC may help exclude obstructive coronary disease and improve the selection of patients that may benefit from further risk stratification.     

Comparison of atherosclerotic plaque burden and composition between diabetic and non diabetic patients by non invasive CT angiography

Type 2 diabetes mellitus (DM) is associated with a higher risk of cardiovascular disease and atherosclerotic burden. However little data exists in regards to plaque distribution and plaque composition in these patients. To assess for differences in the coronary plaques burden and composition among symptomatic patients with and without type 2 DM using multidetector computed tomography angiography (MDCTA). The 416 symptomatic patients (64% males, mean age: 61 ± 13 years) with 61 (15%) reporting type 2 DM, who underwent contrast-enhanced MDCTA were studied. Enrolled patients had an intermediate to high pre-test probability of obstructive coronary artery disease. Multivariate analysis was used to correct for differences in age and gender. Patients with type 2 DM were more likely to have significant stenosis ≥70% in at least one coronary segments (33% in type 2 DM vs. 18% in non diabetic, P = 0.013), whereas 11% of both type 2 DM and non diabetics had stenosis of 50–70% (P = NS). Also type 2 DM patients had a higher number of coronary segments with mixed plaques compared to nondiabetic patients (1.67 ± 2.01 vs. 1.23 ± 1.61, P = 0.05), whereas no such differences were observed for non-calcified or calcified plaques. Nearly half (43%) of type 2 DM had coronary artery calcium scores (CACS) ≥400 vs. 29% in non diabetic patients (P = 0.03). Patients with type 2 DM tend to have atherosclerotic plaques which are more likely to be mixed in nature. Future studies need to elucidate the prognostic value of differences in plaque characteristics observed according to type 2 diabetic status.     

The potential of RF backscattered IVUS data and multidetector-row computed tomography images for tissue characterization of human coronary atherosclerotic plaques

The aim is to compare virtual histology which uses spectral analysis of backscattered intravascular ultrasound (VH–IVUS) and multidetector-row computed tomography (MDCT) for the characterization of coronary atherosclerotic plaques obtained by directional coronary atherectomy (DCA). We performed DCA in 15 de novo native coronary stenotic lesions (15 patients) and selected one or two segments within the plaque from each patient (total 29 segments). Then, we evaluated the accuracy of the VH–IVUS findings in 50 sites among the 29 segments compared with the histopathology findings. MDCT was performed in all patients before percutanous coronary intervention (PCI), and CT density values were measured. VH–IVUS data analysis correlated well with histopathological examination (predictive accuracy: 66.7% for fibrous, 100% for fibro-fatty, 100% for necrotic core, and 100% for dense calcium regions, respectively). In addition, CT density values between fibrous and fibro-fatty plaques classified by histopathology were 100.0 ± 26.0 HU versus 110.4 ± 67.9 HU, there were no difference among them (P = 0.594). These findings indicated that the validation of plaque characteristics using VH–IVUS correlates well with histopathology. While tissue characterization using CT density could be difficult to distinguish between fibro-fatty and fibrous tissue.     

Variation in atherosclerotic plaque composition according to increasing coronary artery calcium scores on computed tomography angiography

Increasing coronary artery calcium scores (CACS) are independently associated with cardiac events. Recent advents in coronary computed tomography angiography (CCTA) have allowed us to better characterize individual plaque. Currently, it is unknown if higher CACS are likely to be associated with more calcified or mixed and heterogeneous plaque burden on CCTA. The study population consisted of 1,043 South Korean asymptomatic subjects (49 ± 10 years, 62% men) who underwent CCTA (64-slice MDCT). Plaques were classified on contrast-enhanced CCTA as non-calcified, mixed, and calcified on a per-segment basis according to the modified American Heart Association classification. The majority of the study participants had no coronary calcification (n = 866, 83%), whereas CACS> 0 was observed in 177 participants (17%). Only 40 (5%) participants in absence of CACS had exclusively non-calcified plaque, whereas 10 (1.2%) had significant coronary artery disease. With increasing CACS, study participants were more likely to have exclusively mixed or combination atherosclerotic plaques (P = 0.001). Among individuals with CACS 1–10, the prevalence of at least two coronary segments with mixed plaques was 4%, increasing up to 18 and 41% with CACS of 11–100 and >100. The respective prevalence of ≥2 coronary segments (calcified plaques) with increasing CACS were 6%, 16 and 26% (P = 0.01) and of non-calcified plaques were 6%, 6 and 11% (P = 0.71). In multivariable adjusted analyses, those with CACS >100 were 7.17 times (95% CI: 1.36–37.68) more likely to have ≥2 coronary segments with calcified plaque comparing with CACS 1–10. On the other hand the respective risk was higher for presence of ≥2 segments with mixed plaques (odds ratio: 15.81, 95% CI: 3.14–79.58). Absence of CAC is associated with a negligible presence of any atherosclerotic disease as detected by CCTA in asymptomatic population. A higher CACS is more likely to be associated with heterogeneous coronary plaque (combination of calcified, non-calcified, and mixed plaques), and appears to be more strongly associated with a higher burden of mixed plaque.     

Comparison of carotid arterial morphology and plaque composition between patients with acute coronary syndrome and stable coronary artery disease: a high-resolution magnetic resonance imaging study

The purpose of this study was to evaluate the differences in carotid arterial morphology and plaque composition between patients with acute coronary syndrome (ACS) and patients with stable coronary artery disease (SCAD). Twenty-eight patients (12 ACS patients and 16 SCAD patients) underwent carotid high-resolution MRI examination using a 3.0-Tesla (3.0T) MRI scanner. The indicators of carotid arterial morphology included the maximum total vessel area (Max-TVA), mean TVA, minimum lumen area (Min-LA), mean LA, maximum wall area (Max-WA), mean WA, maximum wall thickness (Max-WT), mean WT, maximum normalized wall index (Max-NWI), mean NWI, and maximum stenosis (Max-stenosis). The indicators of plaque composition included the prevalence and mean area percentage (%) of lipid-rich necrotic core (LRNC), calcification (Ca), intraplaque hemorrhage (IPH), and fibrous cap rupture (FCR). None of the indicators of carotid arterial morphology had significant differences (all P > 0.05) between the ACS and SCAD patients. The prevalence and plaque composition area percentage of LRNC, Ca, and IPH did not exhibit significant differences between the two groups. However, carotid plaques in the ACS patients presented a higher prevalence of FCR than SCAD patients (P < 0.05). This study revealed a similar carotid arterial morphology between ACS and SCAD patients. However, FCR is more common in carotid plaques with ACS than in those with SCAD. Ruptured carotid plaques may be a forewarning factor for those patients who are at high risk of ACS.     

Association of serum total bilirubin levels with the severity, extent and subtypes of coronary atherosclerotic plaques detected by coronary CT angiography

In this study, we aimed to evaluate whether serum total bilirubin was associated with the severity and morphology of coronary atherosclerotic plaques detected by computed tomography angiography (CTA). The study population consisted of 1,115 patients (55.2 % men) who underwent dual-source 64-slice CTA for the assessment of coronary artery disease (CAD). Coronary arteries were evaluated on 16 segment basis and critical coronary plaque was described as luminal narrowing >50 %, whereas plaque morphology was assessed on per segment basis. Serum bilirubin levels were determined using commercially available assay kits. The critical atherosclerotic lesions were detected in 431/1,115 (38.6 %) subjects by CTA. Serum total bilirubin levels were found to be lower in patients with any coronary plaque (0.62 ± 0.21 vs. 0.70 ± 0.25 mg/dL, p = 0.002). Also bilirubin level was lower in patients with critical stenosis compared to non-critical stenosis (0.57 ± 0.18 vs. 0.70 ± 0.24 mg/dL, p < 0.001). Subjects having primarily noncalcified plaque (NCP) and mixed plaque (MP) have lower bilirubin levels compared to calcified plaque (CP) and normal subjects (0.62 ± 0.20 for NCP and 0.60 ± 0.19 for MP, 0.65 ± 0.26 for CP and 0.71 ± 0.25 for normal subjects, p < 0.001). This independent association was remained for NCP after multinominal regression analysis (OR: 0.76; 95 % CI 0.58–0.88; p < 0.001). Our study demonstrated that serum bilirubin level was significantly associated with the presence, severity and the noncalcified morphology of atherosclerotic plaques detected by CTA. Further prospective clinical studies are needed to clarify the exact physiopathologic and prognostic role of bilirubin in CAD.     

How reliable are 40 MHz IVUS and 64-slice MDCT in characterizing coronary plaque composition? An ex vivo study with histopathological comparison

The present study investigated whether IVUS could serve as a reliable reference in validating MDCT characterization of coronary plaque against a histological gold standard. Twenty-one specimens were postmortem human coronary arteries. Coronary cross-sections were imaged by 40 MHz IVUS and by 64-slice MDCT and characterized histologically as presenting calcified, fibrous or lipid-rich plaques. Plaque composition was analyzed visually and intra-plaque MDCT attenuation was measured in Hounsfield Units (HU). 83 atherosclerotic plaques were identified. IVUS failed to characterize calcified plaque accurately, with a positive predictive value (ppv) of 75% versus 100% for MDCT. Lipid-rich plaque was even less accurately characterized, with ppv of 60 and 68% for IVUS and MDCT respectively. Mean MDCT attenuation was 966 ± 473 HU for calcified plaque, 83 ± 35 HU for fibrous plaque and 70.92 HU ± 41 HU for lipid-rich plaque. No significant difference in mean MDCT attenuation was found between fibrous and lipid-rich plaques (P = 0.276). In vivo validation of MDCT against an IVUS reference thus appears to be an unsuitable and unreliable approach: 40 MHz IVUS suffers from acoustic ambiguities in plaque characterization, and 64-slice MDCT fails to analyze plaque morphology and components accurately.     

Topographic association of angioscopic yellow plaques with coronary atherosclerotic plaque: assessment with quantitative colorimetry in human coronary artery autopsy specimens

Yellow plaques seen during coronary angioscopy are thought to be the surrogates for superficial intimal lipids in coronary plaque. Given diffuse and heterogeneous nature of atherosclerosis, yellow plaques in coronaries may be seen as several yellow spots on diffuse coronary plaque. We examined the topographic association of yellow plaques with coronary plaque. In 40 non-severely stenotic ex-vivo coronary segments (average length: 52.2 ± 3.1 mm), yellow plaques were examined by angioscopy with quantitative colorimetry. The segments were cut perpendicular to the long axis of the vessel at 2 mm intervals, and 1045 slides with 5 μm thick tissue for whole segments were prepared. To construct the plaque surface, each tissue slice was considered to be representative of the adjacent 2 mm. The circumference of the lumen and the lumen border of plaque were measured in each slide, and the plaque surface region was constructed. Coronary plaque was in 37 (93%) of 40 segments, and consisted of a single mass [39.9 ± 3.9 (0–100) mm, 311.3 ± 47.4 (0.0–1336.2) mm²]. In 30 (75%) segments, multiple (2–9) yellow plaques were detected on a mass of coronary plaque. The number of yellow plaques correlated positively with coronary plaque surface area (r = 0.77, P < 0.0001). Yellow plaques in coronaries detected by angioscopy with quantitative colorimetry, some of them are associated with lipid cores underneath thin fibrous caps, may be used to assess the extent of coronary plaque. Further research using angioscopy could be of value to study the association of high-risk coronaries with acute coronary syndromes.     

The impact of cardiac CT on the appropriate utilization of catheter coronary angiography

The purpose of this study was to evaluate the impact of computed tomography coronary angiography (CTCA) on the appropriate utilization of catheter angiography (CA). This observational trial analyzed all patients undergoing CA in 2006 and 2007 in one hospital. In 2007, patients having a low to intermediate cardiovascular risk and suspicion of coronary artery disease (CAD) and those with suspicion of progression of known organic heart disease (OHD) underwent CTCA either prior to CA or as the sole imaging modality. Appropriate utilization of CA was defined as: (1) percentage of patients showing normal or non-significant findings at CA, (2) percentage of self-referred patients to CA, and (3) percentage of patients with known OHD undergoing CA without immediate operative or interventional consequences. Use of CTCA resulted in a significant drop in the percentage of CA examinations in patients with suspected CAD showing normal or non-significant findings (19% in 2006, 10% in 2007, P < 0.001). The percentage of self-referred CA significantly dropped (29% in 2006, 10% in 2007, P < 0.001). CT ruled-out CAD in 74/151 (49%) patients, obviating subsequent CA. During a follow-up of 15 ± 4 months, CA and percutaneous interventions was considered necessary in 2/74 patients. CT ruled-out progression of known OHD in 53/60 (90%) patients, while one patient underwent CA and percutaneous intervention during a follow-up period of 16 ± 4 months. No reduction of CA examinations without immediate consequences was found in patients with known OHD (13% in 2006, 27% in 2007). In patients with suspicion of CAD, CTCA improved the appropriate utilization of CA without jeopardizing patient safety, along with a decrease of self-referred patients for CA. CTCA did not influence the appropriate utilization of CA in patients with known OHD.     

Fusion of CT coronary angiography and whole-heart dynamic 3D cardiac MR perfusion: building a framework for comprehensive cardiac imaging

The purpose of this work was to develop a framework for 3D fusion of CT coronary angiography (CTCA) and whole-heart dynamic 3D cardiac magnetic resonance perfusion (3D-CMR-Perf) image data—correlating coronary artery stenoses to stress-induced myocardial perfusion deficits for the assessment of coronary artery disease (CAD). Twenty-three patients who underwent CTCA and 3D-CMR-Perf for various indications were included retrospectively. For CTCA, image quality and coronary diameter stenoses >?50% were documented. For 3D-CMR-Perf, image quality and stress-induced perfusion deficits were noted. A software framework was developed to allow for 3D image fusion of both datasets. Computation steps included: (1) fully automated segmentation of coronary arteries and heart contours from CT; (2) manual segmentation of the left ventricle in 3D-CMR-Perf images; (3) semi-automatic co-registration of CT/CMR datasets; (4) projection of the 3D-CMR-Perf values on the CT left ventricle. 3D fusion analysis was compared to separate inspection of CTCA and 3D-CMR-Perf data. CT and CMR scans resulted in an image quality being rated as good to excellent (mean scores 3.5?±?0.5 and 3.7?±?0.4, respectively, scale 1–4). 3D-fusion was feasible in all 23 patients, and perfusion deficits could be correlated to culprit coronary lesions in all but one case (22/23?=?96%). Compared to separate analysis of CT and CMR data, coronary supply territories of 3D-CMR-Perf perfusion deficits were refined in two cases (2/23?=?9%), and the relevance of stenoses in CTCA was re-judged in four cases (4/23?=?17%). In conclusion, 3D fusion of CTCA/3D-CMR-Perf facilitates anatomic correlation of coronary lesions and stress-induced myocardial perfusion deficits thereby helping to refine diagnostic assessment of CAD.     

Intra- and interobserver variability in detection and assessment of calcified and noncalcified coronary artery plaques using 64-slice computed tomography

Objective Multislice computed tomography (MSCT) is an emerging noninvasive technique for detecting coronary plaques. The present study investigated agreement in the detection and characterization of coronary plaques and reproducibility of volumetric analysis. Methods A total of 20 patients underwent MSCT coronary angiography using 64 * 0.5 mm detector collimation. Two readers independently visually evaluated all MSCT datasets for the presence of coronary plaques (n = 82 in 262 coronary segments) and then classified them as calcified, mixed and noncalcified. In addition, one of the readers also manually determined total volumes as well as calcified and noncalcified volumes of each plaque. After a period of at least 4 weeks the complete volumetric analysis was repeated. Results Interobserver agreement was good for detection of coronary plaques on the segment level (weighted κ = 0.88, 95% CI [0.76, 0.95]). However, there was only moderate interobserver agreement for plaques classification (unweighted κ = 0.45, 95% CI [0.35, 0.61]). Intraobserver agreement was good for plaque detection on segment level (weighted κ = 0.90, 95% CI [0.77, 0.96]), while it was moderate with respect to their characterization (unweighted κ = 0.65, 95% CI [0.55, 0.80]). There was moderate reproducibility for total plaque volume (limits of agreement = ±6 mm³ at a mean measured volume of 10 mm³ and = ±28 mm³ at a mean measured volume of 100 mm³). Variation of relative differences significantly decreased for total volume and noncalcified volume with increasing mean volume. Conclusions Detection and volumetry of plaques by means of MSCT shows good to moderate reproducibility. Agreement of volume measurements depends on plaque size. Variation of relative differences decrease with increasing mean plaque volume.     

Using clinical cardiovascular risk scores to predict coronary artery plaque severity and stenosis detected by CT coronary angiography in asymptomatic Chinese subjects

We aimed to determine whether the Framingham risk score (FRS), systematic coronary risk evaluation (SCORE), and Chinese multi-provincial cohort study (CMCS) could predict anatomic severity of coronary plaques. From January 2007 to October 2010, we performed a contrast-enhanced 64-slice or 256-slice multidetector computed tomography coronary angiography as part of a health check-up protocol in 806 asymptomatic subjects (70.5% male, 56 ± 9 year-old). Risk scores significantly correlated with calcium volume score, plaque stenosis score and plaque distribution score (P < 0.001). Of the 3 risk scores, the SCORE system showed the best correlation. Overall, 180 (22%) and 37 (5%) subjects were found to have stenosis of 50-69% and more than 70% in at-least one coronary artery segment, respectively. In the prediction of the presence of obstructive CAD (≥50% diameter stenosis), all risk scores had similar discrimination. In the prediction of severe CAD (≥70% diameter stenosis), FRS and CMCS had similar area under curves but SCORE discriminated better than FRS (P < 0.05). The optimal cutoff point to predict obstructive CAD was 9.54% for FRS, 1.05% for CMCS, and 0.95% for SCORE, whereas to predict severe CAD was 9.63, 1.05, 1.15% for FRS, CMCS, SCORE, respectively, with a sensitivity of 0.61–0.70 and a specificity of 0.55–0.66. Cardiovascular risk scores are associated with the severity and extent of coronary artery plaque. The stronger association might translate into a better discrimination using SCORE. These findings will aid in the appropriate selection or recalibration of the risk assessment system for cardiovascular disease screening.     

Sex differences in coronary plaque changes assessed by serial computed tomography angiography

Long-term data on sex-differences in coronary plaque changes over time is lacking in a low-to-intermediate risk population of stable coronary artery disease (CAD). The aim of this study was to evaluate the role of sex on long-term plaque progression and evolution of plaque composition. Furthermore, the influence of menopause on plaque progression and composition was also evaluated. Patients that underwent a coronary computed tomography angiography (CTA) were prospectively included to undergo a follow-up coronary CTA. Total and compositional plaque volumes were normalized using the vessel volume to calculate a percentage atheroma volume (PAV). To investigate the influence of menopause on plaque progression, patients were divided into two groups, under and over 55 years of age. In total, 211 patients were included in this analysis, 146 (69%) men. The mean interscan period between baseline and follow-up coronary CTA was 6.2?±?1.4 years. Women were older, had higher HDL levels and presented more often with atypical chest pain. Men had 434 plaque sites and women 156. On a per-lesion analysis, women had less fibro-fatty PAV compared to men (β -1.3?±?0.4%; p?<?0.001), with no other significant differences. When stratifying patients by 55 years age threshold, fibro-fatty PAV remained higher in men in both age groups (p?<?0.05) whilst women younger than 55 years demonstrated more regression of fibrous (β -0.8?±?0.3% per year; p?=?0.002) and non-calcified PAV (β -0.7?±?0.3% per year; p?=?0.027). In a low-to-intermediate risk population of stable CAD patients, no significant sex differences in total PAV increase over time were observed. Fibro-fatty PAV was lower in women at any age and women under 55 years demonstrated significantly greater reduction in fibrous and non-calcified PAV over time compared to age-matched men. (ClinicalTrials.gov number, NCT04448691.)

     

Diagnostic performance of exercise bicycle testing and single-photon emission computed tomography: comparison with 64-slice computed tomography coronary angiography

To conduct a comparison of the diagnostic performance of exercise bicycle testing and single-photon emission computed tomography (SPECT) with computed tomography coronary angiography (CTCA) for the detection of obstructive coronary artery disease (CAD) in patients with stable angina. 376 symptomatic patients (254 men, 122 women, mean age 60.4 ± 10.0 years) referred for noninvasive stress testing (exercise bicycle test and/or SPECT) and invasive coronary angiography were included. All patients underwent additional 64-slice CTCA. The diagnostic performance of exercise bicycle testing (ST segment depression), SPECT (reversible perfusion defect) and CTCA (≥50% lumen diameter reduction) was presented as sensitivity, specificity, positive and negative predictive value (PPV and NPV) to detect or rule out obstructive CAD with quantitative coronary angiography as reference standard. Comparisons of exercise bicycle testing versus CTCA (n = 334), and SPECT versus CTCA (n = 61) were performed. The diagnostic performance of exercise bicycle testing was significantly (P value < 0.001) lower compared to CTCA: sensitivity of 76% (95% CI, 71–82) vs. 100% (95% CI, 97–100); specificity of 47% (95% CI, 36–58) vs. 74% (95% CI, 63–82). We observed a PPV of 70% (95% CI, 65–75) vs. 91% (95% CI, 87-94); and NPV of 30% (95%, 25–35) vs. 99% (95%, 90–100). There was a statistically significant difference in sensitivity (P value < 0.05) between SPECT and CTCA: 89% (95% CI, 75–96) vs. 98% (95% CI, 87–100); but not in specificity (P value > 0.05): 77% (95% CI, 50–92) vs. 82% (95% CI, 56–95). We observed a PPV of 91% (95% CI, 77–97) vs. 93% (95% CI, 81–98); and NPV of 72% (95%, 46–89) vs. 93% (95%, 66–100). SPECT and CTCA yielded higher diagnostic performance compared to traditional exercise bicycle testing for the detection and rule out of obstructive CAD in patients with stable angina.