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Objectives: To evaluate the diagnostic performance of 320-slice computed tomography coronary angiography (CTA) in the evaluation of patients with prior coronary artery bypass grafting (CABG). Invasive coronary angiography (ICA) served as the standard of reference, using a quantitative approach.Methods: CTA studies were performed using CT equipment with 320 detector-rows, each 0.5 mm wide, and a gantry rotation time of 0.35 s. All grafts, recipient and nongrafted vessels were deemed interpretable or uninterpretable. The presence of significant (≥50%) stenosis and occlusion were determined on vessel and patient basis. Results were compared to ICA using quantitative coronary angiography.Results: A total of 40 patients (28 men, 76 ± 15 years), with 89 grafts, were included in the study. On a graft analysis, the sensitivity, specificity, positive and negative predictive values in the evaluation of significant stenosis were 96%, 92%, 83% and 98% respectively. The diagnostic accuracy for the assessment of recipient and nongrafted vessels was 89% and 80%, respectively. The diagnostic accuracy for the assessment of graft, recipient and nongrafted vessel occlusion was 96%, 92% and 100%, respectively.Conclusions: 320-slice CTA allows accurate non-invasive assessment of significant graft, recipient vessel and nongrafted vessel stenosis in patients with prior CABG. [ABSTRACT FROM AUTHOR]

A considerable number of patients with an acute coronary syndrome (ACS) who present with a 0 or low calcium score (CS) still demonstrate coronary artery disease (CAD) and significant stenosis. The aim of the present study was to evaluate the relation between the CS and the degree and character of atherosclerosis in patients with suspected ACS versus patients with stable CAD obtained by computed tomography angiography and virtual histology intravascular ultrasound (VH IVUS). Overall 112 patients were studied, 53 with ACS and 59 with stable CAD. Calcium scoring and computed tomography angiography were performed and followed by VH IVUS. On computed tomography angiography each segment was evaluated for plaque and classified as noncalcified, mixed, or calcified. Vulnerable plaque characteristics on VH IVUS were defined by percent necrotic core and presence of thin-cap fibroatheroma. If the CS was 0, patients with ACS had a higher mean number of plaques (5.0 ± 2.0 vs 2.0 ± 1.9, p <0.05) and noncalcified plaques (4.6 ± 3.5 vs 1.3 ± 1.9, p <0.05) on computed tomography angiography than those with stable CAD. If the CS was 0, VH IVUS demonstrated that patients with ACS had a larger amount of necrotic core area (0.58 ± 0.73 vs 0.22 ± 0.43 mm(2), p <0.05) and a higher mean number of thin-cap fibroatheromas (0.6 ± 0.7 vs 0.1 ± 0.3, p <0.05) than patients with stable CAD. In conclusion, even in the presence of a 0 CS, patients with ACS have increased plaque burden and increased vulnerability compared to patients with stable CAD. Therefore, absence of coronary calcification does not exclude the presence of clinically relevant and potentially vulnerable atherosclerotic plaque burden in patients with ACS. [ABSTRACT FROM AUTHOR]

Purpose: The coronary calcium score (CCS) predicts significant coronary artery disease (CAD) in the general population. While moderate chronic kidney disease (CKD) is associated with high CCS, the use of CCS to predict significant CAD in these patients is unknown., Methods: A total of 704 patients underwent computed tomography coronary angiography for the assessment of CCS and CAD. Sixty-nine (10 %) patients had moderate CKD, defined by an estimated glomerular filtration rate (eGFR) between 30 and 59 mL/min/1.73m(2), and the remaining patients were considered to be without significant CKD (eGFR ≥ 60 mL/min/1.73m(2))., Results: Patients with moderate CKD were older, had a higher CCS, and a higher prevalence of obstructive CAD than patients without significant CKD. Receiver-operator curve analysis showed that CCS predicted the presence of obstructive CAD in both patients with moderate CKD and those without significant CKD. In patients with moderate CKD, the optimal cut-off value of CCS to diagnose obstructive CAD was 140 (sensitivity 73 % and specificity of 70 %), and is 2.8 fold higher than in patients without significant CKD (cut-off value = 50; sensitivity 75 % and specificity 75 %)., Conclusion: The present results demonstrate that CCS can predict obstructive CAD in patients with moderate CKD, although the optimal cut-off value is higher than in patients without significant CKD.

Previous angiographic studies have shown that almost two-thirds of vulnerable plaques are located in non-obstructive lesions. Possibly, the maximum necrotic core (Max NC) area is not always identical to the site of most severe stenosis. Therefore, the purpose of this study was to evaluate the potential difference in location between the maximum necrotic core area and the site of most severe narrowing as assessed by virtual histology intravascular ultrasound (VH IVUS). Overall, 77 patients (139 vessels) underwent VH IVUS. The Max NC site was defined as the cross section with the largest necrotic core area per vessel. The site of most severe narrowing was defined as the minimum lumen area (MLA). Per vessel, the distance from both the Max NC site and MLA site to the origo of the coronary artery was evaluated. In addition, the presence of a virtual histology-thin cap fibroatheroma (VH-TCFA) was assessed. The mean difference (mm) between the MLA site and Max NC site was 10.8 ± 20.6 mm (p < 0.001). Interestingly, the Max NC site was located at the MLA site in seven vessels (5%) and proximally to the MLA site in 92 vessels (66%). Importantly, a higher percentage of VH-TCFA was demonstrated at the Max NC site as compared to the MLA site (24 vs. 9%, p < 0.001). In conclusion, the present findings demonstrate that the Max NC area is rarely at the site of most severe narrowing. Most often, the Max NC area is located proximal to the site of most severe narrowing.

To determine the rate of subsequent invasive coronary angiography (ICA) and revascularization in relation to computed tomography coronary angiography (CTA) results. In addition, independent determinants of subsequent ICA and revascularization were evaluated. CTA studies were performed using a 64-row (n = 413) or 320-row (n = 224) multidetector scanner. The presence and severity of CAD were determined on CTA. Following CTA, patients were followed up for 1 year for the occurrence of ICA and revascularization. A total of 637 patients (296 male, 56 ± 12 years) were enrolled and 578 CTA investigations were available for analysis. In patients with significant CAD on CTA, subsequent ICA rate was 76%. Among patients with non-significant CAD on CTA, subsequent ICA rate was 20% and among patients with normal CTA results, subsequent ICA rate was 5.7% (p < 0.001). Of patients with significant CAD on CTA, revascularization rate was 47%, as compared to a revascularization rate of 0.6% in patients with non-significant CAD on CTA and no revascularizations in patients with a normal CTA results (p < 0.001). Significant CAD on CTA and significant three-vessel or left main disease on CTA were identified as the strongest independent predictors of ICA and revascularization. CTA results are strong and independent determinants of subsequent ICA and revascularization. Consequently, CTA has the potential to serve as a gatekeeper for ICA to identify patients who are most likely to benefit from revascularization and exclude patients who can safely avoid ICA.

Multidetector computed tomography angiography (CTA) provides information on plaque extent and stenosis in the coronary wall. More accurate lesion assessment may be feasible with CTA as compared to invasive coronary angiography (ICA). Accordingly, lesion length assessment was compared between ICA and CTA in patients referred for CTA who underwent subsequent percutaneous coronary intervention (PCI). 89 patients clinically referred for CTA were subsequently referred for ICA and PCI. On CTA, lesion length was measured from the proximal to the distal shoulder of the plaque. Quantitative coronary angiography (QCA) was performed to analyze lesion length. Stent length was recorded for each lesion. In total, 119 lesions were retrospectively identified. Mean lesion length on CTA was 21.4 ± 8.4 mm and on QCA 12.6 ± 6.1 mm. Mean stent length deployed was 17.4 ± 5.3 mm. Lesion length on CTA was significantly longer than on QCA (difference 8.8 ± 6.7 mm, P < 0.001). Moreover, lesion length visualized on CTA was also significantly longer than mean stent length (CTA lesion length-stent length was 4.2 ± 8.7 mm, P < 0.001). Lesion length assessed by CTA is longer than that assessed by ICA. Possibly, CTA provides more accurate lesion length assessment than ICA and may facilitate improved guidance of percutaneous treatment of coronary lesions.

The purpose of this study was to evaluate the performance of 320-row computed tomography angiography (CTA) in the identification of significant coronary artery disease (CAD) in patients presenting with acute chest pain and to examine the relation to outcome during follow-up. A total of 106 patients with acute chest pain underwent CTA to evaluate presence of CAD. Each CTA was classified as: normal, non-significant CAD (<50% luminal narrowing) and significant CAD (≥50% luminal narrowing). CTA results were compared with quantitative coronary angiography. After discharge, the following cardiovascular events were recorded: cardiac death, non-fatal infarction, and unstable angina requiring revascularization. Among the 106 patients, 23 patients (22%) had a normal CTA, 19 patients (18%) had non-significant CAD on CTA, 59 patients (55%) had significant CAD on CTA, and 5 patients (5%) had non-diagnostic image quality. In total, 16 patients (15%) were immediately discharged after normal CTA and 90 patients (85%) underwent invasive coronary angiography. Sensitivity, specificity, and positive and negative predictive values to detect significant CAD on CTA were 100, 87, 93, and 100%, respectively. During mean follow-up of 13.7 months, no cardiovascular events occurred in patients with a normal CTA examination. In patients with non-significant CAD on CTA, no cardiac death or myocardial infarctions occurred and only 1 patient underwent revascularization due to unstable angina. In patients presenting with acute chest pain, an excellent clinical performance for the non-invasive assessment of significant CAD was demonstrated using CTA. Importantly, normal or non-significant CAD on CTA predicted a low rate of adverse cardiovascular events and favorable outcome during follow-up.

Aims: Previous studies have used semi-automated approaches for coronary plaque quantification on multi-detector row computed tomography (CT), while an automated quantitative approach using a dedicated registration algorithm is currently lacking. Accordingly, the study aimed to demonstrate the feasibility and accuracy of automated coronary plaque quantification on cardiac CT using dedicated software with a novel 3D coregistration algorithm of CT and intravascular ultrasound (IVUS) data sets., Methods and Results: Patients who had undergone CT and IVUS were enrolled. Automated lumen and vessel wall contour detection was performed for both imaging modalities. Dedicated automated quantitative software (QCT) with a unique registration algorithm was used to fuse a complete IVUS run with a CT angiography volume using true anatomical markers. At the level of the minimal lumen area (MLA), percentage lumen area stenosis, plaque burden, and degree of remodelling were obtained on CT. Additionally, mean plaque burden was assessed for the whole coronary plaque. At the identical level within the coronary artery, the same variables were derived from IVUS. Fifty-one patients (40 men, 58 ± 11 years, 103 coronary arteries) with 146 lesions were evaluated. Quantitative computed tomography and IVUS showed good correlation for MLA (n = 146, r = 0.75, P < 0.001). At the level of the MLA, both techniques were well-correlated for lumen area stenosis (n = 146, r = 0.79, P < 0.001) and plaque burden (n = 146, r = 0.70, P < 0.001). Mean plaque burden (n = 146, r = 0.64, P < 0.001) and remodelling index (n = 146, r = 0.56, P < 0.001) showed significant correlations between QCT and IVUS., Conclusion: Automated quantification of coronary plaque on CT is feasible using dedicated quantitative software with a novel 3D registration algorithm.

Chronic kidney disease (CKD) is associated with cardiovascular (CV) events caused by advanced atherosclerosis. Computed tomographic coronary angiography (CTA) can accurately diagnose coronary artery disease (CAD) and predict CV outcomes. The aim of the present study was to evaluate whether moderate CKD provides prognostic information for CV events in patients undergoing CTA. In total 885 patients with suspected CAD underwent CTA and were stratified to moderate CKD (85 patients) or no CKD (770 patients) based on a cut-off estimated glomerular filtration rate of 60 ml/min/1.73 m(2). After 896 days of follow-up, 42 patients developed CV events. Annualized CV event rates were 1.2% in patients with no CKD and no CAD, 2.5% in patients with moderate CKD alone, 2.5% in patients with obstructive CAD alone, and 3.7% in those with moderate CKD and obstructive CAD. Multivariate models demonstrated that moderate CKD (hazard ratio 2.39, confidence interval 1.09 to 5.21, p = 0.03) and obstructive CAD (hazard ratio 2.76, confidence interval 1.40 to 5.44, p <0.01) were independent predictors of CV events. Importantly, moderate CKD provided incremental prognostic information in addition to clinical characteristics and obstructive CAD (chi-square 49.4, p = 0.04). In conclusion, moderate CKD was associated with CV events and provided incremental prognostic information., (Copyright © 2011. Published by Elsevier Inc.)

Background: The purpose of the study was to systematically compare calcification patterns in plaques on computed tomography angiography (CTA) with plaque characteristics on intravascular ultrasound with radiofrequency backscatter analysis (IVUS-VH)., Methods and Results: In total, 108 patients underwent CTA and IVUS-VH. On CTA, calcification patterns in plaques were classified as non-calcified, spotty or dense calcifications. Plaques with spotty calcifications were differentiated into small spotty (<1 mm), intermediate spotty (1-3 mm) and large spotty calcifications (≥3 mm). Plaque characteristics deemed more high-risk on IVUS-VH were defined by % necrotic core (NC) and presence of thin cap fibroatheroma (TCFA). Overall, 300 plaques were identified both on CTA and IVUS-VH. % NC core was significantly higher in plaques with small spotty calcifications as compared to non-calcified plaques (20% vs 13%, P = .006). In addition, there was a trend for a higher % NC in plaques with small spotty calcifications than in plaques with intermediate spotty calcifications (20% vs 14%, P = .053). Plaques with small spotty calcifications had the highest % TCFA as compared to large spotty and dense calcifications (31% vs 9% and 31% vs 6%, P < .05)., Conclusion: Plaques with small spotty calcifications on CTA were related to plaque characteristics deemed more high-risk on IVUS-VH. Therefore, CTA may be valuable in the assessment of the vulnerable plaque.

Coronary computed tomographic angiography allows direct evaluation of the vessel wall and thus positive remodeling, which is a marker of vulnerability. The purpose of this study was to assess the association between positive remodeling on computed tomography angiogram (CTA) and vulnerable plaque characteristics on virtual histologic intravascular ultrasound (VH IVUS) images. Forty-five patients (78% men, 58 ± 11 years old) underwent computed tomographic angiography followed by VH IVUS. On CTA, the remodeling index was determined for each lesion by a blinded observer using quantitative analysis. Positive remodeling was defined based on a remodeling index ≥1.0. Percent necrotic core and presence of thin-capped fibroatheroma (TCFA) were used as markers for plaque vulnerability on VH IVUS images. Ninety-nine atherosclerotic plaques were evaluated, of which 37 lesions (37.4%) were identified as having positive remodeling on CTA. Higher levels of plaque vulnerability were identified in lesions with positive remodeling compared to lesions without positive remodeling. Percent necrotic core was significantly higher in lesions with positive remodeling (15.7 ± 7.8%) compared to lesions without this characteristic (10.2 ± 7.2%, p <0.001). Furthermore, significantly more TCFA lesions were identified in positively remodeled lesions (n = 16, 43.2%) than in lesions without positive remodeling (n = 3, 4.8%, p <0.001). In conclusion, lesions with positive remodeling on CTA are associated with increased levels of plaque vulnerability on VH IVUS images including a higher percent necrotic core and a higher prevalence of TCFA. Thus evaluation of remodeling on CTA may provide a valuable marker for plaque vulnerability., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Aims: The positive predictive value of multidetector computed tomography angiography (CTA) for detecting significant stenosis remains limited. Possibly CTA may be more accurate in the evaluation of atherosclerosis rather than in the evaluation of stenosis severity. However, a comprehensive assessment of the diagnostic performance of CTA in comparison with both conventional coronary angiography (CCA) and intravascular ultrasound (IVUS) is lacking. Therefore, the aim of the study was to systematically investigate the diagnostic performance of CTA for two endpoints, namely detecting significant stenosis (using CCA as the reference standard) vs. detecting the presence of atherosclerosis (using IVUS as the reference of standard)., Methods and Results: A total of 100 patients underwent CTA followed by both CCA and IVUS. Only those segments in which IVUS imaging was performed were included for CTA and quantitative coronary angiography (QCA) analysis. On CTA, each segment was evaluated for significant stenosis (defined as ≥ 50% luminal narrowing), on CCA significant stenosis was defined as a stenosis ≥ 50%. Second, on CTA, each segment was evaluated for atherosclerotic plaque; atherosclerosis on IVUS was defined as a plaque burden of ≥ 40% cross-sectional area. CTA correctly ruled out significant stenosis in 53 of 53 (100%) patients. However, nine patients (19%) were incorrectly diagnosed as having significant lesions on CTA resulting in sensitivity, specificity, positive, and negative predictive values of 100, 85, 81, and 100%. CTA correctly ruled out the presence of atherosclerosis in 7 patients (100%) and correctly identified the presence of atherosclerosis in 93 patients (100%). No patients were incorrectly classified, resulting in sensitivity, specificity, positive, and negative predictive values of 100%. Conclusions The present study is the first to confirm using both CCA and IVUS that the diagnostic performance of CTA is superior in the evaluation of the presence or the absence of atherosclerosis when compared with the evaluation of significant stenosis.

Background: Changes in the microcirculation have been recognized to play a crucial role in many disease processes. In premature neonates, functional capillary density (FCD) decreases during the first months of life., Objectives: The aims of this study were to obtain microcirculatory parameters in term neonates and older children who did not present with compromised respiration or circulation and to determine developmental changes in the microcirculation in young children., Methods: This single-center prospective observational study was performed at a level III university children's hospital. Subjects eligible for inclusion were children up to the age of 3 years who did not have any respiratory compromise, circulatory compromise or signs of dehydration. The buccal mucosa of 45 children was assessed, using orthogonal polarization spectral imaging., Results: We found a significantly higher FCD in neonates younger than 1 week compared with older children. The median FCD was 8.1 cm/cm(2) (range 7.3-9.4) for 0- to 7-day-old neonates (n = 12), 6.9 cm/cm(2) (range 4.7-8.7) for 8- to 28-day-olds (n = 10), 7.3 cm/cm(2) (range 6.1-8.8) for 1- to 6-month-olds (n = 19) and 6.7 cm/cm(2) (range 6.5-9.2) for 3-year-olds (n = 4). After the first week, there was no significant correlation between age and FCD., Conclusion: FCD of the buccal mucosa decreases after the first week of life., (Copyright © 2010 S. Karger AG, Basel.)

The present study tested whether in patients with type 2 diabetes mellitus (DM) the combination of increased waist circumference and increased plasma triglyceride (TG) levels can predict the presence of coronary artery disease (CAD) as assessed by multidetector computed tomographic coronary angiography (CTA). In 202 patients with type 2 DM who were clinically referred for CTA, waist circumference and TG levels were measured. Patients were divided into 4 groups according to waist circumference measurements and TG levels. Increased waist circumference and TG levels (n = 61, 31%) indicated the presence of the hypertriglyceridemic waist phenotype. Patients with low waist circumference and TG (n = 49, 24%) were considered the reference group. Physical examination and blood measurements were performed. CTA was used to determine presence and severity of CAD. In addition, plaque type was evaluated. Plasma cholesterol levels were significantly increased in the group with increased TG levels and waist circumference, whereas high-density lipoprotein cholesterol was significantly lower than in the reference group. There was a significant increase in the presence of any CAD (odds ratio 3.3, confidence interval 1.31 to 8.13, p <0.05) and obstructive CAD (≥50%, odds ratio 2.9, confidence interval 1.16 to 7.28, p <0.05) in the group with increased TG level and waist circumference. In addition, a significantly larger number of noncalcified and mixed plaques was observed. In conclusion, in patients with type 2 DM, presence of the hypertriglyceridemic waist phenotype translated into a deteriorated blood lipid profile and more extensive CAD on CTA. Accordingly, the hypertriglyceridemic waist phenotype may serve as a practical clinical biomarker to improve risk stratification in patients with type 2 DM., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Background: The purpose of this study was to determine the prognostic value of computed tomography coronary angiography (CTA)-derived left ventricular (LV) function analysis and to assess its incremental prognostic value over the detection of significant stenosis using CTA., Methods: In 728 patients (400 males, mean age 55 ± 12 years) with known or suspected CAD, the presence of significant stenosis (≥ 50% stenosis) and LV function were assessed using CTA. LV end-systolic volume (LVESV), LV end-diastolic volume (LVEDV), and LV ejection fraction (LVEF) were calculated. LV function was assessed as a continuous variable and using cutoff values (LVEDV > 215 mL, LVESV > 90 mL, LVEF < 49%). The following events were combined in a composite end-point: all-cause mortality, non-fatal myocardial infarction, and unstable angina pectoris requiring hospitalization., Results: On CTA, a significant stenosis was observed in 221 patients (30%). During follow-up [median 765 days, 25-75th percentile: 493-978] an event occurred in 45 patients (6.2%). After multivariate correction for clinical risk factors and CTA, LVEF < 49% and LVESV > 90 mL were independent predictors of events with an incremental prognostic value over clinical risk factors and CTA., Conclusions: The present results suggest that LV function analysis provides independent and incremental prognostic information beyond anatomic assessment of CAD using CTA.

Background: previous studies have shown that the presence of stenosis alone on multislice computed tomography (MSCT) has a limited positive predictive value for the presence of ischemia on myocardial perfusion imaging (MPI). The purpose of this study was to assess which variables of atherosclerosis on MSCT angiography are related to ischemia on MPI., Methods and Results: both MSCT and MPI were performed in 514 patients. On MSCT, the calcium score, degree of stenosis (≥ 50% and ≥ 70% stenosis), and plaque extent and location were determined. Plaque composition was classified as noncalcified, mixed, or calcified. Ischemia was defined as a summed difference score (≥ 2 on a per-patient basis. Ischemia was observed in 137 patients (27%). On a per-patient basis, multivariate analysis showed that the degree of stenosis (presence of (≥ 70% stenosis, odds ratio=3.5), plaque extent and composition (mixed plaques (≥3, odds ratio=1.7; calcified plaques ≥ 3, odds ratio=2.0), and location (atherosclerotic disease in the left main coronary artery and/or proximal left anterior descending coronary artery, odds ratio=1.6) were independent predictors for ischemia on MPI. In addition, MSCT variables of atherosclerosis, such as plaque extent, composition, and location, had significant incremental value for the prediction of ischemia over the presence of ≥70% stenosis., Conclusions: in addition to the degree of stenosis, MSCT variables of atherosclerosis describing plaque extent, composition, and location are predictive of the presence of ischemia on MPI.

Aims: Multidetector computed tomography coronary angiography (CTA) has emerged as a feasible imaging modality for non-invasive assessment of coronary artery disease (CAD). Recently, 320-row CTA systems were introduced, with 16 cm anatomical coverage, allowing image acquisition of the entire heart within a single heart beat. The aim of the present study was to assess the diagnostic accuracy of 320-row CTA in patients with known or suspected CAD., Methods and Results: A total of 64 patients (34 male, mean age 61 +/- 16 years) underwent CTA and invasive coronary angiography. All CTA scans were evaluated for the presence of obstructive coronary stenosis by a blinded expert, and results were compared with quantitative coronary angiography. Four patients were excluded from initial analysis due to non-diagnostic image quality. Sensitivity, specificity, and positive and negative predictive values to detect > or =50% luminal narrowing on a patient basis were 100, 88, 92, and 100%, respectively. Moreover, sensitivity, specificity, and positive and negative predictive values to detect > or =70% luminal narrowing on a patient basis were 94, 95, 88, and 98%, respectively. With inclusion of non-diagnostic imaging studies, sensitivity, specificity, and positive and negative predictive values to detect > or =50% luminal narrowing on a patient basis were 100, 81, 88, and 100%, respectively., Conclusion: The current study shows that 320-row CTA allows accurate non-invasive assessment of significant CAD.

Objectives: This study sought to demonstrate the feasibility of a dedicated algorithm for automated quantification of stenosis severity on multislice computed tomography in comparison with quantitative coronary angiography (QCA)., Background: Limited information is available on quantification of coronary stenosis, and previous attempts using semiautomated approaches have been suboptimal., Methods: In patients who had undergone 64-slice computed tomography and invasive coronary angiography, the most severe lesion on QCA was quantified per coronary artery using quantitative coronary computed tomography (QCCTA) software. Additionally, visual grading of stenosis severity using a binary approach (50% stenosis as a cutoff) was performed. Diameter stenosis (percentage) was obtained from detected lumen contours at the minimal lumen area, and corresponding reference diameter values were obtained from an automatic trend analysis of the vessel areas within the artery., Results: One hundred patients (53 men; 59.8 +/- 8.0 years) were evaluated, and 282 (94%) vessels were analyzed. Good correlations for diameter stenosis were observed for vessel-based (n = 282; r = 0.83; p < 0.01) and patient-based (n = 93; r = 0.86; p < 0.01) analyses. Mean differences between QCCTA and QCA were -3.0% +/- 12.3% and -6.2% +/- 12.4%. Furthermore, good agreement was observed between QCCTA and QCA for semiquantitative assessment of diameter stenosis (accuracy of 95%). Diagnostic accuracy for assessment of > or =50% diameter stenosis was higher using QCCTA compared with visual analysis (95% vs. 87%; p = 0.08). Moreover, a significantly higher positive predictive value was observed with QCCTA when compared with visual analysis (100% vs. 78%; p < 0.05). Although the visual approach showed a reduced diagnostic accuracy for data sets with moderate image quality, QCCTA performed equally well in patients with moderate or good image quality. However, in data sets with good image quality, QCCTA tended to have a reduced sensitivity compared with visual analysis., Conclusions: Good correlations were found for quantification of stenosis severity between QCCTA and QCA. QCCTA showed an improved positive predictive value when compared with visual analysis., (Copyright 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: Percutaneous coronary intervention with stent implantation is routinely performed to treat patients with obstructive coronary artery disease. However, thus far, noninvasive assessment of in-stent restenosis has been challenging. Recently, 320-row multidetector computed tomography coronary angiography (CTA) was introduced, allowing volumetric image acquisition of the heart in a single heart beat or gantry rotation. The aim of this study was to evaluate the diagnostic performance of 320-row CTA in the evaluation of significant in-stent restenosis. Invasive coronary angiography (ICA) served as the standard of reference, using a quantitative approach., Materials and Methods: The population consisted of patients with previous coronary stent implantation who were clinically referred for cardiac evaluation because of recurrent chest pain and who underwent both CTA and ICA. CTA studies were performed using a 320-row CTA scanner with 320 detector-rows, each 0.5 mm wide, and a gantry rotation time of 350 milliseconds. Tube voltage and current were adapted to body mass index and thoracic anatomy. The entire heart was imaged in a single heart beat, with a maximum of 16-cm craniocaudal coverage. During the scan, the ECG was registered simultaneously for prospective triggering of the data. First, CTA stent image quality was assessed using a 3-point grading scale: (1) good image quality, (2) moderate image quality, and (3) poor image quality. Subsequently, the presence of in-stent restenosis was determined on a stent and patient basis by a blinded observer. Significant in-stent restenosis was defined as >or=50% luminal narrowing in the stent lumen or the presence of significant stent edge stenosis. Overlapping stents were considered to represent a single stent. Results were compared with ICA using quantitative coronary angiography. In addition, CTA stent image quality and diagnostic accuracy were related to stent characteristics and heart rate during CTA image acquisition., Results: The population consisted of 53 patients (37 men, mean age: 65 +/- 13 years) with a total of 89 stents available for evaluation. ICA identified 12 stents (13%) with significant in-stent restenosis. A total of 7 stents (8%) were of nondiagnostic CTA stent image quality, and were considered positive. Sensitivity, specificity, positive, and negative predictive values were 92%, 83%, 46%, and 98%, respectively on a stent basis. Five CTA studies (9%) were of nondiagnostic quality for the evaluation of in-stent restenosis and were considered positive. Sensitivity, specificity, positive, and negative predictive values were 100%, 81%, 58%, and 100%, respectively on a patient level. Stent diameter <3 mm as well as stent strut thickness >or=140 mum were associated with decreased CTA stent image quality and diagnostic accuracy. Heart rate during CTA acquisition and stent overlap were not associated with image degradation., Conclusions: The present results show that 320-row CTA allows accurate noninvasive assessment of significant in-stent restenosis. However, stents with a large diameter and thin struts allowed better in-stent visualization than stents with a small diameter or thick struts. Consequently, noninvasive assessment of in-stent restenosis using CTA may be an attractive and feasible alternative particularly in carefully selected patients.

Background: Multidetector computed tomography (MDCT) has been demonstrated as a feasible imaging modality for noninvasive assessment of coronary artery disease and left ventricular (LV) function. Recently, 320-row systems have become available with 16 cm anatomical coverage allowing image acquisition of the entire heart within a single heartbeat. The purpose of this study was to evaluate the accuracy of 320-row MDCT in the assessment of global LV function compared to two-dimensional (2D) echocardiography as the standard of reference., Methods and Results: A head-to-head comparison between 320-row MDCT and 2D-echocardiography was performed in 114 patients (68 men; mean age 62 +/- 13 years) who were clinically referred for MDCT coronary angiography. The entire heart was imaged in a single heartbeat, using prospective dose modulation. LV end-diastolic volumes (LVEDV) and LV end-systolic volumes (LVESV) were determined and the LV ejection fraction (LVEF) was derived. Average LVEF was 60 +/- 10% (range 26-78%) as determined on MDCT, compared with 59 +/- 10% (range 25-77%) on 2D-echocardiography. Evaluation of LVEF by linear regression analysis showed a good correlation between MDCT and 2D-echocardiography (r(2) = .87; P < .001). Good correlations between MDCT and 2D-echocardiography were demonstrated for the assessment of LVEDV (r(2) = .91; P < .001) and LVESV (r(2) = .94; P < .001). At Bland-Altman analysis, mean differences (+/-SD) of 7.3 +/- 12.1 mL (P < .05) and 1.8 +/- 7.4 mL (P < .05) were observed between MDCT and 2D-echocardiography for LVEDV and LVESV, respectively. LVEF was slightly overestimated with MDCT (.9 +/- 3.6%; P < .05)., Conclusions: Accurate assessment of LV function and volumes is feasible with single heartbeat 320-row MDCT in patients referred for MDCT coronary angiography.

Multidetector computed tomographic coronary angiography (CTA) image quality is inversely related to the heart rate (HR). As a result beta-blocking medication is routinely administered before investigation. In the present study, the use, contraindications, and efficacy of prescan beta blockade with regard to HR reduction and CTA image quality were assessed. In 537 patients referred for CTA, the baseline HR and blood pressure were measured on arrival, and contraindications for beta blockade were noted. Unless contraindicated, a single dose of metoprolol was administered orally 1 hour before data acquisition in patients with a HR of > or =65 beats/min according to a predefined medication protocol. After 1 hour, the HR was remeasured. A total of 283 patients (53%) had a HR of > or =65 beats/min. In this group, beta blockade was contraindicated in 46 patients (16%). Metoprolol was administered to the remaining 237 patients. However, 26 patients (11%) received suboptimal (lower dose than prescribed by protocol) beta blockade because of contraindications. Of the 211 patients receiving optimal beta blockade, 57 (27%) did not achieve the target HR. Of the patients with contraindications to beta blockade, 43 (60%) did not achieve the target HR. Compared to patients with optimal HR control, those receiving no or suboptimal beta blockade because of contraindications had significantly fewer examinations of good image quality (40% vs 74%, p <0.001), and significantly more examinations of poor image quality (20% vs 6%, p <0.001). In conclusion, most patients require HR reduction before CTA. Contraindications to beta blockade are present in a substantial proportion of patients. This results in suboptimal HR control and image quality, indicating the need for alternative approaches for HR reduction., (Copyright 2010 Elsevier Inc. All rights reserved.)

In recent years, multi-slice computed tomography (MSCT) technology has developed rapidly, allowing high-resolution non-invasive imaging of the coronary arteries and surrounding structures. Since the introduction of MSCT, acquisition time, detector number, spatial and temporal resolution have continuously improved with each new scanner generation, resulting in excellent image quality and diagnostic accuracy in the detection of coronary artery disease (CAD). At the same time, developments in MSCT technology have focused on reduction of the radiation dose. In particular, the availability of dose modulation and prospective ECG gating have drastically reduced patient radiation dose. Moreover, with the introduction of 320-slice MSCT, volumetric scanning of the entire heart has become possible in a single heart beat or gantry rotation, thereby eliminating oversampling and stair-step artifact. The present article provides an overview of state of the art clinical applications of cardiac MSCT, including the diagnosis of CAD, evaluation of plaque morphology and composition, prognostification, and the evaluation of left ventricular function and aortic and mitral valve anatomy.

Data evaluating gender- and age-specific differences in plaque observations on multislice computed tomography (MSCT) are scarce. Accordingly, the aim of this study was to evaluate coronary plaque patterns in men and women in relation to age using MSCT. The findings were compared to observations on grayscale intravascular ultrasound (IVUS) and virtual histology (VH) IVUS. In total, 93 patients (59 men, 34 women) underwent 64-slice MSCT followed by conventional coronary angiography with IVUS. Plaque extent and composition were assessed on MSCT, grayscale IVUS, and VH IVUS. Coronary plaque patterns were compared between men and women in 2 age groups (<65 and >or=65 years old). In patients aged <65 years, more plaques were observed on MSCT in men (6 +/- 4 vs 2 +/- 2 in women, p <0.001). Also, a larger plaque burden was observed on grayscale IVUS in men (45.7 +/- 11.4% vs 36.3 +/- 11.6% in women, p <0.001). Similarly, more mixed plaques were observed in men (3 +/- 3 vs 1 +/- 1 in women, p = 0.003), whereas a larger arc of calcium was detected on grayscale IVUS in men (91.7 +/- 93.5 degrees vs 25.7 +/- 51.0 degrees in women, p <0.001). On VH IVUS, the prevalence of thin-cap fibroatheroma was higher in men (31% vs 0%) compared to women. In patients aged >or=65 years old, no important differences in plaque patterns were observed between men and women. In conclusion, more extensive atherosclerosis and more calcified lesions were observed in men than in women. These differences were predominantly present in patients aged <65 years and were lost in those aged >or=65 years., (Copyright 2010 Elsevier Inc. All rights reserved.)

Background: Imaging of coronary plaques has traditionally focused on evaluating degree of stenosis, as the risk for adverse cardiac events increases with stenosis severity. However, the relation between plaque composition and severity of stenosis remains largely unknown., Objective: To assess plaque composition (non-invasively by multislice computed tomography (MSCT) angiography and invasively by virtual histology intravascular ultrasound (VH IVUS)) in relation to degree of stenosis., Methods: 78 patients underwent MSCT (identifying three plaque types; non-calcified, calcified, mixed) followed by invasive coronary angiography and VH IVUS. VH IVUS evaluated plaque burden, minimal lumen area and plaque composition (fibrotic, fibro-fatty, necrotic core, dense calcium) and plaques were classified as fibrocalcific, fibroatheroma, thin-capped fibroatheroma (TCFA), pathological intimal thickening. For each plaque, percentage stenosis was evaluated by quantitative coronary angiography. Significant stenosis was defined >50% stenosis., Results: Overall, 43 plaques (19%) corresponded to significant stenosis. Of the 227 plaques analysed, 70 were non-calcified plaques (31%), 96 mixed (42%) and 61 calcified (27%) on MSCT. Plaque types on MSCT were equally distributed among significant and non-significant stenoses. VH IVUS identified that plaques with significant stenosis had higher plaque burden (67% (11%) vs 53% (12%), p<0.05) and smaller minimal lumen area (4.6 (3.8-6.8) mm(2) vs 7.3 (5.4-10.5) mm(2), p<0.05). Interestingly, no differences were observed in percentage fibrotic, fibro-fatty, necrotic core and dense calcium. Non-significant stenoses were more frequently classified as pathological intimal thickening (46 (25%) vs 3 (7%), p<0.05), although TCFA (more vulnerable plaque) was distributed equally (p = 0.18)., Conclusion: No evident association exists between the degree of stenosis and plaque composition or vulnerability, as evaluated non-invasively by MSCT and invasively by VH IVUS.