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Virtual endoscopy (VE) is a new post-processing method that uses volumetric data sets to simulate the tracks of a “conventional” flexible endoscope. However, almost all studies of this method have involved virtual visualizations of the cardiovascular structures applied to computed tomography (CT) and magnetic resonance (MR) datasets. This paper introduces a novel visualization method called the “three-dimensional echocardiographic intracardiac endoscopic simulation system (3DE IESS)”, which uses 3D echocardiographic images in a virtual reality (VR) environment to diagnose congenital heart disease. The aim of this study was to analyze the feasibility of VE in the evaluation of congenital heart disease in children and its accuracy compared with 2DE. Three experienced pediatric cardiologists blinded to the patients’ diagnoses separately reviewed 40 two-dimensional echocardiographic (2DE) datasets and 40 corresponding VE datasets and judged whether abnormal intracardiac anatomy was present in terms of a five-point scale (1 = definitely absent; 2 = probably absent; 3 = cannot be determined; 4 = probably present; and 5 = definitely present). Compared with clinical diagnosis, the diagnostic accuracy of VE was 98.7% for ASD, 92.4% for VSD, 92.6% for TOF, and 94% for DORV, respectively. Diagnostic accuracy of VE was significantly higher than that of 2DE for TOF and DORV except for ASD and VSD. The receiver operating characteristic (ROC) curve for VE was closer to the optimal performance point than was the ROC curve for 2DE. The area under the ROC curve was 0.96 for VE and 0.93 for 2DE. Kappa values (range, 0.73–0.79) for VE and 2DE indicated substantial agreement. 3D echocardiographic VE can enhance our understanding of intracardiac structures and facilitate the evaluation of congenital heart disease.

Coronary angiography provides excellent visualization of coronary arteries, but has limitations in assessing the clinical significance of a coronary stenosis. Fractional flow reserve (FFR) has been shown to be reliable in discerning stenoses responsible for inducible ischemia. The purpose of this study is to validate a technique for FFR quantification using angiographic image data. The study was carried out on 10 anesthetized, closed-chest swine using angioplasty balloon catheters to produce partial occlusion. Angiography based FFR was calculated from an angiographically measured ratio of coronary blood flow to arterial lumen volume. Pressure-based FFR was measured from a ratio of distal coronary pressure to aortic pressure. Pressure-wire measurements of FFR (FFRP) correlated linearly with angiographic volume-derived measurements of FFR (FFRV) according to the equation: FFRP= 0.41 FFRV+ 0.52 (P-value < 0.001). The correlation coefficient and standard error of estimate were 0.85 and 0.07, respectively. This is the first study to provide an angiographic method to quantify FFR in swine. Angiographic FFR can potentially provide an assessment of the physiological severity of a coronary stenosis during routine diagnostic cardiac catheterization without a need to cross a stenosis with a pressure-wire. © Springer Science+Business Media, B.V. 2010.

Item does not contain fulltext To investigate in type-1 diabetes mellitus (DM1) patients the role of hypertension and of DM1 itself on aortic stiffness by using magnetic resonance imaging (MRI). Consecutive patients from the diabetes and hypertension outpatient clinic and healthy volunteers were included in our study. Subjects were divided into four groups: 32 healthy volunteers (mean age: 54.5 +/- 6.8 years), 20 DM1 patients (mean age: 48.3 +/- 5.9 years), 31 hypertensive patients (mean age: 59.9 +/- 7.2 years) and 28 patients with both DM1 and hypertension (mean age: 50.1 +/- 6.2 years). Aortic stiffness was measured by means of pulse wave velocity (PWV) using velocity-encoded MRI. Analysis of variance (ANOVA), uni- and multivariable regression models and the Bonferroni-test for multiple testing, were used for statistical analyses. Mean aortic PWV was 5.7 +/- 1.2 m/s in healthy volunteers, 5.9 +/- 1.2 m/s in DM1 patients without hypertension, 7.3 +/- 1.2 m/s in hypertensive patients and 7.3 +/- 1.3 m/s in patients with both DM1 and hypertension. Compared to healthy control subjects, aortic PWV was significantly higher in patients with hypertension (P < 0.001) and in patients with both DM1 and hypertension (P < 0.001), whereas aortic PWV was not increased in patients having DM1 alone. Furthermore, aortic PWV was significantly higher in DM1 patients with hypertension than in patients with DM1 alone (P = 0.002). These findings remained after adjustment for confounding factors. Hypertension has a predominant contributive effect on aortic stiffness in DM1 patients whereas the direct diabetic effect on aortic stiffness is small. 01 maart 2012

CT coronary angiography has shown to be a highly accurate noninvasive approach for delineation of the presence, location and severity of coronary artery disease [1–35]. With its high negative predictive value, cardiac CT is optimally suited for the evaluation of patients with a low or intermediate risk of coronary disease, allowing the non-invasive exclusion of coronary disease at relatively low cost and risk [36–48]. Nevertheless, the appropriate radiation dose remains an important issue in cardiac CT. On one hand, a too low radiation dose may result in a high level of image noise and therefore in non-evaluable images. On the other hand, using higher radiation exposure levels may put patients at unnecessary risk of radiation damage [49–58]. Effective strategies to reduce radiation dose, such as prospective gating, ECG-correlated modulation of the tube current, and tube voltage below 100 kV, are becoming more and more available [59–62]. In the recently published PROTECTION II trial, Hausleiter et al. [63] studied 400 non-obese patients undergoing CT angiography with either 100 or 120 kV CT angiography. The study specifically examined the impact of a reduction in tube voltage to 100 kV using 64-slice CT angiography systems from three different manufacturers. It was demonstrated that a further 31% reduction in radiation exposure could be obtained with 100 kV tube voltage settings while image quality was preserved. Gerber et al. [64] produced a scientific statement on radiation doses from the American Heart Association. The authors estimated the doses for retrospective CT coronary angiography at 15 mSv without tube modulation, 9 mSv with dose modulation and 3 mSv for prospectively acquired studies. With either prospective or retrospective ECG tube current modulation, radiation exposure can be minimized and yet high quality imaging can be maintained. Dual-source multi-detector CT allows excellent temporal resolution (83 ms) with improvements in image quality despite increased heart rates. Dual-source multi-detector CT using ECG tube current modulation and retrospective gating exhibit radiation doses in the range of 7–9 mSv which can be further reduced by using a tube voltage of 100 kV in patients with a body mass index

Quantitative SPECT analysis contributes to the diagnostic and prognostic assessment of coronary artery disease. A novel automated scoring system (heart score view) can provide identical quantitative information to that determined by expert visual analysis. The aim of the present study is to evaluate the prognostic value of the automated SPECT scoring system when applied to stress thallium and resting beta-methyl-iodophenyl pentadecanoic acid (BMIPP) SPECT images. After a preliminary validation of the automated system by comparison with expert visual analyses, outcome data from 151 consecutive patients with suspected or known coronary artery disease without prior myocardial infarction were analyzed using automated SPECT scores on stress thallium and resting BMIPP images. The software quantified abnormalities as summed stress (SSS), summed rest and summed difference scores for stress thallium and as summed BMIPP scores (SBS). Cardiac events occurred over a period of 48 months in 29 (19.2 %) patients with diabetes mellitus, a lower left ventricular ejection fraction (LVEF) and more abnormal scores for thallium and BMIPP. Multivariate predictors of all cardiac events included diabetes mellitus and thallium SSS. The global Chi-square value was significantly increased when SSS was added to the clinical information (diabetes mellitus and LVEF). Negative predictive values of thallium SSS and SBS were almost identical at 84 % for all cardiac events and 98 % for hard cardiac events. Automatically quantified perfusion and BMIPP scores are related to cardiac events and these values can improve the risk stratification of coronary patients particularly when stress thallium imaging is combined with clinical information.

Bicuspid aortic valve (BAV) anatomy is associated with increased growth rate of the aortic root compared to tricuspid aortic valves. Statins decrease the growth rate of abdominal aneurysms; however their effect on the aortic root growth rate has not been elucidated. The present study evaluated the association between use of statins and aortic root growth in patients with BAV. A total of 199 patients (43 ± 15 years, 69 % male) with BAV who underwent ≥2 echocardiographic measurements of the aortic root ≥1 year apart were included in this retrospective observational study. Median follow-up duration was 4.7 years (interquartile range 2.7–8.3 years). Growth rate (mm/year) of the aortic root was compared between statin users (n = 41) and non-users (n = 158). Statin users were significantly older and had more cardiovascular risk factors than their counterparts. Ascending aorta diameter was significantly smaller at baseline and at follow-up in statin users compared with non-users when adjusted for coronary artery disease, age and medication. The average annual growth rate was 0.08 mm/year (95 % confidence interval 0.03–0.13) for the aortoventricular junction, 0.16 mm/year (0.11–0.21) for the sinus of Valsalva, 0.12 mm/year (0.07–0.17) for the sinotubular junction and 0.45 mm/year (0.37–0.53) for the ascending aorta. The dilation rate of the aortic segments was not different between statin users and non-users. In conclusion, in patients with BAV, although the use of statins was associated with smaller ascending aorta, the annual dilation rate of the aortic root was not influenced by the use of statins.

We developed and evaluated an automatic stent strut detection method in intravascular optical coherence tomography (IVOCT) pullback runs. Providing very high resolution images, IVOCT has been rapidly accepted as a coronary imaging modality for the optimization of the stenting procedure and its follow-up evaluation based on stent strut analysis. However, given the large number of struts visible in a pullback run, quantitative three-dimensional analysis is only feasible when the strut detection is performed automatically. The presented method first detects the candidate pixels using both a global intensity histogram and the intensity profile of each A-line. Gaussian smoothing is applied followed by specified Prewitt compass filters to detect the trailing shadow of each strut. Next, the candidate pixels are clustered using the shadow information. In the final step, several filters are applied to remove the false positives such as the guide wire. Our new method requires neither a priori knowledge of the strut status nor the lumen/vessel contours. In total, 10 IVOCT pullback runs from a 1-year follow-up study were used for validation purposes. 18,311 struts were divided into three strut status categories (malapposition, apposition or covered) and classified based on the image quality (high, medium or low). The inter-observer agreement is 95 %. The sensitivity was defined as the ratio of the number of true positives and the total number of struts in the expert defined result. The proposed approach demonstrated an average sensitivity of 94 %. For malapposed, apposed and covered stent struts, the sensitivity of the method is respectively 91, 93 and 94 %, which shows the robustness towards different situations. The presented method can detect struts automatically regardless of the strut status or the image quality, and thus can be used for quantitative measurement, 3D reconstruction and visualization of the stents in IVOCT pullback runs.

Contrast-enhanced ultrasound (CEUS) is increasingly being used to evaluate patients with known or suspected atherosclerosis. The administration of a microbubble contrast agent in conjunction with ultrasound results in an improved image quality and provides information that cannot be assessed with standard B-mode ultrasound. CEUS is a high-resolution, noninvasive imaging modality, which is safe and may benefit patients with coronary, carotid, or aortic atherosclerosis. CEUS allows a reliable assessment of endocardial borders, left ventricular function, intracardiac thrombus and myocardial perfusion. CEUS results in an improved detection of carotid atherosclerosis, and allows assessment of high-risk plaque characteristics including intraplaque vascularization, and ulceration. CEUS provides real-time bedside information in patients with a suspected or known abdominal aortic aneurysm or aortic dissection. The absence of ionizing radiation and safety of the contrast agent allow repetitive imaging which is particularly useful in the follow-up of patients after endovascular aneurysm repair. New developments in CEUS-based molecular imaging will improve the understanding of the pathophysiology of atherosclerosis and may in the future allow to image and directly treat cardiovascular diseases (theragnostic CEUS). Familiarity with the strengths and limitations of CEUS may have a major impact on the management of patients with atherosclerosis.

As multiple new procedures now require better visualization of the aortic valve, we sought to better define the central aortic valve coaptation area seen during diastole on multi-detector row cardiac computed tomography (MDCT). 64-MDCT images of 384 symptomatic consecutive patients referred for coronary artery disease evaluation were included in the study. Planimetric measurements of this area were performed on cross-sectional views of the aortic valve at 75% phase of the cardiac cycle. Planimetric measurement of central regurgitation orifice area (ROA) seen in patients with aortic regurgitation and Hounsfield units of the central aortic valve coaptation area were performed. Mean area of the central aortic valve coaptation area was 5.34 ± 5.19 mm(2) and Hounsfield units in this area were 123.69 ± 31.31 HU. The aortic valve coaptation area (mm(2)) measurement in patients without AR was: 4.90 ± 0.17 and in patients with AR: 10.53 ± 0.26 (P ≤ 0.05). On Bland-Altman analysis a very good correlation between central aortic valve coaptation area and central ROA was found (r = 0.80, P ≤ 0.001). Central aortic valve coaptation area is a central area present at the coaptation of nodules of arantius of aortic cusps during diastole; it is incompetent and increased in size in patients with aortic regurgitation.

Chronic ischemic mitral regurgitation (IMR) is associated with a markedly worse prognosis after myocardial infarction (MI).The study aimed to evaluate the relationship between anterior and posterior mitral leaflet angle (MLA) values, left ventricle remodeling and severity of ischaemic mitral regurgitation (IMR). Methods: Forty-two patients (age 63.5 ± 9.7 years, 36 men) with chronic IMR (regurgitant volume, RV > 20 ml; >6 months after MI) underwent transthoracic echocardiography (TTE) and cardiovascular magnetic resonance (CMR) imaging. Anterior and posterior MLA, determined by echocardiography, were correlated with indices of LV remodeling, mitral apparatus deformation and IMR severity by CMR. The anterior and posterior MLA was 25.41 ± 4.28 and 38.37 ± 8.89° (mean ± SD). In 5 patients (11.9%) the posterior MLA was ≥45°. There was a significant correlation between anterior MLA and RV (r = 0.74, P = 0.01). For patients with RV > 30 ml this correlation was stronger (r = 0.97, P = 0.005) and, in addition, there was a correlation between the RV and posterior MLA (r = 0.90, P = 0.037), between tenting area and posterior MLA (r = 0.90, P = 0.04), and between tenting area and anterior MLA (r = 0.82, P = 0.08). With regard to LV remodeling parameters, there was weaker but significant correlation between posterior MLA and LV end-diastolic volume index (r = 0.35, P = 0.031), LV end-systolic volume index (r = 0.37, P = 0.021), stroke volume (r = 0.35, P = 0.03), sphericity index (r = 0.33, P = 0.041). Anterior MLA correlated with wall motion score index (r = 0.41, P = 0.019). Besides, there was a correlation between posterior MLA and left atrial volume (r = 0.41, P = 0.012). Measurement of anterior and posterior MLA may play an important role in evaluating patients with IMR.

Stem cell transplantation following AMI has shown promise for the repair or reduction of the amount of myocardial injury. There is some evidence that these treatment effects appear to be directly correlated to cell residence time. This study aims to assess the effects of (a) the timing of stem cell injection following myocardial infarction, and (b) flow milieu, on cell residence times at the site of transplantation by comparing three time points (day of infarction, week 1 and week 4-5), and two models of acute myocardial infarction (sustained occlusion or reperfusion). Twenty-one dogs received 2 injections of 30 million endothelial progenitor cells. The first injections were administered by epicardial (n = 8) or endocardial injection (n = 13) either on the day of infarction (n = 15) or at 1 week (n = 6). The second injections were administered by only endocardial injection (n = 18) 4 weeks following the first injection. Cell clearance half-lives were comparable between early and late injections. However, transplants into sustained occlusion infarcts resulted in slower cell clearance 77.1 ± 6.1 (n = 18) versus reperfused 59.4 ± 2.9 h (n = 21) p = 0.009. Sustained occlusion infarcts had longer cell retention in comparison to reperfusion whereas the timing of injection did not affect clearance rates. If the potential for myocardial regeneration associated with cell transplantation is, at least in part, linked to cell residence times, then greater benefit may be observed with transplants into infarcts associated with persistent coronary artery occlusion. © 2012 The Author(s).

To compare the image quality of coronary CT angiography (CTA) studies between standard filtered back projection (FBP) and adaptive iterative dose reduction in three-dimensions (AIDR3D) reconstruction using CT noise additional software to simulate reduced radiation exposure. Images from 93 consecutive clinical coronary CTA studies were processed utilizing standard FBP, FBP with 50 % simulated dose reduction (FBP50 %), and AIDR3D with simulated 50 % dose reduction (AIDR50 %). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured within 5 regions-of-interest, and image quality for each reconstruction strategy was assessed by two independent readers using a 4-point scale. Compared to FBP, the SNR measured from the AIDR50 % images was similar or higher (airway: 38.3 ± 12.7 vs. 38.5 ± 14.5, p = 0.81, fat: 5.5 ± 1.9 vs. 5.4 ± 2.0, p = 0.20, muscle: 3.2 ± 1.2 vs. 3.1 ± 1.3, p = 0.38, aorta: 22.6 ± 9.4 vs. 20.2 ± 9.7, p

Recently, Fourier domain OCT (FD-OCT) has been introduced for clinical use. This approach allows in vivo, high resolution (15 micron) imaging with very fast data acquisition, however, it requires brief flushing of the lumen during imaging. The reproducibility of such fast data acquisition under intracoronary flush application is poorly understood. To assess the inter-study variability of FD-OCT and to compare lumen morphometry to the established invasive imaging method, IVUS. 18 consecutive patients with coronary artery disease scheduled for PCI were included. In each target vessel a FD-OCT pullback (MGH system, light source 1,310 nm, 105 fps, pullback speed 20 mm/s) was acquired during brief (3 s) injection of X-ray contrast (flow 3 ml/s) through the guiding catheter. A second pullback was repeated under the same conditions after re-introduction of the FD OCT catheter into the coronary artery. IVUS and OCT imaging was performed in random order. FD-OCT and IVUS pullback data were analyzed using a recently developed software employing semi automated lumen contour and stent strut detection algorithms. Corresponding ROI were matched based on anatomical landmarks such as side branches and/or stent edges. Inter-study variability is presented as the absolute difference between the two pullbacks. FD-OCT showed remarkably good reproducibility. Inter-study variability in native vessels (cohort A) was very low for mean and minimal luminal area (0.10 +/- A 0.38, 0.19 +/- A 0.57 mm(2), respectively). Likewise inter-study variability was very low in stented coronary segments (cohort B) for mean lumen, mean stent, minimal luminal and minimal stent area (0.06 +/- A 0.08, 0.07 +/- A 0.10, 0.04 +/- A 0.09, 0.04 +/- A 0.10 mm(2), respectively). Comparison to IVUS morphometry revealed no significant differences. The differences between both imaging methods, OCT and IVUS, were very low for mean lumen, mean stent, minimal luminal and minimal stent area (0.10 +/- A 0.45, 0.10 +/- A 0.36, 0.26 +/- A 0.54, 0.05 +/- A 0.47 mm(2), respectively). FD-OCT shows excellent reproducibility and very low inter-study variability in both, native and stented coronary segments. No significant differences in quantitative lumen morphometry were observed between FD-OCT and IVUS. Evaluating these results suggest that FD-OCT is a reliable imaging tool to apply in longitudinal coronary artery disease studies.

The purpose of this study was to develop and validate a method for automated segmentation of the carotid artery lumen from volumetric MR Angiographic (MRA) images using a deformable tubular 3D Non-Uniform Rational B-Splines (NURBS) model. A flexible 3D tubular NURBS model was designed to delineate the carotid arterial lumen. User interaction was allowed to guide the model by placement of forbidden areas. Contrast-enhanced MRA (CE-MRA) from 21 patients with carotid atherosclerotic disease were included in this study. The validation was performed against expert drawn contours on multi-planar reformatted image slices perpendicular to the artery. Excellent linear correlations were found on cross-sectional area measurement (r = 0.98, P < 0.05) and on luminal diameter (r = 0.98, P < 0.05). Strong match in terms of the Dice similarity indices were achieved: 0.95 ± 0.02 (common carotid artery), 0.90 ± 0.07 (internal carotid artery), 0.87 ± 0.07 (external carotid artery), 0.88 ± 0.09 (carotid bifurcation) and 0.75 ± 0.20 (stenosed segments). Slight overestimation of stenosis grading by the automated method was observed. The mean differences was 7.20% (SD = 21.00%) and 5.2% (SD = 21.96%) when validated against two observers. Reproducibility in stenosis grade calculation by the automated method was high; the mean difference between two repeated analyses was 1.9 ± 7.3%. In conclusion, the automated method shows high potential for clinical application in the analysis of CE-MRA of carotid arteries.

Right ventricular function (RVF) is often selectively declined after coronary artery bypass graft surgery. In adult patients with congenital heart disease (CHD) the incidence and persistence of declined RVF after cardiac surgery is unknown. The current study aimed to describe RVF after cardiac surgery in these patients. Adult CHD patients operated between January 2008 and December 2009 in the Academic Medical Centre in Amsterdam were studied. Clinical characteristics, laboratory tests, surgical data and intensive care unit outcome were obtained from medical records. RVF was measured by trans-thoracic echocardiography (TTE) and expressed by tricuspid annular plane systolic excursion (TAPSE), tissue Doppler imaging (RV S') and myocardial performance index (MPI) pre-operatively and direct, at intermediate and late follow up. Of a total of 185 operated, 86 patients (mean age 39 +/- A 13 years, 54% male) had echo data available. There was a significant fall in RVF after cardiac surgery. TAPSE and RV S' were significantly higher and MPI was significantly lower pre-operatively compared to direct post-operative values (TAPSE 22 +/- A 5 versus 13 +/- A 3 mm (P

The purpose of this study is to develop a method to estimate the hyperemic blood flow in a coronary artery using the sum of the distal lumen volumes in a swine animal model. The limitations of visually assessing coronary artery disease are well known. These limitations are particularly important in intermediate coronary lesions where it is difficult to determine whether a particular lesion is the cause of ischemia. Therefore, a functional measure of stenosis severity is needed using angiographic image data. Coronary arteriography was performed in 10 swine (Yorkshire, 25-35 kg) after power injection of contrast material into the left main coronary artery. A densitometry technique was used to quantify regional flow and lumen volume in vivo after inducing hyperemia. Additionally, 3 swine hearts were casted and imaged post-mortem using cone-beam CT to obtain the lumen volume and the arterial length of corresponding coronary arteries. Using densitometry, the results showed that the stem hyperemic flow (Q) and the associated crown lumen volume (V) were related by Q = 159.08 V3/4(r = 0.98, SEE = 10.59 ml/min). The stem hyperemic flow and the associated crown length (L) using cone-beam CT were related by Q = 2.89 L (r = 0.99, SEE = 8.72 ml/min). These results indicate that measured arterial branch lengths or lumen volumes can potentially be used to predict the expected hyperemic flow in an arterial tree. This, in conjunction with measured hyperemic flow in the presence of a stenosis, could be used to predict fractional flow reserve based entirely on angiographic data. © Springer Science+Business Media, B.V. 2010.

The objective of the study is to validate intravascular quantitative echogenicity as a surrogate for molecular weight assessment of poly-l-lactide-acid (PLLA) bioresorbable scaffold (Absorb BVS, Abbott Vascular, Santa Clara, California). We analyzed at 9 time points (from 1- to 42-month follow-up) a population of 40 pigs that received 97 Absorb scaffolds. The treated regions were analyzed by echogenicity using adventitia as reference, and were categorized as more (hyperechogenic or upperechogenic) or less bright (hypoechogenic) than the reference. The volumes of echogenicity categories were correlated with the measurements of molecular weight (Mw) by gel permeation chromatography. Scaffold struts appeared as high echogenic structures. The quantification of grey level intensity in the scaffold-vessel compartment had strong correlation with the scaffold Mw: hyperechogenicity (correlation coefficient = 0.75; P

We aimed to investigate whether left ventricular (LV) twist analysis can detect the extent of myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM). This prospective case–control study recruited 81 consecutive patients with HCM examined between January 2012 and April 2013. Data of 76 patients were analyzed after excluding 5 patients whose echocardiographic images were of poor quality. Healthy volunteers (n = 46) served as controls. Both groups underwent comprehensive echocardiographic examination (i.e., Bas-Rotation, AP-Rotation, LVEF, LADs, IVST, LAVi, E/Em, LVMI, advanced LV-twist analysis by speckle tracking echocardiography) and magnetic resonance imaging. Between-group differences were analyzed by independent t test; logistic regression analysis was performed to identify effect factors. No significant differences were found between baseline characteristics of HCM and control groups (all p > 0.05). HCM patients had significantly higher Bas-Rotation, AP-Rotation, LV Twist, LVEF, LADs, IVST, LAVi, E/Em and LVMI than controls (all p

The bioresorbable vascular stent (BVS) is totally translucent and radiolucent, leading to challenges when using conventional invasive imaging modalities. Agreement between quantitative coronary angiography (QCA), intravascular ultrasound (IVUS) and optical coherence tomography (OCT) in the BVS is unknown. Forty five patients enrolled in the ABSORB cohort B1 study underwent coronary angiography, IVUS and OCT immediately post BVS implantation, and at 6 months. OCT estimated stent length accurately compared to nominal length (95% CI of the difference: −0.19; 0.37 and −0.15; 0.47 mm2 for baseline and 6 months, respectively), whereas QCA incurred consistent underestimation of the same magnitude at both time points (Pearson correlation = 0.806). IVUS yielded low accuracy (95% CI of the difference: 0.77; 3.74 and −1.15; 3.27 mm2 for baseline and 6 months, respectively), with several outliers and random variability test–retest. Minimal lumen area (MLA) decreased substantially between baseline and 6 months on QCA and OCT and only minimally on IVUS (95% CI: 0.11; 0.42). Agreement between the different imaging modalities is poor: worst agreement Videodensitometry-IVUS post-implantation (ICCa 0.289); best agreement IVUS-OCT at baseline (ICCa 0.767). All pairs deviated significantly from linearity (P

The purpose of this study was to compare the safety and efficacy of the short-acting β1-receptor blocker, landiolol hydrochloride (0.06 and 0.125-mg/kg), to placebo during coronary computed tomography angiography (CTA) in a phase 2 dose-finding study. A total of 183 patients suspected of having ischemic cardiac disease and scheduled to undergo an invasive coronary angiography were randomized to groups treated with landiolol hydrochloride (0.06 or 0.125-mg/kg) or placebo. The heart rate, safety, and the performance of coronary diagnosis using landiolol hydrochloride were evaluated in a multicenter, double-blind, randomized, parallel study. The patients’ heart rates during the coronary CTA were 67.6 ± 8.7 and 62.6 ± 7.8 beats/min in the 0.06 and 0.125-mg/kg landiolol hydrochloride groups, respectively, both of which were significantly lower than the heat rate of 73.7 ± 11.8 beats/min in the placebo group (P = 0.003 and P < 0.001, respectively). No adverse events or reactions occurred at an incidence of 5 % or greater, confirming the safety of landiolol hydrochloride. The proportion of correctly classified patients was significantly higher in the 0.125-mg/kg landiolol hydrochloride group than in the placebo group (73.6 vs. 50.0 %). Landiolol hydrochloride at doses of 0.06 and 0.125-mg/kg significantly decreased the heart rate compared with a placebo. The present findings suggest that landiolol hydrochloride is safe and useful at a dose of 0.125-mg/kg to improve coronary diagnostic performance during coronary CTA.

Plaque progression in atherosclerosis is closely connected to angiogenesis due to vasa vasorum (VV) growth. Objective of this study was to determine the unknown long-term effect of thalidomide on adventitial VV neovascularization and plaque progression using nano-focussed computed tomography (nano-CT). Proliferation and migration assays in human coronary artery endothelial cells (HCAEC) measured number of viable cells after incubation with thalidomide. Male ApoE(-/-)/LDLR(-/-) (AL) mice (n = 5) received a thalidomide containing western diet (WD) over 29 weeks. Another five male AL mice (WD without thalidomide) served as control group. Descending aortas were scanned with nano-CT at (1.5 μm)(3) isotropic voxel size. Number and area of adventitial VV as well as plaque cross sectional area were measured. Results were complemented by histology. Thalidomide inhibited proliferation and migration of HCAEC dose-dependently. VV neovascularization decreased in number per cross section (7.66 ± 0.301 vs. 8.62 ± 0.164, p 0.001) and in cross sectional area (0.0183 ± 0.0011 vs. 0.0238 ± 0.0008 mm(2), p 0.001). Cross sectional area of plaque decreased significantly when treated with thalidomide (0.57 ± 0.0187 vs. 0.803 ± 0.0148 mm(2), p 0.001). Nano-CT imaging revealed a reduced plaque growth and VV neovascularization after long-term application of thalidomide. Therefore, nano-CT can be considered as a new method to detect therapeutic effects in experimental models of atherosclerosis.

Knowledge about potential differences in infarct tissue characteristics between patients with prior life-threatening ventricular arrhythmia versus patients receiving prophylactic implantable cardioverter-defibrillator (ICD) might help to improve the current risk stratification in myocardial infarction (MI) patients who are considered for ICD implantation. In a consecutive series of (ICD) recipients for primary and secondary prevention following MI, we used contrast-enhanced (CE) cardiovascular magnetic resonance (CMR) imaging to evaluate differences in infarct tissue characteristics. Cine-CMR measurements included left ventricular end-diastolic and end-systolic volumes (EDV, ESV), left ventricular ejection fraction (LVEF), wall motion score index (WMSI), and mass. CE-CMR images were analyzed for core, peri, and total infarct size, infarct localization (according to coronary artery territory), and transmural extent. In this study, 95 ICD recipients were included. In the primary prevention group (n = 66), LVEF was lower (23 ± 9 % vs. 31 ± 14 %; P < 0.01), ESV and WMSI were higher (223 ± 75 ml vs. 184 ± 97 ml, P = 0.04, and 1.89 ± 0.52 vs. 1.47 ± 0.68; P < 0.01), and anterior infarct localization was more frequent (P = 0.02) than in the secondary prevention group (n = 29). There were no differences in infarct tissue characteristics between patients treated for primary versus secondary prevention (P > 0.6 for all). During 21 ± 9 months of follow-up, 3 (5 %) patients in the primary prevention group and 9 (31 %) in the secondary prevention group experienced appropriate ICD therapy for treatment of ventricular arrhythmia (P < 0.01). There was no difference in infarct tissue characteristics between recipients of ICD for primary versus secondary prevention, while the secondary prevention group showed a higher frequency of applied ICD therapy for ventricular arrhythmia.

This study was performed to characterize coronary plaque types by optical coherence tomography (OCT) and intravascular ultrasound (IVUS) radiofrequency (RF) data analysis, and to investigate the possibility of error reduction by combining these techniques. Intracoronary imaging methods have greatly enhanced the diagnostic capabilities for the detection of high-risk atherosclerotic plaques. IVUS RF data analysis and OCT are two techniques focusing on plaque morphology and composition. Regions of interest were selected and imaged with OCT and IVUS in 50 sections, from 14 human coronary arteries, sectioned post-mortem from 14 hearts of patients dying of non-cardiovascular causes. Plaques were classified based on IVUS RF data analysis (VH-IVUS(TM)), OCT and the combination of those. Histology was the benchmark. Imaging with both modalities and coregistered histology was successful in 36 sections. OCT correctly classified 24; VH-IVUS 25, and VH-IVUS/OCT combined, 27 out of 36 cross-sections. Systematic misclassifications in OCT were intimal thickening classified as fibroatheroma in 8 cross-sections. Misclassifications in VH-IVUS were mainly fibroatheroma as intimal thickening in 5 cross-sections. Typical image artifacts were found to affect the interpretation of OCT data, misclassifying intimal thickening as fibroatheroma or thin-cap fibroatheroma. Adding VH-IVUS to OCT reduced the error rate in this study.

Cardiovascular magnetic resonance (CMR) is a multi-parametric, multi-planar, non-invasive imaging technique, which allows accurate determination of biventricular function and precise myocardial tissue characterization in a one-stop-shop technique, free from the use of ionizing radiations. Though CMR has been increasingly applied over the last two decades in every-day clinical practice, its widest application has been in the assessment of ischemic cardiomyopathy.

Current guidelines for measuring cardiac function by tissue Doppler recommend using multiple beats, but this has a time cost for human operators. We present an open-source, vendor-independent, drag-and-drop software capable of automating the measurement process. A database of ~8000 tissue Doppler beats (48 patients) from the septal and lateral annuli were analyzed by three expert echocardiographers. We developed an intensity- and gradient-based automated algorithm to measure tissue Doppler velocities. We tested its performance against manual measurements from the expert human operators. Our algorithm showed strong agreement with expert human operators. Performance was indistinguishable from a human operator: for algorithm, mean difference and SDD from the mean of human operators’ estimates 0.48 ± 1.12 cm/s (R2 = 0.82); for the humans individually this was 0.43 ± 1.11 cm/s (R2 = 0.84), −0.88 ± 1.12 cm/s (R2 = 0.84) and 0.41 ± 1.30 cm/s (R2 = 0.78). Agreement between operators and the automated algorithm was preserved when measuring at either the edge or middle of the trace. The algorithm was 10-fold quicker than manual measurements (p

Over the past years cardiovascular magnetic resonance (CMR) imaging has been increasingly used to detect the presence of coronary artery disease and to assess its functional consequences to the myocardium [1]. Several approaches have been applied to detect coronary artery disease with CMR including direct visualization of coronary arteries and bypass grafts [2– 4] (magnetic resonance coronary angiography), the characterization of myocardial tissue [5–8] (delayed contrast enhancement) or the visualization of the effects of induced ischemia [9–17] (wall motion analysis or perfusion measurements). The latter is particularly valuable in clinical decision making since the detection of epicardial coronary luminal narrowing alone does not necessarily predict its hemodynamic consequences to the underlying myocardium. In the last decades, pharmacological stress has been extensively evaluated as an alternative stress method and is particularly advised to those patients who are not able to perform adequately either due to limited exercise capability or a disabling disease. With the development of rapid gradient systems and the routine application of advanced CMR scanner systems, it has become possible to perform cine imaging of the heart at rest and under stress conditions with CMR. Since space is limited within the MR scanner bore and patient movement impairs image quality, pharmacological stress is preferred for CMR imaging. Research efforts have been focused on the definition of the clinical role of magnetic resonance pharmacological stress for the detection of inducible wall motion abnormalities, preferably using dobutamine stress magnetic resonance (DSMR) [18–30]. High-dose DSMR proved to be highly accurate for the detection of inducible wall motion abnormalities and its usefulness for determination of patient prognosis has been shown [18–24]. DSMR at low-dose dobutamine levels was found to be highly predictive of functional improvement of resting wall motion abnormalities after coronary revascularization procedures (detection of viable myocardium) [25–27]. For induction of ischemic wall motion abnormalities, adenosine/dipyridamole or dobutamine are routinely used and the outcome is often considered alike and interchangeable. In a landmark study by Paetsch et al. [31], the results of a direct comparison of dobutamine stress CMR, adenosine stress CMR and adenosine stress CMR perfusion as assessed during a single, combined examination with all stress tests were evaluated against coronary angiography as the standard of reference. This study proved that dobutamine was superior to adenosine stress for the detection of inducible wall motion abnormalities related to the presence of epicardial coronary Editorial comment to the paper of Karamitsos et al. (doi: 10.1007/s10554-008-9392-3).

In the current issue of the International Journal of Cardiovascular Imaging, Worthley et al. performed a study in New Zealand White rabbits that were fed a 0.2% cholesterol-containing diet for 9 months [1]. At the end of this period a group of rabbits continued having this diet (progression group) for 6 months and a group of rabbits received a normal rabbit diet for 6 months (regression group). At the start of the experiment all rabbits underwent aortic denudation from the aortic arch to the iliac bifurcation by a Fogarty embolectomy catheter passing four times through the lumen from the aortic arch to the iliac bifurcation while inflated. Using fluoro-deoxyglucose positron emission tomography (FDG-PET) the authors imaged the macrophages in the aortic plaques at two moments i.e. at the end of the common 9 months period of 0.2% cholesterol-containing diet, and 6 months later at the end of the progression or regression period. Immediately prior to FDG-PET imaging, aortic localization was defined by cardiovascular magnetic resonance imaging (CMR). Thirty minutes after intravenous administration of FDG, a 30 minute emission scan was obtained. Uptake of FDG by the aortic wall was expressed as the ratio of aortic uptake/blood pool activity. Per aorta a total of 25 consecutive slices were obtained which were pairwise analyzed using the images taken at the start and at the end of the period under study. The results demonstrated a progressive increase in aortic FDG uptake in the progression group (from 0.57 to 0.68, P = 0.001) and a decrease of aortic FDG uptake in the regression group (from 0.67 to 0.53, P = 0.0001). Although these results provide highly significant results despite the low number of rabbits per group (n = 4 in progression and regression groups), the data representing the aortic uptake/blood pool activity obtained before and after the period under study show a broad overlap. Unfortunately, the graphs lack lines between the two values from the same rabbit. Secondly, it is regrettable that the initial values of aortic uptake/blood pool activity of the rabbits in the progression and the regression groups differ from each other, while both groups had the same atherogenic diet for 9 months. Nevertheless, this study is important for several reasons: first—as a proof of concept -, in vivo FDGPET imaging of large vascular structures that are subject to an atherogenic stimulus or relieved from an atherogenic stimulus appears feasible; second, since macrophages are primarily responsible for the FDG uptake in the atherosclerotic aortic wall [2, 3], in vivo FDG-PET imaging of a large artery provides Editoral comments on the paper of Worthley et al. entitled ‘‘In vivo noninvasive serial monitoring of FDG-PET progression and regression in a rabbit model of atherosclerosis’’ (doi:10.1007/s10554-008-9377-2).

Characterization of atherosclerotic plaques in the coronary, carotid or peripheral arteries in vivo is clinically highly relevant. In particular, identification of vulnerable plaques is of utmost importance because of the high risk to precipitate acute thrombotic occlusion [1, 2]. Several techniques are being used nowadays to define the pathology of coronary plaques such as cardiovascular magnetic resonance imaging (CMR) [3–6], intravascular ultrasound (IVUS) [7], optical coherence tomography [8], and multi-slice computed tomography (MSCT) [9–11]. The latter technique combines a number of advantages, such as noninvasiveness and rapid testing, but the downside is that patients are exposed to high levels of radiation. However, recent MSCT systems that have become available, operate at high speed thereby limiting the radiation burden. When looking at the algorithms for dose reduction, the use of ECG pulsing, a reduced tube voltage of 100 kV, and the sequential scan mode are independent predictors for a reduced dose. The effect of the sequential scan mode is largest, followed by the reduced tube voltage of 100 kV. In the paper recently published by de Weert and colleagues [12], the human atherosclerotic carotid plaque is recorded in vivo by MSCT, and analyzed off-line to determine plaque volume and composition. Secondly, the inter-observer variability has been determined. Four patient groups were included in the study, categorized by their carotid artery stenosis grade: 0–29%, 30–49%, 50–69%, and 70–99%. By manually drawing regions of interest (ROI) the pixel intensities within a ROI were divided into three categories: lipid core 130 HU. Before consensus was reached with regard to the lesion length, location of bifurcation and lumen attenuation, inter-observer differences and coefficients of variation (COV) were quite high and interclass correlation coefficients (ICC) were quite low. But if consensus was reached with regard to the lesion length, location of bifurcation and lumen attenuation, inter-observer differences and COV decreased, and ICC increased, to reach values almost similar to those observed after analysis of intra-observer differences. The problems encountered with this technique are: (1) how to differentiate between a normal arterial wall and a slightly thickened arterial wall, (2) how to outline reliably the outer border of the artery where adventitial fat should not be confused with atheromatous lipid in the plaque, and (3) how to differentiate the contrast-enhanced lumen from atherosclerotic plaque. Although the present study lacks validation with histopathological techniques, previous studies of the same group have shown a good correlation between area measurements of arteries recorded by MSCT and histology [13, 14]. The use of MSCT for quantitative assessment of atherosclerotic lesion severity of large arteries in terms of fibrous tissue, lipid, and calcifications will contribute to the rapidly increasing popularity of examinations with MSCT.

Hereditary haemochromatosis is autosomal recessive disorder associated with the HLA-A locus on the short arm of chromosome 6 [1]. It is the most common genetic disorder worldwide [2]. About 56,000 babies are born each year with thalassaemia major, of whom 30,000 require lifelong transfusions to survive [3]. The disease is very prevalent in European countries along the Mediterranean Sea and in South East Asia. In other countries it becomes a problem because of immigration from these areas. Excessive iron deposition occurs mostly in the pancreas, pituitary, but also in the heart. In normal subjects, absorption of iron from the gut is inversely correlated with iron stores. In homozygous hereditary haemochromatosis there is increased absorption of iron, which is not regulated by iron stores [4]. This leads to progressive iron accumulation because there is no normal mechanism for excretion of excess iron once it has been absorbed into the body. The clinical manifestations of iron overload include liver disease in 75% of cases, weakness and lethargy in 74%, skin hyperpigmentation in 70%, diabetes mellitus in 48%, arthralgia in 44%, impotence in 45%, electrocardiographic abnormalities in 31% and heart failure and conduction disturbances in 15% [5, 6]. Heart failure remains a major cause of death in these patients, frequently people younger than 35 years [7]. In the majority of patients iron induced cardiomyopathy can be reversed by intense chelation therapy with desferrioxamine and deferiprone [3, 8]. At this moment T2* magnetic resonance imaging is the best way for early detection of iron overload in patients with haemochromatosis [9–11]. T2* is an unique magnetic resonance parameter measured in milliseconds and shortened in relation to the level iron in the heart. The parameter can be used for screening haemochromatosis patients and to guide chelation therapy in those with established cardiac haemochromatosis [8]. The paper of Mavrogeni et al. [12] in this issue of the International Journal of Cardiac Imaging shows, that heart failure patients with severe iron overload indicated by a T2* value less than 10 ms had a lower exercise capacity than patients with a T2* value higher than 10 ms. The authors also show, that there was a excellent relation of the extent of iron overload measured by T2* and exercise tolerance in thalassemia patients. As shown by others, thalassemia patients present prolonged phase II on-transient oxygen kinetics during submaximal, constant workload exercise, compared with healthy controls, possibly suggesting a slower rate of high energy phosphate production and utilization and reduced oxidative capacity of myocytes [13]. This could also account for their significantly limited exercise tolerance. Reduction of exercise tolerance is also s highly associated with the limited functional status of peripheral muscles in these patients [14]. This study shows again that T2* MRI plays a crucial role in screening cardiac haemochromatosis and guidance of chelation therapy. Early detection of cardiac iron load and early initiation of treatment are crucial for survival of these patients. Recently the chelator deferasirox has been shown to be more effective in better at improving myocardial iron [15]. This could improve outcome in thalassemia patients. As shown, early effects of therapy can only be detected with dedicated MRI sequences. Unfortunately these MRI scanners are not always available in those areas, where the prevalence of haemachromatosis patients is extremely high.