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Background Animal studies demonstrated that serelaxin lessens fibrosis in heart failure. This study assessed its effect on myocardial deformation using cardiac magnetic resonance and elucidated its relationship to gene regulation and histology in a mouse heart failure model. Methods and Results C57 BL /6J mice were subjected to SHAM (n=4) or transverse aortic constriction ( TAC ). At week 10, TAC mice were randomized to receive either serelaxin (0.5 mg/kg per day; n=11) or vehicle (n=13) for 4 weeks. Cardiac magnetic resonance imaging was performed at baseline and repeated at the end of the study (week 14). Cine images were used to calculate left ventricular ( LV ) global longitudinal, circumferential, and radial strain. Hearts were examined for histology and gene expression. Compared with SHAM , mice 10 weeks after TAC showed increased LV mass with significant decreases in LV deformation parameters, indicating subclinical deterioration of myocardial function. At week 14, TAC mice given serelaxin demonstrated significant improvements in all LV strain parameters and no decrease in LV stroke volume and ejection fraction compared with TAC mice given vehicle. A significant positive correlation between global circumferential strain and the extent of myocardial fibrosis was found, and global circumferential strain correlated significantly with the expression of heart failure genes in serelaxin‐treated mice. Conclusions Serelaxin improved cardiac magnetic resonance–derived myocardial deformation parameters as well as histomorphometric and gene expression findings in mice with heart failure. Cardiac magnetic resonance–derived myocardial mechanics correlate with histology and gene expression, stressing its utilization in myocardial remodeling.

Aims The effectiveness of stress cardiac magnetic resonance (CMR) as a gatekeeper for coronary angiography (CA) has been established. Level five HTA studies according to the hierarchical model of diagnostic test evaluation are not available. Methods This cohort study included 1,158 consecutive patients (mean age 63 ± 11 years, 42 % women) presenting at our institution between January 1, 2003 and December 31, 2004 with suspected coronary artery disease (CAD) for an elective CA. The patients were assessed for eligibility and propensity score matching was applied to address selection bias regarding the patients’ allocation to CMR or direct CA. Median patient follow-up was 7.9 years (95 % CI 7.8–8.0 years). The primary effect was calculated as relative survival difference. The cost unit calculation (per patient) at our institute was the source of costs. Results Survival was similar in CMR and CA (p = 0.139). Catheterizations ruling out CAD were significantly reduced by the CMR gate-keeper strategy. Patients with prior CMR had significantly lower costs at the initial hospital stay and at follow-up (CMR vs. CA, initial: 2,904€ vs. 3,421€, p = 0.018; follow-up: 2,045€ vs. 3,318€, p = 0.037). CMR was cost-effective in terms of a contribution of 12,466€ per life year to cover a part of the CMR costs. Conclusion Stress CMR prior to CA was saving 12,466€ of hospital costs per life year. Lower costs at follow-up suggest sustained cost-effectiveness of the CMR-guided strategy. Electronic supplementary material The online version of this article (doi:10.1007/s00392-014-0793-0) contains supplementary material, which is available to authorized users.

This study tests the correlation of coronary angiographic findings with the extent of microvascular reaction in right ventricular endomyocardial biopsies (EMBs) in transplanted hearts. In EMBs (n = 209) of 30 heart transplant patients (8 female, 22 male, mean age 48 years) microvascular reaction, i.e. endothelial cell swelling and vascular wall thickening (both grade 0-2), was graded by light microscopy at ×200. Patients' first and last coronary angiography (CA) (mean time after heart transplantation [HTx] 8 and 44 months) were graded according to the Stanford Classification and the presence of diameter irregularities was evaluated semi-quantitatively. We found a correlation of angiographic type B lesions with endothelial cell swelling during the first 5 months and vascular wall thickening during the fifth to fourteenth month after HTx (p

ObjectivesThe aim of this study was to assess the long-term value of high-dose dobutamine cardiac magnetic resonance (DCMR) for the prediction of cardiac events in a large cohort of patients with known or suspected coronary artery disease.BackgroundHigh-dose DCMR has been shown to be a useful technique for diagnosis and intermediate-term prognostic stratification.MethodsClinical data and DCMR results were analyzed in 1,463 consecutive patients undergoing DCMR between 2000 and 2004. Ninety-four patients were lost to follow-up. The remaining 1,369 patients were followed up for a mean of 44 ± 24 months. Cardiac events, defined as cardiac death and nonfatal myocardial infarction, were related to clinical and DCMR results.ResultsThree-hundred fifty-two patients underwent early revascularization (≤3 months of DCMR) and were excluded from analysis. Of the remaining 1,017 patients, 301 patients (29.6%) experienced inducible wall motion abnormalities (WMA). Forty-six cardiac events were reported. In those with and without inducible WMA, the proportion of patients with cardiac events was 8.0% versus 3.1%, respectively, p = 0.001 (hazard ratio: 3.3; 95% confidence interval: 1.8 to 5.9 for the presence of inducible WMA; p < 0.001). A DCMR without inducible WMA carried an excellent prognosis, with a 6-year cardiac event-free survival of 96.8%. In all 1,369 patients in the patient group with stress-inducible WMA, those patients with medical therapy demonstrated a trend to a higher cardiac event rate (8.0%) than those with early revascularization (5.4%) (p = 0.234). Patients with normal DCMR and medical therapy or early revascularization demonstrated similar cumulative cardiac event rates (3.1% vs. 3.2%, p = 0.964).ConclusionsIn a large cohort of patients, DCMR has an added value for predicting cardiac events during long-term follow-up, improving the differentiation between high-risk and low-risk patients. Patients with inducible WMA and following early revascularization, demonstrate lower cardiac event rates than patients with medical therapy alone.

Objectives The purpose of the present study was to directly compare the diagnostic accuracy of magnetic resonance imaging (MRI) and multislice computed tomography (CT) for the detection of coronary artery stenosis. Background Both imaging modalities have emerged as potential noninvasive coronary imaging modalities; however, CT—unlike MRI—exposes patients to radiation and iodinated contrast agent. Methods One hundred twenty consecutive patients with suspected or known coronary artery disease prospectively underwent 32-channel 3.0-T MRI and 64-slice CT before elective X-ray angiography. The diagnostic accuracy of the 2 modalities for detecting significant coronary stenosis (≥50% luminal diameter stenosis) in segments ≥1.5 mm diameter was compared with quantitative invasive coronary angiography as the reference standard. Results In the patient-based analysis MRI and CT angiography showed similar diagnostic accuracy of 83% (95% confidence interval [CI]: 75 to 87) versus 87% (95% CI: 80 to 92), p = 0.38; sensitivity of 87% (95% CI: 76 to 93) versus 90% (95% CI: 80 to 95), p = 0.16; and specificity of 77% (95% CI: 63 to 87) versus 83% (95% CI: 70 to 91), p = 0.06, respectively. All cases of left main or 3-vessel disease were correctly diagnosed by MRI and CT angiography. In the patient-based analysis MRI and CT angiography were similar in their ability to identify patients who subsequently underwent revascularization: the area under the receiver-operator characteristic curve was 0.78 (95% CI: 0.69 to 0.87) for MRI and 0.82 (95% CI: 0.74 to 0.90) for CT angiography. Conclusions Thirty-two channel 3.0-T MRI and 64-slice CT angiography similarly identify significant coronary stenosis in patients with suspected or known coronary artery disease scheduled for elective coronary angiography. However, CT angiography showed a favorable trend toward higher diagnostic performance.

We compared coronary magnetic resonance angiography (CMRA) and coronary multislice computed tomography angiography (CTA) for prediction of cardiac events in patients with suspected or known coronary artery disease (CAD) scheduled for elective coronary angiography (ICA). We included 110 consecutive

Summary Angiograms of cardiac transplant (HTx) recipients were to be evaluated in a ring experiment and a joint consensus on criteria of angiographic evaluation of coronary arteries of HTx patients was to be reached. Twenty-four coronary angiograms from 11 hospitals were circulated. One hundred eighty-eight blinded evaluations were returned. A joint evaluation by six experienced cardiologists was used as reference standard and a consensus evaluation form was developed. Significant lesions (stenosis 75%, 50% in the left main coronary artery) were diagnosed in 10/23 abnormal coronary angiograms (41.7%). Interventional revascularization was recommended in 8/10 (80%). In 21 coronary angiograms distal pruning was found and in 11/21 (52.4%) cases with distal pruning occlusion of at least one peripheral vessel was detected. The best kappa value (0.7) was found for the presence of at least one clinically significant stenosis. Agreement on the site and grade of local stenosis was much less. Some agreement on remodeling was found in assessing diffuse narrowing in the LCA (kappa = 0.371, P

Purpose To define the reproducibility of strain-encoded (SENC) magnetic resonance imaging (MRI) for assessment of regional left ventricular myocardial strain and timing of contraction in a 3T MRI system. Materials and Methods The study population consisted of 16 healthy subjects. SENC measurements were performed in three short-axis (SA) slices (apical, mid, and basal) and three long-axis (LA) views (two-, three-, and four-chamber) for assessment of maximal transmural systolic strain and time to peak strain. To assess the interobserver and interstudy reproducibility, analysis of SENC MRI was performed by two independent observers who were blinded to each other's results and four studies were repeated on a different day. Results Maximal longitudinal strain was highest at the apex, as was maximal circumferential strain. Peak longitudinal strain occurred earliest at the base, as did peak circumferential strain. Interclass correlation coefficient between observers and repeated studies ranged from 0.92 to 0.98 (P < 0.001 for all). Conclusion The present study demonstrates the ability of SENC MRI to define regional left ventricular strain and the time sequence of regional strain. SENC MRI may represent a highly objective method for quantifying regional left ventricular function. J. Magn. Reson. Imaging 2009;29:799–808. © 2009 Wiley-Liss, Inc.

AimTo study the effects of RD on renal artery wall function non-invasively using magnetic resonance.Methods and results32 patients undergoing RD were included. A 3.0 Tesla magnetic resonance of the renal arteries was performed before RD and after 6-month. We quantified the vessel sharpness of both renal arteries using a quantitative analysis tool (Soap-Bubble®). In 17 patients we assessed the maximal and minimal cross-sectional area of both arteries, peak velocity, mean flow, and renal artery distensibility. In a subset of patients wall shear stress was assessed with computational flow dynamics. Neither renal artery sharpness nor renal artery distensibility differed significantly. A significant increase in minimal and maximal areas (by 25.3%, p = 0.008, and 24.6%, p = 0.007, respectively), peak velocity (by 16.9%, p = 0.021), and mean flow (by 22.4%, p = 0.007) was observed after RD. Wall shear stress significantly decreased (by 25%, p = 0.029). These effects were observed in blood pressure responders and non-responders.ConclusionsRD is not associated with adverse effects at renal artery level, and leads to an increase in cross-sectional areas, velocity and flow and a decrease in wall shear stress.

Background— Epicardial vasculopathy has been shown to be associated with poor outcome after heart transplantation. We demonstrate that histologically proven stenotic microvasculopathy is a novel prognostic factor for long-term survival. Methods and Results— In 9713 biopsies harvested within the first posttransplantation year from 873 patients (83% male; mean age, 49.1±0.6 years), light microscopic evaluations (×200) were performed for microvasculopathy, defined as stenotic endothelial and/or medial disease. Prevalence of severe epicardial vasculopathy was defined by presence of ≥75% luminal stenosis in coronary angiography (available in 611 of 873 patients), which was present in 118 of 611 patients (19%). For Kaplan-Meier analysis, we defined fatal cardiac events as lethal acute myocardial infarction, sudden cardiac death, and graft failure. Stenotic microvasculopathy was present in 379 of 873 patients (43%) and was due to medial (345/379; 91%) rather than endothelial disease (2/379; 1%) or a combination of both (31/379; 8%; P P =0.3329) and nonstenotic medial disease (12.44 [11.14 to 13.74] versus 12.43 years [10.51 to 14.35]; P =0.4047) did not decrease overall survival or time to fatal cardiac event. Stenotic microvasculopathy was associated with poor overall survival (10.90 [9.16 to 12.60] versus 13.40 years [11.79 to 15.07]; P =0.0374) and decreased freedom from fatal cardiac events (1, 5, 10 years, 95.6±1.4%, 86.9±2.3%, 75.5±3.1% versus 99.1±0.5%, 96.8±1.0%, 89.8±1.9%; P P =0.0031). Conclusions— Stenotic microvasculopathy is frequent in routinely processed biopsies and a new prognostic factor for long-term survival after heart transplantation.

Insulin resistance plays a crucial role in the development of type 2 diabetes. Insulin receptor signalling is antagonized and tightly controlled by protein tyrosine phosphatases (PTPs). However, the precise role of the PTP src homology 2 domain-containing phosphatase 1 (SHP-1) in insulin resistance has not been explored. Male C57BL/6J mice were fed a high-fat diet (HFD, 60% kcal from fat), to induce insulin resistance, or a low-fat diet (LFD, 10% kcal from fat) for 10 weeks. Afterwards, HFD-fed mice were pharmacologically treated with the SHP-1 (Ptpn6) inhibitor sodium stibogluconate and the broad spectrum pan-PTP inhibitor bis(maltolato)oxovanadium(IV) (BMOV). Both inhibitors ameliorated the metabolic phenotype, as evidenced by reduced body weight, improved insulin sensitivity and glucose tolerance, which was not due to altered PTP gene expression. In parallel, phosphorylation of the insulin receptor and of the insulin signalling key intermediate Akt was enhanced, and both PTP inhibitors and siRNA-mediated SHP-1 downregulation resulted in an increased glucose uptake in vitro. Finally, recombinant SHP-1 was capable of dephosphorylating the ligand-induced tyrosine-phosphorylated insulin receptor. These results indicate a central role of SHP-1 in insulin signalling during obesity, and SHP-1 inhibition as a potential therapeutic approach in metabolic diseases.

Information regarding the flow properties in bubble columns with a three-phase flow is of great interest for research into its performance, as well as for the validation of computer models. In an earlier paper, we proposed an X-ray based particle tracking velocimetry (PTV), called XPTV. This method allows not only the measurement of the velocities of both solid and fluid phases in a three-phase flow, but also the assessment of the time-averaged local solid phase content. In this paper, we are concerned with the statistical significance of the obtained measurements.

Information regarding the flow in multi-phase systems, such as bubble columns, is necessary for the design of improved devices, as well as for the validation of computer models. Common optical methods are limited in bubble columns with a large void fraction. The reason that this should be is the difference in the refraction indices of liquid and gaseous phases, which leads to reflection and refraction of light. In addition, in flows without optical access, optical methods cannot be used. The method proposed by these authors in their previous paper regarding X-ray based particle tracking velocimetry (PTV)–called XPTV–resolves these problems. It allows us to measure the velocity three-dimensionally, non-invasive, and in devices without optical access. In bubble columns, X-rays are neither reflected nor refracted at the phase boundaries and the flow is penetrated in straight lines. Therefore, it works independently from the void fraction. This has been proved to be a reliable and useful measurement technique, circumventing the limitations of optical methods. This paper reports the latest improvements in the algorithms designed to track and reconstruct particles, a feature which is explained here in detail. The improved algorithms are applied to measure the hydrodynamic parameters in a bubble column under two different flow conditions.

Background Mortality in severe congestive heart failure rises with the incidence of an inter- and intraventricular conduction delay and doubles if atrial fibrillation (AF) occurs. Electrical cardioversion (CV) is frequently regarded as less promising in these patients. Encouraged by first conversions during defibrillation threshold (DFT) testing we consecutively attempted electrical cardioversion in 30 patients selected for cardiac resynchronization therapy (CRT). Methods After successful CV an additional atrial electrode was placed during implantation of a CRT device (ICD or pacemaker) to ensure AV sequential biventricular pacing. Regular clinical follow-up examinations up to 2 years were performed. Results In 23 (75%) of 30 patients (onset of AF at least 6 months earlier), sinus rhythm (SR) could successfully be restored. Under antiarrhythmic medication in 21 patients SR was still present after 333±142 days. Furthermore, a significant increase of EF from 22% to 31% (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(P{

Aims: The scope of this study was to assess the potential value of pulmonary venous flow diastolic deceleration time to predict end-diastolic pressure and stratify patients with regard to elevation of left ventricular end-diastolic pressures. Methods and Results: In 174 consecutive patients, pulmonary venous flow diastolic deceleration time was determined and compared with left ventricular end-diastolic pressures measured invasively. The sample was randomly divided into two subgroups of equal size for modelling of prediction and independent testing of the model. Predicted left ventricular end-diastolic pressures calculated from pulmonary venous flow diastolic deceleration time (left ventricular end-diastolic pressures = −10.87 + 5261/pulmonary venous flow diastolic deceleration time) agreed well with measured left ventricular end-diastolic pressures (mean difference: -1.3 ± 3.4 mmHg). The correlation of left ventricular end-diastolic pressures with pulmonary venous flow diastolic deceleration time is fair (r=0.73989). A value of pulmonary venous flow diastolic deceleration time

The measurement of the local solid velocity and the local solid hold-up in three-phase flows (gas, liquid, solid) is of great interest with regard to the design of three-phase reactors. Moreover, such measurements are necessary for the validation of flow simulations of three-phase flows. The optical methods usually applied for velocity measurements such as particle image velocimetry do not work in three-phase flows. This is due to the opacity of the solid phase or/and because of the reflections and refractions that occur on phase boundaries. Other measurement methods are intrusive and very time consuming. The measurement of the local solid hold-up is even more difficult. The new X-ray based particle tracking velocimetry (XPTV), described in this paper, measures the solid velocity and the solid content simultaneously. This fast working and non-intrusive technique has already been successfully applied in a bubble column to measure the liquid velocity. XPTV is a three-dimensional three-component method. It works independently from void fraction and solid hold-up.

Introduction: Pulmonary vein isolation (PVI) has been established as effective interventional treatment in chronic atrial fibrillation (AF). Impairment of left atrial strain is considered a surrogate parameter of fibrosis. There is considerable variance of strain among different atrial wall segments. We hypothesized that early impairment of strain affects mobile segments and thus reduces inter-segmental variance of strain. Methods: We evaluated 89 consecutive PVI patients and 28 controls (mean age 60 ± 12 y, 33 female). The longitudinal strain of the left atrium in a 4-chamber apical window was determined by speckle tracking (Philips IE33 offline analysis by QLAB™). Success was defined as maintenance of sinus rhythm until last follow-up (minimum 3 months elapsed since PVI). Follow-up comprised repeated Holter-monitoring and echocardiography. Variance was evaluated as standard deviation of segmental strain before PVI (STD). Results: Atrial fibrillation recurred in 40 of 89 patients. STD was 16.5±7.9 in controls, 8.1±5.3 in PVI with persisting success and 4.6±2.2 in late PVI failure (see also box-plot). The group differences between controls, PVI success and PVI failure were all significant (p Conclusions: Standard deviation of segmental left atrial strain is impaired in patients treated by pulmonary vein isolation with late failure and should be further evaluated as predictor for recurrence.

Aims We sought to evaluate the impact of ischemic burden for the prediction of hard cardiac events (cardiac death or nonfatal myocardial infarction) in patients with known or suspected CAD who undergo dobutamine stress cardiac magnetic resonance imaging (DCMR) Methods We included 3166 patients (pts.), mean age 63±12 years, 27% female, who underwent DCMR in 3 tertiary cardiac centres (University Hospital Heildelberg, German Heart Institute and Kings College London). Pts. were separated in groups based on the number of ischemic segments by wall motion abnormalities (WMA) as follows: 1. no ischemic segment, 2. one ischemic segment, 3. two ischemic segments and 4. ≥three ischemic segments. Cardiac death and nonfatal myocardial infarction were registered as hard cardiac events. Pts. with an “early” revascularization procedure (in the first three months after DCMR) were not included in the final survival analysis. Results Pts. were followed for a median of 3.1 years (iqr 2–4.5 years). 187 (5.9%) pts. experienced hard cardiac events. 2349 (74.2%) had no inducible ischemia, 189 (6%) had ischemia in 1 segment, 292 (9.2%) in 2 segments and 336 (10.6%) ≥3 segments. Patients with only 1 ischemic segment showed a high rate of hard cardiac events of ∼6% annually, which was 10-fold higher compared to those without ischemia (0.6% annually, p

Aims: Goals of the study were the assessment of the correlation between flow-dependent and contrast-related vasodilatation, comparison of iodixanol to iopromide and evaluation of the impact of plaque on vasodilatation in coronary arteries. Methods and Results: A controlled randomized paired cross-over comparison between iodixanol (320 mg I.ml-1) and iopromide (300 mg I.ml−1) was performed in 10 consecutive patients. Vessel area (Visions Five-64 F/X™ intra-vascular ultrasound-catheter, Endosonics® and blood flow velocity measurements (0.014 inches Doppler guide wire, Cardiometrics®) were recorded simultaneously at an identical position, at baseline, after i.c. bolus injection of 10 ml physiologic saline (flow-dependent vasodilatation), and after application of contrast agent 1 and contrast agent 2 as randomized. The action of iodixanol and iopromide on the vascular wall did not differ and was equal to local flow-dependent vasodilatation induced by a saline bolus (correlation 0·95– 0·98). The increase in local luminal area after injection of saline, iodixanol and iopromide in morphologically normal vessels (∼2·5 mm2) was absent in atherosclerotic segments. Both contrast agents and saline demonstrated a nearly identical flow increase. Conclusion: If iodixanol or iopromide are used as contrast agents, contrast-related vessel area increase in vivo seems to be endothelium-dependent.

Information regarding the local liquid velocity in bubble columns is of great interest for research into its performance. Common optical methods fail in bubble flows that have large void fractions because of the different refraction indices of the liquid and gaseous phases. The new X-ray particle tracking velocimetry (XPTV) described here solves the problem by the use of X-rays instead of light. X-rays penetrate a gas/liquid flow in straight lines. XPTV enables us to measure the three-dimensional velocity of the liquid phase. This method was applied and validated in two bubble columns. The same method is also applicable to opaque liquids.

renal perfusion may result from a reduction of mean Background. Changes in renal blood flow are considered to arterial blood pressure (MABP) or decreased cardiac outplay a significant role in the induction and maintenance of put or may be due to renal vasoconstriction. The combinakidney failure, but are difficult to monitor with currently availtion of moderately reduced perfusion pressure and inable techniques. The objective was to validate renal flow measurements with Doppler guidewires and to apply this technique creased renal vascular resistance (RVR) is believed to to assess dose and time dependency of the renal vascular effects promote renal failure in patients with sepsis [2] or hepatoof norepinephrine (NE). renal syndrome [3]. The adverse effects of several “nephMethods. In 10 anesthetized pigs, flow velocity in renal arter- rotoxic” agents, including contrast media, on kidney ies (FVart) and veins (FVvein) and volumetric renal blood function are also considered to be partially due to a flow (VBF) were measured before and after intravenous bolus application of incremental doses of NE (2 to 200 mg). temporary reduction in RBF [1]. Some studies have indiResults. FVart curves exactly reflected the changes in VBF. cated that a reduction in RBF persists during the course Beat-to-beat analysis revealed a strong linear correlation over of ARF [4, 5], while others have reported that RBF is a mean VBF range of less than 0.05 to 0.35 L/min (median not an important determinant of the glomerular filtration correlation coefficient with FVart, r 5 0.998), and significant rate (GFR) depression during the maintenance phase of but less close relationships were also found between VBF and FVvein. Ten seconds after the administration of 200 mg NE, postischemic ARF [6, 7]. Therefore, in different clinical FVart dropped from 71 to 6 cm/sec and was 90% reversible situations, monitoring of renal perfusion may be releafter 48 seconds. Similarly, the renal vascular resistance tempo- vant, not only to characterize further the association rarily rose from 988 to 13711 mm Hg · min/L. In contrast, between changes in renal hemodynamics and GFR, but NE-induced increases in systemic vascular resistance were on average a maximum of 1.5-fold but persisted for more than 60 also to identify and prevent ischemic insults to the seconds. kidney. Conclusions. Doppler flow measurements in the renal artery Currently available methods for the measurement of provide an excellent surrogate of volumetric blood flow, which RBF in humans have been useful to detect RBF abnormay be useful for continuous monitoring of renal hemodynammalities in various settings, but are characterized by sevics. The renal vasculature is more sensitive when compared with the systemic vasculature, but also appears to evoke more eral methodological problems that limit their accuracy efficient counter-regulatory mechanisms in response to NE. and applicability. The urinary clearance of p-aminohippurate (PAH) [8] cannot be applied to oligo-anuric subjects, and in postischemic renal failure, PAH extraction A reduction in renal blood flow (RBF) commonly is severely impaired so that the PAH clearance markedly occurs in association with renal dysfunction and can cause underestimates renal plasma flow [6]. Dye dilution techkidney failure. In acute renal failure (ARF), renal hypo- niques require the simultaneous catheterization of the renal artery and vein and allow only bolus measurements [9]. For isotope techniques, the need for external count

Endovascular stent placement for treatment of symptomatic pseudoaneurysms in extracranial carotid arteries proved safe and effective. We aimed at increasing the efficacy of stenting for treatment of an internal carotid artery (ICA) dissecting aneurysm by reducing the stent porosity through placement of oversized overlapping stents. A 55-year-old woman presented with right sided hemiplegia and aphasia. CT revealed an infarction in the left hemisphere, and cerebral angiography showed an extracranial dissection of the left ICA with a 1.0 × 2.0 cm pseudoaneurysm at the C1-level. Two oversized self-expandable stents (8/30, 8/40 Wallstent) were placed, bridging the dissected segment and overlapping at the level of the aneurysmal neck. Immediate control angiography showed remarkably reduced filling of the pseudoaneurysm. Intravascular flow assessment depicted a significant reduction of intraaneurysmal flow (31/0 cm/s). Follow-up arteriograms performed after six days and nine months confirmed complete disappearance of the pseudoaneurysm and a patent vessel lumen. Reduced stent porosity causes significant haemodynamic changes inside the aneurysmal sac and accelerates intraaneurysmal thrombosis. Deployment of oversized and overlapping stents may be helpful in achieving rapid complete occlusion and avoiding additional coil packing.

Two different models of the blood flow are dealt with in this paper: one model is based on vessel casts, the other is based on angiograms. In both models the threedimensional geometry of the vessel is reconstructed. This geometry is the basis for the subsequent computation of the blood flow. This computation renders the flow in the lumen, but more important, the flow at the vessel wall and thus delivers the wall shear stress. This latter parameter is known to be of great influence for various pathological alterations of the vessel wall.

The aim of this study was to evaluate two different magnetic resonance (MR) techniques for the noninvasive assessment of intracoronary blood flow. Coronary blood flow velocities were measured invasively in 26 angiographically normal segments of 12 patients. Noninvasive measurements were performed in identical segments with two MR techniques using a 1.5 T MR tomograph (ACS NT, Philips). A single breath-hold technique (temporal resolution: 140 msec) and a similar non-breath-hold technique with prospective navigator correction and improved temporal resolution (45 msec) were used. Maximal coronary flow velocities determined by MR correlated closely with invasive measurements (breath-hold: r = 0.70; navigator: r = 0.86); however, a significant underestimation of the MR measurements was found (slope = 0.33 and 0.37). The relative difference from the invasive method was lower for the navigator technique compared with the breath-hold technique (P < 0.02). Both MR techniques allow the determination of coronary blood flow velocities. The higher temporal resolution and shorter acquisition window of navigator-corrected non-breath-hold techniques lead to increased accuracy. This approach is a further step toward the diagnostic use of MR flow measurements in coronary artery disease. Magn Reson Med 41:544–549, 1999. © 1999 Wiley-Liss, Inc.

Aims Sympathetic stimulation induces left ventricular hypertrophy and is associated with increased cardiovascular risk. Catheter-based renal denervation (RDN) has been shown to reduce sympathetic outflow and blood pressure (BP). The present multi-centre study aimed to investigate the effect of RDN on anatomic and functional myocardial parameters, assessed by cardiac magnetic resonance (CMR), in patients with resistant hypertension. Methods and results Cardiac magnetic resonance was performed in 72 patients (mean age 66 ± 10 years) with resistant hypertension (55 patients underwent RDN, 17 served as controls) at baseline and after 6 months. Clinical data and CMR results were analysed blindly. Renal denervation significantly reduced systolic and diastolic BP by 22/8 mm Hg and left ventricular mass index (LVMI) by 7.1% (46.3 ± 13.6 g/m1.7 vs. 43.0 ± 12.6 g/m1.7, P < 0.001) without changes in the control group (41.9 ± 10.8 g/m1.7 vs. 42.0 ± 9.7 g/m1.7, P = 0.653). Ejection fraction (LVEF) in patients with impaired LVEF at baseline (

Background Matrix metalloproteinase (MMP)-dependent extracellular matrix (ECM) remodeling is a key feature in cardiometabolic syndrome-associated adipogenesis and atherosclerosis. Activation of membrane-tethered (MT) 1-MMP depends on furin (PCSK3). However, the regulation and function of the natural furin-inhibitor serpinB8 and thus furin/MT1-MMP-activity in obesity-related tissue inflammation/remodeling is unknown. Here we aimed to determine the role of serpinB8/furin in obesity-associated chronic inflammation. Methods and Results Monocyte → macrophage transformation was characterized by decreases in serpinB8 and increases in furin/MT1-MMP. Rescue of serpinB8 by protein overexpression inhibited furin-dependent pro-MT1-MMP activation in macrophages, supporting its role as a furin-inhibitor. Obese white adipose tissue-facilitated macrophage migration was inhibited by furin- and MMP-inhibition, stressing the importance of the furin-MMP axis in fat tissue inflammation/remodeling. Monocytes from obese patients (body mass index (BMI) >30kg/m2) had higher furin, MT1-MMP, and resistin gene expression compared to normal weight individuals (BMI

To the Editor: In the present study we sought to investigate the predictive value of resting and inducible wall motion abnormalities (WMA) and of late gadolinium enhancement (LGE) for hard cardiac outcomes and for revascularization procedures in 3,138 patients undergoing dobutamine cardiac magnetic

The aim of this study was to assess the prognostic value of dobutamine stress cardiovascular magnetic resonance (DCMR) in patients with previous myocardial revascularization. The role of DCMR in the risk stratification of patients with previous coronary revascularization has not been well defined.

Coronary vessel distensibility is reduced with atherosclerosis and normal aging, but direct measurements have historically required invasive measurements at cardiac catheterization. Therefore, we sought to assess coronary artery distensibility noninvasively using 3.0 Telsa coronary magnetic resonance imaging (MRI) and to test the hypothesis that this noninvasive technique can detect differences in coronary distensibility between healthy subjects and those with coronary artery disease (CAD). A total of 38 healthy, adult subjects (23 men, mean age 31 ± 10 years) and 21 patients with CAD, diagnosed using x-ray angiography (11 men, mean age 57 ± 6 years) were studied using a commercial whole-body MRI system. In each subject, the proximal segment of a coronary artery was imaged for the cross-sectional area measurements using cine spiral MRI. The distensibility (mm Hg(-1) × 10(3)) was determined as (end-systolic lumen area - end-diastolic lumen area)/(pulse pressure × end-diastolic lumen area). The pulse pressure was calculated as the difference between the systolic and diastolic brachial blood pressure. A total of 34 healthy subjects and 19 patients had adequate image quality for coronary area measurements. Coronary artery distensibility was significantly greater in the healthy subjects than in those with CAD (mean ± SD 2.4 ± 1.7 mm Hg(-1) × 10(3) vs 1.1 ± 1.1 mm Hg(-1) × 10(3), respectively, p = 0.007; median 2.2 vs 0.9 mm Hg(-1) × 10(3)). In a subgroup of 10 patients with CAD, we found a significant correlation between the coronary artery distensibility measurements assessed using MRI and x-ray coronary angiography (R = 0.65, p = 0.003). In a group of 10 healthy subjects, the repeated distensibility measurements demonstrated a significant correlation (R = 0.80, p = 0.006). In conclusion, 3.0-Tesla MRI, a reproducible noninvasive method to assess human coronary artery vessel wall distensibility, is able to detect significant differences in distensibility between healthy subjects and those with CAD.

We thank Hiemann et al for their interest in our work.1 In their letter, they suggest that immunostaining for CD34, a marker of endothelial cells, should not be used for assessment of capillary density unless concomitant α-actin immunostaining is performed. In our research, capillaries were tagged and counted by 2 experienced pathologists in CD34-stained biopsy samples; microvessels and arterioles with stained …

Methods Clinical data and DCMR results were analyzed in patients with peripheral arterial disease undergoing DCMR between 2000 and 2004. Peripheral arterial disease was defined as significant stenosis or occlusion of peripheral arteries of the lower and upper extremity or of the carotid artery. After an average of 35 ± 17 months, 140 patients (median age, 65 years) were contacted and medical records were reviewed. Wall motion abnormalities (WMA) at rest and the presence of stress-induced WMA (ischemia) were assessed for each patient. Cardiac events, defined as cardiac death and non-fatal myocardial infarction, were assessed.

Purpose To prospectively determine the feasibility and accuracy of strain-encoded (SENC) magnetic resonance imaging (MRI) for the characterization of the right ventricular free wall (RVFW) strain and timing of contraction at 3.0 Tesla (3T) MRI. Materials and Methods In 12 healthy volunteers the RVFW was divided into three segments (anterior, lateral, and inferior) in each of three short-axis (SA) slices (apical, mid, and basal) and into three segments (apical, mid, and basal) in a four-chamber view. The study was repeated on a different day and interobserver and interstudy agreements were evaluated. Results Maximal systolic longitudinal strain values were highest at the apex and base, with a pronounced decrease in the medial segments (apex: –19.1% ± 1.4; mid: –17.4% ± 2; base: –19.4% ± 2.4, P < 0.001), and maximal systolic circumferential strain showed the highest values at the apex (apex: –18.1% ± 1.7; mid: –17.6% ± 1.2; base: –16.6% ± 0.9, P < 0.001). Peak systolic longitudinal and circumferential shortening occurred earliest at the apex compared to the mid-ventricle and base. Excellent interobserver and interstudy correlation and agreement were observed. Conclusion The use of SENC MRI for the assessment of normal RV contraction pattern is feasible and accurate in 3T MRI. J. Magn. Reson. Imaging 2008;28:1379–1385. © 2008 Wiley-Liss, Inc.

The study tested the prevalence of graft vessel disease (GVD) in 54 paediatric heart transplant (HTx) patients (32 male, age 0-17 years) who underwent coronary angiographic investigations (N=117). These were evaluated according to the Stanford classification and additional criteria (peripheral obliterations, diameter fluctuations, pathologic tapering) were applied for risk assessment (no GVD/minimal lesions, GVD without Stanford lesions, accelerated GVD). In H&E stainings from right ventricular endomyocardial biopsies (EMB=169) diagnosis of acute cellular rejection (ACR, ISHLT) and microvasculopathy were performed. Mild rejection was found in 43% (N=44) and severe rejection in 7% (N=7) of EMB early (1st year) and mild rejection in 31% (N=32) and severe in 8% (N=9) late (>3 years) after HTx. Microvasculopathy was present in 22% of EMB. Risk assessment of coronary angiographies showed no GVD/minimal disease in 25% (N=29), GVD without Stanford lesions in 12% (N=14) and different grades of accelerated GVD in 74% (N=74) of studies. All patients dying due to cardiac related causes of death (N=6, 3-12 years after HTx) had evidence of GVD. The data show GVD to be an important cause of late cardiac related deaths in this population.

Summary To determine risk factors for small vessel disease after heart transplantation (HTx), characteristics of donors and organ harvesting were evaluated in 246 HTx patients (205 male, 41 female, mean survival 5.4 years). In right ventricular endomyocardial biopsies (EMB, n = 5421) evidence of microvascular disease [endothelial cell (EC) swelling/vessel wall thickening] was evaluated by light microscopy (hematoxylin and eosin staining, ×200). Mild EC swelling/vessel wall thickening were found in 204 and 213 patients, severe EC swelling/vessel wall thickening were present in 23 and 142 patients respectively. Evidences of mild and severe acute cellular rejection were found in 2064 and 421 EMB respectively. Microvascular disease was positively correlated with mild acute rejection episodes (P

Background— Low-dose dobutamine challenge (DSMR) by MRI was compared with delayed enhancement imaging with Gd-DTPA (SCAR) as a predictor of improvement of wall motion after revascularization (RECOVERY). Methods and Results— In 29 patients with coronary artery disease (68±7 years of age, 2 women, 32±8% ejection fraction), wall motion was evaluated semiquantitatively by MRI before and 3 months after revascularization. SCAR and DSMR were performed before revascularization. The transmural extent of scar was assessed semiquantitatively. Binary prediction of RECOVERY was performed by logistic regression in 288 segments with wall motion abnormalities at rest. Receiver operating characteristic–area under curve (AUC) statistics were used to compare different models. Low-dose DSMR (AUC 0.838) was superior to SCAR (AUC 0.728) in predicting RECOVERY. SCAR did not improve accuracy of prediction by DSMR. Subgroup analysis showed superiority of DSMR for 1% to 74% transmural extent of infarction. Conclusions— Low-dose DSMR is superior to SCAR in predicting RECOVERY. This advantage is largest in segments with a delayed enhancement of 1% to 74%.

Background— In patients with coronary artery stents, no direct noninvasive coronary artery imaging is possible with magnetic resonance (MR). A well-established method for the assessment of the functional significance of a coronary lesion is the measurement of coronary flow reserve by invasive intracoronary Doppler. The purpose of the study was to determine coronary flow velocity reserve (CFVR) with MR after stent deployment. Methods and Results— Thirty-eight patients after successful PTCA and stent deployment were included. CFVR was measured perpendicular to the artery distal to the stent using phase-contrast velocity quantification at rest and during adenosine-stimulated hyperemia with a 1.5T MR tomograph (ACS NT, Philips). Measurements were repeated after 3 months and compared with invasive coronary angiography. In 18 patients, additional invasive Doppler flow measurements were obtained. CFVR could be determined in 29 of 38 (76%) of the patients. After 3 months, significant differences were obtained between coronary arteries with and without restenosis. Using a threshold of 1.2, a sensitivity of 83% with a specificity of 94% was achieved for ≥75% stenoses. CFVR with CMR was similar to Doppler results ( r =0.87), with a mean relative difference of 7.5%. Conclusions— In patients with preserved coronary microcirculating vasoreactivity that are suitable for MR coronary angiography and flow assessments, CMR measures of coronary blood flow velocities reserve may be used to detect in-stent restenosis.

Background Left ventricular myocardial motion analysis and the assessment of regional dysfunction are crucial for the detection and prognosis in different cardiac pathologies. Myocardial tagging (MT) is a cardiac magnetic resonance (CMR) based method for tracking myocardial motion, which has been established as reference standard for assessment of strain. Currently, strain can also be assessed by CMR using feature tracking (FT) or by echocardiography with speckle tracking (ST). Aim of our study was to evaluate intraindividually and compare myocardial circumferential strain (Ecc) using MT, FT and ST.

The purpose of this study was to determine whether steady-state free precession (SSFP) could improve accuracy of geometric models for evaluation of left ventricular (LV) function in comparison to turbo gradient echo (TGrE) and thereby reduce the acquisition and post-processing times, which are commonly long by use of the Simpson's Rule. In 25 subjects, cine loops of the complete heart in short and horizontal long-axis planes were acquired using TGrE (TR/TE/flip = 5.0/1.9/25) compared with SSFP (TR/TE/flip = 3.2/1.2/60). LV volumes and EF were measured with various geometric models for TGrE and SSFP. With three-dimensional data, the LV volumes were higher and the resulting EF lower for SSFP in contrast to TGrE (51 +/- 15% vs. 57 +/- 15%, p0.001). With SSFP, various geometric models yielded good to excellent correlations for LV volumes and LVEF compared to volumetric data (r = 0.94-0.98, mean relative difference 7.0-11.4%). In contrast, correlations were low using biplane or single-plane ellipsoid models in TGrE (r = 0.71-0.75, mean relative difference 15.9-30.2%). A new combined geometric model, taking all three dimensions into account, yielded the highest accuracy for SSFP in comparison to volumetric data (r = 0.99, mean relative difference 4.7%). Geometric models for assessment of LV volumes and EF yield higher accuracy and reproducibility by use of the SSFP sequence than by standard TGrE. This may increase clinical utility of magnetic resonance by shorter acquisition and processing times.