Beneficial effects of reconstituted high-density lipoprotein (rHDL) on circulating CD34+ cells in patients after an acute coronary syndrome

Background: High-density lipoproteins (HDL) favorably affect endothelial progenitor cells (EPC). Circulating progenitor cell level and function are impaired in patients with acute coronary syndrome (ACS). This study investigates the short-term effects of reconstituted HDL (rHDL) on circulating progenitor cells in patients with ACS. Methods and Findings: The study population consisted of 33 patients with recent ACS: 20 patients from the ERASE trial (randomized to receive 4 weekly intravenous infusions of CSL-111 40 mg/kg or placebo) and 13 additional patients recruited as controls using the same enrolment criteria. Blood was collected from 16 rHDL (CSL-111)-treated patients and 17 controls at baseline and at 6–7 weeks (i.e. 2–3 weeks after the fourth infusion of CSL-111 in ERASE). CD34+ and CD34+/kinase insert domain receptor (KDR+) progenitor cell counts were analyzed by flow cytometry. We found preserved CD34+ cell counts in CSL-111-treated subjects at follow-up (change of 1.6%), while the number of CD34+ cells was reduced (-32.9%) in controls (p = 0.017 between groups). The level of circulating SDF-1 (stromal cell-derived factor-1), a chemokine involved in progenitor cell recruitment, increased significantly (change of 21.5%) in controls, while it remained unchanged in CSL-111-treated patients (p = 0.031 between groups). In vitro exposure to CSL-111 of early EPC isolated from healthy volunteers significantly increased CD34+ cells, reduced early EPC apoptosis and enhanced their migration capacity towards SDF-1. Conclusions: The relative increase in circulating CD34+ cells and the low SDF-1 levels observed following rHDL infusions in ACS patients point towards a role of rHDL in cardiovascular repair mechanisms

Evaluation of a new semiautomated external defibrillator technology: a live cases video recording study.

AIM: To determine the effect of a new automated external defibrillator (AED) system connected by General Packet Radio Service (GPRS) to an external call centre in assisting novices in a sudden cardiac arrest situation. METHOD: Prospective, interventional study. Layperson volunteers were first asked to complete a survey about their knowledge and ability to give cardiopulmonary resuscitation (CPR) and use an AED. A simulated cardiac arrest scenario using a CPR manikin was then presented to volunteers. A telephone and semi-AED were available in the same room. The AED was linked to a call centre, which provided real-time information to 'bystanders' and emergency services via GPRS/GPS technology. The scene was videotaped to avoid any interaction with examiners. A standardised check list was used to record correct actions. RESULTS: 85 volunteers completed questionnaires and were recorded. Mean age was 44±16, and 49% were male; 38 (45%) had prior CPR training or felt comfortable intervening in a sudden cardiac arrest victim; 40% felt they could deliver a shock using an AED. During the scenarios, 56 (66%) of the participants used the AED and 53 (62%) successfully delivered an electrical shock. Mean time to defibrillation was 2 min 29 s. Only 24 (28%) participants dialled the correct emergency response number (112); the live-assisted GPRS AED allowed alerted emergency services in 38 other cases. CPR was initiated in 63 (74%) cases, 26 (31%) times without prompting and 37 (44%) times after prompting by the AED. CONCLUSIONS: Although knowledge of the general population appears to be inadequate with regard to AED locations and recognition, live-assisted devices with GPS-location may improve emergency care. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions

Prognostic Impact of Hypertrabeculation and Noncompaction Phenotype in Dilated Cardiomyopathy: A CMR Study.

OBJECTIVES: The purpose of this study was to evaluate the impact of hypertrabeculation and left ventricular (LV) myocardial noncompaction phenotype by cardiac magnetic resonance (CMR) on outcomes of patients with nonischemic dilated cardiomyopathy (DCM). BACKGROUND: Myocardial trabeculations and noncompaction are increasingly observed in patients with DCM, but their prognostic impact remains unknown. METHODS: We prospectively evaluated outcomes of 162 consecutive patients (102 men; age 55 ± 15 years; ejection fraction [EF] 25 ± 8%) with DCM undergoing CMR. The amount of noncompaction was quantified as noncompacted/compacted (NC/C) length in the long-axis view and as the ratio of NC/C mass in the short-axis view and compared against 48 healthy control subjects (age 60 ± 10 years). RESULTS: Fifty-eight DCM patients (36%) had NC/C length ≥2.3, and 71 (44%) had NC/C mass greater than the 95% confidence interval (CI) of control subjects. NC/C length and NC/C mass did not correlate with any clinical, echocardiographic, or CMR parameters. Over a 3.4-year median follow-up, 29 patients experienced major adverse cardiovascular events (MACE) (12 cardiovascular deaths, 8 heart transplantations, 4 LV assist device implantations, and 5 resuscitated cardiac arrests or appropriate device shocks). Cox univariate analysis identified smoking, New York Heart Association functional class, blood pressure, LV and right ventricular end-diastolic and end-systolic volumes, LV EF, right ventricular EF, and late gadolinium enhancement as predictors of MACE. In multivariate analysis, only LV EF and late gadolinium enhancement were independent predictors of MACE-free survival (hazard ratio: 0.922, 95% CI: 0.878 to 0.967, p = 0.001 and HR: 1.096, 95% CI: 1.004 to 1.197, p = 0.04, respectively). Neither NC/C length nor NC/C mass had significant predictive value for MACE-free survival, either unadjusted or after adjustment for baseline variables. Also, there was no difference in cardioembolic event rate between groups with high and low NC/C length or mass. CONCLUSIONS: Cardiovascular outcomes of adult patients with nonischemic DCM do not appear to be influenced by the degree of trabeculation. This argues against a noncompaction phenotype designating a more severe form of DCM

Comparison of Extravascular volume by cardiac MR T1 mapping by conventional look locker versus modified look locker techniques to predict histologically measured fibrosis in valve disease

Background: Valvular heart disease is associated with left ventricular hypertrophy, remodeling and development of diffuse interstitial fibrosis. So far, histopathology remains the gold standard for evaluating diffuse myocardial fibrosis. Gadolinium enhanced Cardiac Magnetic Resonance (CMR) T1 mapping is new method which allows to quantify the myocardial extracellular volume (ECV). Look locker and modified look locker (MOLLI) are two techniques to assess ECV. Hence, it was suggested that the two techniques are equivalents. Therefore the aim of this study is to compare these two techniques against histological measurement. Methods and results: 18 patients (age=58±14 years, 72% men) with either severe aortic valve disease (stenosis or regurgitation) or severe mitral regurgitation, but without coronary artery disease preoperatively underwent ECV measurement by CMR two beat look locker and MOLLI 3-3-5 single breathhold T1 mapping. LV biopsies were performed at the time of surgery 24±38 days later and stained with Sirius red. The amount of fibrosis quantified by biopsy was 9.0±8.9% [2.1;39.2]. ECV by T1 mapping mesured by look locker normalized to heart rate of 60bpm was 38.7±13.9% [23.9;64.4] and by MOLLI was 28.7±4.8% [23.3;38.6] (values are presented as mean±SD [min;max]). The two T1 mapping values are significantly different (p=0,010). There was a good correlation between histologically measured fibrosis and T1 mapping ECV by MOLLI (r=0.72, p<0.001, cfr figure) but not by look locker (r=-0.16, p=0.52) mesurement. Conclusion: ECV determined by CMR T1 mapping mesured by MOLLI technique closely correlates with histologically determined diffuse interstitial fibrosis. By contrast the look locker method does not provide accurate mesurement of ECV, likely because the shot interval does not allow complete relaxation of T1

Extravascular volume by cardiac MR T1 mapping accurately predicts histologically measured fibrosis in valve disease

Background: Valvular heart disease is associated with left ventricular hypertrophy, remodeling and development of diffuse interstitial fibrosis. So far, histopathology remains the gold standard for evaluating diffuse myocardial fibrosis. Gadolinium enhanced Cardiac Magnetic Resonance (CMR) T1 mapping is new method which allows to quantify the myocardial extracellular volume (ECV). Hence, it was suggested that this ECV measurements allows to non-invasive estimate diffuse fibrosis. However validations studies are scars. Therefore the aim of this study was to validate measurements of ECV by T1-Modified Lock-locker (MOLLI) CMR against histological measurement. Methods and results: Between June 2012 and September 2013, 15 patients (age=57±15 years, 73% men) with either severe aortic valve disease (stenosis or regurgitation) or severe mitral regurgitation, but without coronary artery disease preoperatively underwent ECV measurement by CMR MOLLI T1 mapping. LV biopsies were performed at the time of surgery 7±8 days later and stained with Sirius red. The amount of fibrosis quantified by biopsy was 6.6±4.8% [2.1;15.9]. ECV by T1 mapping was 28.3±4.7% [23.3;38.6] (values are presented as mean±SD [min;max]). There was a good correlation between histologically measured fibrosis and T1 mapping ECV (r=0.77, p<0.001, cfr figure). Conclusion: ECV determined by CMR T1 mapping closely correlates with histologically determined diffuse interstitial fibrosis and could thus be used to non-invasively quantify interstitial fibrosis in patients with heart diseases

Head-to-Head Comparison of Global and Regional Two-Dimensional Speckle Tracking Strain Versus Cardiac Magnetic Resonance Tagging in a Multicenter Validation Study.

BACKGROUND: Despite widespread use to characterize and refine prognosis, validation data of two-dimensional (2D) speckle tracking (2DST) echocardiography myocardial strain measurement remain scarce. METHODS AND RESULTS: Global and regional subendocardial peak-systolic Lagrangian longitudinal (LS) and circumferential strain (CS) by 2DST and 2D-tagged (2DTagg) cardiac magnetic resonance imaging were compared against sonomicrometry in a dynamic heart phantom and among each other in 136 patients included prospectively at 2 centers. The ability of regional LS and CS 2DST and 2DTagg to identify late gadolinium enhancement was compared using receiver operating characteristics curves. In vitro, both LS-2DST and 2DTagg highly agreed with sonomicrometry (intraclass correlation coefficient [ICC], 0.89 and ICC, 0.90, both P<0.001 with -3±2.8% and 0.34±4.35% bias, respectively). In patients, both global LS and global CS 2DST agreed well with 2DTagg (ICC, 0.89 and ICC, 0.80; P<0.001); however, they provided systematically greater values (relative bias of -37±27% and -25±37% for global LS and global CS, respectively). On regional basis, however, ICC (from 0.17 to 0.81) and relative bias (from -9 to -98%) between 2DST and 2DTagg varied strongly among segments. Ability to discriminate infarcted versus noninfarcted segments by late gadolinium enhancement was similarly good for regional LS 2DTagg and 2DST (area under the curve, 0.66 versus 0.59; P=0.08), while it was lower for CS 2DST than 2DTagg (area under the curve, 0.61 versus 0.75; P<0.001). CONCLUSIONS: The high accuracy against sonomicrometry and good agreement of global LS and global CS by 2DST and 2DTagg confirm the overall validity of 2DST strain measurement. Yet, higher intertechnique segmental variability and lower ability for detecting infarct suggest that 2DST strain estimates may be less performant on regional than on global basis

<i>In vitro</i> exposure of circulating progenitor cells to CSL-111.

<p>Peripheral blood mononuclear cells (PBMCs) were isolated from healthy donors (n = 7) and plated on fibronectin-coated plates in the absence or presence of CSL-111 (1 mg/mL) from day 0 to day 4 (D0-4), 4 to 7 (D4-7) or 0 to 7 (D0-7). After 7 days of culture, adherent cells were harvested and analyzed by flow cytometry. (A) All adherent cells were quantified by flow cytometry using cell counting beads for enumeration. (B) CSL-111 treatment increases the total number of CD34⁺ cells when added to cell culture media at D0-4 and D0-7; CD34⁺ cells were quantified by flow cytometry. (C) CSL-111 treatment reduces basal apoptosis in eEPCs when added to cell culture media at D0-4 and D0-7. Apoptosis was measured by flow cytometry using Annexin V labeling. Each box plot shows the median, the interquartile range, the maximum and the minimum of the relative change. * indicates p < 0.05 between groups from Wilcoxon signed-rank tests.</p

Representative example of sequential gating strategy for flow cytometric analysis of endothelial progenitor cells.

<p>A modified ISHAGE strategy was applied for EPC quantification. 1) Representative sample stained with CD45-FITC. Region R6 represents lymphocytes. 2) Anti-CD34-PE staining of cells from R1. Region R2 represents CD34⁺ cells. 3) Region R3 is placed to include the low Side Scatter and low to intermediate CD45 staining. 4) R4 represents all events from regions R1, R2 and R3 displayed on a FSC vs SSC dot plot to confirm that the selected events fall into a lymph-blast region. 5) Displays the events included in regions R1, R2, R3 and R4. A quadrant was positioned to separate the positive and the negative cells for VEGFR2 staining. An appropriate isotype control was used to adequately place the quadrant. Region R5 represents the total EPCs (CD34+/VEGFR2+ cells). 6) Events from region R6. This region is used to set the region R4. 7) All events. This histogram is useful to establish the lower limit of CD45 expression for the CD34⁺ events. The region R8 is placed in the right top of the histogram to count all Stem-count fluorospheres accumulated for each sample for absolute quantification. 8) Events from region R8. This region includes the Stem-count fluorospheres singlet population.</p