Bone marrow mononuclear cells (BMMCs) have been evaluated for their ability to improve cardiac repair and benefit patients with severe ischemic heart disease and heart failure. In our single-center trial in 2006–2011 we demonstrated the safety and efficacy of BMMCs injected intramyocardially in conjunction with coronary artery bypass surgery. The effect persisted in the follow-up study 5 years later. In this study, we investigated the efficacy of BMMC therapy beyond 10 years. A total of 18 patients (46%) died during over 10-years follow-up and 21 were contacted for participation. Late gadolinium enhancement cardiac magnetic resonance imaging (CMRI) and clinical evaluation were performed on 14 patients, seven from each group. CMRIs from the study baseline, 1-year and 5-years follow-ups were re-analyzed to enable comparison. The CMRI demonstrated a 2.1-fold larger reduction in the mass of late gadolinium enhancement values between the preoperative and the over 10-years follow-up, suggesting less scar or fibrosis after BMMC treatment (− 15.1%; 95% CI − 23 to − 6.7% vs. − 7.3%; 95% CI − 16 to 4.5%, p = 0.039), compared to placebo. No differences in mortality or morbidity were observed. Intramyocardially injected BMMCs may exert long-term benefits in patients with ischemic heart failure. This deserves further evaluation in patients who have received BMMCs in international clinical studies over two decades.
Objectives. Several approaches devised for clinical utilization of cell-based therapies for heart failure often suffer from complex and lengthy preparation stages. Epicardial delivery of autologous atrial appendage micrografts (AAMs) with a clinically used extracellular matrix (ECM) patch provides a straightforward therapy alternative. We evaluated the operative feasibility and the effect of micrografts on the patch-induced epicardial foreign body inflammatory response in a porcine model of myocardial infarction. Design. Right atrial appendages were harvested and mechanically processed into AAMs. The left anterior descending coronary artery was ligated to generate acute infarction. Patches of ECM matrix with or without AAMs were transplanted epicardially onto the infarcted area. Four pigs received the ECM and four received the AAMs patch. Cardiac function was studied by echocardiography both preoperatively and at 3-week follow-up. The primary outcome measures were safety and feasibility of the therapy administration, and the secondary outcome was the inflammatory response to ECM. Results. Neither AAMs nor ECM patch-related complications were detected during the follow-up time. AAMs patch preparation was feasible according to time and safety. Inflammation was greatly reduced in AAMs when compared with ECM patches as measured by the amount of infiltrated inflammatory cells and area of inflammation. Immunohistochemistry demonstrated an increased CD3+ cell density in the AAMs patch infiltrate. Conclusions. Epicardial AAMs transplantation demonstrated safety and clinical feasibility. The use of micrografts significantly inhibited ECM-induced foreign body inflammatory reactivity. Transplantation of AAMs shows good clinical applicability as adjuvant therapy to cardiac surgery and can suppress acute inflammatory reactivity.
AbstractObjectivesCardio-regenerative cell therapies offer additional biologic support to coronary artery bypass surgery (CABG) for treating the myocardium suffering from or damaged by ischemia. This phase 1, open-label study assessed the safety and feasibility of epicardial transplantation of atrial appendage micrografts (AAMs) in patients undergoing CABG surgery.MethodsTwelve consecutive patients destined for CABG surgery were included in the study. Six patients received AAMs during their operation and six patients were CABG-operated without AAMs treatment. Data from 30 elective CABG patients was collected for a conjunctive control group. The AAMs were processed during the operation from a biopsy collected from the right atrial appendage. They were delivered epicardially on the infarct scar site identified in preoperative CMR. The primary outcome measures at six-months follow-up were i) patient safety in terms of hemodynamic and cardiac function over time and ii) feasibility of therapy administration in a clinical setting. Secondary outcome measures were left ventricular wall thickness, change in myocardial scar tissue volume, changes in left ventricular ejection fraction, plasma concentrations of N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, NYHA class, number of days in hospital and changes in the quality of life.ResultsEpicardial transplantation of AAMs was safe and feasible to be performed in conjunction with CABG surgery. CMR demonstrated an increase in viable cardiac tissue at the infarct site in patients receiving AAMs treatment.ConclusionTransplantation of AAMs shows good clinical applicability as adjuvant therapy to cardiac surgery and can additionally serve as a delivery platform for cardiac gene therapies.Trial RegistrationClinicalTrials.gov identifier NCT02672163
Background: Although many pathological changes have been associated with ischemic heart disease (IHD), molecular-level alterations specific to the ischemic myocardium and their potential to reflect disease severity or therapeutic outcome remain unclear. Currently, diagnosis occurs relatively late and evaluating disease severity is largely based on clinical symptoms, various imaging modalities, or the determination of risk factors. This study aims to identify IHD-associated signature RNAs from the atrial myocardium and evaluate their ability to reflect disease severity or cardiac surgery outcomes. Methods and Results: We collected right atrial appendage (RAA) biopsies from 40 patients with invasive coronary angiography (ICA)-positive IHD undergoing coronary artery bypass surgery and from 8 patients ICA-negative for IHD (non-IHD) undergoing valvular surgery. Following RNA sequencing, RAA transcriptomes were analyzed against 429 donors from the GTEx project without cardiac disease. The IHD transcriptome was characterized by repressed RNA expression in pathways for cell–cell contacts and mitochondrial dysfunction. Increased expressions of the CSRNP3, FUT10, SHD, NAV2-AS4, and hsa-mir-181 genes resulted in significance with the complexity of coronary artery obstructions or correlated with a functional cardiac benefit from bypass surgery. Conclusions: Our results provide an atrial myocardium-focused insight into IHD signature RNAs. The specific gene expression changes characterized here, pave the way for future disease mechanism-based identification of biomarkers for early detection and treatment of IHD.
Background: Cardio-regenerative cell therapies offer additional biologic support to coronary artery bypass surgery (CABG) and are aimed at functionally repairing the myocardium that suffers from or is damaged by ischemia. This non-randomized open-label study assessed the safety and feasibility of epicardial transplantation of atrial appendage micrografts (AAMs) in patients undergoing CABG surgery. Methods: Twelve consecutive patients destined for CABG surgery were included in the study. Six patients received AAMs during their operation and six patients were CABG-operated without AAMs transplantation. Data from 30 elective CABG patients was collected for a center- and time-matched control group. The AAMs were processed during the operation from a biopsy collected from the right atrial appendage. They were delivered epicardially onto the infarct scar site identified in preoperative late gadolinium enhancement cardiac magnetic resonance imaging (CMRI). The primary outcome measures at the 6-month follow-up were (i) patient safety in terms of hemodynamic and cardiac function over time and (ii) feasibility of therapy administration in a clinical setting. Secondary outcome measures were left ventricular wall thickness, change in myocardial scar tissue volume, changes in left ventricular ejection fraction, plasma concentrations of N-terminal pro-B-type natriuretic peptide levels, NYHA class, number of days in hospital and changes in the quality of life. Results: Epicardial transplantation of AAMs was safe and feasible to be performed during CABG surgery. CMRI demonstrated an increase in viable cardiac tissue at the infarct site in patients receiving AAMs treatment. Conclusions and Relevance: Transplantation of AAMs shows good clinical applicability as performed during cardiac surgery, shows initial therapeutic effect on the myocardium and has the potential to serve as a delivery platform for cardiac gene therapies. Trial Registration: ClinicalTrials.gov, identifier: NCT02672163.
Ischemic heart disease remains the leading cause of mortality and morbidity worldwide despite improved possibilities in medical care. Alongside interventional therapies, such as coronary artery bypass grafting, adjuvant tissue-engineered and cell-based treatments can provide regenerative improvement. Unfortunately, most of these advanced approaches require multiple lengthy and costly preparation stages without delivering significant clinical benefits. We evaluated the effect of epicardially delivered minute pieces of atrial appendage tissue material, defined as atrial appendage micrografts (AAMs), in mouse myocardial infarction model. An extracellular matrix patch was used to cover and fix the AAMs onto the surface of the infarcted heart. The matrix-covered AAMs salvaged the heart from infarction-induced loss of functional myocardium and attenuated scarring. Site-selective proteomics of injured ischemic and uninjured distal myocardium from AAM-treated and untreated tissue sections revealed an increased expression of several cardiac regeneration-associated proteins (i.e. periostin, transglutaminases and glutathione peroxidases) as well as activation of pathways responsible for angio- and cardiogenesis in relation to AAMs therapy. Epicardial delivery of AAMs encased in an extracellular matrix patch scaffold salvages functional cardiac tissue from ischemic injury and restricts fibrosis after myocardial infarction. Our results support the use of AAMs as tissue-based therapy adjuvants for salvaging the ischemic myocardium.
Background: The atrial appendages are a tissue reservoir for cardiac stem cells. During on-pump coronary artery bypass graft (CABG) surgery, part of the right atrial appendage can be excised upon insertion of the right atrial cannula of the heart-lung machine. In the operating room, the removed tissue can be easily cut into micrografts for transplantation. This trial aims to assess the safety and feasibility of epicardial transplantation of atrial appendage micrografts in patients undergoing CABG surgery. Methods/design: Autologous cardiac micrografts are made from leftover right atrial appendage during CABG of 6 patients. Atrial appendage is mechanically processed to micrografts consisting of atrial appendage-derived cells (AADCs) and their extracellular matrix (ECM). The micrografts are epicardially transplanted in a fibrin gel and covered with a tissue-engineered ECM sheet. Parameters including echocardiography—reflecting cardiac insufficiency—are studied preand post-operatively as well as at 3 and 6 months of the follow-up. Cardiac functional magnetic resonance imaging is performed preoperatively and at 6-month follow-up. The primary outcome measures are patient safety in terms of hemodynamic and cardiac function over time and feasibility of therapy administration in a clinical setting. Secondary outcome measures are left ventricular wall thickness, change in the amount of myocardial scar tissue, changes in left ventricular ejection fraction, plasma concentrations of N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, New York Heart Association class, days in hospital, and changes in the quality of life. Twenty patients undergoing routine CAGB surgery will be recruited to serve as a control group. Discussion: This study aims to address the surgical feasibility and patient safety of epicardially delivered atrial appendage micrografts during CABG surgery. Delivery of autologous micrografts and AADCs has potential applications for cell and cell-based gene therapies. Trial registration: ClinicalTrials.gov Identifier: NCT02672163. Date of registration: 02.02.2016
We present the production and clinical application of autologous atrial micrografts during coronary artery bypass grafting (CABG). Micrografts are isolated from otherwise discarded atrial appendage (AA) tissue and are combined with fibrin gel 1 Spotnitz W.D. Fibrin sealant: the only approved hemostat, sealant, and adhesive—a laboratory and clinical perspective. ISRN Surg. 2014; 2014: 203943 Crossref PubMed Google Scholar and a decellularized small intestinal submucosa (SIS) matrix sheet (Figure 1a). 2 Mosala N.Z. Poncelet A. de Kerchove L. et al. Small intestinal submucosa extracellular matrix (CorMatrix®) in cardiovascular surgery: a systematic review. Interact Cardiovasc Thorac Surg. 2016; 22: 839-850 Crossref PubMed Scopus (93) Google Scholar The technique—mechanical tissue processing, preparation of the transplant, and its topical application with a matrix sheet—is performed during CABG (Figure 1a, b). The protocol is provided in Appendix 1 (available online at www.jhltonline.org).
This review focuses on the possibilities for intraoperative processing and isolation of autologous cells, particularly atrial appendage-derived cells (AADCs) and cellular micrografts, and their straightforward use in cell transplantation for heart failure therapy. We review the potential of autologous tissues to serve as sources for cell therapy and consider especially those tissues that are used in surgery but from which the excess is currently discarded as surgical waste. We compare the inculture expanded cells to the freshly isolated ones in terms of evidence-based cost-efficacy and their usability as gene- and RNA therapy vehicles. We also review how financial and authority-based decisions and restrictions sculpt the landscape for patients to participate in academic-based trials. Finally, we provide an insight example into AADCs isolation and processing for epicardial therapy during coronary artery bypass surgery.
Therapeutic effects of skeletal myoblast transplantation into the myocardium are mediated via paracrine factors. We investigated the ability of myoblast-derived soluble mediators to protect cardiomyocytes from oxidative stress. Fetal rat cardiac cells were treated with conditioned medium from cultures of myoblasts or cardiac fibroblasts, and oxidative stress was induced with H2O2. Myoblast-derived factors effectively prevented oxidative stress-induced cardiac cell death and loss of mitochondrial membrane potential. This protective effect was mediated via epidermal growth factor (EGF) receptor and c-Met signaling, and mimicked by neuregulin 1 but not EGF. Microarray analysis of cardiac cells treated with myoblast versus cardiac fibroblast-derived mediators revealed differential regulation of genes associated with antioxidative effects: cystathionine-γ-lyase (est), xanthine oxidase, and thioredoxin-interacting protein as well as nibbles homolog 3 (trib3). Cardiac cell pretreatment with tunicamycin, an inducer of trib3, also protected them against H2O2-induced cell death. Epicardial transplantation of myoblast sheets in a rat model of acute myocardial infarction was used to evaluate the expression of CST and trib3 as markers of myoblasts' paracrine effect in vivo. Myoblast sheets induced expression of the CST as well as trib3 in infarcted myocardium. CST localized around blood vessels, suggesting smooth muscle cell localization. Our results provide a deeper molecular insight into the therapeutic mechanisms of myoblast-derived paracrine signaling in cardiac cells and suggest that myoblast transplantation therapy may prevent oxidative stress-induced cardiac deterioration and progression of heart failure.
Although cell therapy of the failing heart by intramyocardial injections of myoblasts to results in regenerative benefit, it has also been associated with undesired and prospectively fatal arrhythmias. We hypothesized that intramyocardial injections of myoblasts could enhance inflammatory reactivity and facilitate electrical cardiac abnormalities that can be reduced by epicardial myoblast sheet delivery. In a rat model of ischemic heart failure, myoblast therapy either by intramyocardial injections or epicardial cell sheets was given 2 weeks after occlusion of the coronary artery. Ventricular premature contractions (VPCs) were assessed, using an implanted three-lead electrocardiograph at 1, 7, and 14 days after therapy, and 16-point epicardial electropotential mapping (EEPM) was used to evaluate ventricular arrhythmogenicity under isoproterenol stress. Cardiac functioning was assessed by echocardiography. Both transplantation groups showed therapeutic benefit over sham therapy. However, VPCs were more frequent in the Injection group on day 1 and day 14 after therapy than in animals receiving epicardial or sham therapy (p < 0.05 and p < 0.01, respectively). EEPM under isoproterenol stress showed macroreentry at the infarct border area, leading to ventricular tachycardias in the Injection group, but not in the myoblast sheet- or sham-treated groups (p = 0.045). Both transplantation types modified the myocardial cytokine expression profile. In animals receiving epicardial myoblast therapy, selective reductions in the expressions of interferon gamma, interleukin (IL)-1β and IL12 were observed, accompanied by reduced infiltration of inflammatory CD11b- and CD68-positive leukocytes, compared with animals receiving myoblasts as intramyocardial injections. Intramyocardial myoblast delivery was associated with enhanced inflammatory and immunomodulatory reactivity and increased frequency of VPCs. In comparison to intramyocardial injection, the epicardial route may serve as the preferred method of skeletal myoblast transplantation to treat heart failure.
Complex skin wounds, such as chronic ulcers and deep burns, require lengthy treatments and cause extensive burdens on healthcare and the economy. Use of biomaterials and cell transplantation may improve traditional treatments and promote the healing of difficult‐to‐treat wounds. In this study, we investigated the use of recombinant human collagen III (rhCol‐III) gel as a delivery vehicle for cultured autologous skin cells (keratinocytes only or keratinocyte–fibroblast mixtures). We examined its effect on the healing of full‐thickness wounds in a porcine wound‐healing model. Two Landrace pigs were used for the study. Fourteen deep dermal wounds were created on the back of each pig with an 8 mm biopsy punch. Syringes containing acellular rhCol‐III gel (n = 8) or rhCol‐III gel with autologous keratinocytes (n = 8) or rhCol‐III gel with autologous keratinocytes and fibroblasts (n = 8) were applied into wounds. Untreated wounds were used as controls for the treatment groups (n = 4). We used rhCol‐III gel to manufacture a cell‐delivery syringe containing autologous skin cells. In a full‐thickness wound‐healing model, we observed that rhCol‐III gel enhances early granulation tissue formation. Interestingly, we found cell type‐dependent differences in the stability of rhCol‐III in vivo. Fibroblast‐containing gel was effectively removed from the wound, whereas gels without cells or with keratinocytes only remained intact. Our results demonstrate that the properties of rhCol‐III gel for skin cell transplantation can be significantly altered in a cell type‐dependent manner. Copyright © 2013 John Wiley & Sons, Ltd.
AIMS:Single-photon emission computed tomography (SPECT) and positron emission tomography (PET) are suggested to improve clinical decision-making in ischaemic cardiomyopathy. Here, we present a unique cohort of patients who underwent nuclear medicine studies and cardiac magnetic resonance imaging (MRI) both before and 1 year after coronary artery bypass (CABG) surgery to assess benefit from surgery.METHODS AND RESULTS:Before CABG, we applied three quantitative techniques using (18)F-fluorodeoxyglucose-PET and (99m)technetium-tetrofosmin-SPECT with a software tool to measure defects with hypoperfused but viable and non-viable myocardium in 15 patients. One method used solely PET, two others combined PET and SPECT at different thresholds. As a reference, we used change in left-ventricular (LV) function and volume by MRI. Preoperatively, ischaemic but viable areas detected by the method with a 10% threshold combining PET-SPECT and the PET-only method correlated significantly with preoperative regional wall thickening (WT; P = 0.03 and P = 0.005, respectively). When compared with global functional outcome (change in LV ejection fraction) and LV remodelling (change in end-diastolic volume) 1 year postoperatively, no correlation appeared with preoperative PET- or PET-SPECT-derived viable or non-viable tissue. Neither was any correlation observable between local change in WT and local preoperative defect size evaluated by any of these three methods.CONCLUSION:Preoperatively, PET and PET-SPECT with 10% threshold detected dysfunctional myocardium, but all analysis methods failed to predict 1-year functional outcome assessed by MRI. In patients with three-vessel disease and heart failure, SPECT perfusion and PET viability study results show substantial heterogeneity; this should be considered when selecting patients for revascularization.
Cell therapy for the failing heart has advanced in distinct phases or era with a first transition from dynamic to cellular cardiomyoplasty. Currently, the quest is to find the optimal replacement cell type or to engineer a substitute for the dysfunctional scarred tissue. Cell therapies still require major refinements before they can—in a truly therapeutic manner—aid the suffering myocardium that fails either to adequately support contraction or to permit dilatation. Here, we outline the road so far and provide an insight into current and future challenges that await resolving. Keywords: Autologous cell therapy, cardiomyoplasty, extracellular matrix, heart failure, micrografts, tissue.
BACKGROUND: Long-term results regarding treatment of chronic ischemic heart failure with bone marrow mononuclear cells (BMMCs) have been few. We received encouraging results at the 1-year follow-up of patients treated with combined coronary artery bypass grafting (CABG) and BMMCs, so we decided to extend the follow-up.METHODS: The study patients had received injections of BMMCs or vehicle into the myocardial infarction border area during CABG in a randomized and double-blind manner. We could contact 36 of the 39 patients recruited for the original study. Pre-operatively and after an extended follow-up period, we performed magnetic resonance imaging, measured pro-B-type amino-terminal natriuretic peptide, reviewed patient records from the follow-up period, and determined current quality of life with the Medical Outcomes Study Short-Form 36 (SF-36) Health Survey.RESULTS: The median follow-up time was 60.7 months (interquartile range [IQR], 45.1-72.6 months). No statistically significant difference was detected in change of pro-B-type amino-terminal natriuretic peptide values or in quality of life between groups. The median change in left ventricular ejection fraction was 4.9% (IQR, -2.1% to 12.3%) for controls and 3.9% (IQR, -5.2% to 10.2%) for the BM:MC group (p = 0.647). Wall thickening in injected segments increased by a median of 17% (IQR, -5% to 30%) for controls and 15% (IQR, -12% to 19%) for BMMC patients (p = 0.434). Scar size in injected segments increased by a median of 2% (IQR, -7% to 19%) for controls but diminished for BMMC patients, with a median change of -17% (IQR, -30% to -6%; p = 0.011).CONCLUSIONS: In the treatment of chronic ischemic heart failure, combining intramyocardial BMMC therapy with CABG fails to affect cardiac function but can sustainably reduce scar size, even in the long-term. (C) 2015 International Society for Heart and Lung Transplantation. All rights reserved.
OBJECTIVESWe present here a sub-study of our prospective, randomized, double-blinded trial of bone marrow mononuclear cell (BMMC) transplantation with coronary artery bypass surgery (CABG) (ClinicalTrials.gov Identifier: NCT00418418), evaluating our secondary end-point concerning hospital stay as well as perioperative morbidity. Injecting a substantial amount of biologically active cells into a diseased myocardium inspires concerns for safety, a concern overlooked in previous trials.METHODSWe evaluated the immediate perioperative effects of intramyocardial injection of autologous BMMCs combined with CABG. In a randomized double-blinded manner, 39 patients received injections either of BMMCs (n = 20) or of vehicle medium (n = 19). The patients' haemodynamics, arterial blood gases, systemic vein oxygen level, blood glucose, acid-base balance, lactate, haemoglobin, body temperature and diuresis, as well as medications needed, were recorded in the operating theatre and in the intensive care unit (ICU) every 4 h throughout the first postoperative 24 h.RESULTSNo dissimilarities in these parameters were detectable. In the ICU, the median need for adrenaline was 0.0086 µg/kg/min (first quartile 0.0000, third quartile 0.0204) for controls and 0.0090 µg/kg/min (0.0000, 0.0353) for BMMC patients (P = 0.757); for noradrenaline, 0.0586 µg/kg/min (0.0180, 0.0888) for controls and 0.0279 µg/kg/min (0.0145, 0.0780) for BMMC patients (P = 0.405). The median stay at the ICU was 2 days for both groups (1, 2 for controls; 1, 3 for BMMCs; P = 0.967). Within the first postoperative day, one control patient had an elevated level of creatine kinase-myocardial band fraction mass (CK-MBm) up to >100 µg/l; no BMMC patient showed elevated CK-MBm levels (P = 0.474).CONCLUSIONSBoth intramyocardial BMMC and placebo injections appear safe during surgery and immediate ICU stay after treatment of heart failure.
Background: Mesenchymal stromal cell (MSC) reportedly induce immune tolerance against allogenic antigens via inflammation-related expression of inducible nitric oxide synthase (iNOS). Combination of MSC may be promising therapeutic option in treating allogenic cell for cell therapy. However, tumorigenic conversion of MSCs is a major concern. Here, we hypothesized that immunomodulation property induced by iNOS in MSC impacts their tumorigenic conversion. We evaluated tumor formation following combined transplantation of iNOS-expressing MSCs with allogenic skeletal myoblasts in a rat model of myocardial infarction. Methods and Results: Fischer rat-derived MSCs were prepared as a cell sheet for transplantation on the surface of the infarcted or normal myocardium of Wistar rats. Seven days after transplantation, iNOS expression of the cell sheet which was transplanted on the infarcted myocardium was greater than that transplanted on the normal myocardium. Next, iNOS expression in the MSC was enhanced by interferon-γ and lipopolysaccharide (IL) treatment before creating cell sheet. Survivals of luciferase-expressing L6 skeletal myoblasts following subcutaneous cell-sheet transplantation were evaluated by in vivo imaging. Addition of the MSCs to the L6 sheet prolonged the survival of the L6 cells, which was further extended by IL treatment of MSCs prior to the cell sheet preparation. Then, we transplanted cell sheets over the infarcted myocardium of Wistar rats. Tumor growth was not observed in the rats that received allogenic skeletal myoblast sheets at 28 days. While, mixed cell sheets transplanted over the infarcted myocardium showed formation of MSC-derived tumors (2 / 10), and tumor formation elevated by the IL pre-treatment in MSCs (8 / 10). Conclusion: Inflammatory stimulation, such as transplantation to the infarcted myocardium or IL treatment in vitro enhanced iNOS expression in MSCs, prolonging the survival of transplanted allogenic myoblast cell sheets. However, iNOS expression in the MSCs was also associated with tumorigenic conversion, indicating that iNOS expression in MSCs should be considered when optimizing the concomitant transplantation therapy of MSCs and allogenic cells for treatment of heart failure.
BACKGROUND: Bone marrow mononuclear cell (BMMC) transplantation for heart failure has shown inconsistent therapeutic efficacy.METHODS: We enrolled 104 ischemic heart failure patients scheduled for coronary artery bypass surgery (CABG). After 4- to 12-week pharmacotherapy optimization, 39 patients with left ventricular ejection fraction (LVEF) of <= 45% received injections of BMMC or vehicle intra-operatively into the myocardial infarction border area in a randomized, double-blind manner.RESULTS: The median number of cells injected was 8.4 x 10(8) (interquartile range [IQR]: 5.2 x 10(8) to 13.5 x 10(8)). We measured LV function and myocardial scar size by magnetic resonance imaging (MRI), and viability by positron emission tomography (PET) and single-photon emission computed tomography (SPECT), pre-operatively and after 1-year follow-up. LVEF, the pre-defined primary end-point measure, improved by a median of 5.6% in the control group (IQR 0.2 to 10.1) and by 4.8% in the BMMC group (IQR -0.5 to 8.2) (p = 0.59). Wall thickening in injected segments rose by a median of 4.5% among controls (IQR -18.1 to 23.9) and by 5.5% in the BMMC group (IQR -6.6 to 26.5) (p = 0.68). Changes in viability by PET and SPECT did not differ between groups. Myocardial scar size by MRI in injected segments rose by a median of 5.1% among controls (IQR -3.3 to 10.8), but fell by 13.1% in the BMMC group (IQR -21.4 to -6.5) (p = 0.0002).CONCLUSIONS: BMMC therapy combined with CABG failed to improve LV systolic function, or viability, despite reducing myocardial scar size. (C) 2014 International Society for Heart and Lung Transplantation. All rights reserved.