Anders Bruun Mathiasen

Exenatide reduces reperfusion injury in patients with ST-segment elevation myocardial infarction.

AIMS Exenatide, a glucagon-like-peptide-1 analogue, increases myocardial salvage in experimental settings with coronary occlusion and subsequent reperfusion. We evaluated the cardioprotective effect of exenatide at the time of reperfusion in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). METHODS AND RESULTS A total of 172 patients with STEMI and Thrombolysis in Myocardial Infarction flow 0/1 were randomly assigned to exenatide or placebo (saline) intravenously. Study treatment was commenced 15 min before intervention and maintained for 6 h after the procedure. The primary endpoint was salvage index calculated from myocardial area at risk (AAR), measured in the acute phase, and final infarct size measured 90 ± 21 days after pPCI by cardiac magnetic resonance (CMR). In 105 patients evaluated with CMR, a significantly larger salvage index was found in the exenatide group than in the placebo group (0.71 ± 0.13 vs. 0.62 ± 0.16; P= 0.003). Infarct size in relation to AAR was also smaller in the exenatide group (0.30 ± 0.15 vs. 0.39 ± 0.15; P= 0.003). In a regression analysis, there was a significant correlation between the infarct size and the AAR for both treatment groups and an analysis of covariance showed that datapoints in the exenatide group lay significantly lower than for the placebo group (P= 0.011). There was a trend towards smaller absolute infarct size in the exenatide group (13 ± 9 vs. 17 ± 14 g; P= 0.11). No difference was observed in left ventricular function or 30-day clinical events. No adverse effects of exenatide were observed. CONCLUSION In patients with STEMI undergoing pPCI, administration of exenatide at the time of reperfusion increases myocardial salvage.

Enrichment of autologous fat grafts with ex-vivo expanded adipose tissue-derived stem cells for graft survival: a randomised placebo-controlled trial

BACKGROUND Autologous fat grafting is increasingly used in reconstructive surgery. However, resorption rates ranging from 25% to 80% have been reported. Therefore, methods to increase graft viability are needed. Here, we report the results of a triple-blind, placebo-controlled trial to compare the survival of fat grafts enriched with autologous adipose-derived stem cells (ASCs) versus non-enriched fat grafts. METHODS Healthy participants underwent two liposuctions taken 14 days apart: one for ASC isolation and ex-vivo expansion, and another for the preparation of fat grafts. Two purified fat grafts (30 mL each) taken from the second liposuction were prepared for each participant. One graft was enriched with ASCs (20 × 10(6) cells per mL fat), and another graft without ASC enrichment served as a control. The fat grafts were injected subcutaneously as a bolus to the posterior part of the right and left upper arm according to the randomisation sequence. The volumes of injected fat grafts were measured by MRI immediately after injection and after 121 days before surgical removal. The primary goal was to compare the residual graft volumes of ASC-enriched grafts with those of control grafts. This study is registered at www.clinicaltrialsregister.eu, number 2010-023006-12. FINDINGS 13 participants were enrolled, three of whom were excluded. Compared with the control grafts, the ASC-enriched fat grafts had significantly higher residual volumes: 23·00 (95% CI 20·57-25·43) cm(3) versus 4·66 (3·16-6·16) cm(3) for the controls, corresponding to 80·9% (76·6-85·2) versus 16·3% (11·1-21·4) of the initial volumes, respectively (p<0·0001). The difference between the groups was 18·34 (95% CI 15·70-20·98) cm(3), equivalent to 64·6% (57·1-72·1; p<0·0001). No serious adverse events were noted. INTERPRETATION The procedure of ASC-enriched fat grafting had excellent feasibility and safety. These promising results add significantly to the prospect of stem cell use in clinical settings, and indicate that ASC graft enrichment could render lipofilling a reliable alternative to major tissue augmentation, such as breast surgery, with allogeneic material or major flap surgery. FUNDING Danish Cancer Society, Centre of Head and Orthopaedics Rigshospitalet, and Moalem Weitemeyer Bendtsen.

Bone marrow-derived mesenchymal stromal cell treatment in patients with severe ischaemic heart failure: a randomized placebo-controlled trial (MSC-HF trial)

AIMS Regenerative treatment with mesenchymal stromal cells (MSCs) has been promising in patients with ischaemic heart failure but needs confirmation in larger randomized trials. We aimed to study effects of intra-myocardial autologous bone marrow-derived MSC treatment in patients with severe ischaemic heart failure. METHODS AND RESULTS The MSC-HF trial is a randomized, double-blind, placebo-controlled trial. Patients were randomized 2 : 1 to intra-myocardial injections of MSC or placebo, respectively. The primary endpoint was change in left ventricular end-systolic volume (LVESV), measured by magnetic resonance imaging or computed tomography at 6 months follow-up. Sixty patients aged 30-80 years with severe ischaemic heart failure, New York Heart Association (NYHA) classes II-III, left ventricular ejection fraction (LVEF) <45% and no further treatment options were randomized. Fifty-five patients completed the 6-month follow-up (37 MSCs vs. 18 placebo). At 6 months, LVESV was reduced in the MSC group: -7.6 (95% CI -11.8 to -3.4) mL (P = 0.001), and increased in the placebo group: 5.4 (95% CI -0.4 to 11.2) mL (P = 0.07). The difference between groups was 13.0 (95% CI 5.9-20.1) mL (P = 0.001). Compared with placebo, there were also significant improvements in LVEF of 6.2% (P<0.0001), stroke volume of 18.4 mL (P < 0.0001), and myocardial mass of 5.7 g (P = 0.001). No differences were found in NYHA class, 6-min walking test and Kansas City cardiomyopathy questionnaire. No side effects were identified. CONCLUSION Intra-myocardial injections of autologous culture expanded MSCs were safe and improved myocardial function in patients with severe ischaemic heart failure. STUDY REGISTRATION NUMBER NCT00644410 (ClinicalTrials.gov).

Adipose-derived mesenchymal stromal cells for chronic myocardial ischemia (MyStromalCell Trial): study design

Adipose tissue represents an abundant, accessible source of multipotent adipose-derived stromal cells (ADSCs). Animal studies have suggested that ADSCs have the potential to differentiate in vivo into endothelial cells and cardiomyocytes. This makes ADSCs a promising new cell source for regenerative therapy to replace injured tissue by creating new blood vessels and cardiomyocytes in patients with chronic ischemic heart disease. The aim of this special report is to review the present preclinical data leading to clinical stem cell therapy using ADSCs in patients with ischemic heart disease. In addition, we give an introduction to the first-in-man clinical trial, MyStromalCell Trial, which is a prospective, randomized, double-blind, placebo-controlled study using culture-expanded ADSCs obtained from adipose-derived cells from abdominal adipose tissue and stimulated with VEGF-A(165) the week before treatment.

Rationale and design of the first randomized, double-blind, placebo-controlled trial of intramyocardial injection of autologous bone-marrow derived Mesenchymal Stromal Cells in chronic ischemic Heart Failure (MSC-HF Trial)

BACKGROUND Stem cell therapy is an emerging treatment modality in cardiovascular disease. The best cell type and delivery method in different cardiovascular diseases remain to be determined. STUDY DESIGN The MSC-HF trial is a phase 2, single-center, double-blind, randomized, placebo-controlled trial of intramyocardial delivery of autologous bone-marrow derived mesenchymal stromal cells (MSCs) in patients with chronic ischemic heart failure. A total of 60 patients will be randomized in a 2:1 pattern to receive intramyocardial injections of either MSCs or placebo. Patients will be followed up for 12 months. METHODS Bone marrow will be obtained by aspiration from the iliac crest. Mesenchymal stromal cells will be isolated, and culture will be expanded for 6 to 8 weeks. A total of 12 to 15 MSC or placebo injections will be placed in an ischemic viable region of the myocardium using the electromechanical NOGA-XP system (Biologics Delivery Systems Group, Johnson & Johnson, Irwindale, CA). ENDPOINTS The primary endpoint is change in left ventricle end-systolic volume, measured by magnetic resonance imaging (MRI) or computed tomography (CT) at 6-month follow-up. Secondary endpoints are left ventricle ejection fraction, ventricular volumes, wall thickness, and systolic wall thickening measured by MRI or CT in addition to measurement of myocardial scar tissue by MRI. Other secondary endpoints are safety of treatment, clinical symptoms and functional capacity, weekly angina attacks, use of short-term nitroglycerine, and quality of life. CONCLUSION A randomized, double-blind, placebo-controlled, clinical trial of intramyocardial delivery of MSCs in patients with ischemic heart failure has been set up to confirm the positive findings in open-labeled clinical trials.

Mesenchymal stromal cell derived endothelial progenitor treatment in patients with refractory angina

Abstract Aims. We evaluated the feasibility, safety and efficacy of intra-myocardial injection of autologous mesenchymal stromal cells derived endothelial progenitor cell (MSC) in patients with stable coronary artery disease (CAD) and refractory angina in this first in man trial. Methods and results. A total of 31 patients with stable CAD, moderate to severe angina and no further revascularization options, were included. Bone marrow MSC were isolated and culture expanded for 6–8 weeks. It was feasible and safe to establish in-hospital culture expansion of autologous MSC and perform intra-myocardial injection of MSC. After six months follow-up myocardial perfusion was unaltered, but the patients increased exercise capacity (p < 0.001), reduction in CCS Class (p < 0.001), angina attacks (p < 0.001) and nitroglycerin consumption (p < 0.001), and improved Seattle Angina Questionnaire (SAQ) evaluations (p < 0.001). For all parameters there was a tendency towards improved outcome with increasing numbers of cells injected. In the MRI substudy: ejection fraction (p < 0.001), systolic wall thickness (p = 0.03) and wall thickening (p = 0.03) all improved. Conclusions. The study demonstrated that it was safe to treat patients with stable CAD with autologous culture expanded MSC. Moreover, MSC treated patients had significant improvement in left ventricular function and exercise capacity, in addition to an improvement in clinical symptoms and SAQ evaluations. Trial registration: ClinicalTrials.gov identifier: NCT00260338.

Mesenchymal stromal cells for cardiovascular repair: current status and future challenges.

Ischemic heart disease is the most common cause of death in most industrialized countries. Early treatment with stabilizing drugs and mechanical revascularization by percutaneous coronary intervention or coronary bypass surgery has reduced the mortality significantly. In spite of improved offers of treatments in patients with heart failure, the 1-year mortality is still approximately 20% after the diagnosis has been established. Treatment with stem cells with the potential to regenerate the damaged myocardium is a relatively new approach. Mesenchymal stromal cells are a promising source of stem cells for regenerative therapy. Clinical studies on stem cell therapy for cardiac regeneration have shown significant improvements in ventricular pump function, ventricular remodeling, myocardial perfusion, exercise potential and clinical symptoms compared with conventionally treated control groups. The results of most studies are promising, but there are still many unanswered questions. In this review, we explore present preclinical and clinical knowledge regarding the use of stem cells in cardiovascular regenerative medicine, with special focus on mesenchymal stromal cells. We take a closer look at sources of stem cells, delivery method and methods for tracking injected cells.

Left atrial volume and function in patients following ST elevation myocardial infarction and the association with clinical outcome: a cardiovascular magnetic resonance study

AIMS The left atrium (LA) transfers blood to the left ventricle in a complex manner. LA function is characterized by passive emptying (LA passive fraction), active emptying (LA ejection fraction), and total emptying (LA fractional change). Despite this complexity, the clinical relevance of the LA is based almost exclusively on LA maximal volume (LAmax), which may not glean the full prognostic potential. Cardiovascular magnetic resonance (CMR) is considered the most accurate method for studying LA function and size. The aim of the present study was to evaluate the prognostic importance of LA function in patients following ST elevation myocardial infarction (STEMI). METHODS AND RESULTS In 199 patients, a CMR scan was performed within 1-3 days after STEMI to measure LAmax and minimal volume (LAmin) and LA function. The incidence of death, re-infarction, stroke, and admission for heart failure [major adverse cardiac event (MACE)] were registered during the follow-up period [2.3 years (inter-quartile range: 2.0-2.5)]. A total of 40 patients (20%) met the clinical endpoint of MACE during follow-up. In a Cox regression analysis adjusting for known risk factors, LA fractional change remained independently associated with MACE [adjusted hazard ratio: 0.66 (95% confidence interval: 0.46-0.95)]. LAmax, LAmin, or LA passive fraction was not independently associated with MACE. Furthermore, LA fractional change provided incremental prognostic value to LAmax and other known predictors (Wald χ(2) 31.0 vs. 39.9, P= 0.016). CONCLUSION In STEMI patients, impaired LA fractional change is independently associated with outcome and provide incremental prognostic information to established predictors including LAmax.

Pooled human platelet lysate versus fetal bovine serum—investigating the proliferation rate, chromosome stability and angiogenic potential of human adipose tissue-derived stem cells intended for clinical use

BACKGROUND AIMS Because of an increasing focus on the use of adipose-derived stem cells (ASCs) in clinical trials, the culture conditions for these cells are being optimized. We compared the proliferation rates and chromosomal stability of ASCs that had been cultured in Dulbeccos modified Eagles Medium (DMEM) supplemented with either pooled human platelet lysate (pHPL) or clinical-grade fetal bovine serum (FBS) (DMEM(pHPL) versus DMEM(FBS)). METHODS ASCs from four healthy donors were cultured in either DMEM(pHPL) or DMEM(FBS), and the population doubling time (PDT) was calculated. ASCs from two of the donors were expanded in DMEM(pHPL) or DMEM(FBS) and cultured for the final week before harvesting with or without the addition of vascular endothelial growth factor. We assessed the chromosomal stability (through the use of array comparative genomic hybridization), the expression of ASC and endothelial surface markers and the differentiation and angiogenic potential of these cells. RESULTS The ASCs that were cultured in pHPL exhibited a significantly shorter PDT of 29.6 h (95% confidence interval, 22.3-41.9 h) compared with those cultured in FBS, for which the PDT was 123.9 h (95% confidence interval, 95.6-176.2 h). Comparative genomic hybridization analyses revealed no chromosomal aberrations. Cell differentiation, capillary structure formation and cell-surface marker expression were generally unaffected by the type of medium supplement that was used or by the addition of vascular endothelial growth factor. CONCLUSIONS We observed that the use of pHPL as a growth supplement for ASCs facilitated a significantly higher proliferation rate compared with FBS without compromising genomic stability or differentiation capacity.

Autotransplantation of mesenchymal stromal cells from bone-marrow to heart in patients with severe stable coronary artery disease and refractory angina — Final 3-year follow-up☆

BACKGROUND The study assessed long-term safety and efficacy of intramyocardial injection of autologous bone-marrow derived mesenchymal stromal cells (BMMSCs) in patients with severe stable coronary artery disease (CAD) and refractory angina. METHODS Thirty-one patients with severe stable CAD and refractory angina were included. Patients had reversible myocardial ischemia and no further revascularization options. Autologous BMMSCs were isolated, culture expanded and stimulated with vascular endothelial growth-factor to facilitate endothelial differentiation. BMMSCs were injected into an ischemic, viable region of the myocardium. Patients were followed for 3 years. RESULTS We found significant clinical improvements in exercise time (p=0.0016), angina class (CCS) (p<0.0001), weekly number of angina attacks (p<0.0001) and use of nitroglycerine from (p=0.0017). In the Seattle Angina Questionnaire there were significant improvements in physical limitation score, angina stability score, angina frequency score and quality of life score (all p<0.0001). When comparing all hospital admissions from 3 years before to 3 years after treatment, we observed highly reduced admission rates for stable angina (p<0.0001), revascularization (p=0.003) and overall cardiovascular disease (p<0.0001). No early or late side-effects of the treatment were observed. CONCLUSIONS The final 3-year follow-up data after intramyocardial injection of autologous BMMSCs, in patients with severe CAD and refractory angina, demonstrated sustained clinical effects, reduced hospital admissions for cardiovascular disease and excellent long-term safety. The results indicate that autotransplantation of BMMSCs to the heart does not only improve symptoms but also slows down disease progression.