The effect of intracoronary infusion of bone marrow-derived mononuclear cells on all-cause mortality in acute myocardial infarction: rationale and design of the BAMI trial.

Over the past 13 years bone marrow-derived mononuclear cells (BM-MNCs) have been widely investigated for clinical efficacy in patients following acute myocardial infarction (AMI). These early phase II trials have used various surrogate markers to judge efficacy and, although promising, the results have been inconsistent. The phase III BAMI trial has therefore been designed to demonstrate that intracoronary infusion of BM-MNCs is safe and will significantly reduce the time to first occurrence of all-cause death in patients with reduced left ventricular ejection fraction after successful reperfusion for ST-elevation AMI (powered with the aim of detecting a 25% reduction in all-cause mortality). This is a multinational, multicentre, randomized, open-label, controlled, parallel-group phase III study aiming to enrol approximately 3000 patients in 11 European countries with at least 17 sites. Eligible patients who have impaired left ventricular ejection (≤45%) following successful reperfusion for AMI will be randomized to treatment or control group in a 1:1 ratio. The treatment group will receive intracoronary infusion of BM-MNCs 2-8 days after successful reperfusion for AMI added on top of optimal standard of care. The control group will receive optimal standard of care. The primary endpoint is time from randomization to all-cause death. The BAMI trial is pivotal and the largest trial to date of BM-MNCs in patients with impaired left ventricular function following AMI. The aim of the trial is to provide a definitive answer as to whether BM-MNCs reduce all-cause mortality in this group of patients.

Benefit of cardiopoietic mesenchymal stem cell therapy on left ventricular remodelling: results from the Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART-1) study.

AIMS: Left ventricular (LV) reverse remodelling is an important marker of improved outcomes in patients with advanced heart failure (HF). We examined the impact of the intramyocardial administration of bone-marrow-derived, lineage-directed, autologous cardiopoietic mesenchymal stem cells (C3BS-CQR-1) on LV remodelling in patients with advanced HF enrolled in the CHART-1 study. METHODS AND RESULTS: Patients (n=351) with symptomatic advanced HF secondary to ischaemic heart disease, and reduced LV ejection fraction (LVEF <35%) were randomized to receive C3BS-CQR-1 or a sham procedure. In a post hoc analysis we examined the effect of C3BS-CQR-1 on LV reverse remodelling within 1 year of the procedure and the influence of C3BS-CQR-1 dosing in the 271 patients treated as randomized. Delivery of C3BS-CQR-1 was associated with a progressive decrease in both LV end-diastolic volume (LVEDV) and end-systolic volume (LVESV) within 52 weeks after treatment. At 1 year, the LVEDV and LVESV of treated patients decreased by 17.0 mL and 12.8 mL greater than controls (P=0.006 and P=0.017, respectively). The effect on LVEDV was maintained after multivariable adjustment for baseline age, systolic blood pressure, LVEDV, LVEF and history of myocardial infarction. The largest reverse remodelling was evident in the patients receiving a moderate number of injections (<20). CONCLUSION: In CHART-1, intramyocardial administration of cardiopoietic stem cells led to reverse remodelling as evidenced by significant progressive decreases in LVEDV and LVESV through the 52 weeks of follow-up. Further studies are needed to explore the dose response with regard to cell number and injected volume, and reverse remodelling.

Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART-1) trial design.

AIMS: Cardiopoiesis is a conditioning programme that aims to upgrade the cardioregenerative aptitude of patient-derived stem cells through lineage specification. Cardiopoietic stem cells tested initially for feasibility and safety exhibited signs of clinical benefit in patients with ischaemic heart failure (HF) warranting definitive evaluation. Accordingly, CHART-1 is designed as a large randomized, sham-controlled multicentre study aimed to validate cardiopoietic stem cell therapy. METHODS: Patients (n = 240) with chronic HF secondary to ischaemic heart disease, reduced LVEF (<35%), and at high risk for recurrent HF-related events, despite optimal medical therapy, will be randomized 1:1 to receive 600 × 10(6) bone marrow-derived and lineage-directed autologous cardiopoietic stem cells administered via a retention-enhanced intramyocardial injection catheter or a sham procedure. The primary efficacy endpoint is a hierarchical composite of mortality, worsening HF, Minnesota Living with Heart Failure Questionnaire score, 6 min walk test, LV end-systolic volume, and LVEF at 9 months. The secondary efficacy endpoint is the time to cardiovascular death or worsening HF at 12 months. Safety endpoints include mortality, readmissions, aborted sudden deaths, and serious adverse events at 12 and 24 months. CONCLUSION: The CHART-1 clinical trial is powered to examine the therapeutic impact of lineage-directed stem cells as a strategy to achieve cardiac regeneration in HF populations. On completion, CHART-1 will offer a definitive evaluation of the efficacy and safety of cardiopoietic stem cells in the treatment of chronic ischaemic HF. TRIAL REGISTRATION: NCT01768702.

Optimized delivery system achieves enhanced endomyocardial stem cell retention.

BACKGROUND: Regenerative cell-based therapies are associated with limited myocardial retention of delivered stem cells. The objective of this study is to develop an endocardial delivery system for enhanced cell retention. METHODS AND RESULTS: Stem cell retention was simulated in silico using 1- and 3-dimensional models of tissue distortion and compliance associated with delivery. Needle designs, predicted to be optimal, were accordingly engineered using nitinol, a nickel and titanium alloy displaying shape memory and superelasticity. Biocompatibility was tested with human mesenchymal stem cells. Experimental validation was performed with species-matched cells directly delivered into Langendorff-perfused porcine hearts or administered percutaneously into the endocardium of infarcted pigs. Cell retention was quantified by flow cytometry and real-time quantitative polymerase chain reaction methodology. Models, computing optimal distribution of distortion calibrated to favor tissue compliance, predicted that a 75°-curved needle featuring small-to-large graded side holes would ensure the highest cell retention profile. In isolated hearts, the nitinol curved needle catheter (C-Cath) design ensured 3-fold superior stem cell retention compared with a standard needle. In the setting of chronic infarction, percutaneous delivery of stem cells with C-Cath yielded a 37.7±7.1% versus 10.0±2.8% retention achieved with a traditional needle without effect on biocompatibility or safety. CONCLUSIONS: Modeling-guided development of a nitinol-based curved needle delivery system with incremental side holes achieved enhanced myocardial stem cell retention.

Cardiopoietic stem cell therapy in heart failure: the C-CURE (Cardiopoietic stem Cell therapy in heart failURE) multicenter randomized trial with lineage-specified biologics.

OBJECTIVES: This study sought to evaluate the feasibility and safety of autologous bone marrow-derived and cardiogenically oriented mesenchymal stem cell therapy and to probe for signs of efficacy in patients with chronic heart failure. BACKGROUND: In pre-clinical heart failure models, cardiopoietic stem cell therapy improves left ventricular function and blunts pathological remodeling. METHODS: The C-CURE (Cardiopoietic stem Cell therapy in heart failURE) trial, a prospective, multicenter, randomized trial, was conducted in patients with heart failure of ischemic origin who received standard of care or standard of care plus lineage-specified stem cells. In the cell therapy arm, bone marrow was harvested and isolated mesenchymal stem cells were exposed to a cardiogenic cocktail. Derived cardiopoietic stem cells, meeting release criteria under Good Manufacturing Practice, were delivered by endomyocardial injections guided by left ventricular electromechanical mapping. Data acquisition and analysis were performed in blinded fashion. The primary endpoint was feasibility/safety at 2-year follow-up. Secondary endpoints included cardiac structure/function and measures of global clinical performance 6 months post-therapy. RESULTS: Mesenchymal stem cell cocktail-based priming was achieved for each patient with the dose attained in 75% and delivery without complications in 100% of cases. There was no evidence of increased cardiac or systemic toxicity induced by cardiopoietic cell therapy. Left ventricular ejection fraction was improved by cell therapy (from 27.5 ± 1.0% to 34.5 ± 1.1%) versus standard of care alone (from 27.8 ± 2.0% to 28.0 ± 1.8%, p < 0.0001) and was associated with a reduction in left ventricular end-systolic volume (-24.8 ± 3.0 ml vs. -8.8 ± 3.9 ml, p < 0.001). Cell therapy also improved the 6-min walk distance (+62 ± 18 m vs. -15 ± 20 m, p < 0.01) and provided a superior composite clinical score encompassing cardiac parameters in tandem with New York Heart Association functional class, quality of life, physical performance, hospitalization, and event-free survival. CONCLUSIONS: The C-CURE trial implements the paradigm of lineage guidance in cell therapy. Cardiopoietic stem cell therapy was found feasible and safe with signs of benefit in chronic heart failure, meriting definitive clinical evaluation. (C-Cure Clinical Trial; NCT00810238).

Guided cardiopoiesis enhances therapeutic benefit of bone marrow human mesenchymal stem cells in chronic myocardial infarction.

OBJECTIVES: The goal of this study was to guide bone marrow-derived human mesenchymal stem cells (hMSCs) into a cardiac progenitor phenotype and assess therapeutic benefit in chronic myocardial infarction. BACKGROUND: Adult stem cells, delivered in their naïve state, demonstrate a limited benefit in patients with ischemic heart disease. Pre-emptive lineage pre-specification may optimize therapeutic outcome. METHODS: hMSC were harvested from a coronary artery disease patient cohort. A recombinant cocktail consisting of transforming growth factor-beta(1), bone morphogenetic protein-4, activin A, retinoic acid, insulin-like growth factor-1, fibroblast growth factor-2, alpha-thrombin, and interleukin-6 was formulated to engage hMSC into cardiopoiesis. Derived hMSC were injected into the myocardium of a nude infarcted murine model and followed over 1 year for functional and structural end points. RESULTS: Although the majority of patient-derived hMSC in their native state demonstrated limited effect on ejection fraction, stem cells from rare individuals harbored a spontaneous capacity to improve contractile performance. This reparative cytotype was characterized by high expression of homeobox transcription factor Nkx-2.5, T-box transcription factor TBX5, helix-loop-helix transcription factor MESP1, and myocyte enhancer factor MEF2C, markers of cardiopoiesis. Recombinant cardiogenic cocktail guidance secured the cardiopoietic phenotype across the patient cohort. Compared with unguided counterparts, cardiopoietic hMSC delivered into infarcted myocardium achieved superior functional and structural benefit without adverse side effects. Engraftment into murine hearts was associated with increased human-specific nuclear, sarcomeric, and gap junction content along with induction of myocardial cell cycle activity. CONCLUSIONS: Guided cardiopoiesis thus enhances the therapeutic benefit of bone marrow-derived hMSC in chronic ischemic cardiomyopathy.

Pretreatment of adult bone marrow mesenchymal stem cells with cardiomyogenic growth factors and repair of the chronically infarcted myocardium.

The in vivo cardiac differentiation and functional effects of unmodified adult bone marrow mesenchymal stem cells (MSCs) after myocardial infarction (MI) is controversial. We postulated that ex vivo pretreatment of autologous MSCs using cardiomyogenic growth factors will lead to cardiomyogenic specification and will result in superior biological and functional effects on cardiac regeneration of chronically infarcted myocardium. We used a chronic dog MI model generated by ligation of the coronary artery (n = 30). Autologous dog bone marrow MSCs were isolated, culture expanded, and specified into a cardiac lineage by adding growth factors, including basic FGF, IGF-1, and bone morphogenetic protein-2. Dogs underwent cell injection >8 wk after the infarction and were randomized into two groups. Group A dogs (n = 20) received MSCs specified with growth factors (147 +/- 96 x 10(6)), and group B (n = 10) received unmodified MSCs (168 +/- 24 x 10(6)). After the growth factor treatment, MSCs stained positive for the early muscle and cardiac markers desmin, antimyocyte enhancer factor-2, and Nkx2-5. In group A dogs, prespecified MSCs colocalized with troponin I and cardiac myosin. At 12 wk, group A dogs showed a significantly larger increase in regional wall thickening of the infarcted territory (from 22 +/- 8 to 32 +/- 6% in group A; P < 0.05 vs. baseline and group B, and from 19 +/- 7 to 21 +/- 7% in group B, respectively) and a decrease in the wall motion score index (from 1.60 +/- 0.05 to 1.35 +/- 0.03 in group A; P < 0.05 vs. baseline and group B, and from 1.58 +/- 0.07 vs. 1.56 +/- 0.08 in group B, respectively). The biological ex vivo cardiomyogenic specification of adult MSCs before their transplantation is feasible and appears to improve their in vivo cardiac differentiation as well as the functional recovery in a dog model of the chronically infarcted myocardium.