G-CSF treatment for STEMI: final 3-year follow-up of the randomised placebo-controlled STEM-AMI trial

Efficacy and Safety of Granulocyte-Colony Stimulating Factor Therapy in Chagas Cardiomyopathy: A Phase II Double-Blind, Randomized, Placebo-Controlled Clinical Trial

Aim

Previous studies showed that granulocyte-colony stimulating factor (G-CSF) improved heart function in a mice model of Chronic Chagas Cardiomyopathy (CCC). Herein, we report the interim results of the safety and efficacy of G-CSF therapy vs. placebo in adults with Chagas cardiomyopathy.

Methods

Patients with CCC, New York Heart Association (NYHA) functional class II to IV and left ventricular ejection fraction (LVEF) 50% or below were included. A randomization list using blocks of 2 and 4 and an allocation rate of 1:1 was generated by R software which was stratified by functional class. Double blinding was done to both arms and assessors were masked to allocations. All patients received standard heart failure treatment for 2 months before 1:1 randomization to either the G-CSF (10 mcg/kg/day subcutaneously) or placebo group (1 mL of 0.9% saline subcutaneously). The primary endpoint was either maintenance or improvement of NYHA class from baseline to 6–12 months after treatment, and intention-to-treat analysis was used.

Results

We screened 535 patients with CCC in Salvador, Brazil, of whom 37 were randomized. Overall, baseline characteristics were well-balanced between groups. Most patients had NYHA class II heart failure (86.4%); low mean LVEF was 32 ± 7% in the G-CSF group and 33 ± 10% in the placebo group. Frequency of primary endpoint was 78% (95% CI 0.60–0.97) vs. 66% (95% CI 0.40–0.86), p = 0.47, at 6 months and 68% (95% CI 0.43–0.87) vs. 72% (95% CI 0.46–0.90), p = 0.80, at 12 months in placebo and G-CSF groups, respectively. G-CSF treatment was safe, without any related serious adverse events. There was no difference in mortality between both arms, with five deaths (18.5%) in treatment vs. four (12.5%) in the placebo arm. Exploratory analysis demonstrated that the maximum rate of oxygen consumption during exercise (VO₂ max) showed an improving trend in the G-CSF group.

Conclusion

G-CSF therapy was safe and well-tolerated in 12 months of follow-up. Although prevention of symptom progression could not be demonstrated in the present study, our results support further investigation of G-CSF therapy in Chagas cardiomyopathy patients.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT02154269].

Increased serum pro-B-type natriuretic peptide in hematopoietic progenitor cell donors stimulated with G-CSF

Hematopoietic stem cells (HPCs) donors mobilized by granulocyte-colony-stimulating factor (G-CSF) can develop various signs and symptoms. proBNP (pro-B-type natriuretic peptide) is a serum marker of heart failure. A donor who developed severe adverse reactions after G-CSF mobilization was found to have high serum proBNP levels. We followed additional donors who received identical mobilization regimen to investigate the prevalence of this phenomenon. Eighteen healthy donors underwent a mobilization regimen of 10 μg/Kg G-CSF daily for 5 days prior to allogeneic HPC collection using Spectra Optia between January 2016 and February 2017 were included in this study. Serum proBNP levels were measured before and after G-CSF stimulation and immediately after apheresis. Apheresis collection parameters and other laboratory results were also reviewed. The majority of donors (86.7%) had post-G-CSF elevation of serum proBNP. Seven of those had elevated proBNP above upper normal range (124 pg/ml). The subgroup of donors with normal proBNP is younger (median age of 37 vs 42 years), with majority being male (90.9% vs 28.6%) and with smaller processed blood volume (2.2 vs 3 × total blood volume). This case series demonstrates an increase of serum proBNP can be common in HPC donors stimulated with 5 days of 10 mcg/kg G-CSF. This is an adverse reaction that has not been described before. The temporary elevation of proBNP in these donors is not associated with ventricular dysfunction of the heart. The risk factors for marked elevation of proBNP post-G-CSF should be further investigated.

The Effects of Granulocyte Colony-Stimulating Factor in Patients with a Large Anterior Wall Acute Myocardial Infarction to Prevent Left Ventricular Remodeling: A 10-Year Follow-Up of the RIGENERA Study

Background: the RIGENERA trial assessed the efficacy of granulocyte-colony stimulating factor (G-CSF) in the improvement of clinical outcomes in patients with severe acute myocardial infarction. However, there is no evidence available regarding the long-term safety and efficacy of this treatment. Methods: in order to evaluate the long-term effects on the incidence of major adverse events, on the symptom burden, on the quality of life and the mean life expectancy and on the left ventricular (LV) function, we performed a clinical and echocardiographic evaluation together with an assessment using the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and the Seattle Heart Failure Model (SHFM) at 10-years follow-up, in the patients cohorts enrolled in the RIGENERA trial. Results: thirty-two patients were eligible for the prospective clinical and echocardiography analyses. A significant reduction in adverse LV remodeling was observed in G-CSF group compared to controls, 9% vs. 48% (p = 0.030). The New York Heart Association (NYHA) functional class was lower in G-CSF group vs. controls (p = 0.040), with lower burden of symptoms and higher quality of life (p = 0.049). The mean life expectancy was significantly higher in G-CSF group compared to controls (15 ± 4 years vs. 12 ± 4 years, p = 0.046. No difference was found in the incidence of major adverse events. Conclusions: this longest available follow-up on G-CSF treatment in patients with severe acute myocardial infarction (AMI) showed that this treatment was safe and associated with a reduction of adverse LV remodeling and higher quality of life, in comparison with standard-of-care treatment.

G-CSF for Extensive STEMI

RATIONALE

In the exploratory Phase II STEM-AMI (Stem Cells Mobilization in Acute Myocardial Infarction) trial, we reported that early administration of G-CSF (granulocyte colony-stimulating factor), in patients with anterior ST-segment-elevation myocardial infarction and left ventricular (LV) dysfunction after successful percutaneous coronary intervention, had the potential to significantly attenuate LV adverse remodeling in the long-term.

OBJECTIVE

The STEM-AMI OUTCOME CMR (Stem Cells Mobilization in Acute Myocardial Infarction Outcome Cardiac Magnetic Resonance) Substudy was adequately powered to evaluate, in a population showing LV ejection fraction ≤45% after percutaneous coronary intervention for extensive ST-segment-elevation myocardial infarction, the effects of early administration of G-CSF in terms of LV remodeling and function, infarct size assessed by late gadolinium enhancement, and myocardial strain.

METHODS AND RESULTS

Within the Italian, multicenter, prospective, randomized, Phase III STEM-AMI OUTCOME trial, 161 ST-segment-elevation myocardial infarction patients were enrolled in the CMR Substudy and assigned to standard of care (SOC) plus G-CSF or SOC alone. In 119 patients (61 G-CSF and 58 SOC, respectively), CMR was available at baseline and 6-month follow-up. Paired imaging data were independently analyzed by 2 blinded experts in a core CMR lab. The 2 groups were similar for clinical characteristics, cardiovascular risk factors, and pharmacological treatment, except for a trend towards a larger infarct size and longer symptom-to-balloon time in G-CSF patients. ANCOVA showed that the improvement of LV ejection fraction from baseline to 6 months was 5.1% higher in G-CSF patients versus SOC (P=0.01); concurrently, there was a significant between-group difference of 6.7 mL/m² in the change of indexed LV end-systolic volume in favor of G-CSF group (P=0.02). Indexed late gadolinium enhancement significantly decreased in G-CSF group only (P=0.04). Moreover, over time improvement of global longitudinal strain was 2.4% higher in G-CSF patients versus SOC (P=0.04). Global circumferential strain significantly improved in G-CSF group only (P=0.006).

CONCLUSIONS

Early administration of G-CSF exerted a beneficial effect on top of SOC in patients with LV dysfunction after extensive ST-segment-elevation myocardial infarction in terms of global systolic function, adverse remodeling, scar size, and myocardial strain.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01969890.

New therapies for acute myocardial infarction: current state of research and future promise

Progress has been made into research on new therapies, mechanical and pharmacological approaches and repair/regenerative cellular therapy to treat irreversible cardiovascular pathologies, such as acute myocardial infarction. Research into cellular therapies is exploring the use of new cellular types. Although the therapeutic effects of cell therapy remain modest, results from clinical trials are encouraging. To expand this improvement, advances are being made that involve the paracrine function of stem cells, the use of growth factors, miRNA and new biomaterials. In the near future, these therapies should become part of routine clinical practice.

Cell therapy for heart disease after 15 years: Unmet expectations

Over the past two decades cardiac cell therapy (CCT) has emerged as a promising new strategy to cure heart diseases at high unmet need. Thousands of patients have entered clinical trials for acute or chronic heart conditions testing different cell types, including autologous or allogeneic bone marrow (BM)-derived mononuclear or selected cells, BM- or adipose tissue-derived mesenchymal cells, or cardiac resident progenitors based on their potential ability to regenerate scarred or dysfunctional myocardium. Nowadays, the original enthusiasm surrounding the regenerative medicine field has been cushioned by a cumulative body of evidence indicating an inefficient or modest efficacy of CCT in improving cardiac function, along with the continued lack of indisputable proof for long-term prognostic benefit. In this review, we have firstly comprehensively outlined the positive and negative results of cell therapy studies in patients with acute myocardial infarction, refractory angina and chronic heart failure. Next, we have discussed cell therapy- and patient-related variables (e.g. cell intrinsic and extrinsic characteristics as well as criteria of patient selection and proposed methodologies) that might have dampened the efficacy of past cell therapy trials. Finally, we have addressed critical factors to be considered before embarking on further clinical trials.

Stem cell mobilisation by granulocyte-colony stimulating factor in patients with acute myocardial infarction. Long-term results of the REVIVAL-2 trial

Treatment with granulocyte-colony stimulating factor (G-CSF) mobilises cells from the bone marrow to the peripheral blood. Previous preclinical and early clinical trials may suggest that treatment with G-CSF leads to improved myocardial perfusion and function in acute or chronic ischaemic heart disease. In the REVIVAL-2 study we found that stem cell mobilisation by G-CSF does not influence infarct size, left ventricular function and coronary restenosis in patients with acute myocardial infarction (MI) that underwent successful percutaneous coronary intervention. The objective of the present analysis was to assess the impact of G-CSF treatment on seven-year clinical outcomes from the REVIVAL-2 trial. In the randomized, double-blind, placebo-controlled REVIVAL-2 study, 114 patients with the diagnosis of acute myocardial infarction were enrolled five days after successful reperfusion by percutaneous coronary intervention. Patients were assigned to receive 10 µg/kg G-CSF (n=56) or placebo (n=58) for five days. The primary endpoint for this long-term outcome analysis was the composite of death, myocardial infarction or stroke seven years after randomisation. The endpoint occurred in 14.3 % of patients in the G-CSF group versus 17.2 % assigned to placebo (p=0.67). The combined incidence of death or myocardial infarction occurred in 14.3 % of the patients assigned to G-CSF and 15.5 % of the patients assigned to placebo (p=0.85). In conclusion, these long-term follow-up data show that G-CSF does not improve clinical outcomes of patients with acute myocardial infarction.

Granulocyte-colony stimulating factor for large anterior ST-elevation myocardial infarction: rationale and design of the prospective randomized phase III STEM-AMI OUTCOME trial

BACKGROUND

Granulocyte-colony stimulating factor (G-CSF) has been clinically tested in ST-elevation myocardial infarction (STEMI) with mixed results. Our 3-year follow-up data from STEM-AMI trial documented a sustained benefit of G-CSF on adverse ventricular remodeling after large anterior STEMI, when administered early and at a high-dose in patients with left ventricular (LV) dysfunction. The Aim of the present trial is to establish whether G-CSF improves hard clinical long-term outcomes.

METHODS

The STEM-AMI OUTCOME is a prospective, multicenter, randomized, open-label, phase III trial. It will include 1,530 patients with anterior STEMI undergoing primary percutaneous coronary intervention 2 to 24 hours after symptoms onset and with LV ejection fraction ≤45% after successful reperfusion. Patients will be randomized 1:1 to G-CSF and/or standard treatment. The primary end point is a reduced occurrence of all-cause death, recurrence of myocardial infarction, or hospitalization due to heart failure in G-CSF-treated patients. Left ventricular remodeling will be assessed via cardiac ultrasound and a substudy with cardiac magnetic resonance will be carried out in 120 subjects. Accrual and follow-up periods will last 3 and 2 years, respectively.

CONCLUSIONS

The STEM-AMI OUTCOME study is designed to be a rigorous controlled phase III trial with adequate statistical power to conclusively assess efficacy of G-CSF treatment in STEMI.

The hematopoietic system in the context of regenerative medicine

Hematopoietic stem cells (HSC) represent the prototype stem cell within the body. Since their discovery, HSC have been the focus of intensive research, and have proven invaluable clinically to restore hematopoiesis following inadvertent radiation exposure and following radio/chemotherapy to eliminate hematologic tumors. While they were originally discovered in the bone marrow, HSC can also be isolated from umbilical cord blood and can be "mobilized" peripheral blood, making them readily available in relatively large quantities. While their ability to repopulate the entire hematopoietic system would already guarantee HSC a valuable place in regenerative medicine, the finding that hematopoietic chimerism can induce immunological tolerance to solid organs and correct autoimmune diseases has dramatically broadened their clinical utility. The demonstration that these cells, through a variety of mechanisms, can also promote repair/regeneration of non-hematopoietic tissues as diverse as liver, heart, and brain has further increased their clinical value. The goal of this review is to provide the reader with a brief glimpse into the remarkable potential HSC possess, and to highlight their tremendous value as therapeutics in regenerative medicine.

High number of transplanted stem cells improves myocardial recovery after AMI in a porcine model

OBJECTIVE

The clinical data considering the bone marrow mononuclear cell (BMMNC) therapy in treatment for acute myocardial infarction (AMI) are controversial and the mechanisms remain unknown. Our objective was to study the cardiac function and changes in cytokine levels after administration of BMMNC in experimental AMI model.

DESIGN

Unlabeled or Super-Paramagnetic-Iron-Oxide-labeled BMMNCs or saline was injected into myocardium of 31 pigs after circumflex artery occlusion. Ejection fraction (EF) was measured preoperatively, postoperatively and at 21 days by echocardiography. Cardiac MRI was performed postoperatively and after 21 days in 7 BMMNC animals. Serum cytokine levels were measured at baseline, 24 h and 21 days. Cellular homing was evaluated comparing MRI and histology.

RESULTS

From baseline to 21 days EF decreased less in BMMNC group (EF mean control -19 SD 12 vs. BMMNC -4 SD 15 percentage points p = 0.02). Cytokine concentrations showed high variability between the animals. MRI correlated with histology in cell detection and revealed BMMNCs in the infarction area. By MRI, EF improved 11 percentage points. The improvement in EF was associated with the number of transplanted BMMNCs detected in the myocardium.

CONCLUSION

BMMNC injection after AMI improved cardiac function. Quantity of transplanted BMMNCs correlated with the improvement in cardiac function after AMI.

Bone marrow-derived progenitor cells attenuate inflammation in lipopolysaccharide-induced acute respiratory distress syndrome

Background

Acute respiratory distress syndrome (ARDS) is the most common cause of respiratory failure among critically ill patients. Novel treatment strategies are required to address this common clinical problem. The application of exogenous adult stem cells was associated with a beneficial outcome in various pre-clinical models of ARDS. In the present study we evaluated the functional capacity and homing ability of bone marrow-derived progenitor cells (BMDPC) in vitro and investigated their potential as a treatment strategy in lipopolysaccharide (LPS)-induced ARDS.

Results

Evaluation of the BMDPC showed functional capacity to form endothelial outgrowth cell colonies, which stained positive for CD133 and CD31. Furthermore, DiI-stained BMDPC were demonstrated to home to injured lung tissue. Rats treated with BMDPC showed significantly reduced histopathological changes, a reduced expression of ICAM-1 and VCAM-1 by the lung tissue, an inhibition of proinflammatory cytokine synthesis, a reduced weight loss and a reduced mortality (p < 0.03) compared to rats treated with LPS alone.

Conclusions

These findings suggest that the application of exogenous BMDPC can attenuate inflammation in LPS-induced ARDS and thereby reduce the severity of septic organ damage. Cell therapy strategies using adult stem cells might therefore become a novel and alternative option in ARDS therapy.