Safety and efficacy of percutaneous intramyocardial bone marrow cell injection for chronic myocardial ischemia: Long-term results.

BACKGROUND: Intramyocardial injection of bone marrow cells (BMC) in refractory angina patients with chronic myocardial ischemia has shown to be safe and improve clinical status during short-term follow-up. However, scarce data are available on long-term (>12 months) safety and efficacy. Therefore, the occurrence of clinical events and the long-term clinical effects of intramyocardial BMC injection were evaluated in patients with chronic myocardial ischemia up to 10 years after treatment. METHODS AND RESULTS: Patients (n = 100, age 64 ± 9 years, male 88%) with chronic myocardial ischemia who underwent intramyocardial BMC injection between 2004 and 2010 were evaluated. During yearly outpatient clinic visits, the occurrence of clinical events was documented. In addition, clinical status was assessed according to the Canadian Cardiovascular Society (CCS) score and quality of life was measured using the Seattle Angina Questionnaire. These parameters were evaluated at baseline and during the first year, followed by cross-sectional long-term follow-up which was performed in 2011 and 2014. No adverse events considered related to the procedure occurred during 10 years of follow-up. Observed annual mortality rate and annual myocardial infarction rate were 3.8% and 1.9% per year, respectively. When compared to baseline, CCS class and quality of life remained significantly better during 5-year follow-up after BMC treatment (both P < 0.05). CONCLUSIONS: The present long-term follow-up study shows that intramyocardial BMC injection in patients with chronic myocardial ischemia is safe and improves both angina complaints and quality of life up to 5 years after BMC treatment.

Repeated Intramyocardial Bone Marrow Cell Injection in Previously Responding Patients With Refractory Angina Again Improves Myocardial Perfusion, Anginal Complaints, and Quality of Life.

BACKGROUND: Intramyocardial bone marrow cell injection is associated with improvements in myocardial perfusion and anginal symptoms in patients with refractory angina pectoris. This study evaluates the effect of repeated intramyocardial bone marrow cell injection in patients with residual or recurrent myocardial ischemia. METHODS AND RESULTS: Twenty-three patients (17 men; 69±9 years) who had improved myocardial perfusion after the first injection but had residual or recurrent angina and ischemia on single-photon emission computed tomographic myocardial perfusion imaging were included. Patients again received intramyocardial injection of 100×10(6) autologous bone marrow mononuclear cells, 4.6±2.5 years after their first injection. No periprocedural complications occurred. Myocardial perfusion assessed using single-photon emission computed tomographic myocardial perfusion imaging improved from a summed stress score of 27.3±5.8 at baseline to 24.5±4.4 at 3 months (P=0.002) and 25.4±4.9 at 12 months of follow-up (P=0.002). Perfusion improvement after 3 months was comparable with the effect of the first injection (P=0.379). Anginal complaints improved ≤12 months after cell injection in Canadian Cardiovascular Society score (mean change at 3, 6, and 12 months: 0.6±0.9%, 0.5±0.9%, and 0.6±0.9%, respectively; Pslope=0.007, first versus repeated; P=0.188) and in quality of life score as measured by Seattle Angina Questionnaire (mean change at 3, 6, and 12 months: 7±14%, 8±14%, and 7±15%, respectively; Pslope=0.020, first versus repeated; P=0.126). CONCLUSIONS: Repeated bone marrow cell injection in previously responding patients with refractory angina is associated with improvements in myocardial perfusion, anginal complaints, and quality of life score ≤12 months of follow-up. CLINICAL TRIAL REGISTRATION: URL: http://www.trialregister.nl. Unique identifier: NTR2664.

Predictors of response to intramyocardial bone marrow cell treatment in patients with refractory angina and chronic myocardial ischemia.

BACKGROUND: We previously showed that intramyocardial bone marrow cell (BMC) injection in patients with refractory angina and chronic myocardial ischemia improves myocardial perfusion, cardiac function and disease-related complaints. Treatment effect varied between patients, but the predictors of response remain to be identified. Therefore, the aim of the present study was to assess whether patient characteristics, procedural data and baseline measurements influence the response to intramyocardial BMC treatment in a large cohort of refractory angina patients. METHODS AND RESULTS: In 120 patients (64 ± 9 years, 88% men) with refractory angina, 97 ± 13 × 10(6) BMCs were injected intramyocardially in regions with stress-inducible ischemia as assessed by single photon emission computed tomography (SPECT). Canadian Cardiovascular Society angina (CCS) class, quality-of-life score, exercise testing, SPECT and magnetic resonance imaging were performed at baseline and at 3 months follow-up demonstrating significant improvements in CCS class, quality-of-life, exercise capacity, myocardial perfusion and left ventricular function (all variables P<0.001). Multivariate analysis was performed to evaluate the influence of patient characteristics, procedural data and baseline measurements on BMC treatment response. Based on the improvement of myocardial perfusion at stress, diabetes and a large number of ischemic segments at baseline were shown to be independently associated with a large response to BMC therapy. CONCLUSION: The present study demonstrates that diabetes and a large number of ischemic segments are predictors of a large response to intramyocardial BMC injection in refractory angina and chronic ischemia. Furthermore, the safety and efficacy results of previous trials are now confirmed in a larger study population.

Effect of intramyocardial bone marrow-derived mononuclear cell injection on cardiac sympathetic innervation in patients with chronic myocardial ischemia.

Intramyocardial bone marrow cell injection has been associated with improvements in myocardial perfusion and left ventricular function. The current substudy of a randomized, placebo-controlled, double-blinded study, investigated the effect of intramyocardial bone marrow cell injection on myocardial sympathetic innervation in patients with chronic myocardial ischemia. In a total of 16 patients (64 ± 8 years, 13 men), early and late iodine-123 metaiodobenzylguanidine (MIBG) imaging was performed before and 3 months after intramyocardial bone marrow cell injection. No improvements were observed in global early H/M ratio (P = 0.40), late H/M ratio (P = 0.43) and cardiac washout rate (P = 0.98). However, late 123-I MIBG SPECT defect score showed a trend to improvement in the bone marrow cell group (from 31.0 ± 7.1 to 28.1 ± 14.9) as compared to the placebo group (from 33.6 ± 8.5 to 34.5 ± 9.8, P = 0.055 between groups). This trend was mainly driven by a substantial improvement in three bone marrow cell-treated patients, which all had diabetes and severe MIBG defects. In these patients, the extent and severity of MIBG defects improved substantially independent of myocardial perfusion and cell injection sites. The present study does not demonstrate improvements in global cardiac sympathetic nerve innervation after intramyocardial bone marrow cell injection in patients with chronic myocardial ischemia. However, regional analysis of sympathetic nerve innervation reveals improvements in three diabetic patients independent of myocardial perfusion, suggestive of a therapeutic effect on diabetic cardiac sympathetic dysinnervation.

Intramyocardial injection of autologous bone marrow-derived ex vivo expanded mesenchymal stem cells in acute myocardial infarction patients is feasible and safe up to 5 years of follow-up.

In experimental studies, mesenchymal stem cell (MSC) transplantation in acute myocardial infarction (AMI) models has been associated with enhanced neovascularization and myogenesis. Clinical data however, are scarce. Therefore, the present study evaluates the safety and feasibility of intramyocardial MSC injection in nine patients, shortly after AMI during short-term and 5-year follow-up. Periprocedural safety analysis demonstrated one transient ischemic attack. No other adverse events related to MSC treatment were observed during 5-year follow-up. Clinical events were compared to a nonrandomized control group comprising 45 matched controls. A 5-year event-free survival after MSC-treatment was comparable to controls (89 vs. 91 %, P = 0.87). Echocardiographic imaging for evaluation of left ventricular function demonstrated improvements up to 5 years after MSC treatment. These findings were not significantly different when compared to controls. The present safety and feasibility study suggest that intramyocardial injection of MSC in patients shortly after AMI is feasible and safe up to 5-year follow-up.

Intramyocardial injection of bone marrow mononuclear cells in chronic myocardial ischemia patients after previous placebo injection improves myocardial perfusion and anginal symptoms: an intra-patient comparison.

BACKGROUND: We recently demonstrated in a randomized, double-blind, placebo-controlled trial that intramyocardial bone marrow cell (BMC) injection is associated with improvements in myocardial perfusion and anginal symptoms in chronic myocardial ischemia patients. In the present study the results of the crossover phase of this trial, in which patients previously treated with placebo received autologous BMC injections are reported. This allows a unique intra-patient comparison on the effect of BMC versus placebo injection with elimination of patient-related confounding factors. METHODS: In 16 patients (14 male, 64 ± 10 years), who previously received intramyocardial placebo injections in the setting of a randomized trial, 100 × 10(6) BMC were injected using the NOGA-system. Canadian Cardiovascular Society angina score and quality of life were evaluated at baseline, 3 and 6 months. Tc-99m single photon emission computed tomography and magnetic resonance imaging were performed at baseline and 3 months to assess myocardial perfusion and left ventricular (LV) function. RESULTS: Canadian Cardiovascular Society score and quality of life improved significantly after BMC injection as compared to placebo (P = 0.01 and P = 0.02, respectively). Single photon emission computed tomography revealed a significant greater improvement (P = 0.03) in summed stress score after BMC injection as compared to placebo. LV end-systolic volume significantly decreased after BMC injection but not after placebo injection. LV end-diastolic volume and LV ejection fraction did not change. CONCLUSION: Intramyocardial BMC injection in patients with chronic myocardial ischemia who previously received intramyocardial placebo treatment resulted in significant improvement in angina symptoms and myocardial perfusion. These results confirm the outcome of our previously reported randomized trial.

Cell therapy for the treatment of chronic ischemic heart disease.

Over the last decade, much was learned about the biology of several types of stem and progenitor cells. It has become apparent that various cell sources may have the capacity to promote cardiomyogenesis and new blood vessel formation through different mechanisms, forming the rationale for cell-based therapy in patients with chronic ischemic heart disease. After initial clinical studies have provided evidence for safety of cell administration, larger randomized trials demonstrated variable effects on myocardial perfusion and contractile performance. Although cell-based therapy is a promising strategy for the treatment of myocardial disease, many questions remain to be answered with respect to the optimal cell type, delivery route and mechanism of action in order to improve the outcome of cardiac cell therapy. This paper aims to provide an overview of the methods available to apply cell-based therapy in chronic ischemic myocardial disease. The different cell types that have been tested in (pre)clinical trials and their proposed mechanism of action will be discussed, along with the possible routes of cell delivery. Furthermore, the experience from experimental and clinical studies will be summarized, and innovative strategies to enhance the efficacy of cell therapy, for example by improving cell retention and survival, will be reviewed.

Bone marrow cell injection for chronic myocardial ischemia: the past and the future.

Intramyocardial bone marrow cell injection is currently being investigated as a new therapeutic option for the treatment of chronic myocardial ischemia. Experimental studies and early phase clinical trials established a favorable safety profile of this approach and suggested that bone marrow cell injection was associated with clinical and functional improvements. Recently, a randomized, double-blind, placebo-controlled trial demonstrated that intramyocardial bone marrow cell injection was associated with beneficial effects on myocardial perfusion and anginal symptoms. However, the mechanisms by which bone marrow cells may improve myocardial perfusion are only partially understood, and several issues remain to be addressed. This review aims to provide a summary of the current experience with bone marrow cell therapy as a novel treatment option for patients with chronic myocardial ischemia. Therefore, the most frequently used cell types will be reviewed along with the mechanisms through which bone marrow cells may improve myocardial perfusion and function. In addition, possible routes of delivery are compared, and the results of currently available experimental and clinical studies are discussed.

Intramyocardial bone marrow-derived mononuclear cell injection for chronic myocardial ischemia: the effect on diastolic function.

BACKGROUND: The present substudy of a recently published randomized trial aimed to investigate the effect of intramyocardial bone marrow cell injection on diastolic function in patients with chronic myocardial ischemia. METHODS AND RESULTS: In a total of 50 patients, diastolic function was evaluated before and 3 months after bone marrow cell injection using standard echocardiography and strain analysis. In addition, MRI-derived transmitral flow measurements were obtained in a subset of 36 patients. Left ventricular ejection fraction increased from 50±5% to 54±7% in the bone marrow cell group, which was a significant improvement as compared with the placebo group (52±5% versus 51±7%, P=0.001). Filling pressure estimate E/E' ratio improved from 14±5 at baseline to 12±4 at 3 months in the bone marrow cell group, whereas no improvement was observed in the placebo group (13±4 versus 13±5). The improvement in E/E' ratio was significantly larger in the bone marrow cell group (P=0.008). Furthermore, the E/A peak flow ratio as assessed by MRI showed a significant increase in the bone marrow cell group as compared with the placebo group (+0.16±0.25 versus -0.04±0.21, P=0.01), which was mainly related to an increase in the early (E) peak flow rate in the bone marrow cell group (from 407±96 mL/s to 468±110 mL/s, P=0.009 as compared with the placebo group). CONCLUSIONS: The current study demonstrates that intramyocardial bone marrow cell injection is associated with a beneficial effect on myocardial relaxation and filling pressures in patients with chronic myocardial ischemia.