Mesenchymal stromal cells to treat patients with non-ischaemic heart failure: Results from SCIENCE II pilot study.

AIMS: Allogeneic stem cell therapy is more logistically suitable compared with autologous cell therapy for large-scale patient treatment. We aim to investigate the clinical safety and efficacy profile of the allogeneic adipose tissue derived mesenchymal stromal cell product (CSCC_ASC) as an add-on therapy in patients with chronic non-ischaemic heart failure with reduced left ventricular ejection fraction (HFrEF) < 40%. METHODS AND RESULTS: This is a single-centre investigator-initiated randomized phase I/II study with direct intra-myocardial injections of 100 million allogeneic CSCC_ASC. A total of 30 HFrEF patients with New York Heart Association (NYHA) class ≥II despite optimal anticongestive heart failure medication and plasma NT-proBNP > 300 pg/mL (>35 pmol/L) were included and randomized 2:1 to CSCC_ASC or standard care. The primary endpoint left ventricular end systolic volume (LVESV) and other echo related parameters were analysed by an investigator blinded for treatment allocation. No difference in serious adverse events was observed between groups. LVESV decreased significantly from baseline to 6 months follow-up in the ASC group (153.7 ± 53.2 mL and 128.7 ± 45.6 mL, P < 0.001) and remained unchanged in the standard care group (180.4 ± 39.4 mL and 186.7 ± 48.9 mL, P = 0.652). There was a significant difference between the groups in LVESV change (31.3 ± 11.0 mL, P = 0.009). The difference from baseline to follow-up between the two groups in left ventricular end diastolic volume (LVEDV) was 18.7 ± 12.4 mL, P = 0.146 and in left ventricular ejection fraction (LVEF) -7.8 ± 2.1%, P = 0.001. Considering the baseline values of LVESV, LVEDV and LVEF as covariates, the difference between groups for change from baseline to follow-up resulted in a P-value of 0.056, 0.076, and 0.738, respectively. NYHA class and self-reported health did also improve significantly in the ASC group compared with the standard care group (0.7 ± 0.2, P = 0.001 and -12.8 ± 5.3, P = 0.025; respectively). There was no difference in NT-proBNP (-371 ± 455 pmol/L, P = 0.422) or in 6 min walk test (12 ± 31 m, P = 0.695) between groups. CONCLUSIONS: Intramyocardial injections of allogeneic CSCC_ASC in patients with chronic non-ischaemic HFrEF was safe and improved LVESV, LVEF, NYHA class, and self-reported health compared with standard care group.

Effect of allogeneic adipose tissue-derived mesenchymal stromal cell treatment in chronic ischaemic heart failure with reduced ejection fraction - the SCIENCE trial.

AIMS: The aim of the SCIENCE trial was to investigate whether a single treatment with direct intramyocardial injections of adipose tissue-derived mesenchymal stromal cells (CSCC_ASCs) was safe and improved cardiac function in patients with chronic ischaemic heart failure with reduced ejection fraction (HFrEF). METHODS AND RESULTS: The study was a European multicentre, double-blind, placebo-controlled phase II trial using allogeneic CSCC_ASCs from healthy donors or placebo (2:1 randomization). Main inclusion criteria were New York Heart Association (NYHA) class II-III, left ventricular ejection fraction (LVEF) <45%, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels >300 pg/ml. CSCC_ASCs or placebo (isotonic saline) were injected directly into viable myocardium. The primary endpoint was change in left ventricular end-systolic volume (LVESV) at 6-month follow-up measured by echocardiography. A total of 133 symptomatic HFrEF patients were included. The treatment was safe without any drug-related severe adverse events or difference in cardiac-related adverse events during a 3-year follow-up period. There were no significant differences between groups during follow-up in LVESV (0.3 ± 5.0 ml, p = 0.945), nor in secondary endpoints of left ventricular end-diastolic volume (-2.0 ± 6.0 ml, p = 0.736) and LVEF (-1.6 ± 1.0%, p = 0.119). The NYHA class improved slightly within the first year in both groups without any difference between groups. There were no changes in 6-min walk test, NT-proBNP, C-reactive protein or quality of life the first year in any groups. CONCLUSION: The SCIENCE trial demonstrated safety of intramyocardial allogeneic CSCC_ASC therapy in patients with chronic HFrEF. However, it was not possible to improve the pre-defined endpoints and induce restoration of cardiac function or clinical symptoms.

A pilot clinical trial of cell therapy in heart failure with preserved ejection fraction.

AIMS: We investigated the effects of CD34+ cell therapy in patients with heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS: In a prospective pilot study, we enrolled 30 patients with HFpEF. In Phase 1, patients were treated with medical therapy for 6 months. Thereafter, all patients underwent CD34+ cell transplantation. Using electroanatomical mapping, we measured local mechanical diastolic delay and myocardial viability to guide the targeting of cell injections. Patients were followed for 6 months after cell transplantation (Phase 2), and the primary endpoint was the difference in change in E/e' between Phase 1 and Phase 2. In Phase 1, the decrease in E/e' was significantly less pronounced than in Phase 2 (-0.33 ± 1.72 vs. -3.77 ± 2.66, p = 0.001). During Phase 1, there was no significant change in global systolic strain (GLS; from -12.5 ± 2.4% to -12.8 ± 2.6%, p = 0.77), N-terminal pro-B-type natriuretic peptide (NT-proBNP; from 1463 ± 1247 pg/ml to 1298 ± 931 pg/ml, p = 0.31), or 6-min walk test (6MWT; from 391 ± 75 m to 402 ± 93 m, p = 0.42). In Phase 2, an improvement was noted in NT-proBNP (from 1298 ± 931 pg/ml to 887 ± 809 pg/ml, p = 0.02) and 6MWT (from 402 ± 93 m to 438 ± 72 m, p = 0.02). Although GLS did not change significantly in Phase 2 (from -12.8 ± 2.6% to -13.8 ± 2.7%, p = 0.36), we found improved local systolic strain at cell injection sites (-3.4 ± 6.8%, p = 0.005). CONCLUSIONS: In this non-randomized trial, transendocardial CD34+ cell therapy in HFpEF was associated with an improvement in E/e', NT-proBNP, exercise capacity, and local myocardial strain at the cell injection sites. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT02923609.

Cell Therapy in Heart Failure with Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) is the most common cause of hospitalisation for heart failure. However, only limited effective treatments are available. Recent evidence suggests that HFpEF may result from a systemic proinflammatory state, microvascular endothelial inflammation and microvascular rarefaction. Formation of new microvasculature in ischaemic tissues is dependent on CD34+ cells, which incorporate into the newly developing vasculature and produce pro-angiogenic cytokines. In HFpEF patients, worsening of diastolic function appears to correlate with decreased numbers of CD34+ cells. Therefore, it is plausible that increasing the myocardial numbers of CD34+ cells could theoretically lead to improved microvascular function and improved diastolic parameters in HFpEF. In accordance with this hypothesis, recent pilot clinical data suggest that CD34+ cell therapy may indeed be associated with improved diastolic function and better functional capacity in HFpEF patients and could thus represent a promising novel therapeutic modality for this patient population.

Transendocardial CD34+ Cell Therapy Improves Local Mechanical Dyssynchrony in Patients With Nonischemic Dilated Cardiomyopathy.

We investigated the effects of cell therapy on local mechanical dyssynchrony (LMD) in patients with nonischemic dilated cardiomyopathy (NICM). We analyzed electromechanical data of 30 NICM patients undergoing CD34+ cell transplantation. All patients underwent bone marrow stimulation; CD34+ cells were collected by apheresis and injected transendocardially. At baseline and at 6 months after therapy, we performed electromechanical mapping and measured unipolar voltage (UV) and LMD at cell injection sites. LMD was defined as a temporal difference between global and segmental peak systolic displacement normalized to the average duration of the RR interval. Favorable clinical response was defined as increase in the left ventricular ejection fraction (LVEF) ≥5% between baseline and 6 months. Using paired electromechanical point-by-point analysis, we were able to identify 233 sites of CD34+ cell injections in 30 patients. We found no overall differences in local UV between baseline and 6 months (10.7 ± 4.1 mV vs 10.0 ± 3.6 mV, P = 0.42). In contrast, LMD decreased significantly (17 ± 17% at baseline vs 13 ± 12% at 6 months, P = 0.00007). Favorable clinical response at 6 months was found in 19 (63%) patients (group A), and 11 (37%) patients did not respond to cell therapy (group B). At baseline, the two groups did not differ in age, gender, LVEF, or N terminal-pro brain natriuretic peptide (NT-proBNP) levels. Similarly, we found no differences in baseline UV (9.5 ± 2.9 mV in group A vs 8.6 ± 2.4 mV in group B, P = 0.41) or LMD at cell injection sites (17 ± 19% vs 16 ± 14%, P = 0.64). In contrast, at 6 months, we found higher UV in group A (10.0 ± 3.1 mV vs 7.4 ± 1.9 mV in group B, P = 0.04). Furthermore, when compared with group B, patients in group A displayed a significantly lower LMD (11 ± 12% vs 16 ± 10%, P = 0.002). Thus, it appears that favorable clinical effects of cell therapy in NICM patients may be associated with a decrease of LMD at cell injection sites.

Efficacy and Mode of Action of Mesenchymal Stem Cells in Non-Ischemic Dilated Cardiomyopathy: A Systematic Review.

Non-ischemic dilated cardiomyopathy (NIDCM) constitutes one of the most common causes to non-ischemic heart failure. Despite treatment, the disease often progresses, causing severe morbidity and mortality, making novel treatment strategies necessary. Due to the regenerative actions of mesenchymal stem cells (MSCs), they have been proposed as a treatment for NIDCM. This systematic review aims to evaluate efficacy and mode of action (MoA) of MSC-based therapies in NIDCM. A systematic literature search was conducted in Medline (Pubmed) and Embase. A total of 27 studies were included (3 clinical trials and 24 preclinical studies). MSCs from different tissues and routes of delivery were reported, with bone marrow-derived MSCs and direct intramyocardial injections being the most frequent. All included clinical trials and 22 preclinical trials reported an improvement in cardiac function following MSC treatment. Furthermore, preclinical studies demonstrated alterations in tissue structure, gene, and protein expression patterns, primarily related to fibrosis and angiogenesis. Consequently, MSC treatment can improve cardiac function in NIDCM patients. The MoA underlying this effect involves anti-fibrosis, angiogenesis, immunomodulation, and anti-apoptosis, though these processes seem to be interdependent. These encouraging results calls for larger confirmatory clinical studies, as well as preclinical studies utilizing unbiased investigation of the potential MoA.

Larger End-Diastolic Volume Associates With Response to Cell Therapy in Patients With Nonischemic Dilated Cardiomyopathy.

OBJECTIVE: To investigate the association of left ventricular end-diastolic volume (LVEDV) and the response to cell therapy in patients with nonischemic dilated cardiomyopathy (NICM). PATIENTS AND METHODS: Five-year registry data from 133 consecutive patients with NICM who underwent CD34+ cell treatment were analyzed. All patients received granulocyte-colony stimulating factor; CD34+ cells were collected by apheresis and delivered by transendocardial injections. Patients with baseline LVEDV less than 200 mL (group A; n=72) and patients with LVEDV 200 to 370 mL (group B; n=54) were included. Patients with LVEDV greater than 370 mL were excluded (n=7). Favorable ejection fraction response was pre-defined by improvement in left ventricular ejection fraction (LVEF) greater than or equal to 5% at 1 y post-cell therapy. RESULTS: At baseline, groups A and B were comparable with regards to age (52±11 y in group A vs 53±10 y in group B; P=.95), sex (male: 79% vs 83%, respectively; P=.55), creatinine (1.07±0.28 mg/dL vs 1.03±0.21 mg/dL, respectively; P=.21), or N-terminal probrain natriuretic peptide (1454±1658 pg/mL vs 1589±1338 pg/mL, respectively; P=.80). Baseline LVEF was higher in group A (32.8±8.7%) than in group B (30.2±8.7%; P=.03). During follow-up, there were four deaths in group A (5.6%), and 2 in group B (3.7%, P=.63). At 1-year post-cell therapy, LVEDV decreased significantly in group B (-56±30 mL; P=.003), but not in group A (+12±97 mL; P=.13). On multivariate analysis, baseline LVEDV was an independent correlate of favorable response in LVEF to therapy (P=.02). CONCLUSION: Larger LVEDV was associated with more pronounced increase in LVEF after transendocardial CD34+ cell therapy in NICM patients, informing target individuals with the highest likelihood of regenerative response. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT02445534.

Long-Term Effects of Angiotensin Receptor-Neprilysin Inhibitors on Myocardial Function in Chronic Heart Failure Patients with Reduced Ejection Fraction.

BACKGROUND: We sought to evaluate the long-term effects of angiotensin receptor blocker-neprilysin inhibitor (ARNI) therapy on reverse remodeling of the failing myocardium in HFrEF patients. METHODS: We performed a prospective non-randomized longitudinal study on 228 HFrEF patients treated with ARNI at our center. Prior to ARNI introduction all patients received stable doses of ACEI/ARB for at least six months. Clinical, biochemical and echocardiography data were obtained at ARNI introduction and 12-month follow-up. Results At follow-up, we found significant improvements in LVEF (29.7% ± 8% vs. 36.5% ± 9%; p < 0.001), LVOT-VTI (14.8 ± 4.2 cm vs. 17.2 ± 4.2 cm; p < 0.001), TAPSE (1.7 ± 0.5 cm vs. 2.1 ± 0.6 cm; p < 0.001) and LV-EDD (6.5 ± 0.8 cm vs. 6.3 ± 0.9 cm; p = 0.001). NT-proBNP serum levels also decreased significantly (1324 (605, 3281) pg/mL vs. 792 (329, 2022) pg/mL; p = 0.001). A total of 102 (45%) of patients responded favorably to ARNI (ΔLVEF < +5%; Group A) and 126 (55%) patients achieved ΔLVEF ≥ +5% (Group B). The two groups differed significantly in age, heart failure etiology, baseline LVEF and baseline NT-proBNP. On multivariable analysis, nonischemic heart failure, LVEF < 30% and NT-proBNP < 1500 pg/mL emerged as independent correlates of favorable response to ARNI therapy. CONCLUSION: ARNI therapy appears to improve echocardiographic parameters of left and right ventricular function in HFrEF patients above the effect of pre-existing optimal medical management. These effects may be particularly pronounced in patients with nonischemic heart failure, LVEF < 30% and lower degree of neurohumoral activation.

Stem Cell Therapy for Chronic and Advanced Heart Failure.

PURPOSE OF REVIEW: The purpose of this review is to discuss recent advances in the field of cell therapy in patients with heart failure with reduced ejection fraction (HFrEF) of ischemic (iCMP) and nonischemic (dCMP) etiology, heart failure with preserved ejection fraction (HFpEF), and in advanced heart failure patients undergoing mechanical circulatory support (LVAD). RECENT FINDINGS: In HFrEF patients (iCMP and dCMP cohorts), autologous and/or allogeneic cell therapy was shown to improve myocardial performance, patients' functional capacity, and neurohumoral activation. In HFpEF patient population, the concept of cell therapy in novel and remains largely unexplored. However, initial data are very encouraging and suggest at least a similar benefit in improvements of myocardial performance (also diastolic function of the left ventricle), exercise capacity, and neurohumoral activation. Recently, cell therapy was explored in the sickest population of advanced heart failure patients undergoing LVAD support also showing a potential benefit in promoting myocardial reverse remodeling and recovery. In the past decade, several cell therapy-based clinical trials showed promising results in various chronic and advanced heart failure patient cohorts. Future cell treatment strategies should aim for more personalized therapeutic approaches by defining optimal stem cell type or their combination, dose, and delivery method for an individual patient adjusted for patient's age and stage/duration of heart failure.

Impairment of myocardial perfusion correlates with heart failure severity in patients with non-compaction cardiomyopathy.

AIMS: Non-compaction cardiomyopathy (NCM) is a congenital heart disease characterized by an arrest of the myocardial compaction process. Although NCM patients have impaired formation of microvasculature, the functional impact of these changes remains undefined. We sought to analyse a potential correlation between myocardial ischemia and heart failure severity in NCM patients. METHODS AND RESULTS: We enrolled 41 NCM patients (28 male and 13 female), aged 21-70 years. In all patients, we have determined left ventricular end-diastolic volume (LVEDV), left ventricular ejection fraction (LVEF), and global longitudinal strain (GLS) by echocardiography. At the same time, serum levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) have been measured, and myocardial single-photon emission computed tomography at rest and on stress was used to define significant myocardial ischemia defined as summed difference score ≥ 2. Myocardial ischemia has been demonstrated in 11 patients (27%, Group A), and 30 patients showed no significant ischemic changes (73%, Group B). The groups did not differ in sex, age, kidney, or liver function. When compared with Group B, Group A had significantly lower LVEF (35 ± 15% in Group A vs. 53 ± 11% in Group B, P < 0.001), higher LVEDV (188 ± 52 mL vs. 136 ± 52 mL, P = 0.007), lower GLS (-9.9 ± 5.2% vs. -14.5 ± 4.1%, P = 0.001), and higher NT-proBNP levels (1691 ± 1883 pg/mL vs. 422 ± 877 pg/mL, P = 0.006). Overall, higher summed difference score was associated with lower LVEF (r = -0.48, P = 0.001), higher LVEDV (r = 0.39, P = 0.012), lower GLS (r = 0.352, P = 0.024), and higher levels of NT-proBNP (r = 0.66, P < 0.001). CONCLUSIONS: The presence of myocardial ischemia in patients with NCM is associated with worse left ventricular function, dilation of the left ventricle, and more pronounced neurohumoral activation.

Favorable Response to CD34+ Cell Therapy Is Associated with a Decrease of Galectin-3 Levels in Patients with Chronic Heart Failure.

BACKGROUND: Galectin-3 plasma levels (gal-3) were shown to correlate with the scar burden in chronic heart failure (CHF) setting. As scar burden predicts response to stem cell therapy, we sought to explore a correlation between gal-3 and response to CD34+ cell transplantation in patients with CHF. METHODS: We performed a post hoc analysis of patients, enrolled in 2 prospective trials investigating the clinical effects of CD34+ cell therapy in patients with ischemic cardiomyopathy (ICMP) and nonischemic dilated cardiomyopathy (DCMP). CD34+ cells were mobilized by G-CSF, collected via apheresis, and injected transendocardially using NOGA system. Patients were followed for 3 months and demographic, echocardiographic, and biochemical parameters and gal-3 were analyzed at baseline and at follow-up. Response to cell therapy was defined as an LVEF increase of ≥5%. RESULTS: 61 patients were included in the analysis. The mean age of patients was 52 years and 83% were male. DCMP and ICMP were present in 69% and 31% of patients, respectively. The average serum creatinine was 86 ± 23 µmol/L, NT-proBNP 1132 (IQR 350-2279) pg/mL, and LVEF 30 ± 6%. Gal-3 at baseline and at 3 months did not differ significantly (13.4 ± 5.5 ng/mL vs. 13.1 ± 5.8 ng/mL; p = 0.72), and there were no differences in baseline gal-3 with respect to heart failure etiology (15.1 ± 7.2 ng/mL in ICMP vs. 12.7 ± 4.3 ng/mL in DCMP; p = 0.12). Comparing responders (N = 49) to nonresponders (N = 18), we found no differences in baseline gal-3 (13.6 ± 5.7 ng/mL vs. 13.2 ± 4.9 ng/mL; p = 0.80). However, responders had significantly lower gal-3 at 3-month follow-up (12.1 ± 4.0 ng/mL vs. 15.7 ± 8.4 ng/mL; p < 0.05). Also, responders demonstrated a significant decrease in gal-3 over 3 months, while in nonresponders, an increase in gal-3 occurred (-1.5 ± 5.4 ng/mL vs. +2.7 ± 4.3 ng/mL; p = 0.01). CONCLUSIONS: In patients with chronic heart failure undergoing CD34+ cell therapy, a decrease in galectin-3 plasma levels is associated with beneficial response to this treatment modality. Further prospective data is warranted to confirm our findings and to deepen our understanding of the role of gal-3 in the field of stem cell therapy.

Transendocardial CD34+ Cell Therapy does not Increase the Risk of Ventricular Arrhythmias in Patients with Chronic Heart Failure.

Ventricular arrhythmias (VA) are of major concern in the field of cell therapy, potentially limiting its safety and efficacy. We sought to investigate the effects of CD34+ cell therapy on VA burden in patients with chronic heart failure (CHF). We performed registry data analysis of patients with CHF and implanted ICD/CRT devices treated with transendocardial CD 34+ cell therapy. Demographic, echocardiographic, and biochemical parameters were analyzed. Device records were reviewed and the number and type of VA 1 year prior to and 1 year after cell therapy were analyzed. All patients underwent electroanatomical mapping, and myocardial scar was defined as unipolar voltage (UV) <8.3 mV and linear local shortening (LLS) <6%. Of 209 patients screened, 48 met inclusion criteria. The mean age of the patients was 52 years and 88% were male. Nonischemic and ischemic cardiomyopathy were present in 55% and 45% of patients. The average serum creatinine was 91±26 µmol/L, serum bilirubin 18±9 µmol/L, NT-proBNP 1767 (468, 2446) pg/mL, LVEF 27±9% and 6' walk test 442±123 m. The average scar burden in patients with nonischemic and ischemic DCM was 58±15% and 51±25% (P=0.48). No significant difference in VA burden was observed before and after cell therapy (48% vs. 44%; P=0.68). ICD activation occurred in 19% and 27% of patients before and after cell therapy (P=0.33). According to our results, transendocardial CD34+ cell therapy does not appear to increase the risk of VA in chronic heart failure patients.

Transendocardial CD34+ Cell Transplantation in Noncompaction Cardiomyopathy: First-in-Man Case Study.

Noncompaction cardiomyopathy is a rare congenital heart disorder characterized by an arrest of the myocardial compaction process. This results in the altered formation of coronary microvessels with a resulting decrease in myocardial perfusion. Transendocardial CD34+ cell transplantation has been shown to increase myocardial perfusion and function in patients with non-ischemic heart failure. In our first-in-man case study, we investigated the feasibility, safety and clinical effect of transendocardial CD34+ cell therapy in a patient with noncompaction cardiomyopathy.

Effects of Repetitive Transendocardial CD34+ Cell Transplantation in Patients With Nonischemic Dilated Cardiomyopathy.

RATIONALE: Preclinical data in heart failure models suggest that repetitive stem cell therapy may be superior to single-dose cell administration. OBJECTIVE: We investigated whether repetitive administration of CD34+ cells is superior to single-dose administration in patients with nonischemic dilated cardiomyopathy. METHODS AND RESULTS: Of 66 patients with dilated cardiomyopathy, New York Heart Association functional class III, and left ventricular ejection fraction (LVEF) <40% enrolled in the study, 60 were randomly allocated to repetitive cell therapy (group A, n=30) or single-cell therapy (group B, n=30). Patients received G-CSF (granulocyte colony-stimulating factor) for 5 days, and 80 million CD34+ cells were collected by apheresis and injected transendocardially. In group A, cell therapy was repeated at 6 months. All patients were followed for 1 year, and the primary end point was the difference in change in LVEF between the groups. At baseline, the groups did not differ in age, sex, LVEF, NT-proBNP (N-terminal pro-B-type natriuretic peptide), or 6-minute walk test distance. When directly comparing groups A and B at 1 year, there was no significant difference in change in LVEF (from 32.2±9.3% to 41.2±6.5% in group A and from 30.0±7.0% to 37.9±5.3% in group B, P=0.40). From baseline to 6 months, both groups improved in LVEF (+6.9±3.3% in group A, P=0.001 and +7.1±3.5% in group B, P=0.001), NT-proBNP (-578±211 pg/mL, P=0.02 and -633±305 pg/mL, P=0.01), and 6-minute walk test (+87±21 m, P=0.03 and +92±25 m, P=0.02). In contrast, we observed no significant changes between 6 months and 1 year (LVEF: +2.1±2.3% in group A, P=0.19 and +0.8±3.1% in group B, P=0.56; NT-proBNP: -215±125 pg/mL, P=0.26 and -33±205 pg/mL, P=0.77; 6-minute walk test: +27±11 m, P=0.2 and +12±18 m, P=0.42). CONCLUSIONS: In patients with dilated cardiomyopathy, repetitive CD34+ cell administration does not seem to be associated with superior improvements in LVEF, NT-proBNP, or 6-minute walk test when compared with single-dose cell therapy. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02248532.

Stem Cell Therapy in Patients with Chronic Nonischemic Heart Failure.

AIM OF THE REVIEW: The aim of this review is to discuss recent advances in clinical aspects of stem cell therapy in chronic nonischemic heart failure (DCMP) with emphasis on patient selection, stem cell types, and delivery methods. RECENT FINDINGS: Several stem cell types have been considered for the treatment of DCMP patients. Bone marrow-derived cells and CD34+ cells have been demonstrated to improve myocardial performance, functional capacity, and neurohumoral activation. Furthermore, allogeneic mesenchymal stem cells were also shown to be effective in improving heart function in this patient population; this may represent an important step towards the development of a standardized stem cell product for widespread clinical use in patients with DCMP. SUMMARY: The trials of stem cell therapy in DCMP patients have shown some promising results, thus making DCMP apparently more inviting target for stem cell therapy than chronic ischemic heart failure, where studies to date failed to demonstrate a consistent effect of stem cells on myocardial performance. Future stem cell strategies should aim for more personalized therapeutic approach by establishing the optimal stem cell type or their combination, dose, and delivery method for an individual patient adjusted for patient's age and stage of the disease.

CD34+ Cell Transplantation Improves Right Ventricular Function in Patients with Nonischemic Dilated Cardiomyopathy.

We investigated the effects of CD34+ cell therapy on right ventricular (RV) function in patients with nonischemic dilated cardiomyopathy (DCM). We enrolled 60 patients with DCM who were randomized to CD34+ cell therapy (Stem Cells (SC) Group n = 30), or no cell therapy (Controls, n = 30). The SC Group received granulocyte-colony stimulating factor, and CD34+ cells were collected by apheresis and injected transendocardially. Patients were followed for 6 months. At baseline, the groups did not differ in age, gender, left ventricular ejection fraction, N-terminal probrain natriuretic peptide, or parameters of RV function. At 6 months, we found a significant improvement in RV function in the SC Group (tricuspid annular plane systolic excursion [TAPSE]: +0.44 ± 0.64 cm, p = .001; peak systolic tissue Doppler velocity of tricuspid annulus [St]: +1.5 ± 2.1 cm/s; p = .001; percent of fractional area change [FAC]: +8.6% ± 5%, p = .01), but not in Controls (TAPSE: -0.07 ± 0.32 cm, p = .40; St: -0.1 ± 1.2 cm/s; p = .44; FAC: -1.2% ± 3.2%, p = .50). On repeat electroanatomical mapping, we found an improvement in interventricular septum viability in 19 of 30 patients from the SC Group; this correlated with the improvements in RV function (13/19 in the improved septum group versus 3/11 in the remaining cohort, p = .029). These results suggest that patients with DCM, changes in RV function correlate with changes of viability of interventricular septum. CD34+ cell therapy appears to be associated with improved right ventricular function in this patient cohort. (Clinical Trial Registration Information: www.clinicaltrials.gov; NCT02248532). Stem Cells Translational Medicine 2018;7:168-172.

Effects of Transendocardial CD34+ Cell Transplantation on Diastolic Parameters in Patients with Nonischemic Dilated Cardiomyopathy.

We sought to evaluate the physiological background and the effects of CD34+ cell transplantation on diastolic parameters in nonischemic dilated cardiomyopathy patients (DCM). We enrolled 38 DCM patients with NYHA class III and LVEF < 40% who underwent transendocardial CD34+ cell transplantation. Peripheral blood CD34+ cells were mobilized by G-CSF, collected via apheresis, and injected transendocardially in the areas of myocardial hibernation. Patients were followed for 1 year. At baseline, estimated filling pressures were significantly elevated (E/e' ≥ 15) in 18 patients (Group A), and moderately elevated (E/e '< 15) in 20 patients (Group B). The groups did not differ in age (54 ± 9 years vs. 52 ± 10 years; p = .62), gender (male: 85% vs. 78%; p = .57), or LVEF (31 ± 7% vs. 34 ± 6%; p = .37). When compared to Group B patients in Group A had more segments with myocardial scar (4.9 ± 2.7 vs. 2.7 ± 2.9; p = .03), myocardial hibernation (2.2 ± 1.6 vs. 0.9 ± 1.1; p = .02), and longer average local relaxation time on electroanatomical mapping (378 ± 41 ms vs. 333 ± 34 ms, p = .01). During follow-up there was an improvement in diastolic parameters in Group A (E/e': from 24.3 ± 12.1 to 16.3 ± 8.0; p = .005), but not in Group B (E/e': from 10.2 ± 3.7 to 13.2 ± 9.1; p = .19). Accordingly, in Group A, we found an increase in 6-minute walk distance (from 463 ± 83 m to 546 ± 91 m; p = .03), and a decrease in NT-proBNP (from 2140 ± 1743 pg/ml to 863 ± 836 pg/ml; p = .02). In nonischemic DCM, diastolic dysfunction appears to correlate with areas of myocardial scar and hibernation. Transendocardial CD34+ cell transplantation may improve diastolic parameters in this patient cohort. Stem Cells Translational Medicine 2017;6:1515-1521.