Does transendocardial injection of mesenchymal stem cells improve myocardial function locally or globally?: An analysis from the Percutaneous Stem Cell Injection Delivery Effects on Neomyogenesis (POSEIDON) randomized trial.

RATIONALE: Transendocardial stem cell injection (TESI) with mesenchymal stem cells improves remodeling in chronic ischemic cardiomyopathy, but the effect of the injection site remains unknown. OBJECTIVE: To address whether TESI exerts its effects at the site of injection only or also in remote areas, we hypothesized that segmental myocardial scar and segmental ejection fraction improve to a greater extent in injected than in noninjected segments. METHODS AND RESULTS: Biplane ventriculographic and endocardial tracings were recorded. TESI was guided to 10 sites in infarct-border zones. Sites were mapped according to the 17-myocardial segment model. As a result, 510 segments were analyzed in 30 patients before and 13 months after TESI. Segmental early enhancement defect (a measure of scar size) was reduced by TESI in both injected (-43.7 ± 4.4%; n=95; P<0.01) and noninjected segments (-25.1 ± 7.8%; n=148; P<0.001; between-group comparison P<0.05). Conversely, segmental ejection fraction (a measure of contractile performance) improved in injected scar segments (19.9 ± 3.3-26.3 ± 3.5%; P=0.003) but not in noninjected scar segments (21.3 ± 2.6-23.5 ± 3.2%; P=0.20; between-group comparison P<0.05). Furthermore, segmental ejection fraction in injected scar segments improved to a greater degree in patients with baseline segmental ejection fraction <20% (12.1 ± 1.2-19.9 ± 2.7%; n=18; P=0.003), versus <20% (31.7 ± 3.4-35.5 ± 3.3%; n=12; P=0.33, between-group comparison P<0.0001). CONCLUSIONS: These findings illustrate a dichotomy in regional responses to TESI. Although scar size reduction was evident in all scar segments, scar size reduction and ventricular functional responses preferentially occurred at the sites of TESI versus non-TESI sites. Furthermore, improvement was greatest when segmental left ventricular dysfunction was severe.

Intramyocardial stem cell injection in patients with ischemic cardiomyopathy: functional recovery and reverse remodeling.

RATIONALE: Transcatheter, intramyocardial injections of bone marrow-derived cell therapy produces reverse remodeling in large animal models of ischemic cardiomyopathy. OBJECTIVE: We used cardiac MRI (CMR) in patients with left ventricular (LV) dysfunction related to remote myocardial infarction (MI) to test the hypothesis that bone marrow progenitor cell injection causes functional recovery of scarred myocardium and reverse remodeling. METHODS AND RESULTS: Eight patients (aged 57.2±13.3 years) received transendocardial, intramyocardial injection of autologous bone marrow progenitor cells (mononuclear or mesenchymal stem cells) in LV scar and border zone. All patients tolerated the procedure with no serious adverse events. CMR at 1 year demonstrated a decrease in end diastolic volume (208.7±20.4 versus 167.4±7.32 mL; P=0.03), a trend toward decreased end systolic volume (142.4±16.5 versus 107.6±7.4 mL; P=0.06), decreased infarct size (P<0.05), and improved regional LV function by peak Eulerian circumferential strain in the treated infarct zone (-8.1±1.0 versus -11.4±1.3; P=0.04). Improvements in regional function were evident at 3 months, whereas the changes in chamber dimensions were not significant until 6 months. Improved regional function in the infarct zone strongly correlated with reduction of end diastolic volume (r(2)=0.69, P=0.04) and end systolic volume (r(2)=0.83, P=0.01). CONCLUSIONS: These data suggest that transcatheter, intramyocardial injections of autologous bone marrow progenitor cells improve regional contractility of a chronic myocardial scar, and these changes predict subsequent reverse remodeling. The findings support the potential clinical benefits of this new treatment strategy and ongoing randomized clinical trials.

Comparison of allogeneic vs autologous bone marrow­derived mesenchymal stem cells delivered by transendocardial injection in patients with ischemic cardiomyopathy: the POSEIDON randomized trial.

CONTEXT: Mesenchymal stem cells (MSCs) are under evaluation as a therapy for ischemic cardiomyopathy (ICM). Both autologous and allogeneic MSC therapies are possible; however, their safety and efficacy have not been compared. OBJECTIVE: To test whether allogeneic MSCs are as safe and effective as autologous MSCs in patients with left ventricular (LV) dysfunction due to ICM. DESIGN, SETTING, AND PATIENTS: A phase 1/2 randomized comparison (POSEIDON study) in a US tertiary-care referral hospital of allogeneic and autologous MSCs in 30 patients with LV dysfunction due to ICM between April 2, 2010, and September 14, 2011, with 13-month follow-up. INTERVENTION: Twenty million, 100 million, or 200 million cells (5 patients in each cell type per dose level) were delivered by transendocardial stem cell injection into 10 LV sites. MAIN OUTCOME MEASURES: Thirty-day postcatheterization incidence of predefined treatment-emergent serious adverse events (SAEs). Efficacy assessments included 6-minute walk test, exercise peak VO2, Minnesota Living with Heart Failure Questionnaire (MLHFQ), New York Heart Association class, LV volumes, ejection fraction (EF), early enhancement defect (EED; infarct size), and sphericity index. RESULTS: Within 30 days, 1 patient in each group (treatment-emergent SAE rate, 6.7%) was hospitalized for heart failure, less than the prespecified stopping event rate of 25%. The 1-year incidence of SAEs was 33.3% (n = 5) in the allogeneic group and 53.3% (n = 8) in the autologous group (P = .46). At 1 year, there were no ventricular arrhythmia SAEs observed among allogeneic recipients compared with 4 patients (26.7%) in the autologous group (P = .10). Relative to baseline, autologous but not allogeneic MSC therapy was associated with an improvement in the 6-minute walk test and the MLHFQ score, but neither improved exercise VO2 max. Allogeneic and autologous MSCs reduced mean EED by −33.21% (95% CI, −43.61% to −22.81%; P < .001) and sphericity index but did not increase EF. Allogeneic MSCs reduced LV end-diastolic volumes. Low-dose concentration MSCs (20 million cells) produced greatest reductions in LV volumes and increased EF. Allogeneic MSCs did not stimulate significant donor-specific alloimmune reactions. CONCLUSIONS: In this early-stage study of patients with ICM, transendocardial injection of allogeneic and autologous MSCs without a placebo control were both associated with low rates of treatment-emergent SAEs, including immunologic reactions. In aggregate, MSC injection favorably affected patient functional capacity, quality of life, and ventricular remodeling. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01087996.

Rationale and design of the Transendocardial Injection of Autologous Human Cells (bone marrow or mesenchymal) in Chronic Ischemic Left Ventricular Dysfunction and Heart Failure Secondary to Myocardial Infarction (TAC-HFT) trial: A randomized, double-blind, placebo-controlled study of safety and efficacy.

Although there is tremendous interest in stem cell (SC)-based therapies for cardiomyopathy caused by chronic myocardial infarction, many unanswered questions regarding the best approach remain. The TAC-HFT study is a phase I/II randomized, double-blind, placebo-controlled trial designed to address several of these questions, including the optimal cell type, delivery technique, and population. This trial compares autologous mesenchymal SCs (MSCs) and whole bone marrow mononuclear cells (BMCs). In addition, the study will use a novel helical catheter to deliver cells transendocardially. Although most trials have used intracoronary delivery, the optimal method is unknown and data suggest that the transendocardial approach may have important advantages. Several trials support the benefit of SCs in patients with chronic ischemic cardiomyopathy (ICMP), although the sample sizes have been small and the number of trials sparse. After a pilot phase of 8 patients, 60 patients with ICMP (left ventricular ejection fraction 15%-50%) will be randomized to group A (30 patients further randomized to receive MSC injection or placebo in a 2:1 fashion) or group B (30 patients further randomized to BMCs or placebo in a 2:1 fashion). All patients will undergo bone marrow aspiration and transendocardial injection of SCs or placebo. The primary and secondary objectives are, respectively, to demonstrate the safety and efficacy (determined primarily by cardiac magnetic resonance imaging) of BMCs and MSCs administered transendocardially in patients with ICMP.

Safety of serial MRI in patients with implantable cardioverter defibrillators.

OBJECTIVE: While patients with cardiac implantable electronic devices could benefit from magnetic resonance (MR) imaging, the presence of such devices has been designated as an absolute contraindication to MR. Although scanning algorithms are proposed for cardiac implantable electronic devices, their safety remains uncertain. To address this issue, the safety of serial cardiac MR scans was evaluated in patients with implantable cardioverter defibrillators (ICDs). METHODS: Three serial cardiac MR scans were prospectively performed at 1.5 T on 10 patients (9 men) of median age 56 years (range 51-68) with ICDs. ICD interrogation was performed before and after the MR scan and at a follow-up of median 370 days (range 274-723). Image quality was also assessed. RESULTS: In all patients MR scanning occurred without complications. There were no differences between pre- and post-MR pacing capture threshold, pacing lead or high voltage lead impedance, or battery voltage values. During follow-up there were no occurrences of ICD dysfunction. Although most patients had image artifacts, the studies were generally diagnostic regarding left ventricular function and wall motion. Delayed enhancement imaging was of good quality for inferior wall and inferolateral infarcts, but ICD artifacts often affected the imaging of anterior wall infarcts. CONCLUSION: Serial MR scans at 1.5 T in patients with ICDs, when carefully performed in a monitored setting, have no adverse effects on either patient or device. When required, single or multiple MR scans at 1.5 T may therefore be considered for clinical diagnostic purposes in these patients.

Screening newborns for galactosemia using total body galactose oxidation to CO2 in expired air.

Classic galactosemia is caused by impaired galactose-1-phosphate uridyltransferase (GALT EC 2.7.712). If discovered and treated within the first days of life, the acute problems of hepatocellular damage, sepsis, and death are prevented. However, chronic problems such as ataxia, tremor, dyspraxic speech, and ovarian failure may occur. To determine whether screening newborns before discharge from the nursery for GALT deficiency is feasible and whether acute and chronic signs could be prevented by earlier intervention, we developed a simplified "breath test." We quantitated total body oxidation of C-D-galactose to CO2 in expired air by normal newborns between 2 h and 2 mo of age and compared their results to older children with GALT deficiency. We found no differences in total body galactose oxidation (TBGO) among normal newborns up to 48 h of age, but a 2-fold rise in TBGO developed during their first 2 wk of life. Older children with galactosemia had significantly less oxidative capacity than normal newborns. We conclude that newborn breath testing for total body galactose oxidation is feasible before discharge from nursery. It has potential utility for both preventing acute neonatal toxicity and determining the mechanisms producing long-term complications such as ovarian failure, dyspraxia, ataxia, and tremors.