[Show abstract][Hide abstract] ABSTRACT: While accumulating data support the efficacy of intramyocardial cell-based therapy to improve LV function in patients with chronic ischemic cardiomyopathy undergoing CABG, the underlying mechanism and impact of cell injection site remain controversial. Mesenchymal stem cells (MSCs) improve LV structure and function through several effects including: reducing fibrosis, neoangiogenesis and neomyogenesis.
To test the hypothesis that the impact on cardiac structure and function following intramyocardial injections of autologous MSCs results from a concordance of pro-recovery phenotypic effects.
Six patients were injected with autologous MSCs into akinetic/hypokinetic myocardial territories not receiving bypass graft for clinical reasons. MRI was used to measure scar, perfusion, wall thickness and contractility at baseline, 3, 6 and 18 months and to compare structural and functional recovery in regions that received MSC injections alone, revascularization alone, or neither. A composite score of MRI variables was used to assess concordance of antifibrotic effects, perfusion, and contraction at different regions. After 18 months, subjects receiving MSCs exhibited increased LVEF (+9.4±1.7%, p=0.0002) and decreased scar mass (-47.5±8.1%; p<0.0001) compared to baseline. MSC-injected segments had concordant reduction in scar size, perfusion and contractile improvement (concordant score: 2.93±0.07), whereas revascularized (0.5±0.21) and non-treated segments (-0.07±0.34) demonstrated non-concordant changes (p<0.0001 vs. injected segments).
Intramyocardial injection of autologous MSCs into akinetic yet non-revascularized segments produces comprehensive regional functional restitution, which in turn drives improvement in global LV function. These findings, although inconclusive due to lack of placebo group, have important therapeutic and mechanistic hypothesis-generating implications. Clinical Trial Registration: NCT00587990 URL: http://clinicaltrials.gov/show/NCT00587990.
Circulation Research 02/2014; · 11.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Transendocardial Stem Cell Injection (TESI) with mesenchymal stem cells improves remodeling in chronic ischemic cardiomyopathy, but the impact of the injection site remains unknown.
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 non-injected segments.
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 (SEED, a measure of scar size) was reduced by TESI in both injected (-43.7±4.4%, n=95, p<0.01) and non-injected segments (-25.1±7.8%, n=148, p<0.001; between group comparison p<0.05). Conversely, segmental ejection fraction (SEF, a measure of contractility) improved in injected scar segments (19.9±3.3 to 26.3±3.5%, p=0.003) but not in non-injected scar segments (21.3±2.6 to 23.5±3.2%, p=0.20, between group comparison p<0.05). In the subgroup of scar segments with baseline SEF<20%, the SEF improvement was even greater in injected segments (12.1±1.2% to 19.9±2.7%, n=18, p=0.003) vs. non-injected segments (13.3±1.3% to 16.1±2.1%, n=15, p=0.05; between group comparison p<0.05).
These findings illustrate a dichotomy in regional responses to TESI. Although scar reduction was evident at the site of TESI and remotely, ventricular functional responses occurred preferentially at the sites of TESI. Furthermore, improvement was greatest when segmental left ventricular dysfunction was severe.
Circulation Research 01/2014; · 11.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives
To determine the incidence of new-onset atrial fibrillation (AF) associated with different methods of isolated aortic valve replacement (AVR): transfemoral (TF-), transapical (TA-) and transaortic (TAo-) catheter-based valve replacement and conventional surgical approaches.
The relative incidences of AF associated with the various access routes for AVR have not been well characterized.
In this single-center, retrospective cohort study, we evaluated a total of 231 consecutive patients undergoing AVR for degenerative aortic stenosis (AS) between March 2010 and September 2012. Patients with a history of either paroxysmal, persistent, or chronic AF, with bicuspid aortic valves, and patients who expired within 48 hours after AVR were excluded. A total of 123 patients (53% of total group) qualified for inclusion. Data on documented episodes of new-onset AF, along with all clinical, echocardiographic, procedural and 30-day follow up data, were collated.
AF occurred in 52 patients (42.3%). AF incidence varied according to the procedural method. AF occurred in 60% of patients undergoing surgical AVR (SAVR), 53% after TA-TAVR, 33% after TAo-TAVR cases and 14% after TF-TAVR. The episodes occurred at a median time interval of 53 (41,87) hours after completion of the procedure. Procedures without pericardiotomy had 82% risk reduction of AF when compared with those with pericardiotomy (adjusted OR 0.18 (95% CI 0.05-0.59)).
AF is a common complication of AVR with a cumulative incidence of >40% in elderly patients with degenerative AS who underwent either SAVR or TAVR. AF was most common with SAVR and least common with TF-TAVR. Procedures without pericardiotomy were associated with a lower incidence of AF.
Journal of the American College of Cardiology 01/2014; · 14.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Transcatheter aortic valve implantation (TAVI) for failing aortic root and valve homografts has been described primarily via a transapical approach. We report the successful treatment of two patients with failing homografts by transfemoral (TF) TAVI. In both cases, TF TAVI was accomplished without technical difficulty and with good clinical outcomes.
Journal of Cardiac Surgery 12/2013; · 1.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: IMPORTANCE Whether culture-expanded mesenchymal stem cells or whole bone marrow mononuclear cells are safe and effective in chronic ischemic cardiomyopathy is controversial. OBJECTIVE To demonstrate the safety of transendocardial stem cell injection with autologous mesenchymal stem cells (MSCs) and bone marrow mononuclear cells (BMCs) in patients with ischemic cardiomyopathy. DESIGN, SETTING, AND PATIENTS A phase 1 and 2 randomized, blinded, placebo-controlled study involving 65 patients with ischemic cardiomyopathy and left ventricular (LV) ejection fraction less than 50% (September 1, 2009-July 12, 2013). The study compared injection of MSCs (n=19) with placebo (n = 11) and BMCs (n = 19) with placebo (n = 10), with 1 year of follow-up. INTERVENTIONS Injections in 10 LV sites with an infusion catheter. MAIN OUTCOMES AND MEASURES Treatment-emergent 30-day serious adverse event rate defined as a composite of death, myocardial infarction, stroke, hospitalization for worsening heart failure, perforation, tamponade, or sustained ventricular arrhythmias. RESULTS No patient had a treatment-emergent serious adverse events at day 30. The 1-year incidence of serious adverse events was 31.6% (95% CI, 12.6% to 56.6%) for MSCs, 31.6% (95% CI, 12.6%-56.6%) for BMCs, and 38.1% (95% CI, 18.1%-61.6%) for placebo. Over 1 year, the Minnesota Living With Heart Failure score improved with MSCs (-6.3; 95% CI, -15.0 to 2.4; repeated measures of variance, P=.02) and with BMCs (-8.2; 95% CI, -17.4 to 0.97; P=.005) but not with placebo (0.4; 95% CI, -9.45 to 10.25; P=.38). The 6-minute walk distance increased with MSCs only (repeated measures model, P = .03). Infarct size as a percentage of LV mass was reduced by MSCs (-18.9%; 95% CI, -30.4 to -7.4; within-group, P = .004) but not by BMCs (-7.0%; 95% CI, -15.7% to 1.7%; within-group, P = .11) or placebo (-5.2%; 95% CI, -16.8% to 6.5%; within-group, P = .36). Regional myocardial function as peak Eulerian circumferential strain at the site of injection improved with MSCs (-4.9; 95% CI, -13.3 to 3.5; within-group repeated measures, P = .03) but not BMCs (-2.1; 95% CI, -5.5 to 1.3; P = .21) or placebo (-0.03; 95% CI, -1.9 to 1.9; P = .14). Left ventricular chamber volume and ejection fraction did not change. CONCLUSIONS AND RELEVANCE Transendocardial stem cell injection with MSCs or BMCs appeared to be safe for patients with chronic ischemic cardiomyopathy and LV dysfunction. Although the sample size and multiple comparisons preclude a definitive statement about safety and clinical effect, these results provide the basis for larger studies to provide definitive evidence about safety and to assess efficacy of this new therapeutic approach. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00768066.
JAMA The Journal of the American Medical Association 11/2013; · 29.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: A large proportion of candidates for transcatheter aortic valve replacement (TAVR) have inadequate ileofemoral vessels for transfemoral (TF) access. The transapical route (TAP) is the current alternative, but is associated with less favorable outcomes. Other access options need to be explored. OBJECTIVES: We investigated the technical feasibility and safety of the transaortic (TAO) TAVR approach in patients not eligible for TF access, using the commercially-available device (Edwards SAPIEN® valve) in the United States. METHODS: Forty-four consecutive patients with severe, inoperable aortic stenosis (AS) underwent TAO TAVR in our institution. Procedural and 30-day clinical outcomes data were compared with 76 consecutive patients who underwent TAP TAVR at our site. Technical learning curves were assessed by comparing outcomes of the first 20 cases with the subsequent patients who underwent each procedure. RESULTS: The TAO and TAP TAVR groups were similar in terms of VARC-defined device success (89% vs. 84%; P=0.59) and rates of the 30-day combined safety endpoint of all-cause mortality, myocardial infarction, major stroke, disabling bleeding, severe acute kidney injury, and valve re-intervention (20% vs. 33%; P=0.21). The TAO approach, compared to TAP TAVR, was associated with lower combined bleeding and vascular event rate (27% vs. 46%; P=0.05), shorter median ICU length of stay (3 vs. 6 days; P=0.01), and a favorable learning curve. CONCLUSION: TAVR via the TAO approach is technically feasible, appears to be associated with favorable outcomes, and expands the current alternative options for access sites in inoperable AS patients who are ineligible for TF TAVR.
Journal of the American College of Cardiology 04/2013; · 14.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Intramyocardial injection of mesenchymal stem cells (MSCs) in chronic ischemic cardiomyopathy is associated with reverse remodeling in experimental models and humans. Here, we tested the hypothesis that allogeneic MSC therapy drives ventricular remodeling by producing durable and progressive scar size reduction in ischemic cardiomyopathy. METHODS AND RESULTS: Gottingen swine (n=12) underwent left anterior descending coronary artery myocardial infarction (MI), and 3 months post-MI animals received either intramyocardial allogeneic MSC injection (200 mol/L cells; n=6) or left ventricle (LV) catheterization without injection (n=6). Swine were followed with serial cardiac magnetic resonance imaging for 9 months to assess structural and functional changes of the LV. Intramyocardial injection was performed using an integrated imaging platform combining electroanatomical mapping unipolar voltage and 3-dimensional cardiac magnetic resonance imaging angiography-derived anatomy to accurately target infarct border zone injections. MSC-treated animals had a 19.62±2.86% reduction in scar size at 3 months postinjection, which progressed to 28.09±2.31% from 3 to 6 months postinjection (P<0.0001). MSC-treated animals had unchanged end-diastolic volume (EDV; P=0.08) and end-systolic volume (ESV; P=0.28) from preinjection to 6 months postinjection, whereas controls had progressive dilatation in both EDV (P=0.0002) and ESV (P=0.0002). In addition, MSC-treated animals had improved LV sphericity index. Percentage change in infarct size correlated with percentage change in EDV (r=0.68; P=0.01) and ESV (r=0.77; P=0.001). Ejection fraction increased from 29.69±1.68% to 35.85±2.74% at 3 months post-MSC injection and progressed to 39.02±2.42% 6 months postinjection (P=0.0001), whereas controls had a persistently depressed ejection fraction during follow-up (P=0.33). CONCLUSION: Intramyocardial injection of allogeneic MSCs leads to a sustained and progressive reduction in infarct size, which in turn drives reverse remodeling and increases in ejection fraction. These findings support ongoing biological activity of cell therapy for substantial periods and suggest optimal end points for future clinical trials.
Journal of the American Heart Association. 01/2013; 2(3):e000140.
[Show abstract][Hide abstract] ABSTRACT: Transcatheter aortic valve replacement is an increasingly common treatment of critical aortic stenosis. Many aortic stenosis patients have concomitant left ventricular dysfunction, which can instigate the formation of thrombus resistant to anticoagulation. Recent trials evaluating transcatheter aortic valve replacement have excluded patients with left ventricular thrombus. We present a case in which an 86-year-old man with known left ventricular thrombus underwent successful transcatheter aortic valve replacement under cerebral protection.
Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 01/2013; 40(4):477-480. · 0.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: As mesenchymal stem cells (MSCs) induce proliferation and differentiation of c-kit+ cardiac stem cells (CSCs) in vivo and in vitro, we hypothesized that combining human (h)MSCs with c-kit+ hCSCs produces greater infarct size reduction compared to either cell administered alone after MI. METHODS AND RESULTS: Yorkshire swine underwent balloon occlusion of the LAD coronary artery followed by reperfusion, and were immunosuppressed after MI with cyclosporine and methylprednisolone. Intramyocardial injection of either: combination hCSCs/hMSCs (1M/200M, n=5), hCSCs alone (1M, n=5), hMSCs alone (200M, n=5), or placebo (PBS, n=5) was administered to the infarct border zones at 14 days post-MI. Phenotypic response to cell therapy was assessed by cardiac MRI and micromanometer conductance catheterization hemodynamics. While each cell therapy group had reduced MI size relative to placebo (p<0.05), the MI size reduction was 2-fold greater in combination vs. either cell therapy alone (p<0.05). Accompanying enhanced MI size reduction was substantial improvement in LV chamber compliance (end-diastolic pressure volume relationship, p<0.01) and contractility (preload recruitable stroke work and dP/dt(max), p<0.05) in combination treated swine. EF was restored to baseline in cell treated pigs, while placebo pigs had persistently depressed LV function (p<0.05). Immunohistochemistry showed 7-fold enhanced engraftment of stem cells in the combination therapy group vs. either cell type alone (P<0.001). CONCLUSIONS: Combining hMSCs and hCSCs as a cell therapeutic enhances scar size reduction, and restores diastolic and systolic function toward normal after MI. Taken together these findings illustrate important biological interactions between c-kit+ CSCs and MSCs that enhance cell-based therapeutic responses.
[Show abstract][Hide abstract] ABSTRACT: 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.
JAMA The Journal of the American Medical Association 11/2012; · 29.98 Impact Factor