Transforming Perspectives in Cardiac Cell Therapy: Hypothesis and Commentary Following Updated Results of a Pilot Study Investigating Very Long-Term Clinical Outcomes in Severe AMI Patients Following Trans-Epicardial Injection of Peripheral Blood CD34+ Cells.

Ischemic heart attack is the leading cause of death worldwide. Ten percent of cases will die within an hour. Of the survivors, around 30% will have suffered a severe infarction which will lead to the irreparable destruction of 1 to 2 billion myocardial cells, causing an irreversible secondary heart failure with a poor prognosis in the short. The heart is a totally differentiated organ with a very low capacity for self-regeneration. No current treatment can prevent this fatal outcome, but only slow it down. For these reasons, cell therapy has generated enormous hope, but achieved somewhat disappointing results, depending on the type/source of cells which were used. From the end of 2002, our group conducted a Pilot study using immuno-selected autologous peripheral-blood (PB) CD34+ cells in a small cohort of patients who had experienced a heart attack with poor prognosis. Three of these patients were immediately considered for heart transplant but lacked a readily available donor. CD34+ cells were trans-epicardially delivered at the end of a coronary artery by-pass graft (CABG) operation without reperfusing the ischemic area, which was performed on a compassionate basis. All but one patient showed a marked and sustained improvement in their cardiac function parameters from the baseline values, associated with both cardiac tissue repair and revascularization, as demonstrated by PetScan examination. The patients' outcomes have been recently updated. Six out of seven patients have survived in good enough conditions for at least 12 years after cell therapy, including those three initially recommended for heart transplant and who have avoided it. Presently, five out of seven patients are still alive with an average follow-up of 17 years (range 16-20 years), which is very unusual after CABG for patients with such a poor initially prognosis.

Six-Month Performance of a 3-Dimensional Annuloplasty Ring for Repair of Functional Tricuspid Regurgitation.

BACKGROUND: Functional tricuspid regurgitation (FTR) secondary to left-sided heart disease may lead to poor quality of life and reduced long-term survival. This study evaluated clinical and functional outcomes of patients undergoing tricuspid valve (TV) repair using a rigid three-dimensional ring (Contour 3D, Medtronic) concomitant with another procedure. METHODS: From September 2011 to July 2015, 112 patients (mean age 70.9 ± 9.0 years) were enrolled at 10 centers in Europe, Israel, and the United States. Inclusion criteria were FTR ≥ moderate and/or tricuspid annular diameter (TAD) ≥ 40 mm. Echocardiography was planned before surgery and at discharge with echocardiographic and clinical follow-ups performed 6 months postoperatively. RESULTS: Three fourths (74.4%) of patients had higher than moderate TR. Mean TAD was 41.0 ± 7.3 mm; 61.7% of patients were in the New York Heart Association (NYHA) class III/IV. The most common concomitant procedure was mitral valve repair (57 patients, 53.3%). The 30-day mortality rate was 0.9% (n = 1). The mean EuroSCORE II was 8.9 ± 8.4% (median: 5.9%; interquartile range: 3.5-11.5%). The observed to expected ratio (O/E) based on the median was 0.1. Six deaths occurred during follow-up (three cardiac related). Mean implanted ring size was 30.3 ± 2.7. At 6 months, 94.4% of patients showed ≤ mild TR, and 92.0% were in NYHA class I/II (p < 0.001 vs baseline for both). Mean pressure gradient across the TV was 2.0 ± 1.1 mm Hg; leaflet coaptation length was 7.5 ± 3.3 mm. CONCLUSION: The Contour 3D annuloplasty ring used for treatment of FTR substantially reduced TR for up to 6 postoperative months with low mean pressure gradients across the TV and significant improvement in NYHA class. REGISTRATION: www.ClinicalTrials.gov, NCT01532921.

Mitral bioprosthesis hypertrophic scaring and native aortic valve fibrosis during benfluorex therapy.

The authors describe the case of a simultaneous mitral bioprosthesis hypertrophic scaring and native aortic valve fibrosis during benfluorex therapy in a 40-year-old woman. Four years before, she underwent a mitral valve replacement after the diagnosis of mitral regurgitation during benfluorex treatment (150 mg/day). This drug was reintroduced postoperatively. She presented with exercise and sometimes resting dyspnoea. The bioprosthesis and aortic valves exhibited similar histopathological lesions. Thickening and plaque deposits made by smooth muscle alpha actin- and vimentin-positive cells in a glycosaminoglycan matrix were observed. The study discusses the putative contribution of circulating progenitor cells activated by 5-HT(2B) receptor agonists in the development of drug-induced heart disease.

Long-term benefit of intracardiac delivery of autologous granulocyte-colony-stimulating factor-mobilized blood CD34+ cells containing cardiac progenitors on regional heart structure and function after myocardial infarct.

BACKGROUND AIMS: Starting from experimental data proposing hematopoietic stem cells as candidates for cardiac repair, we postulated that human peripheral blood (PB) CD34+ cells mobilized by hematopoietic growth-factor (G-CSF) would contain cell subpopulations capable of regenerating post-ischemic myocardial damages. METHODS: In a phase I clinical assay enrolling seven patients with acute myocardial infarct, we directly delivered to the injured myocardium autologous PB CD34+ cells previously mobilized by G-CSF, collected by leukapheresis and purified by immunoselection. In parallel, we looked for the eventual presence of cardiomyocytic and endothelial progenitor cells in leukapheresis products of these patients and controls, using flow cytometry, reverse transcription-quantitative (RTQ)-polymerase chain reaction (PCR), cell cultures and immunofluorescence analyzes. RESULTS: The whole clinical process was feasible and safe. All patients were alive at an average follow-up of 49 months (range 24-76 months). Improvement of heart function parameters became obvious from the third month following cell reinjection. Left ventricular ejection fraction values progressively and dramatically increased with time, associated with PetScan demonstration of myocardial structure regeneration and revascularization and New York Heart Association (NYHA) grade improvement. Furthermore, we identified PB CD34+ cell subpopulations expressing characteristics of both immature and mature endothelial and cardiomyocyte progenitor cells. In vitro CD34+ cell cultures on a specific medium induced development of adherent cells featuring morphologies, gene expression and immunocytochemistry characteristics of endothelial and cardiac muscle cells. CONCLUSIONS: Mobilized CD34+ cells contain stem cells committed along endothelial and cardiac differentiation pathways, which could play a key role in a proposed two-phase mechanism of myocardial regeneration after direct intracardiac delivery, probably being responsible for the long-term clinical benefit observed.

Morphological and functional rescue in RCS rats after RPE cell line transplantation at a later stage of degeneration.

PURPOSE: It is well documented that grafting of cells in the subretinal space of Royal College of Surgeons (RCS) rats limits deterioration of vision and loss of photoreceptors if performed early in postnatal life. What is unclear is whether cells introduced later, when photoreceptor degeneration is already advanced, can still be effective. This possibility was examined in the present study, using the human retinal pigment epithelial cell line, ARPE-19. METHODS: Dystrophic RCS rats (postnatal day [P] 60) received subretinal injection of ARPE-19 cells (2 x 10(5)/3 microL/eye). Spatial frequency was measured by recording optomotor responses at P100 and P150, and luminance threshold responses were recorded from the superior colliculus at P150. Retinas were stained with cresyl violet, retinal cell-specific markers, and a human nuclear marker. Control animals were injected with medium alone. Animals comparably treated with grafts at P21 were available for comparison. All animals were treated with immunosuppression. RESULTS: Later grafts preserved both spatial frequency and threshold responses over the control and delayed photoreceptor degeneration. There were two to three layers of rescued photoreceptors even at P150, compared with a scattered single layer in sham and untreated control retinas. Retinal cell marker staining showed an orderly array of the inner retinal lamination. The morphology of the second-order neurons was better preserved around the grafted area than in regions distant from graft. Sham injection had little effect in rescuing the photoreceptors. CONCLUSIONS: RPE cell line transplants delivered later in the course of degeneration can preserve not only the photoreceptors and inner retinal lamination but also visual function in RCS rats. However, early intervention can achieve better rescue.