Cell-based therapy for heart failure.
PURPOSE OF REVIEW: Chronic heart failure is a leading cause of hospitalization and is associated with a poor prognosis. Current therapeutic strategies do not address the underlying cause of the disease. Experimental studies have suggested that stem cells can exert beneficial effects on the failing heart by transdifferentiating into cardiac cell types and/or by providing a source of cardioprotective paracrine factors. RECENT FINDINGS: Early cell therapy studies in patients with heart failure have explored the suitability of distinct stem and progenitor cell populations for cardiac repair and the feasibility of different cell delivery methods. Autologous, unfractionated bone marrow cells or skeletal myoblasts have been used in the majority of clinical trials so far. One safety concern that has arisen from these studies is that myoblast grafts may represent an arrhythmogenic substrate. Improvements of regional systolic function and/or tissue viability have been reported. Due to the small number of patients in these studies and a lack of randomized control groups, meaningful conclusions regarding efficacy cannot be drawn at this time. SUMMARY: Cell therapy for patients with heart failure is still in its infancy. While early clinical studies suggest that stem and progenitor cell transfer to the failing heart may be feasible, firm conclusions regarding efficacy cannot be drawn at this time. The cell types that have undergone clinical testing so far, i.e. bone marrow cells and skeletal myoblasts, cannot promote true tissue regeneration. Further research into cell types with true cardiac transdifferentiation capacity is necessary in order to realize the prospects of cell therapy in this patient population.