Abstract
The prevalence of heart failure (HF) in developed countries has reached epidemic proportions and continues to rise. Despite therapeutic advances, HF remains associated with significant morbidity and mortality and thus constitutes a major public health problem that necessitates new treatment options. Cell therapy is a potential new approach to improve outcomes in HF that was first introduced two decades ago and has evolved significantly since then. Although the mechanism of action remains unclear and pivotal, large-scale trials have not been performed, numerous studies have demonstrated the safety of using various cell products in patients with HF, and several randomized, double-blind, Phase II or III trials have shown beneficial effects of cell therapy, particularly with mesenchymal stromal cells (MSCs), on clinical outcomes in ischemic and nonischemic cardiomyopathy, after administration of a single dose of cells. These potential efficacy signals, coupled with the robust record of safety, provide a solid rationale for pursuing further studies that will conclusively evaluate efficacy. New cell types, such as induced pluripotent cell-derived myocytes, and new strategies, such as repeated doses and intravenous delivery, are being tested in ongoing trials. In contrast, embryonic stem cells are unlikely to become a clinical therapy. Rigorous, well-designed, large clinical trials have the potential to pave the way for cell therapy to become a useful treatment option for patients with HF. This review summarizes the conceptual and clinical progress made in our understanding of cell therapy for HF, particularly over the past decade, and explores future horizons for the application of this treatment in HF.