Cell Therapy for Heart Disease: Ready for Prime Time or Lost in Translation?

Abstract

Over the past two decades, cell therapy has emerged as a potential therapeutic approach for various forms of heart disease. Several different cell types of adult progenitor cells have been tested clinically, including bone marrow-derived mononuclear cells, mesenchymal stromal cells (derived from the bone marrow or from adipose tissue), skeletal myoblasts, and heart-derived cells (c-kit+ cells and cardiosphere-derived cells). In addition, embryonic stem cells have also recently entered the arena of clinical testing. Overall, cell therapy for heart disease has established an excellent safety profile. However, results from clinical trials regarding its potential efficacy have been conflicting and perhaps (given the overwhelmingly positive results of preclinical studies) disappointing. Moving forward, the field is focusing on (a) optimization of delivery methods and development of tissue engineering approaches to boost cardiac retention and engraftment of administered cells, (b) elucidation of the indirect paracrine mechanism of action of administered cells, (c) development of highly standardized, carefully characterized allogeneic cellular products that could potentially facilitate widespread application of cell therapy, and (d) conduction of large, pivotal clinical trials using hard, clinically meaningful endpoints.