Remuscularization of the failing heart.

Myocardial remuscularization can be achieved by cardiomyocyte implantation. Electromechanical integration and long-term survival of cardiomyocyte grafts are essential for maximal therapeutic impact. Cardiomyocyte application with support material has been instrumental in enhancing cell retention. Co-administration of pro-survival factors and immunological matching are additional strategies for increased cell graft survival. Finally, larger cardiomyocyte grafts, although therapeutically desirable, will increase the risk for arrhythmias and, if pluripotent stem cells are used to derive cardiomyocytes, tumour formation. This review introduces major challenges pertaining to myocardial remuscularization (cardiomyocyte retention, arrhythmogenicity and tumourigenicity), discusses studies addressing these challenges, and suggests strategies to overcome remaining challenges for the translation of myocardial remuscularization.