Stem cell therapy for heart diseases.

BACKGROUND: Cardiovascular disease is the leading cause of morbidity and mortality worldwide. Despite the advances in medical and catheter-based therapy for acute myocardial infarction the 1-year mortality remains as high as 13% and the 5-year prognosis for patients with heart failure remains as high as 50%. Left ventricular systolic dysfunction, a major determinant of prognosis, is associated with significant loss of cardiomyocytes which was previously thought to be irreversible as the heart was considered a post-mitotic organ. SOURCES OF DATA: Review of literature published in peer reviewed journals and ClinicalTrials.Gov website. AREAS OF AGREEMENT: There is now growing evidence that the human heart is capable of undergoing repair and in recent years there has been an increase in basic and clinical research with the aim of harnessing the regenerative properties of stem cells in order to facilitate restoration of myocardial function. AREAS OF CONTROVERSY: The mechanisms of action of cell therapy with regards to cardiac repair remain unsatisfactorily understood and the magnitude of benefit demonstrated in animal models is yet to be fully translated in humans. GROWING POINTS: The number of clinical trials continues to increase and include treating patients with acute myocardial infarction and chronic heart failure secondary to ischaemic heart disease or dilated cardiomyopathy. AREAS TIMELY FOR DEVELOPING RESEARCH: The future of this field of research will require closer collaboration between scientists and clinicians to understand how cell therapy works and to define the ideal cell type and method of delivery to be able to derive maximum benefit.