Heart conditions account for significant mortality and morbidity throughout the world. It is therefore not surprising that stem cell therapy for heart conditions has been the focus of intense research over the past two decades. Although many of these trials used adult bone marrow cells, exciting evidence has also been generated about the capability of cardiac stem cells to repair damaged hearts.
The human trials were based on promising data that were generated from various animal models of heart disease. These preclinical studies showed improvement in heart structure and function with injection of adult stem cells, including bone marrow-derived cells. The mechanisms underlying these benefits with stem cell therapy continue to be of explored in numerous laboratories around the world.
Although the total number of clinical trials of cardiac cell therapy has been substantive, each study included relatively small number of patients and used different BMC types with highly variable numbers, routes, and timings of transplantation. Importantly, these trials included patients with acute heart attacks, chronic coronary heart disease, as well as heart failure due to previous heart attacks. The outcomes from these studies have been somewhat discordant, and subjected to meta-analysis repeatedly. At this time, the cardiac cell therapy field remains relatively nascent, and newer data from larger trials are expected over the next few years.