The global health and economic impact of cardiovascular disease, specifically heart attacks, is tremendous. Patient prognosis following a major heart attack, including progressive heart failure, repeat heart attacks, arrhythmias, and mortality, depends on the damage sustained to the heart. Cellular therapies that aim to repair damaged heart muscle have the potential to positively impact post-infarct clinical outcomes.
One of the most comprehensive phase II clinical trials of bone marrow cell therapy for cardiac repair in the U.S. has shown positive initial data, specifically that intracoronary transplantation of a large number of bone marrow-derived endothelial progenitor cells is beneficial to patient outcome. The study, led by Dr. Arshed Quyyumi of Emory University School of Medicine, in collaboration with NeoStem Inc., a cellular therapeutics company, treated 161 heart attack patients from 60 sites with autologous bone marrow cells. The cells were extracted from the patients’ own bone marrow, endothelial progenitors were specifically targeted and selected, and this subset of cells was injected into the patients’ compromised hearts in order to ameliorate recovery.
The initial results of the trial show that patients who received higher doses of transplanted cells (up to 40 million), showed the greatest improvement in cardiac function and the greatest reduction in mortality, serious adverse events and major adverse cardiac events, up to 12 months following treatment. While it is too soon to draw conclusions regarding the mechanisms responsible for these improvements, researchers believe that the ability of endothelial progenitor cells to stimulate vascular healing and subsequent restoration of blood flow may play a role. Overall, the rigor of this study and the positive initial data are encouraging both as indicators of clinical relevance and as a model for assessing cell therapeutics.