Stem Cell Treatment Improves Heart Function, Large-Scale Study Suggests
Stem cell therapy may become an opportunity for patients with ischemic heart disease and heart failure, the largest study involving stem cell treatment known as the FOCUS trial suggests. Patients’ own bone marrow stem cells, when injected back to their hearts, helped improve the cardiac function impaired with the disease. The study results were announced at the 2012 American College of Cardiology Meeting in Chicago on March 26, 2012, and will be published online in the Journal of the American Medical Association.
This multi-centre study conducted in the US by the Cardiovascular Cell Therapy Research Network (CCTRN) and supported by a grant from the National Institutes of Health's National, Heart, Lung and Blood Institute (NHLBI) aimed to assess new treatment strategies involving stem cell transplantation for patients with cardiovascular diseases. In particular, study was designed to determine whether stem cell treatment could improve myocardial oxygen consumption and the volume of the left ventricle of the heart at the end of a contraction, as well as lead to a reversible change in perfusion defects.
Although this trial is not the first in its attempt to apply stem cell treatment for heart patients, it is the largest in the history by both the number of participants involved and bone marrow stem cell doses administered to them. The whole study took two years to conduct (from April 2009 to April 2011) and involved 92 patients with cardiovascular diseases. Aged 63 on average, all the patients had chronic ischemic heart disease accompanied with heart failure and/or angina. The conventional treatment could no longer help them, and they could not count any more on revascularization. Stem cell treatment remained the only opportunity to them.
The participants were divided into two groups, one receiving placebo and the other stem cell transplant. After collecting, bone marrow was processed to get only the mononuclear fraction of it. The patients randomly selected to receive a transplant were injected via catheter 100 million stem cells into more than 15 damaged sites of their hearts’ left ventricle.
Though the treatment did not have significant impact on the indicators chosen by the researchers, they discovered that ejection fraction (the percentage of blood pumped out of the left ventricle during each contraction) was 2.7 percent higher in the group that had undergone stem cell treatment than in the control group. Though this improvement is not a big one, it is still statistically significant. Moreover, the improvement was higher in patients younger than 62 whose bone marrows contained more certain stem cells, namely CD34+ and CD133+.
The researchers were able to find a linear correlation between the number of CD34+ cells injected and the ejection fraction improvement. Importance of certain stem cell types in treating heart patients may help the scientists to develop effective therapies for cardiovascular diseases involving these particular cells.