Public  release date: 5-Nov-2012  [ |   E-mail   |  Share    ]  
    Contact: NHLBI Communications    NHLBI_news@nhlbi.nih.gov    301-496-7510    NIH/National Heart, Lung and Blood    Institute
    Administering to patients stem cells derived from their own    bone marrow either three or seven days after a heart attack is    safe but does not improve heart function six months later,    according to a clinical trial supported by the National    Institutes of Health.  
    The results of the trial, called Transplantation In Myocardial    Infarction Evaluation (TIME), mirror a previous, related study,    LateTIME, which found that such cells (called autologous stem    cells) given two to three weeks after a heart attack did not    improve heart function. Both TIME and LateTIME were conducted    by the Cardiovascular Cell Therapy Research Network (CCTRN),    sponsored by the NIH's National Heart, Lung, and Blood    Institute.  
    The findings will be presented Tuesday, Nov. 6, at the American    Heart Association (AHA) 2012 Scientific Sessions in Los Angeles    and will appear concurrently in the Journal of the American    Medical Association.  
    "This study was extremely valuable even though it did not    provide a demonstrated health benefit after six months," said    Sonia Skarlatos, Ph.D., deputy director of NHLBI's Division of    Cardiovascular Sciences and member of the CCTRN. "Heart stem    cell therapy research is still in its infancy, and results from    early trials have varied greatly due to differences in the    numbers of stem cells injected, the delivery methods used, and    the compositions of the study populations. With TIME and    LateTIME, we have established both safety and baseline results    in two large studies that followed the same procedures for    growing and then administering stem cells. This standard will    inform the next steps in research on the use of stem cells to    repair damaged hearts."  
    "With this baseline now set, we can start to adjust some of the    components of the protocol to grow and administer stem cell to    find cases where the procedure may improve function," added    fellow CCTRN member Jay Travese, M.D., of the Minneapolis Heart    Institute, who will present the results at the meeting. "For    example, this therapy may work better in different population    groups, or we might need to use new cell types or new methods    of delivery."  
    Skarlatos noted that another advantage of the TIME study is    that CCTRN is storing samples of the stem cells taken from the    participants. Investigators can examine the relationship    between people who showed significant improvement during the    study and the characteristics of their stem cells. Such a    comparison may offer insights on the cell traits that are    associated with clinical improvement.  
    Between July 2008 and February 2011, TIME researchers enrolled    120 volunteers (average age 57, 87.5 percent male) who suffered    from moderate to severe impairment in their left ventricles     the part of the heart that pumps oxygen-rich blood to the body     and had undergone stenting procedures following heart    attacks. Those selected for the trial were assigned randomly to    one of four groups: day three after heart attack stem cell    injection, day three after heart attack placebo injection, day    seven after heart attack stem cell treatment, or day seven    after heart attack placebo treatment. The researchers developed    a method of processing and purifying the stem cells to ensure    that participants in the stem cell groups received a uniform    dose of 150 million cells about 8 hours after the cells were    harvested from their bone marrow. This ensured that results    would not be skewed by differences in the quantity or quality    of stem cells administered.  
    Researchers assessed heart improvement six months after stem    cell therapy by measuring the percentage of blood that was    pumped out of the left ventricle during each contraction (known    as the left-ventricular ejection fraction, or LVEF). The study    found no significant differences between the change in LVEF    readings at the six-month follow-up in either the day three or    the day seven stem cell groups compared with placebo groups or    with each other. Every group showed about a three percent    improvement in LVEF.  
Read more from the original source:
Therapy with bone marrow-derived stem cells does not improve short-term recovery after heart attack