Rhune
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Study: Bone marrow cells renew broken heart
« on: Nov 11th, 2003, 8:59am » |
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Study: Bone marrow cells renew broken heart Monday, November 10, 2003 Posted: 2:39 PM EST (1939 GMT) WASHINGTON (Reuters) -- Cells taken directly from the bone marrow and washed into the heart soon after heart attack helped patients recover better than patients given standard care, German researchers reported on Monday. They do not quite understand how the new cells are working, but believe they may help the damaged heart regenerate itself before too much of the tissue dies. Several studies being presented to a meeting of the American Heart Association are looking at the possibility that immature cells in a patient's own body can be used to renew a damaged heart and perhaps even prevent some of the worst damage caused by heart attack. "This is the first demonstration that this treatment is effective," Dr. Helmut Drexler of Hannover Medical School, who led one of the studies, told a news conference. The 30 patients who got the cells had an average 6.7 percent improvement in left ventricular ejection fraction -- meaning their hearts pumped much more efficiently. "It is a highly significant improvement," Drexler said. Dr. Ray Gibbons of the Mayo Clinic in Rochester, Minnesota, agreed, saying a 6.7 percent improvement could be enough to tip a patient over from questionable survival to long-term survival -- depending on how bad he or she was in the first place. A heart attack can damage the left ventricle, making it less able to pump blood through the body. Measuring the ejection fraction of the left ventricle is the best predictor of how likely a patient is to die after a heart attack. The 30 patients who got angioplasty alone had, on average, only a 1 percent improvement in ejection fraction. Too few to determine survival Drexler said the group is too small to tell whether the better ejection fraction translates into feeling better or better survival, but all patients are doing well. "Since the patient knows he got bone marrow cells, there is a tendency to say 'I know I got new cells so I must feel better,'" Drexler said. All the patients had balloon angioplasty, a procedure under which the clogged artery is unblocked and stretched open. Then mesh tubes called stents were put in to hold the artery open. Thirty patients had a little bit of bone marrow taken out of their hips. Drexler's team quickly removed the red blood cells and cleaned up the cell mixture to try to isolate the so-called stem or progenitor cells. They blocked blood flow to the heart to keep it from washing away the marrow cells, and infused the cells into the artery as close as possible to where the blockage had been. Drexler said he believes the cells went directly to the damaged area, which would have still been sending out distress signals. Some may become heart muscle cells, Drexler said. They may also stimulate stem cells that live in the heart to divide and grow, form tiny blood vessels to feed the tissue and perhaps also secrete proteins that stop damaged tissue from dying. He said more study will be needed, but the research is expensive and drug companies are unlikely to take it on because the procedure itself cannot be patented. In a second study Dr. Bodo Strauer of Heinrich Heine University in Dusseldorf and colleagues tested 40 heart attack patients -- half of whom got bone marrow cells. They looked at the area of heart tissue actually damaged by the heart attack, and found that the patients given stem cells seemed to regenerate new heart tissue. The area damaged shrank, and the heart's contraction speed doubled. They also had a modest improvement in ejection fraction.
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