Stem Cell Therapy Shrinks Enlarged Hearts03/17/11
THURSDAY, March 17 (HealthDay News) -- The promise of stem cell
therapy may have gotten a little closer to reality, with
researchers reporting that they've used the cells to help shrink
hearts that were dangerously swollen after heart attacks.
The approach involves taking stem cells from a heart patient's
own bone marrow, then injecting them into the patient's damaged
The result: a significant improvement of heart performance
within months, and a significant reduction in both scar tissue and
heart size within a year after the initial therapy.
However, the study is small -- a phase one clinical trial
involving just eight male patients -- and still described as
"experimental." But the research team says that if confirmed in
larger trials, the approach could be a big advance over current
treatments for this type of enlarged heart.
"The results are very encouraging," said study co-author Dr. Joshua M. Hare, a professor of medicine and director of the Interdisciplinary Stem Cell Institute at the University of Miami Miller School of Medicine. The therapy has "been under development for about ten years, and finally now we are starting to take a big step forward," he said.
But Hare was also quick to note that much more research and time
is needed before the novel treatment could become available to
patients. "We can't say whether that'll be in three or seven years
down the road. It's hard to speculate precisely. But we're talking
sometime this decade," he said.
Hare and his colleagues discussed the findings in the March 17
Circulation Research. The study received funding from the U.S. National Institutes of Health, the University of Miami Interdisciplinary Stem Cell Institute and BioCardia, which makes a catheter used in the procedure.
According to the American Heart Association (AHA), heart
enlargement can result from a number of health complications,
including heart attack, congestive heart failure, and a form of
heart muscle inflammation known as cardiomyopathy. Heart valve
disease and high blood pressure can also contribute to heart
enlargement as a result of heart muscle thickening.
Over 5 million Americans are burdened now with an enlarged heart
due to prior heart attack, the AHA says.
Right now, according to the researchers, chronic use of
medications and/or heart transplant are the only means of reducing
the increased risk for death, disability, and hospitalization that
accompanies an enlarged heart.
To test the new stem cell approach, the study team focused on
eight men with an average age of 57. All had suffered a heart
attack as far back as 11 years prior to their treatment.
The researchers removed the bone marrow cells from each
patient's hip bone, Hare said, adding that they either used the
whole bone marrow or took the stem cells in the bone marrow to the
laboratory, where the cells could grow and expand.
"To inject the cells into the heart," he continued, "we used a special catheter that could be placed in the heart chamber in such a way as to allow us to inject stem cells directly into the damaged part of the heart."
The scientists used two types of stem cells -- mononuclear and
mesenchymal. Although it was not clear whether one type of stem
cell had more of a beneficial impact on heart health than another,
overall the approach produced impressive results.
Three months after stem cell injection into each patient's
heart, the team observed significant "functional recovery" in the
heart contraction capacity of those heart areas that had
experienced previous damage.
What's more, by the one-year point after a single stem cell
injection, heart size was found to have diminished by an average of
15 to 20 percent. That reduction, they noted, is roughly three
times what's achievable with current therapies. The approach also
reduced the presence of scar tissue by an average of more than 18
The team said the stem cell treatment was well-tolerated with no
serious side effects. Hare estimated that the procedure and the
cells would cost approximately $10,000 to $15, 000, "not including
a hospital fee if one was needed."
According to Hare, the findings may advance the field of stem
cell therapy generally. "In fact, we see this as eventually having
a broad application, even for patients with non-cardiac
conditions," he said. "And certainly for heart patients, this
approach appears to be a safe way to get better clinical results
and improve on our limited treatment options."
One outside expert agreed that there are currently few effective
treatments for patients with enlarged hearts.
"We don't have very much that works right now," said Dr. Murray A. Mittleman, director of the Cardiovascular Epidemiology Research Unit with the Beth Israel Deaconess Medical Center at Harvard Medical School in Boston. "So if this sort of novel treatment improves outcomes that would certainly be helpful. Especially if it helps patients avoid getting to the stage where they would need a heart transplant."
For more on enlarged hearts and heart disease, visit the
American Heart Association.
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