Bone marrow stem
cell therapy holds promise as a novel therapy for heart failure,
offering a sustained improvement up to six months, according to
research presented at the American Heart Association’s
Scientific Sessions 2003.
Researchers at the
Texas Heart Institute in Houston tested mononuclear bone marrow
cell transplant injections in patients with severe ischemic
heart failure — the first such study in a severely ill
population. There are few treatment options for patients with
end-stage ischemic heart failure, according to the study’s lead
author Emerson C. Perin, M.D., Ph.D., a clinical assistant
professor of medicine at Baylor College of Medicine at the
University of Texas Health Science Center in Houston.
laboratory research has shown that mononuclear cells taken from
bone marrow then injected into human tissue can promote growth
in oxygen-deprived tissue. Mononuclear cells can differentiate
into tissue and new blood vessels, and secrete a wide variety of
proteins and growth factors, said Perin, who is also director of
new cardiovascular interventional technology at the Texas Heart
had better blood flow and could walk longer on treadmill tests
than controls. They also reported less chest pain and were able
to breathe better.
“To have the
sustained ability to exercise at six months is significantly
different than the controls. They’re functional and they have
their lives back,” Perin said.
conducted a controlled, open label, non-blinded study of 20
patients (average age 58) with severe heart failure.
received injections in the left ventricle of their heart with
their own mononuclear cells. The procedure involved extracting
50 milliliters of bone marrow and isolating the mononuclear
cells. Using a guided imaging and mapping system, researchers
carefully aimed the cells into the areas of the heart with
blocked blood flow. The procedure takes about an hour and a
The nine patients
in the control group received no treatment.
monitored on treadmill tests and had blood tests to see if the
stem cells caused inflammation.
measured “reversible defects” (live heart muscle tissue that’s
not getting enough blood flow) and “fixed defects” (dead tissue
that has become scar tissue) at baseline, two and six months.
In the treatment
group, the total reversible defect made up about 15 percent of
the tissue at baseline. That was reduced to an average 4.5
percent at two months and 8.8 percent at six months. Among
controls, reversible defects increased from an average 10
percent at baseline to 32 percent at two and six months.
significant change in the amount of scar tissue between the two
groups. The scar didn’t change or get worse in the treated
group, and the area that lacked blood flow got better in the
treatment group,” Perin said.
consumption (VO2 max) and the body’s ability to exercise are
directly related to how well the heart can pump. “Patients who
have a VO2 max of less than 14 are generally near death. A lot
of the patients in this trial were close to that number at the
beginning of the study,” Perin said.
Patients in the
treatment group started with an average VO2 max of 18ml/Kg/min
(milliliters per kilogram per minute) and the
control group had 17.7ml/Kg/min. The treatment group went up to
23ml/Kg/min in the first two months while the controls were at
an average 18ml/Kg/min. At six months, the treatment group
averaged 24ml/Kg/min, while the control group was at
equivalents (METs), which also relate to the heart’s function on
a treadmill, rose for the treatment group from an average 5 at
baseline to 7 at six months. The control group, which started
at an average MET of 5, finished the study at 4.9.
Blood tests taken
at six months revealed no evidence of significant inflammation.
“The group as a
whole was severely limited in their physical capacity or
activity at baseline and now the treated group are leading
pretty active lives, Perin said. “One of the participants in
the treatment group was in his apartment building during a
blackout and had to walk up eight flights of stairs. He did it,
and it wasn’t a problem.”
Perin warned that
these results need confirmation in a placebo-controlled, blinded
and randomized trial. “This is the first step. It’s incredible
to see that this is a safe procedure with sustained
improvement,” he said. “It’s the impetus we need to go forward
Hans F. Dohmann, Radovan Borojevic, Suzana A. Silva, Andre L.
Sousa, Guilherme V. Silva, Claudio T. Mesquita, Luciano Belem,
Fernando O Rangel, Joao A. Assad, Antonio C. Carvalho, Isabel
Rossi, Hans J. Dohmann, and James T. Willerson.