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Stem Cell News
Healing with one's own stem cells
Trial uses regenerative medicine to treat heart
conditions
By JOHN FAUBER
Milwaukee Journal Sentinel
MILWAUKEE
- Here's just one of Steve Myrah's
problems: He is such a huge fan of the University of
Wisconsin basketball team that games, literally, are
painful to watch, causing his angina to flare up and
forcing him to pop nitroglycerin tablets to ease his
chest pain.
"A good basketball game is a three-nitro game
for me," said Myrah, 68.
You might think that Myrah would just stay away
from the TV when the Badgers are playing, but he and
his doctors have another idea.
Last week, he became the first heart patient in
Wisconsin to enter a novel stem cell clinical trial
using patients' own cells to treat their heart
disease.
Doctors at the University of Wisconsin Hospital and
Clinics harvested adult stem cells from Myrah's bone
marrow so they could be injected into various
blood-deprived areas of his heart. The hope is that
the cells will stimulate the formation of new blood
vessels or the expansion of existing vessels,
restoring blood flow.
The experiment could help overturn a dismal dogma
that has pervaded the field of cardiology for decades:
We are born with all the heart cells we will ever
have, and if some die, they can't be replaced.
Over the last several years, the field of
regenerative medicine has gained promise as
researchers have started a variety of human
experiments using adult stem cells, genes and growth
factors to fix damaged hearts.
Promise of embryonic
cells|
Researchers around the country believe that,
further down the road, embryonic stem cells might
provide even more reason for optimism.
University of Wisconsin researchers already have
coaxed embryonic stem cells to become heart muscle
cells that can be seen beating under a microscope.
Unlike Myrah's adult stem cells, which most likely are
limited to forming new blood vessels, embryonic stem
cells are envisioned as cells that might replace
nonfunctioning muscle cells in the wall of the heart,
as well as form new blood vessels.
Although some small preliminary trials have shown
promise, others have not, said Timothy Gardner, a
heart surgeon and medical director of Christiana
Care's Center for Heart and Vascular Health in
Wilmington, Del. And it still is unclear what the
cells actually do after they are transplanted, he
said.
It might be that they merely are stimulating a type
of beneficial inflammation that improves the
physiology of the heart, he said.
"The jury is still out," Gardner said.
"We've seen intriguing and promising clinical
results, but they haven't been overwhelming, and they
haven't explained the mechanism."
About 150 people will be treated around the
country, including about 10 at University of Wisconsin
Hospital.
Nationally, an estimated 125,000 to 250,000 people
a year develop so-called chronic myocardial ischemia,
which involves blockages of blood vessels that often
are too small to be treated with conventional
therapies such as bypass surgery or angioplasty.
Optimistic|
These patients are limited to treating their chest
pain with drugs such as nitroglycerin.
Myrah wears time-release nitroglycerin patches 16
hours a day. For the other eight hours, he takes
nitroglycerin tablets that dissolve under his tongue.
If he walks just a block, he will get chest pain.
"I used to love to walk," he said.
"I would do anything to get rid of this. If they
could snip these two (blocked) blood vessels, even if
it killed a little bit of the heart muscle, I'd do it
in a minute."
Myrah already has undergone coronary bypass surgery
and angioplasty, but both eventually failed to relieve
his chest pain.
One of the realities of clinical trials is that in
order to be truly rigorous, a placebo or control group
of patients often must be used.
For Myrah's trial, one-third of the patients will
receive about 50 million stem cells, another third
will get 10 million cells, and the rest will be
injected with a placebo saline solution.
Neither the doctors nor the patients know who is
getting what.
"I feel optimistic that I'm going to get the
stem cells and that it is going to work," Myrah
says two days before his treatment.
Even if it turns out that doctors have injected
saltwater into his heart, Myrah and his wife, Dagny,
have motivation for him to be in the trial.
The couple have a 9-year-old granddaughter who was
born with a serious congenital heart defect, Myrah's
wife says.
Stem cell research eventually may lead to
breakthroughs that could be used to treat her, she
says.
"That's what we hope," she says.
It's late in the afternoon, and Myrah lies in the
cardiac catheterization lab as doctors thread a sensor
up through an artery in his groin into his left
ventricle, the main pumping chamber of the heart.
The sensor picks up movement in the heart wall, as
well as electrical impulses coming from the tissue,
both of which are surrogates for blood flow.
"No signal is dead (tissue)," says
cardiologist Matthew Wolff. "Strong is normal.
Weak is viable but impaired blood flow. That's where
we want to go."
After a couple of hours, Wolff and cardiologist
Amish Raval develop a colorful map of the blood flow
in Myrah's heart.
They zero in on an oblong area roughly 1-inch by ¼-inch
in the lower back portion of the chamber. The clear
fluid in the syringes will be injected into 10 spots
in that area.
Raval removes the injection catheter from its
packaging and sets the length of the tip. The wall of
Myrah's ventricle is 8 millimeters at its thinnest
point.
"We need to go half of that," Raval says.
Puncturing the wall is one of several small but
serious risks of the procedure.
Raval and Wolff begin picking the injection sites.
The first injection is done at 4:40 p.m., and each
one lasts from 30 to 40 seconds.
Myrah, who is sedated but awake, moves on the
table.
"Keep your arm down, Steve," Raval says.
"You can't move."
"Can I get another nitro?" Myrah asks.
A nurse puts a nitro tablet in his mouth.
At 5:11 p.m., the final injection is made.
If the treatment works, it could be a couple of
months before Myrah notices any lessening of his
angina, says Raval, who also is head of cardiovascular
regenerative medicine at the University of Wisconsin's
School of Medicine and Public Health.
Two days after the procedure, Myrah says he's a
little tired, but feeling well.
"I'm bruised and full of holes," he
jokes.
In August, he and his wife will go on a cruise of
the Greek islands.
"I'd love to be able to go up the steps of the
Parthenon," he says. "But if I have to, I'll
just sit on the beach with a novel."
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