The first patient to receive this type of stem cell therapy,
James Culross, a 67-year-old man from Etobicoke, will be
discharged this week after 2.83 million stem
cells^[1] were
injected into seven sites where his heart had been damaged by a
heart
attack^[2] in November
2011. The stem cells were injected following coronary artery
bypass graft^[3] (CABG)
surgery, by a multi-disciplinary team led by Dr. Terrence Yau,
Cardiac
Surgeon^[4] and
Director of the Cardiac Stem Cell Therapy Program at the Peter
Munk Cardiac Centre. A second patient underwent successful stem
cell implantation and CABG surgery at the Peter Munk Cardiac
Centre this week.

"When a patient suffers a heart attack, part of the heart
muscle^[5] dies and is
replaced by scar. The larger the heart attack, the more likely
that patient is to develop heart
failure^[6], in which
the heart becomes progressively weaker. Patients develop
shortness of
breath^[7], initially
during activity but later at rest as heart failure progresses,
and ultimately die of this disease," says Dr. Yau, who holds
the Angelo & Lorenza DeGasperis Chair in Cardiovascular
Surgery Research.

After a diagnosis of severe heart failure, the average life
expectancy is one and a half years for men and three years for
women, a prognosis worse than most cancers. Current treatments
for heart attacks, including angioplasty, stenting and coronary bypass
surgery^[8], have saved
many lives and prevented further heart attacks, but they cannot
reverse the effect of heart attacks that have already occurred.
While researchers hope that stem cell therapy will improve the
function of hearts injured by heart attacks, the safety and
efficacy of stem cell therapy must first be clearly
demonstrated in clinical
trials^[9] such as the
IMPACT-CABG Trial.

Using a novel process, unique in Canada, in which stem cells
are isolated by means of a rigorously-tested process in the
University Health Network's Organ Regeneration Laboratory,
located entirely within operating room suite, researchers
removed, prepared and injected the stem cells back into the
patient on the same day.

"Manipulating the cells in-house preserves cell viability.
Injecting the stem cells into the heart as soon as possible
after they are isolated from the patient's bone
marrow^[10] may
improve their ability to improve heart function," says Dr.
Richard Weisel, Cardiac Surgeon at the Peter Munk Cardiac
Centre and Senior Scientist at the McEwen Centre for
Regenerative Medicine.

Here's how the process works: 100 millilitres of bone marrow is
acquired the morning of the patient's bypass surgery from the
iliac crest – the flat portion of the hip bone located near the
lower back – which is rich in bone marrow. The bone marrow is
then brought to the Organ Regeneration Laboratory, where
research technicians use a clinical-grade magnetic separating
device called the CliniMACS to separate the CD133 stem cells
from other components of the bone marrow. During the stem cell
isolation procedure, which takes four to six hours, the patient
rests until their surgery, which is scheduled to begin in the
early afternoon.

The end result is two millilitres of clear fluid containing
several million stem cells that have been rigorously tested to
ensure that they pass Health Canada-approved release criteria.
The cells are brought in a sterile tube to the operating
room^[11] where Dr.
Yau's coronary
artery bypass^[12] graft
(CABG) surgery is underway. After the bypass grafts have been
completed, Dr. Yau fills a syringe with the stem cells and
injects them into the area of the heart that has been damaged
by a heart attack.

"This intraoperative approach to cardiac stem cell
therapy^[13] is an
important component of the new Organ Regeneration Laboratory at
the University Health Network," says Dr. Shaf Keshavjee,
Surgeon-in-Chief at UHN. "Whether it is repairing hearts or
lungs, the Organ Regeneration Laboratory is at the leading edge
of regenerative medicine."

To date, over 500 heart patients worldwide have been treated
with a variety of stem cell preparations. Eight patients have
been treated at the Maisonneuve-Rosemont Hospital in Montreal
as part of the IMPACT-CABG Clinical Trial. Toronto and Montreal
researchers will merge their results after each centre performs
stem cell transplants in 20 patients. The objective of the
IMPACT-CABG Trial is to demonstrate the safety of injecting
stem cells into the hearts of patients undergoing CABG surgery,
and to gather information on the feasibility and efficacy of
this approach.

"This clinical trial marks an important milestone in
regenerative medicine therapy at the University Health Network
and paves the way for collaborative studies between scientists
at the McEwen Centre and Dr. Yau and the team at the Peter Munk
Cardiac Centre," says Dr. Gordon Keller, Director of the McEwen
Centre for Regenerative Medicine.

Dr. Barry Rubin, Medical Director of the Peter Munk Cardiac
Centre, commented, "The Peter Munk Cardiac Centre is leading
innovation into new treatments for cardiovascular diseases. We
are very pleased to partner with scientists in the McEwen
Centre and to work together to provide novel stem cell
therapies for our patients."

Provided by University Health Network

References

1. ^{^} stem cells
   (www.physorg.com)
2. ^{^} heart attack
   (www.physorg.com)
3. ^{^} coronary artery bypass
   graft (www.physorg.com)
4. ^{^} Cardiac Surgeon
   (www.physorg.com)
5. ^{^} heart muscle
   (www.physorg.com)
6. ^{^} heart failure
   (www.physorg.com)
7. ^{^} shortness of breath
   (www.physorg.com)
8. ^{^} coronary bypass surgery
   (www.physorg.com)
9. ^{^} clinical trials
   (www.physorg.com)
10. ^{^} bone marrow
    (www.physorg.com)
11. ^{^} operating room
    (www.physorg.com)
12. ^{^} coronary artery bypass
    (www.physorg.com)
13. ^{^} stem cell therapy
    (www.physorg.com)