Heart’s healing power unlocked
Clinical trial taps into stem cells’ unique ability to help organ regenerate
OTTAWA — A team of cardiac researchers led by Canadian scientists has launched groundbreaking clinical trials of a stem cell therapy that helps the heart heal itself.
Each year, about 70,000 Canadians suffer a heart attack. Many patients return to health after treatment, but others suffer from scarring, which affects their chances of long-term survival.
“Scar tissue leads to stretching of the heart and that leads to consequences, including heart failure and early death,” says Dr. Duncan Stewart, chief executive and scientific director of The Ottawa Hospital Research Institute and the trial’s lead principal investigator.
This trial enlists stem cells and their amazing ability to help organs regenerate.
The first study participant is Harriet Garrow, 68, who had a heart attack on July 2 at home in Cornwall, Ont.
After her heart stopped beating, Garrow was resuscitated by paramedics and taken to a hospital in Cornwall, then transferred to the University of Ottawa Heart Institute. She received all available heart attack therapies, including opening up a blocked artery with a balloon catheter, but her heart still had extensive damage.
She agreed to the experimental therapy and had an infusion on July 18.
Like all the participants, Garrow doesn’t know if she received stem cells, lab-enhanced stem cells, or a placebo. But she notes that on Sunday she walked up the 13 stairs in her home for the first time since her heart attack.
“I feel good,” she says. “Not quite back to normal, but better than last week.”
In about a dozen studies on about 2,000 patients, stem cells have been proven to have modest but promising benefits.
The problem is heart attack patients’ stem cells don’t have the same healing powers as those from young, healthy patients, says Stewart.
Heart attack patients, often in their 60s or older, have cells that have been exposed to high blood pressure, diabetes and other conditions, and the cells have been damaged.
So there’s a twist to this therapy. It rejuvenates the cells, which are extracted from the patient’s own blood soon after a heart attack.
The cells are enhanced with extra copies of a gene, endothelial nitric oxide synthase, which is essential to blood vessel function. The enhanced cells are then returned to the patient through an infusion. The entire process, from extracting the cells to the infusion, takes about six days.
Then the cells go to work to stimulate heart repair, reduce scar tissue and restore the heart’s ability to pump blood efficiently.