The first patient has been treated in a groundbreaking medical trial in Ottawa that could lead to a new way to repair damaged tissues following a heart attack.
Researchers announced Thursday that Harriet Garrow of Cornwall, Ont., who suffered a severe heart attack in July, was their first test subject. Her heart had stopped beating before she was resuscitated, causing major damage to her cardiac muscle.
The hope is that a new form of combined gene and stem cell therapy will be able to better repair her heart and those of potentially millions of other heart attack patients.
The therapy involves injecting a patient's own stem cells into their heart to help fix areas that become damaged in a heart attack. Stem cells are a fertile regenerative tissue that can replicate into millions of new, healthy cells.
But the Ottawa study, led by cardiologist Duncan Stewart of the Ottawa Hospital Research Institute, takes the technique one step further, combining the stem-cell treatment with gene therapy — which the researchers say is novel.
"Stem cells are stimulating the repair. That's what they're there to do," Stewart said in an interview. "But what we've learned is that the regenerative activity of the stem cells in these patients with heart disease is very low, compared to younger, healthy patients."
To try to restore some of that regenerative capacity, Stewart and his colleagues will supply the stem cells with extra copies of a gene. The gene makes the cells produce more of an enzyme called endothelial nitric oxide synthase, which helps the damaged heart build up new blood vessels and heal itself.
"That, we think, is the key element," he said. We really think it's the genetically enhanced cells that will provide the advantage."
100 patients in 3 cities
The study will see 100 severe heart attack patients in Ottawa, Toronto and Montreal randomly selected to receive the combined gene-and-stem-cell therapy, stem cell therapy alone, or a placebo.
It follows years of landmark research by prominent German cardiologist Bodo-Eckehard Strauer on using stem cells to treat heart attack patients. Strauer long held that stem cells can help repair diseased hearts, but his findings have come under increasing attack. A paper published earlier this summer in the International Journal of Cardiology picked apart 48 published papers from Strauer's research group, finding evidence of hundreds of arithmetic errors, inconsistencies in the data and other problems.
The Ottawa study differs from Strauer's work, though, because it harvests stem cells from a patient's blood, whereas Strauer used stem cells from the bone marrow at a much lower concentration.
"What we're doing is a next-generation therapy on many levels," Stewart said.
Other studies have looked at using cardiac stem cells to repair badly damaged hearts, but some of those trials involved patients also undergoing bypass surgery.
Funding for the Ottawa study comes from the Canadian Institutes of Health Research, the Ottawa Hospital foundation and the St. Michael's Hospital foundation in Toronto. Some equipment was donated by drug and medical products company Abbott.