Heart Stem Cell Study: Researcher's Perspective
An interview with Roberto Bolli, MD.
How does this compare to other stem cell trials? continued...
In contrast, one year after being injected with their own heart stem cells, Bolli's patients gained an average increase of 10 percentage points in ejection fraction.
For example, a patient with a baseline ejection fraction of 30% would have increased to 40%, he says.
"That is huge when you consider that previous studies of stem cells in these kinds of patients -- patients with ischemic heart failure -- have reported improvements of three, four, five [percentage] points in ejection fraction," Bolli says.
Also, in Bolli's patients, cardiac tissue scarred by heart attack had shrunk by an average of 50% one year after the experimental procedure.
"This is amazing," Bolli says. "You are given one shot of stem cells and that scarring in the heart shrinks by half in one year. Correspondingly, there's an increase in viable tissue in the heart, which is strongly suggestive of regeneration."
In other words, the patients are making new heart tissue to replace the damaged tissue -- something no drug or surgery can do.
Two years after the procedure, partial results were available for eight patients who had gotten echocardiograms. On average, their ejection fraction had improved by 13 percentage points.
"At two years, we continue to see the improvement in ejection fraction," Bolli says. "It actually seems to be greater than it is at one year. So in other words, as time goes by, the effects of these cells becomes bigger, rather than smaller, which is really quite exciting."
What about cost?
Such a regenerative therapy would be less costly and burdensome than current options for heart failure, including a heart transplant or a mechanical pump called a ventricular assist device, Bolli says.
Also, Bolli hopes to make the heart stem cell procedure available to a much larger pool of heart failure patients. During the Phase I trial, all 20 patients had undergone heart bypass surgery, during which surgeons extracted heart tissue that contained stem cells.
Patients won't need to undergo bypass surgery for the next clinical trials.
"Now we can isolate the stem cells from a biopsy. We don't need a surgical specimen anymore," Bolli says.