NEW ORLEANS, March 26, 2007 -- Scientists have announced that they have been able to use stem cells to treat patients with heart failure, some of the first evidence that the much-hyped therapy could have significant clinical benefits.
In two studies reported at the American College of Cardiology conference, scientists used adult stem cells -- not the more controversial embryonic stem cells -- to treat patients and saw marked improvement in their health. Experts note these early studies need to be replicated in larger groups to confirm the results.
The findings are welcome news for patients like Joseph Glasser, 74, who received a bleak prognosis nine years ago after suffering a heart attack that left his heart so weakened he had to have a pacemaker implanted. Seventy-five percent of his heart muscle had died, his cardiologist told him, and there was nothing more he could do.
In the years afterward, Glasser frequently felt fatigued and short of breath, so he sought out new treatment options and eventually enrolled in a stem cell study at the University of California San Diego. There, doctors took cells from his leg, cultivated them in a lab and then injected them into his heart.
Today, two years after treatment, he says he no longer has problems maintaining energy, and even walks on a treadmill and swims.
"My ejection fraction went up. My heart reduced a little in size," he said, "but I don't need any numbers or proof that I am doing great. I have my body to tell me. I feel excellent, and I can do whatever I want to do."
He insists the procedure added years to his life. "My first cardiologist said he couldn't do anything for me and I would only live for five years, and now it is nine years later."
The study's leader, Nabil Dib, director of clinical cardiovascular cell therapy at the University of California San Diego, said one of the most notable aspects of the treatment was how minimally invasive it was -- patients don't even require anesthesia.
"We can do it with a catheter so they are awake during the procedure and can go home within 24 hours," he said.
That kind of targeted therapy is particularly valuable for high-risk patients like Glasser, who might be excluded from general surgery.
23 Patients Undergo Procedure
In the study, Dib and his colleagues extracted stem cells from the thigh muscles of 23 patients who, like Glasser, had poor heart function or heart failure. They then grew the cells in a lab and delivered them directly to patients' hearts through a catheter.
After six months, patients who had received the treatment showed improvements in health and quality of life, while those who had standard medical therapies worsened.
In a second study done at 10 medical institutions, researchers took muscle stem cells from donors, not the patients themselves, and infused them intravenously into cardiac patients within 10 days of a heart attack.
The researchers found that after six months patients had fewer side effects than those who had not received stem cells, and that they also showed improved heart and lung function.
"There was a lot of concern in the medical community about whether taking cells from an unrelated donor would cause a rejection reaction or cause tumors," said Joshua M. Hare, chief of cardiology and director of the Stem Cell Institute at the University of Miami School of Medicine.
Hare led the study. "We felt we had a solid footing, and to our great surprise the stem cells are more than safe. We got significant evidence that the cells were helping the patients on a number of measures."
Because these cells came from donors and not the patients, they could potentially be made in large quantities and administered like an off-the-shelf drug.
Using stem cells may also prove cheaper than heart transplants, which can cost upward of $200,000 over three years. Stem cell therapy is expected to run between $20,000 and $25,000, possibly even as low as $8,000, Dib said.
Not Many Doctors Know the Procedure
There are still very few doctors capable of performing the treatment though, which requires a specialized method of coaxing stem cells into heart tissue, while avoiding tumor formation -- a risk associated with all stem cell treatments.
Experts caution the trials are still in the early stages, and it remains to be seen how well the therapies will work in a larger population.
"Obviously, in 23 patients you can't say anything definitive, but it at least it gives you the green light now to do many more patients and do some definitive trials," said William O'Neill, executive dean for clinical affairs at the Miller School of Medicine at the University of Miami.
Dib is hopeful that the wait won't be long before it is standard treatment. "This procedure will be available in five years worldwide. I think it will be part of the standard of care."
Hare sees an even larger goal: ending cardiovascular disease, as we know it. With the advent of these treatments, he said he envisioned heart disease -- now the No. 1 killer of Americans -- becoming more like infectious disease, which has been more easily treatable and much less fatal since antibiotics were introduced.
Additional reporting by Dr. Mark Abdelmalek, M.D.