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View Full Version : After stem cell hype, a new hope for heart therapy in Minneapolis



barbara
08-13-2011, 04:06 PM
Posted by iCELL News, on 07th August 2011, in Stem Cell Research.

After stem cell hype, a new hope for heart therapy in Minneapolis

By Christopher Snowbeck



For many years, Bill Garten lived what he calls “the casino life.”

As an electronics technician, Garten worked on slot machines and was often asked to drive across the Upper Midwest on a moment’s notice to verify that machines had properly awarded big jackpots. The lifestyle meant a steady diet of greasy food along with smoking, stress and not much exercise.

In the end, Garten lost his unhealthy wager, suffering two major heart attacks and related health problems that left him with few options for his angina chest pain. But now, he’s starting to feel like a winner, thanks to an experimental stem cell treatment.

“I attribute my health and my quality of life to the stem cells,” said Garten, 61, who lives in the central Minnesota town of Jenkins.

Garten’s story helps explain why doctors at the Minneapolis Heart Institute Foundation are pushing ahead with studies of the heart treatment. Even so, doctors are being careful not to overstate the potential benefits of the treatment.

They point out that stem cell therapies have generated a lot of hype over the years that just hasn’t panned out.

“People are over-skeptical right now, simply because the initial results of the initial trials were not that spectacular,” said Dr. Catalin Toma, a heart expert at the University of Pittsburgh Medical Center. “The expectations were set too high.”

“One of the problems when you start a therapy like this is that there’s just so much hype that people want too much,” said Dr.

Tim Henry, a heart expert at the Minneapolis Heart Institute. “Cell therapy is not a panacea.”
Angina is characterized by chest discomfort due to a lack of blood to the heart, often as a function of obstructive coronary artery disease. More than 850,000 patients in the United States experience what’s called “refractory” angina, meaning it doesn’t respond to treatments. The condition reduces a patient’s activity level and lowers the person’s quality of life.

CHEST PAIN REDUCED

In July, researchers from the Minneapolis Heart Institute and other medical centers across the country published study results showing that patients with refractory angina who received injections of a stem cell called CD34+ had fewer reports of chest pain and could better tolerate exercise.

Garten was one of the 167 patients in the study, in which patients received injections of stem cells directly into damaged heart tissue. The stem cells came from the patients themselves, Henry noted, and are not the embryonic stem cells that have generated so much controversy over the years.

About one-fourth of study participants were enrolled through the Minneapolis Heart Institute, at Abbott Northwestern Hospital.

Doctors gave the patients a drug to increase the number of CD34+ cells circulating in the blood stream. Then, they removed the stem cells and injected them into the heart – giving some patients a lower dose and others a higher dose. A third group received a placebo injection.

“You’re trying to grow blood vessels, because the problem is you don’t have enough blood supply” in the damaged portions of the heart, Henry said. “These are the cells that grow new blood vessels.”

After six months, low-dose patients had 6.8 angina attacks per week compared with the 10.9 attacks per week for those who received the placebo. The improvement for those in the low-dose group persisted 12 months after the injections.

After six months, low-dose patients saw a 139-second improvement in their ability to exercise on a treadmill compared with a 69-second improvement for those in the placebo group.

There was not a statistically significant difference in angina episodes or exercise tolerance between patients who received the high-dose treatment and those who received the placebo.

TREATMENTS OF LIMITED HELP



The numerical results were “not spectacular,” said Toma of the University of Pittsburgh Medical Center, which also participated in the study. Still, he said, the findings suggest the therapy might be a viable treatment for those angina patients with no other options.

Dr. Doris Taylor, a heart expert at the University of Minnesota, made a similar point.

“The exciting thing about this study,” she said, “is that it seems to be positive in patients who have not really been responsive to other current therapies.”

Still, research into stem cell treatments for the heart remains in the early stages, said Dr. Harlan Krumholz, a cardiologist at Yale University.

“The history of new interventions is littered by studies of interventions with great promise that wind up not producing better patient outcomes,” Krumholz said. “We expect that there’s going to be a lot of false starts before someone stumbles on a strategy that really works.”

Researchers noted there were risks with the injection procedure to deliver cells to the heart. One patient in the study died after the injection punctured the heart and a second patient also suffered what doctors call a “perforation.”

Toma said he thought this complication would be minimized as doctors got more experience.

“The heart is full of blood,” Taylor said. “It’s also under pressure, so you can imagine a situation where bleeding could occur….It’s always an issue when dealing with a thinned-out, damaged region of the heart.”

HYPE VS. REALITY

Such words of caution have been conspicuously absent from many reports about experimental stem cell treatments – particularly on the Internet, said Art Caplan, a bioethicist at the University of Pennsylvania. Overseas clinics have too often been successful in persuading patients from the United States to spend big money on unproven stem cell treatments for the heart and other ailments.

This summer has seen a new chapter in stem cell hype, Caplan noted, when New York Yankees pitcher Bartolo Colon seemed to tap the fountain of youth by going to a little-known clinic for a stem cell treatment.

“In the pantheon of potential medical cure-alls, stem-cell therapy has enjoyed a long and storied existence in the public imagination,” Caplan wrote last year in a medical journal. “Sadly, the number of ways in which patients with terminal and chronic diseases may be potentially exploited is growing rapidly as well.”

But such practices contrast with the development of the stem cell treatment for refractory angina, said Henry of the Minneapolis Heart Institute. The most recent study was funded by Illinois-based Baxter Healthcare, which has been “conservative” in its presentation of findings and with the pace of development, Henry said.

This fall, Baxter is scheduled to begin its “phase III” study of the treatment, which Henry said will include about 440 patients and could be the basis for a product approval in the United States. The Minneapolis Heart Institute will participate in that study, too.

“It’s the opposite end of the spectrum – it’s as traditional and scientifically based as you can be,” Henry said of research on the stem cell treatment for angina. He added that the results thus far suggest “a major advance for patients who have disabling chest pain.”

That’s how it feels to Garten, the retired electrical engineer from central Minnesota.

QUALITY OF LIFE IMPROVED

Prior to the treatment, Garten’s nose and lips would start turning blue following a simple walk of 200 feet or so between his house and mailbox. The coloring was a symptom of his distressed heart.

But shortly after the treatment: “I wouldn’t turn blue – I wasn’t a Smurf anymore,” Garten said.

The experimental treatment had its problems, Garten said. The process of doctors harvesting the stem cells was “very uncomfortable,” he said.

But Garten doesn’t regret it. Other signs of improvement with the treatment include his ability to mow the lawn, work on cars and go for walks with his wife.

“I had been spending 16 hours a day in bed,” Garten said. The change, he added, “was just night and day.”

Christopher Snowbeck can be reached at 651-228-5479.