By Laura Ungar
Special to The Washington Post
Monday, November 22, 2010; 12:38 PM
You might think fat is bad for your heart.
But a growing group of scientists says that's not always true.
The same stuff that can make you pudgy around the middle and clog your arteries, they say, might also heal your damaged heart.
Inside a person's own fat are stem cells that they say can limit the loss of heart function after a heart attack and repair heart failure damage. These cells could someday become a new weapon in the fight against heart disease, which kills more than 400,000 Americans a year.
"For eons, fat has been considered something that is bad," said Stuart Williams, scientific director of the Cardiovascular Innovation Institute, a partnership between the University of Louisville and Jewish Hospital & St. Mary's HealthCare, and one of the leading researchers in the field. "But God made love handles for a reason."
More than 300 scientists from around the world, including in Virginia, are studying the fat-derived stem cells for various applications. About eight years ago, researchers began sharing their knowledge by forming the International Federation of Adipose Therapeutics and Science Society, or IFATS.
Fat-derived stem cells are now being tested on cardiac patients in Europe.
Six-month results from a 14-patient heart attack trial in the Netherlands and Spain showed not only a reduction in the size of the heart injury but also improvements in the amount of blood supplied to the heart muscle and the amount of blood the heart can pump.
Data from a second trial, a 27-patient chronic heart disease study in Spain, showed a reduction in the amount of damage in the left ventricle. It also showed that patients receiving stem cells had better oxygen consumption and improved ability to perform physical activity.
Williams and other U.S. researchers have shown success in mice and plan human trials in the next couple of years. But even if those trials are successful, they say it will be several years before treatments based on fat-derived stem cells are widely available.
Erin Peiffer of Eldersburg, Md., said she's excited about the possibilities.
In 2001, she received a diagnosis of congestive heart failure after feeling a rattling sensation in her chest while doing water aerobics. She learned that her heart's left main artery was 99 percent blocked. She was 39 at the time, with no risk factors for heart disease except high cholesterol.
She had a heart catheterization and now takes several medications. Her two teenage sons share her genes for sky-high cholesterol and have been on statin medications since they were 10 years old. She worries about their future heart health.
"I have lots of hopes pinned on the up-and-coming research. . . . I'm counting on it," said Peiffer, 49. "I would love to have the option of stem cells from fat. I've got plenty of fat they can take. Sign me up."Apolitical stem cells
Scientists say getting fat-derived cells into a patient is fairly easy.
Doctors perform liposuction to remove a chunk of fat about the size of a golf ball from, for example, the abdomen. They then extract the stem cells, and then inject them into diseased tissue. (To reach the heart, the cells are delivered via a device inserted into a blood vessel in the leg.) There's no chance of rejection since the cells come from the patient.
"Everyone has an easily sufficient reservoir of fat, even thin people," said Keith March, director of the Vascular and Cardiac Center for Adult Stem Cell Therapy at Indiana University. "You can readily harvest the stem cells."
Scientists point out that fat is filled with tiny blood vessels and say its stem cells can stimulate new vessels to grow.
"This is the most promising technique to rebuild blood vessels in the heart," Williams said.
"Many people did not expect fat to be so useful," added March.
Adam Katz, an associate professor of plastic surgery and biomedical engineering at the University of Virginia, said that when research began, scientists thought the fat-derived stem cells would just replace dead heart cells. But he said there's little evidence that happens on a significant scale. Instead, he posits, the replacement cells release growth factors and wrap around new blood vessels, stabilizing them. Katz likened the process to bolstering a road that an army builds to get to a remote place.
When the heart is injured, he said, the body responds by forming small blood vessels to provide blood flow to the injured area. If they are not stabilized, they get pruned back.
Adding the fat-derived stem cells stops this loss of blood vessels, he said, making the "roads" more permanent. And that helps salvage tissue that otherwise has a 50-50 chance of dying.
"More vessels mean more life," he said.
Katz and other scientists said that because fat-derived cells come from the patients themselves and not from embryos that are destroyed in the process of extracting their stem cells, their use sidesteps the ethical dilemmas that bitterly divide many Americans. Katz said it also avoids the scientific pitfalls of embryonic stem cells, which can prompt the growth of tumors when implanted.
"Clearly," he said, "the embryonic stem cells have several issues to overcome."Caution amid optimism
While many researchers are optimistic about fat-derived cells, some experts urge caution, saying it's too early to know whether these cells will be as good as cardiac and other types of stem cells, or other treatments such as new medications.
One concern is that fat-derived stem cells may cause fat to develop in the heart. Another is that there's no assurance that the cells will respond as heart cells would, said Julio Panza, director of the division of cardiology at Washington Hospital Center.
Panza said he has been hearing about the fat-based research for about five years, and although it sounds promising, he's not convinced it will revolutionize heart care anytime soon.
"It's kind of been around the corner for a while," he said. "But it's still not viewed as something that's ready for prime time."
Williams and others said they are aware of concerns regarding the research and are cautiously testing the treatment in animals before trying it in people. But they said the cells seem to be safe and helpful for heart attack victims, judging from initial results from the European trials.
San Diego-based Cytori Therapeutics, which sponsored the two European trials, said they plan to begin the process of seeking regulatory approvals in Europe early next year for the treatment tested in the 27-patient trial.
Cytori provided video interviews with two participants in the chronic heart disease trial who were identified only by one name. One of them, Vistoriano, recalled having had several heart attacks and five bypass surgeries that forced him to retire from work and made him weak, pale and unable to climb stairs. Since the stem-cell procedure, he said he walks more, climbs stairs and feels "strong," "happier and better." He spoke in Spanish, with English subtitles on the video.
The other, Cilfredo, said he feels less fatigued than he did before the procedure and no longer needs someone to hold his arm when he walks. "My life has gotten better," he said, "because I find myself more alive, with more strength, and more will to live as well."
Hope abounds among those touched by heart disease.
"Research is critical when you have a family history," said Gail Mates of Haymarket, whose parents and grandparents suffered from heart problems and who was worried she was heading toward a heart attack herself before she started exercising more and eating healthful foods. "I'm excited at the fact something like this could be so helpful."
So is Annie Lawler of Lutherville, Md.
A 53-year-old swim instructor, Lawler last year felt intense chest pain and pressure while in a swimming pool; she was having a heart attack. She is now living with six stents in her heart's left anterior descending artery and takes five medications a day. She said it would be "a great thing" to see the promise of fat-derived stem cells realized.
"If we can use our own tissue to heal ourselves," she asked, "why not?"
Ungar, the medical writer at the Courier-Journal in Louisville, has been a journalist for 20 years.