Study launched to study effect of using ADULT stem cells to prevent congestive heart failure

Researchers at the Minneapolis Heart Institute Foundation have launched a study to examine whether administration of stem cells to first time heart attack patients can prevent the development of congestive heart failure (CHF). CHF diagnosis is the cause of hospitalization in the United States and is responsible for more than 50,000 deaths a year. Currently, heart transplantation is the only available cure. Each year more than one million Americans have their first heart attack, putting them at risk of developing CHF as a result of cardiac cell death and scar formation which results in diminished pumping ability of the heart and leads to exercise intolerance and fluid retention. However, researchers believe that patients' own bone marrow-derived stem cells, which are capable of secreting a variety of growth and survival factors, can improve cardiac function after a heart attack and fend off the development of CHF.

To date, several clinical trials in Europe have demonstrated the safety and feasibility of using adult stem cells for cardiac repair following acute myocardial infarction, but in most of the studies the heart attacks were small and unlikely to lead to the development of CHF. The Minneapolis Heart Institute Foundation study is being done in conjunction with the University of Minnesota and is intended to look exclusively at patients with moderate to large heart attacks, putting them at risk of developing CHF.

This first-of-its-kind study in the United States is randomized and placebo-controlled, involving 60 patients with moderate to large anterior infarctions who will receive an intra-coronary infusion of their own stem cells or placebo. All patients will receive standard treatment including aspirin, beta-blockers, ACE inhibitors and statins. Patients with acute myocardial infarctions will be admitted to the University of Minnesota or to Abbott Northwestern Hospital through its Level 1 Heart Attack Program, which allows patients to undergo immediate angioplasty and stenting. Patients will then undergo bone marrow aspiration and harvesting of their stem cells 3 to 7 days later, which will be followed by an intra-coronary infusion of the isolated stem cells on the same day.

Of the 60 patients in the study, 45 patients will have their stem cells infused through a catheter in the region of their heart attack and 15 will receive a placebo. In an effort to examine whether late administration of stem cells is effective for repairing damaged heart muscle, patients in the placebo group will receive cell therapy 6 months following their heart attack. This study, which is funded by the Minneapolis Heart Institute Foundation, the Abbott Northwestern Hospital Foundation and the National Institutes of Health, is being conducted following approval from the U.S. Food and Drug Administration (FDA) in September 2005. Patients will be monitored for 2 years following stem cell treatment to determine whether stem cell therapy reduces scarring and improves cardiac function as determined by cardiac MRI. The Minneapolis Heart Institute Foundation is a nonprofit organization dedicated to improving heart health through meaningful advancements in research and education.

Valley group researches revolution in heart care When Nabil Dib addresses his fellow cardiologists at their convention in Scottsdale this week, he'll tell them about the research he and others are doing at the Arizona Heart Institute that could potentially contradict everything they learned in medical school. Specifically, his research is finding that heart tissue damaged by a heart attack can be repaired. One of the most exciting clinical trials involves the use of adult stem cells. Dib, chief of cardiac research at the institute in Phoenix, says that 12 patients have participated since March. Each patient had a heart attack and within 10 days received the stem cells, which are delivered via a regular intravenous catheter. "The cells follow a phenomenon called 'homing,' where the cell travels to the site of an injury," Dib says. "That injury of a heart attack produces certain proteins or hormones that attract (stem) cells to that area for repair."

Dib says that in animal studies, the stems cells convert to heart cells and blood vessels, increasing the blood supply.
"They differentiate to a variety of tissues in the heart, mainly muscles and arteries," he says. "They excrete a lot of growth factors and hormones to ameliorate the inflammatory response and decrease the damage." Osiris Therapeutics, a company based in Baltimore, harvests the bone marrow from adult donors. Stem cells occur in only 1 in 100,000 cells in human bone marrow, so the first step is to isolate the stem cells. They are then replicated a thousandfold, packaged and frozen. The cells are tested several times during the process, and the donor's health is monitored for several years.

Research with embryonic stem cells is controversial because the stem cells come from human embryos that are fertilized in a laboratory. They are easy to duplicate in a culture. Research with adult stem cells, called somatic stem cells, is generally unopposed, although the adult stem cells are more difficult to acquire and duplicate. The Arizona Heart Institute trial is double-blind, meaning that some of the patients receive the real treatment and some receive a placebo. The trial will run until 48 patients are treated, and neither Dib nor the patients will know until then who got which treatment.

Overall, 16 patients will get a placebo and 32 will get the stem cell treatment. Men and women ages 18 to 85 who have had a heart attack within the previous 10 days and whose heart function is between 30 percent and 60 percent are eligible. After receiving the treatment, the patients will be monitored for two years. Even though the stem cells are from a donor, they aren't rejected, Dib says. So far, no side effects have been found, he says. In the follow-ups, the researchers will look for any tumor growth, due to the cells' growth hormone, as well as look at liver and lung function, and, most importantly, heart function. In animals, the stem cell treatment increased heart function after a heart attack by 10 percent. Dib says that if the treatment increases heart function by 5 percent in humans, it will be successful.

"That would make a significant difference clinically in the quality of life and terms of survival," he says. Dib will address the International Congress on Endovascular Interventions, held in Scottsdale this week. Besides the adult stem cell trial, he will discuss other research going on at the institute, including myoblast cell transplantation. In that procedure, a patient with congestive heart failure has regenerative muscle cells removed from his or her thigh. The cells are cultured in a lab and then injected into the heart using a three-dimensional color mapping system. Dib says that doctors are waiting to see whether the cells help convert scar tissue into new muscle. The cardiologists will open their convention to the public next Tuesday, when Edward Diethrich, medical director of the Arizona Heart Institute, will discuss progress in cardiovascular medicine. The forum is co-sponsored by the American Heart Association's Phoenix chapter.

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