- The Washington Times - Monday, February 13, 2006

Dr. Joshua Hare and his colleagues at the Johns Hopkins University School of Medicine and its Heart Institute in Baltimore are hoping that dying hearts can be made new. Because of recent research, many doctors believe the heart has regenerative capacity.

Since March 2005, Dr. Hare, professor of medicine at the school and institute, has been enrolling heart attack patients in a trial to see if mesenchymal stem cells from bone marrow can regenerate a damaged heart. He previously performed trials with pig hearts.

“The primary purpose of the study is to access the safety of the procedure,” Dr. Hare says. “We’re thrilled with the progress we’ve made. We should finish in 2006.”

Five years ago, most doctors never would have considered using stem cell therapy to help heart attack victims, but today, many experts say the procedure could redefine the field of cardiology. Though much research is still needed, cardiologists are excited about the possibilities it could provide.

After people have a heart attack, if they are enrolled in Dr. Hare’s study, they are infused with mesenchymal stem cells from bone marrow and followed for six months. He won’t know the results until six months after the last of the 52 patients is enrolled.

The cells, which are grown in culture, are prepared with good quality control, he says. They are not harvested from the patients, but from an unrelated donor and prepared in advance.

Making a new therapy available to the public is a difficult and heavily regulated process, Dr. Hare says.

Though the study is approved by the U.S. Food and Drug Administration, many other trials will have to take place before the new therapy is approved, he says. Johns Hopkins Hospital recently received a grant from the National Institutes of Health to be a specialized center for cell therapy.

“It’s frustrating for certain patients,” Dr. Hare says. “They feel they have run out of options. Certain people leave the country for the therapy. It’s something we are concerned about because we’re not sure those people are getting a safe or proven therapy.”

After the studies focusing on heart attack patients are completed, Dr. Hare will run trials concerning stem cell treatment for congestive heart failure in pigs and then in humans.

The effectiveness of taking stem cell cultures from patients’ own hearts also is being studied, says Dr. Eduardo Marban, professor and chief of the cardiology

division at the medical school and the institute. Trials are being performed in pigs. By the end of 2006, research will begin in humans.

“The big race is on to find the best kind of stem cell,” Dr. Marban says. “We can take human cells from the heart and put them in mice, and it improves the hearts of mice that had heart attacks.”

Significant regrowth in the hearts of mice takes three weeks, he says. He estimates that it may take two to four months to have the same effect in human hearts.

In the future, trials probably will be performed combining and comparing mesenchymal stem cells from bone marrow and cardiac stem cells, he says.

While mesenchymal stem cells are universally compatible, cardiac cells from a patient’s own heart are a genetic match, meaning there is less chance for rejection, he says.

Further, cardiologists have begun to consider that stem cell therapy may be used preventively.

“There is no question that stem cell treatments are going to change the way we practice cardiology,” Dr. Marban says. “The benefit need not be limited to the heart.”

Cardiac and bone-marrow stem cells offer an alternative to using the controversial embryonic stem cells, says Dr. Richard Lange, professor and chief of clinical cardiology at the medical school and institute. Dr. Lange and Dr. Marban are working together on the cardiac stem cell trials.

Because approximately 20,000 to 30,000 people per year in the United States need a heart transplant but just about 2,500 receive hearts, most of the people die, he says. After receiving a heart, the person runs the risk of infection and rejection of the organ. Further, people older than 65 usually aren’t put on a transplant list.

“Your heart cells do divide and grow,” Dr. Lange says. “What we’re doing is dividing them up and replacing them a lot faster.”

Apart from stem cell therapy, new methods for surgery are being explored, says Dr. David D. Yuh, associate professor of surgery and director of cardiac surgical research and robotic cardiac surgery at the medical school and institute.

There is an effort to do the same operations through smaller incisions, he says, and robotic surgery for mitral valve repairs is becoming less experimental and more widely adopted.

“The jury is still out as to whether or not the current robot will endure,” Dr. Yuh says. “It’s still very expensive. The learning curve is steep. Many surgeons have backed off for that reason.”

Most patients are pleased by the better cosmetic results, he says.

“There is less scarring,” Dr. Yuh says. “Patients are out of the hospital earlier with less pain. They return to activities earlier. More patients ask for it instead of physicians referring to it.”

Medical students and doctors have been training to perform robotic surgeries on equipment that looks as if it is used to play video games, says Dr. Phillip Rand Brown, associate professor of surgery, comparative medicine and orthopedic surgery at Hopkins medical school.

“I fully believe the surgical instrument for the next generation is an Xbox controller,” Dr. Brown says.

Further, although an echocardiogram, or ultrasound, is the most used device to image the heart, the CAT scan has emerged as an effective way to view the organ, says Dr. Joao A.C. Lima, associate professor of medicine and radiology at the medical school and institute.

The procedure helps distinguish whether someone has cholesterol buildup or is suffering from heartburn, he says. The drawback is that a CAT scan of the heart involves as much radiation as an invasive cardiac catheterization, a procedure done frequently in people with chest pain. In that procedure, contrast materials are injected into the heart arteries to detect blockages .

A magnetic resonance imaging device, which doesn’t use radiation, continues to be helpful for measuring the function of the heart, he says.

“We want to see if we can detect who is at risk for sudden death from a heart attack,” Dr. Lima says. “Then we would use an implantable defibrillator to prevent sudden death after a heart attack.”


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