Japanese doctors claim heart disease breakthrough

TOKYO - (KRT) - A doctor at Saitama Medical School announced Saturday that a 61-year-old heart attack patient had been successfully treated using bone marrow cells.

Dr. Shunei Kyo said at a press conference that the patient was discharged by the hospital after being disconnected from an artificial heart.

This could be the first case worldwide in which a patient has recovered sufficient heart function to survive without an artificial heart, according to Kyo.

The patient had a heart attack on Feb. 3 and was admitted to the Saitama Medical Center in Kawagoe, Saitama Prefecture, which is operated by Saitama Medical School in Moroyamamachi.

He was fitted with an external artificial heart, but because of his age and other factors, was judged by doctors to be unsuitable for heart transplant.

On May 18, a group of doctors led by Kyo and Dr. Satoshi Gojo, a lecturer at the medical school, conducted regenerative stem cell treatment from the patient's bone marrow. The patient's heart function recovered to the extent that he could live without the artificial heart. The artificial heart was removed on June 30.

Kyo said doctors were unsure why the patient's heart function had recovered to that extent.

Under the treatment, bone marrow cells are extracted then transplanted into the damaged ventricle of the heart. The medical school had long been engaged in research into regenerative treatment for heart disease and had conducted a number of animal trials.

In November 2003, the school's ethics committee approved use of the treatment for humans.

"This is the first case (in which a patient was successfully treated with the method), and there are differences of opinions about the effectiveness of the treatment," Kyo said.

"But I believe that we've established a treatment that is safe and side-effect free. The treatment will save patients who are unsuitable for transplants. We intend to use this treatment in clinical practice," Kyo said.

Observers welcomed the progress made in regenerative medicine, but warned that one case alone did not provide enough evidence that the treatment was safe and effective. Further scientific data need to be collected, they said.

Researchers are still unsure how bone marrow cells transplanted into the heart work. Further studies are needed to determine whether stem cells contained in bone marrow transform into cardiac muscle cells or blood vessel cells, or whether stem cells simply assist cardiac muscle cells to develop.

The long-term recovery of patients treated with stem cells also needs to be examined. Some patients who have received treatment using bone marrow or embryonic stem cells for leukemia and other diseases have developed new cancers.

A Health, Labor and Welfare Ministry committee has been working on guidelines for clinical studies of the stem cell therapy, but discussions have reached a deadlock.

Observers said that guidelines need to be established as soon as possible to ensure careful application of regenerative medicine in clinical practice.

Yasunaru Kawashima, president emeritus of the National Cardiovascular Center in Suita, Osaka Prefecture, said, "It's significant that heart patients can be successfully treated with regenerative therapies because artificial heart devices, which are as large as a small suitcase, are inconvenient for patients, although an internal artificial heart with external charging equipment has recently been developed."