Japan hospital performs first heart surgery using muscle stem cells

A hospital in Japan has carried out the world's first surgery using sheets of commercially available heart muscle stem cells after the ground-breaking therapy was approved this year, one of the surgeons said.

Sheets of muscle cells derived from regenerative products known as induced pluripotent stem cells, or iPS cells, were transplanted into the heart of a woman in her 50s during the hour-long surgery performed on Tuesday.

It marked the first clinical use of the regenerative therapy since it received conditional government approval in March.

"Our hope is that this will improve the patient's quality of life," surgeon Yoshiki Sawa, the head of Osaka Keisatsu Hospital, told reporters after the surgery.

Trials of the regenerative therapy were conducted on eight patients suffering from ischemic heart disease -- damage caused by narrowed heart arteries.

All eight experienced an easing of their symptoms, including four whose heart functions improved, Japanese media said.

Sawa developed the technology in collaboration with Japanese scientist Shinya Yamanaka, who won the Nobel Prize in 2012 for his research into iPS cells, which have the potential to develop into any cell in the body.

Sawa's therapy is primarily designed for heart patients who have exhausted other treatment options.

It is expected to improve heart muscle function, resulting in improved heart failure symptoms, cardiac performance, and exercise tolerance.

His team plans to conduct similar operations on 75 patients by 2033 and to report on the treatment's efficacy, media reports said.

The treatment would then be fully authorised after its benefits and safety are proved over the next seven years, the Asahi Shimbun daily said.

Japan also gave conditional approval in March for a Parkinson's disease treatment that transplants iPS cells into a patient's brain, following a successful clinical trial.

iPS cells are created by stimulating mature, already specialised cells back into a juvenile state -- basically cloning without the need for an embryo.