British researchers have grown a disc of heart valve tissue from stem cells, raising hopes that such tissue could be used in transplants in as little as three years, a British newspaper said.

Similar three-centimetre discs will be tested in animals later this year, the report in the Guardian said. If the discs work there, they could move on to human trials within three years, chief researcher Prof. Magdi Yacoub said.

Artificial valves are already widely used, but an organic replacement has advantages, he said. A living valve changes its shape and size in response to changes in the circulatory system, in contrast to an artificial valve, "which will just open and shut."

Yacoub, a noted heart researcher, is a professor of cardiac surgery at Imperial College London and works with the Harefield Heart Science Centre. On its website, he says one of its research aims is "the development of a viable cardiac valve capable of reproducing the sophisticated functions of the normal valve."

As well as being more sophisticated, a stem cell cardiac valve is less likely to be rejected.

Yacoub worked with physicists, biologists, engineers, pharmacologists, cellular scientists and clinicians, the Guardian said.

A report on the work is expected to be published in August in the Philosophical Transactions of the Royal Society.