The research, currently being conducted by the department of cardiothoracic surgery at Groote Schuur Hospital and the Red Cross Memorial Children's hospital, has identified a new technology that enables doctors to perform a heart valve-replacement operation without open-heart surgery.

Professor Peter Zilla said yesterday that the idea stemmed from a realisation that although globally 33million people were suffering from HIV/Aids, 70 million were battling rheumatic heart disease, for which a heart valve replacement was needed.

"In the whole of Africa there are about 200000 new serious cases a year. In terms of South Africa, there are about 7000 to 10000 [new cases]," Zilla said.

He said developed countries had to spearhead the research as the disease was not prevalent in F irst- World countries.

"It's a disease of living under crowded conditions, slums and poor socioeconomic conditions.

"Once it's contracted, for the majority, the only therapy is to replace the heart valve with a prosthetic [valve]. You don't find it in the First World.

"It was eradicated in the '50s, therefore no First-World country lobbied for it," said Zilla.

He said the survival rate, without treatment, was also very low, and that a large proportion of people who contracted the disease died very young.

"The irony is that it's precisely those countries, where those 70million live, who are poor and have no access to heart surgery," Zilla said.

He said heart valve-replacement surgery was not being performed because of the high costs of the valve and the large surgical team needed, making it in accessible to the majority of the poor.

"One of these heart valves alone costs R250000."

In terms of the envisaged new procedure, a plastic valve would be inserted, which would possibly last longer than a tissue valve. It would also have a "self-homing" mechanism that would mean that a balloon, normally used in the operation, would not be needed.

Zilla said a joint team of inventors and researchers from Brazil, Europe, India, China, the US and South Africa secured the patent.

Research was also continuing after a cash injection from the Department of Science and Technology and corporate giant Bidvest.

Zilla said the government contributedR12-million and Bidvest R18-million.