Affordable heart valves to help rheumatic heart disease sufferers

Cardiac surgery techniques and technology were driven, in the 1960s in Europe and America, by the high death toll from rheumatic heart disease (RHD). In the 1970s the global burden of disease changed and RHD all but disappeared in the global north, however it continues to kill hundreds of thousands in the developing world. A locally developed heart valve is set to change that.

RHD is caused by the very common streptococcal throat infection (strep throat). If untreated, the antibodies that attack the bacteria in the throat also attack the valves of the heart, and this in many cases proves fatal to the patient. It is not completely understood why it is that rheumatic heart disease is so virulent in the under-resourced parts of the globe, but access to antibiotics is understood to be an important factor. One of the few ways to treat RHD is surgery – replacing the heart valves.

"Today, in the countries where there is relatively easy access to cardiac surgery, such as the USA, Europe and Japan, there is a negligible rate of RHD," says Peter Zilla, head of the Department of Cardiothoracic Surgery at Groote Schuur Hospital and Red Cross Children's Hospital. "But in the remaining majority of the population, who live in Africa, India and poorer regions of Asia, an estimated 70 to 75 million patients live with rheumatic heart disease. Of those, about 24% will need heart-valve surgery, and of those who need it, about 70% are likely to be dead by the age of 27 if they do not have surgery."

Speaking at a Café Scientifique event organised by Research Contracts and Intellectual Property Services (RCIPS) at the Irma Stern Museum earlier this month, Zilla explained why and how his company, Strait Access Technologies, developed plastic heart valve technology that will be both affordable and accessible in the developing world.

With the current focus in the global north on lifestyle diseases, such as heart attacks and strokes, it became apparent to Zilla that the solutions for rheumatic heart disease needed to be developed locally. Strait Access Technologies thus developed plastic heart valves, which can be inserted without the use of non-invasive surgery, at a significantly lower cost than those produced in the global north.

"Since access to cardiac surgery is limited in these countries, it is crucial that our treatments for heart valve diseases are not reliant on the specialised infrastructure needed to perform open-heart surgery, and the valve eliminates the need for continuous anti-coagulation medication," Zilla explains.

These plastic heart valves, expected to be ready for clinical use in the next two or three years, are already attracting significant international attention from China and other countries. Thus, notes Zilla, while high-tech first-world surgery may cater for only the few, we in Africa are developing novel and simple procedures that hold the key to closing the gap in treatment between the rich countries of the global north and the under-resourced countries of the developing world.