SA doctors develop affordable heart valves


7 May 2015

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 – but it continues to kill hundreds of thousands in the developing world. A locally developed heart valve is set to change that.

Rheumatic heart disease is caused by a preceding group A streptococcal (strep) infection – or strep throat. If left 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.

While is not completely understood why rheumatic heart disease is so common in the under-resourced parts of the globe, access to antibiotics is thought to be an important factor.

One of the few ways to treat RHD is surgery – replacing the heart valves, says Professor Peter Zilla, head of the Department of Cardiothoracic Surgery at Groote Schuur Hospital and Red Cross Children’s Hospital.

Zilla is also the medical director and chief executive of Strait Access Technologies, a start-up with support from the University of Cape Town that aims to develop, manufacture and market cardiac-related medical devices that address the need of the millions of RHD patients worldwide.

“Today, in the countries where there is relatively easy access to cardiac surgery, such as the US, Europe and Japan, there is a negligible rate of RHD,” Zilla says. “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.”

Strait Technologies says on its website that 1.4-million deaths per year are caused by Rheumatic Heart Disease. And the majority of these are preventable through valve replacement or repair.

Estimates put the rate of RHD in Mozambique at 30 cases per 1 000; at 33 cases per 1 000 in Tonga; and up to 51 cases per 1 000 in India.

With the current focus in the global north on lifestyle diseases, such as heart attacks and strokes, Zilla says it became apparent that the solutions for rheumatic heart disease needed to be developed locally.

Affordable and accessible

Speaking at an event in Cape Town in April, Zilla says his company, Strait Access Technologies, has developed plastic heart valve technology that will be both affordable and accessible in the developing world.

The plastic heart valves can be inserted by 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 said.

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.

Zilla said that while high-tech first-world surgery may cater for only the few, Africa was developing novel and simple procedures that could 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.

SAinfo and UCT.