Implant research to give heart patients hope


  Hope is on the horizon for heart patients all over the world with news of a $3,5-million (R23-million) collaborative agreement between UCT's Cardiovascular Research Unit and one of the biggest medical device companies in the world. 

UCT's Cardiovascular Research Unit will use the money to develop an implant that is expected to revolutionise the management of cardiovascular patients around the world. 

The funding from Medtronic Incorporated based in Minneapolis, USA, has resulted in the establishment of the Medtronic Institute within the Cardiovascular Research Unit. 

Researchers will spend the next five years researching ways of combining molecular and cell biology with polymer science in order to trick the body into regrowing diseased structures such as heart valves and arteries. 

"We hope to offer the body an artificial scaffold which includes specific signals which allow the body to do what it did as an embryo - grow heart valves or arteries," said Director of the Cardiovascular Research Unit and the Medtronic Institute, Professor Peter Zilla. 

At present approximately 3 000 South Africans, many of them from remote rural areas, have to have their heart valves surgically replaced each year as a result of diseases such as rheumatic heart disease. The ideal replacement valve is made of titanium and theoretically outlasts the patient's life expectancy, but these valves only work successfully if patients are on life-long anti-coagulation medication. 

"Unfortunately anti-coagulation is potentially life threatening when not properly controlled, leading to deadly haemorrhages. Since most of the rheumatic heart valve patients come from rural areas, such a follow up cannot be guaranteed for the majority of them," said Prof Zilla.  As a consequence treated pig valves, which have a lower likelihood of developing blood clots on their surfaces, are implanted into these patients. However, these valves usually degenerate within about 7 years making it necessary to re-operate on many of these patients. 

"Apart from the trauma of undergoing repeated open heart surgery and an operative mortality rate which steeply increases with the number of re-operations, the costs involved are exorbitant and deprive an already overstretched health budget of badly needed resources. Therefore, the development of a long-lasting heart valve which does not require anti-coagulation is paramount for a threshold country like South Africa," said Prof Zilla. 

"If the body can be stimulated to regrow its replaced diseased heart valve, or a diseased artery, along a sophisticated scaffold, this would not only be a breakthrough for a third world population but also for the first world. The motivation and driving force for this development would come out of the needs and the specific situation of a threshold country like South Africa but in the end would provide a solution for first world countries as well," he said. 


December 2002