Advances in cardiovascular therapies rely heavily on bringing together different disciplines – surgery, engineering, biomaterials, and cell biology. UCT’s Chris Barnard Department of Cardiothoracic Surgery, with its Cardiovascular Research Unit, led by Prof Peter Zilla has always followed this approach and was recently supported by the NRF in the acquisition of state-of-the-art intra-operative medical imaging equipment. NRF’s Strategic Platforms Programme funded a Philips BV Pulsera C-arm x-ray and angiography system (grant holder: Prof Peter Zilla) and a General Electrics Vivid I portable cardiovascular ultrasound system (grant holder: Prof Thomas Franz). Exciting research and innovation enabled by this equipment includes the study of therapies for heart attacks and subsequent heart failure, and the development of an affordable prosthetic heart valve for easy implantation outside of big centres for millions of South African and Africans with rheumatic heart diseases.

Heart attacks (when part of the cardiac muscle dies from a lack of oxygen due to the blockage of a coronary artery of the heart) remain a major treatment challenge. According to the South African Heart and Stroke Foundation 33 people die of heart attacks per day in South Africa. Similarly, low-and middle-income countries accounted for more than 80% of the 7.25 million deaths worldwide caused by ischaemic heart disease including heart attacks in 2008. There is no treatment that can restore infarcted dead heart tissue at present – with the infarcted heart tending to enlarge and eventually fail to effectively pump blood through the body. The only cure for this end-stage condition called heart failure is a heart transplant. A team around Dr Neil Davies at the Cardiovascular Research Unit combines bioengineering and pre-clinical experiments to advance a therapy concept involving the injection of a hydrogel in the infarcted region of the heart. The hypothesis is that the hydrogel injections help prevent the heart from undergoing the pathological enlargement that can lead to heart failure. Success of the treatment is assessed by measuring the dimensions of treated and untreated infarcted hearts– a challenging procedure made possible by the NRF funded GE Vivid I ultrasound system. Dr Davies’ work has indeed shown that the hydrogel injections improve the heart’s function after an infarct and alleviate the heart’s enlargement [1]. This work has also shown that treating a patient several days after the infarct may be more beneficial that immediate biomaterial injection.

The second major project enormously benefiting from the NRF equipment at the Chris Barnard Department of the University of Cape Town deals with Rheumatic Heart Disease (RHD) which is a major cause of juvenile death in developing countries. RHD is caused by streptococcal bacteria that indirectly damage the heart valves irreversible. The disease mainly affects children between the ages 5 -15 – and predominantly in developing countries, especially South Africa and sub–Saharan Africa. RHD claims the lives of 1.4 million people per annum up to 70% of which will be dying before the age of 26. Although Rheumatic heart disease affects mainly the poor of developing countries, all available heart valve technologies target degenerative heart valve disease of the elderly in industrialised countries and as such are based on highly sophisticated implant technologies requiring both advanced monitoring equipment and specialised operators. Neither skilled surgeons or cardiologists nor monitoring equipment and hospital facilities are available in developing countries where RHD prevalence is highest. As a result, only 2 out of every 100 patients with RHD requiring heart valve replacement are treated worldwide. Strait Access Technologies (Pty) Ltd, a University of Cape Town based company spun out of its Chris Barnard Department of Cardiothoracic Surgery has been established to develop low cost, durable heart valves that can be deployed using simple technologies. The company already undertakes pre-clinical studies at its UCT base. While the heart valves, once fully developed, will allow implantation under simple clinical settings, the technology development is demanding and relies on multi-modality imaging deployment and functional assessment. Prof Deon Bezuidenhout, SAT’s technical director, stated that the successful development of the prosthetic heart valves and swift translation into the clinic would not be possible without the NRF-funded medical imaging equipment.

[1] Kadner K, Dobner S, Franz T, Bezuidenhout D, Sirry MS, Zilla P, Davies NH. The beneficial effects of deferred delivery on the efficiency of hydrogel therapy post myocardial infarction. Biomaterials. 2012;33:2060-6 [full-text]