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Making heart tissue valves last a lifetime

As part of his PhD, Dr Steve Waqanivavalagi is engineering tissue heart valves in the lab and hopes his new Heart Foundation funding will help make the valves last a patient’s lifetime.

Dr Steve Waqanivavalagi

"When I was at school, I always struggled to find interest in studying. My year 10 mathematics teacher sparked my interest in mathematics and general science, and rather surprisingly, I ended up doing quite well in my final examinations. The following year, while I was dissecting a sheep heart in biology class, I had a penny drop moment and realised that I could enjoy investigating problems related to the heart and perhaps even find myself privileged enough to look after patients with heart-related conditions." – Dr Steve Waqanivavalagi.

The Heart Foundation announced $3.7 million of funding today for heart research and specialist training for New Zealand cardiologists in 2019, bringing the total awarded by the charity since its formation in 1968, to more than $74 million dollars.

Dr Steve Waqanivavalagi received a Postgraduate Scholarship to continue his work making tissue valves to replace a human aortic value, from pig valves or cow pericardium which is the sac that surrounds the heart. 

Currently tissue valves only last approximately 15 years, requiring patients to have multiple surgeries. Mechanical heart valves require the patient to take blood-thinning medications which carry risk of life-threatening bleeding. 

There is currently no valve that can last the human lifespan, does not require blood thinners, and can grow and repair once implanted.

"If we can produce an artificial heart valve that can last the human lifespan, performed without the need for lifelong blood thinners, and grow and repair once implanted, we can expect to see patients requiring fewer redo heart valve operations and avoiding the complications that come with taking blood thinners," says Dr Waqanivavalagi.

Heart valve replacement surgery is performed for patients who have severe disease of one of the valves of the heart. The aortic valve, which separates the main pumping chamber of the heart from the largest artery in the body and most commonly requires surgical intervention when it is severely diseased. The valve might be too narrow, fail to form a tight seal upon closure or be affected by a combination of the two. The common causes of these problems are age-related calcification, rheumatic heart disease and congenital problems.

We are excited because we are not aware of any other group that has performed this work in New Zealand, or any group worldwide that has yet developed an artificial valve which meets all the requirements of a desired conduit,” says Dr Waqanivavalagi.

"We believe that this work has the potential to revolutionise heart valve replacement surgery. However, realising this potential can only be achieved with funding support from the Heart Foundation to enable us to purchase laboratory consumables and equipment and to personally support me through my PhD. The research that I am involved in would not be able to proceed without this generous award." – Dr Steve Waqanivavalagi.

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