Innovative heart valves designed to last a lifetime, aim to reduce complications and use of revision surgery and medication

Patients who require the implantation of heart valves may benefit in the future from this ground-breaking medical device, which aims to reduce side effects and lessen the need for repeated surgery.

A novel heart valve which has been designed to be more durable and cause less side effects, has received development support via a Medical Devices Fund grant from the Office for Health and Medical Research. Named ‘Formosus’ (a Latin word which means ‘finely formed’) it was invented by LevTech Lifesciences. The spinout biotechnology company was co-founded by Sina Naficy, Associate Professor at the University of Sydney, where he leads the Polymeric Heart Valve Replacement Lab in the Faculty of Engineering. 

Naficy is a polymer engineer with expertise in cardiovascular medical devices, polymer physics, the mechanics of soft matter, and physical modelling of materials. In 2019, he was recognised as one of the 25 most Innovative Engineers, by Engineers Australia, which is Australia’s national body for engineering and has branches in every state. To find out more about his work on the Formosus heart valve and how the device may impact patient health outcomes and quality of life, the Office spoke to Naficy: 
 

What kind of conditions are heart valves used to treat? 
“Heart valves are implanted to treat conditions including ‘leaky’ valves (also called ‘regurgitation’), and ‘stenosis’ where heart valves thicken or stiffen, restricting blood flow. These issues may develop in adulthood or can be congenital (children are born with them). The human heart beats around 100,000 times a day. With each heartbeat, valves in the heart open and close to keep blood circulating around the body. These valves are located in the four different chambers of the heart. When they don’t work properly, health complications can occur, including dizziness, irregular heartbeats, heart strain and in more severe cases, heart attacks and stroke.  

What challenges and side effects do current heart valves cause? 
“Tissue-based valves are made of a matrix from animal tissue and they tend to degrade over time, so surgery is needed to replace them. Mechanical heart valves are made of rigid components such as titanium and stainless steel and can cause thrombosis, so patients must take anticoagulants (blood thinning medications) when they have these valves in their heart. When mechanical valves have been used, patients will at some time need a replacement. They may also no longer be good candidates for transcatheter delivery, a newer approach where a new valve is inserted into the heart without the removal of the old, damaged valve.”

What is unique about the LevTech heart valve design?  
“Formosus heart valves are made of polymers, which are long molecules that look a little like spaghetti. The valve ‘leaflets’, which are little flaps that control the direction of blood, are made out of polymer called elastomer, which is like rubber that stretches then returns to its original shape. Unlike other polymers which often cause side effects, the chemistry of the polymer used in the Formosus heart valves has been formulated to be inert. This means it causes less side effects as it does not interact adversely with blood, enzymes and proteins or cause blood clotting risks that require use of blood thinning medications.” 

What was the catalyst for designing these novel heart valves? 
“LevTech co-founder, Dr David Winlaw, a highly renowned paediatric heart valve surgeon, approached our team at University of Sydney. He wanted to see if we could design a heart valve that would reduce side effects and lessen the need for replacement surgeries in order to reduce pain and distress for families and children with heart valve issues. My fellow colleague Nick Northcott, joined the team due to his own personal experience, as his nephew was born with a heart condition that meant he had heart valves put in at birth and will need them throughout his life. Over the last seven years, Formosus has gone through numerous transformations linked to a computational modelling process, design improvements and polymer development. At this stage, we are finalising our prototypes.” 

Will some patients particularly benefit from Formosus heart valves?  
“Formosus valves aim to benefit people of all ages. Some patient groups are also more prone to negative effects from anticoagulants, which are not needed with Formosus heart valves. So, the valve may be additionally beneficial for young people who have more reactive immune systems and women who can be more affected by anticoagulants.” 

What research will the Medical Devices Fund grant help to support?   
“The grant is absolutely vital for our next steps. The Formosus valve is a class III medical device. In Australia, class III medical devices require the most stringent regulatory controls and typically are life-sustaining or life-supporting including items like pacemakers, heart valves and implantable defibrillators. This funding will support us to meet the demanding criterion of the Therapeutic Goods Administration. It will also help us bring our process into compliance with the International Organisation for Standardisation, which sets the standards for medical devices. In addition, the funding will help us to conduct a clinical study and accelerate the process of producing the Formosus heart valves.”