Watch: How space engineers are helping people with severe heart failure
Katherine Woods finds out how BHF researchers and space engineers are working together to create a device to help damaged hearts.
When the first ‘partial artificial heart’ was implanted in a patient in 1963, the 1960s was shaping up to be a decade of firsts. The first manned spaceflight had orbited Earth, the world celebrated the first heart transplant in 1967 and Apollo 11 landed on the moon in 1969.
Fifty years on, research continues to offer new hope for heart patients, thanks to a surprising collaboration between distant scientific fields.
What is an LVAD and how does it work?
A left ventricular assist device (LVAD) is an artificial heart pump used to treat people with severe heart failure.
Heart failure occurs when the heart muscle has been damaged, for example after a heart attack, and the heart is not pumping blood around the body as well as it should.
LVADs are often used as a 'bridge to transplant', when patients being considered for a heart transplant are unlikely to survive until a donor heart becomes available.
The LVAD models used to treat patients today are fitted inside the heart and pump blood out into the aorta. A cable connects the LVAD to a unit outside the body, and patients need to carry a battery pack to power the device at all times.
Challenges for people with LVADs
Today’s LVADs are smaller and more portable than earlier models, but still make daily life difficult. Nic Jennings, from Wiltshire, was fitted with an LVAD in 2015 at the age of 53.
“Every single moment is dictated by the device. The controller and batteries weigh over 2kg, and I always carry spares, even in the house,” he explains.
Today’s LVADs are smaller but still make daily life difficult.
“I struggled with not being able to shower, and there’s nothing worse than catching the cable on a door handle or someone knocking into me.”
At the University of Leicester, Dr David Adlam is hoping to reduce these issues and solve another problem with current devices – that many people in need of an LVAD aren’t well enough to undergo the surgery required.
“Someone who’s had a severe heart attack, for example, often isn’t well enough to be transferred for surgery”, he says.
“What we need is a device that can be put in through the skin when and where it's needed, and for the patients who only need temporary support, it can be taken out when the heart has had time to recover.”
The future of LVADs
Dr Adlam started working on a new type of LVAD in 2013, in collaboration with engineers led by Mr Piyal Samara-Ratna at the Space Research Centre in Leicester. He explains that space engineers are particularly suited to thinking about the kind of challenges that medical devices face.
“Landing a Mars rover is a challenge and putting something into the heart is a challenge – you’ve got to create something that’s compact and can function in harsh environments and you need to be 100 per cent certain it will do its job when it arrives.”
They went on to build a prototype device, and with BHF funding are developing it further and testing it in animal models, with the hope of being able to test it in humans within the next three years.
Benefits of new LVADs
“A key feature of our device is that fitting it doesn’t require major surgery,” Dr Adlam says. “With a small incision, it can be inserted through the chest wall.”
Another benefit is that it doesn’t sit inside the heart, reducing the risk of infection and blood clotting.
A key feature of our device is that fitting it doesn’t require major surgery
The device relies on two silicone balloons – a larger ‘positioning’ balloon and a smaller ‘actuator’ balloon – which sit between the heart and pericardium (the protective sac that surrounds the heart).
The smaller actuator balloon inflates and deflates in time with the heartbeat, compressing the left ventricle, forcing blood to pump through the heart more powerfully.
The device is fitted with an in-built electrocardiogram (ECG), which monitors the electrical signals that make the heart beat, and makes sure that the actuator balloon inflates and deflates at the right moment, and with the right force.
The larger positioning balloon acts to tense up the side of the pericardium, so when the smaller balloon inflates it delivers its force to the heart more effectively.
Like existing LVADs, the device currently requires an external power supply, but Dr Adlam believes with further research it could become fully implantable, as its innovative design has relatively low power requirements.
“The work we're doing is happening in parallel with simultaneous advances, such as battery technology,” he explains.
“We’re seeing the development of smaller, lighter batteries that can potentially be re-charged across the skin. Think of a pacemaker – in the early days they had huge batteries that had to be carried around, but they progressed to ever smaller devices that now sit entirely under the skin.”
Help after a heart attack
Dr Adlam hopes that his device could improve the chances of recovery for patients who have suffered a severe heart attack.
Currently, drugs can make the heart beat harder but can also have side effects and are only a short-term solution. There are also temporary assist devices that can be used for a few days, but not long enough for the heart to recover.
“We want our device to offer longer-term support for the heart during this period of recovery,” he explains.
New hope for heart failure patients
In future, this device could also be used to help thosealready living with heart failure, whether caused by a heart attack or another condition such as cardiomyopathy.
“Even with current treatments, many of these people still have symptoms that reduce their quality of life,” says Dr Adlam. “There’s a real unmet need for new technologies to help these patients.”
An estimated 920,000 people are living with heart failure in the UK.
An estimated 920,000 people are living with heart failure in the UK. Some patients can be fitted with an LVAD, but surgery comes with risks and isn’t suitable for every patient. In fact, only around 120 LVADs are implanted each year in the UK.
Heart transplants are another option, but with organs being a limited resource, only around 200 are carried out annually in the UK.
As with any giant leaps in medicine, it takes dedicated teams of experts taking small steps to eventually help people like Nic.
“When my LVAD was implanted, I had no idea what I was putting myself through. Thanks to research, I’m living and enjoying life within my limitations, and always with hope for the future.”
LVADs and the heart: Stats and figures
- 920,000 people are living with heart failure in the UK
- 120 LVADs are implanted each year in the UK
- 200+ heart transplants are carried out in the UK each year