Heart ‘patches’ developed by the British Heart Foundation (BHF) have proven themselves safe in animal lab trials — and will be moving on human trials.

Image credits Peggy Lachmann-Anke , Marco Lachmann-Anke.

The patches could one day help people manage and recover from debilitating heart failure, a condition which affects an estimated 920,000 people in the UK alone, and is on the rise worldwide, say researchers from the BHF. The patches are thumb-sized bits of heart tissue measuring 3cm by 2cm and containing up to 50 million human stem cells. These cells have the ability to turn into fully-functional heart tissue, and are meant to be applied to the heart of someone after they’ve had a heart attack. Used in this fashion, they can limit, and even reverse, the loss of the heart’s pumping ability.

Heart attack, heart defense

“One day, we hope to add heart patches to the treatments that doctors can routinely offer people after a heart attack,” says Dr Richard Jabbour who carried out the research at the London BHF Centre of Regenerative Medicine.

“We could prescribe one of these patches alongside medicines for someone with heart failure, which you could take from a shelf and implant straight in to a person.”

During a heart attack, our hearts’ supply of nutrients and oxygen can become compromised, killing off parts of the heart muscle. This leaves the organ weakened and could even lead to heart failure later on. This condition involves the heart not being able to pump sufficient blood to the rest of the body, making even mundane tasks such as climbing stairs or getting dressed extremely tiring.

The patches are meant to be sewn into place on the damaged heart, where they will offer physical support to the damaged muscle and help it pump more efficiently. At the same time, the patch delivers compounds that stimulate its healing and regeneration. Eventually, the team hopes, these patches will be incorporated into the heart muscle.

The patches start to beat spontaneously after three days, and start to mimic the structure of mature heart tissue within one month, the team explains. After this, they can be grafted into the damaged heart to help it repair and recover normal functionality.

Rabbit trials showed these patches to be safe and that they lead to an improvement in the functioning of the heart after a heart attack. Four weeks after the patches were applied, heart scans showed that the heart’s left ventricle (the one which pumps blood out to the body) was recovering nicely, without any abnormal heart rhythms. Other stem cell delivery methods run the risk of such abnormal rhythms developing, the team explains.

So far, the patches have proven their efficacy. The next steps include a clinical trial with human subjects, first to test how safe they are, then to see if they can achieve the same levels of healing in humans. They were developed as an alternative to the more traditional approach of injecting stem cells directly into damaged hearts, which has had mixed results. In the absence of a patch, the stem cells are quickly cleared from the heart before they can produce any significant repairs.

“One day, we hope to add heart patches to the treatments that doctors can routinely offer people after a heart attack,” says Dr Richard Jabbour, who carried out the research at the London BHF Centre of Regenerative Medicine said.

“We could prescribe one of these patches alongside medicines for someone with heart failure, which you could take from a shelf and implant straight in to a person.”

The findings were presented at the British Cardiovascular Society (BCS) Conference in Manchester on Monday, June 3rd.