If you go back 20 years the thought of the heart repairing itself after being damaged by a heart attack was unthinkable. It was completely out of reach for the brightest minds working in labs around the world.
Then a decade ago, scientists in America discovered that a few cells in your heart, about 1 in 1,000, could divide. It was an exciting discovery because it offered hope that the heart might have the capacity to repair itself.
If we fast-forward to the present day then we're edging closer to the holy grail of mending broken hearts.
It's apt that during National Heart Month we hear about a small clinical trial in which scientists appear to have reduced heart damage following a heart attack by injecting cells taken from a healthy part of the heart back into the damaged hearts.
The study involved 25 people; eight received standard care while 17 received cardiosphere-derived cells (CDCs). CDCs are special cells that grow out of heart tissue when it is placed in cell culture in the laboratory.
The scientists took small pieces of healthy heart from patients who had suffered a heart attack. After a few days in a culture dish they produce collections of cells called cardiospheres. Cells from these cardiospheres are then propagated in the laboratory before being injected, a few weeks later, into the coronary artery feeding the damaged portion of the heart.
Importantly, the study showed that the procedure was safe (a primary objective of this early clinical trial). Encouragingly, it showed that, compared with patients who did not receive the cells, the hearts of patients who had received CDCs had smaller scars and more healthy heart muscle.
This is the most promising of a series of studies on the effects of 'cell therapy' to improve the function of damaged hearts. Although it's known that CDCs can become new heart cells in the laboratory, the researchers don't believe that they are doing the same thing in patients. The most likely explanation is the CDCs stimulate repair processes in the surrounding tissues. Similar results have been reported by others using other types of cells, such as bone marrow-derived cells.
Much more research is needed. Firstly, to confirm the effects seen in this small trial are real and sustained in the long term and, secondly, to try and understand just how such cells exert their beneficial impact.
This latest research is undoubtedly encouraging and the British Heart Foundation believes a way to repair a damaged heart will ultimately be found, which is why we launched our Mending Broken Hearts appeal to support research in regenerative medicine.