‘Groundbreaking’: scientists develop patch that can repair damaged hearts | Medical research

Damaged hearts can literally be patched up to help them work, say researchers, in what has been hailed as a groundbreaking development for people with advanced heart failure.

According to a recent study, heart failure affects more than 64 million people worldwide, with causes including heart attacks, high blood pressure and coronary artery disease.

For heart transplants there is a shortage of available organs, while artificial heart pumps are expensive and come with a high rate of complications.

Now scientists believe they have made a breakthrough by creating implantable patches composed of beating heart muscle that can help the organ contract.

Prof Ingo Kutschka, the co-author of the work from University Medical Center Göttingen in Germany, said: “We now have, for the first time, a laboratory grown biological transplant available, which has the potential to stabilise and strengthen the heart muscle.”

The patches are made from cells taken from blood and “reprogrammed” to act as stem cells, which can develop into any cell type in the body.

In the case of the patches, these cells are turned into heart muscle and connective tissue cells. They are embedded in a collagen gel and grown in a custom-made mould before the resulting hexagonal patches are attached, in arrays, to a membrane. For humans this membrane is about 5cm by 10cm in size.

Prof Wolfram-Hubertus Zimmermann, another author of the work from University Medical Center Göttingen, said the muscle in the patches had the characteristics of a heart that was just four to eight years old.

“We are implanting young muscle into patients with heart failure,” he said.

The team say the patches are an important development because directly injecting heart muscle cells into the heart can lead to the growth of tumours or result in the development of an irregular heartbeat – which can be deadly.

The patches, however, allow many more heart muscle cells to be administered with a higher retention and, it appears, no risk of such unwanted effects.

Writing in the journal Nature, Zimmermann and colleagues report how they tested the patches in healthy rhesus macaques, finding no evidence of irregular heartbeats, tumour formation, or deaths or disease related to the patches.

When the team studied the hearts of the animals up to six months after the patches were implanted, they found a thickening of the heart wall – with the extent dependent on the number of patches used.

The team also tested the patches in monkeys with a disease akin to chronic heart failure. In this case the team found signs of improved heart function, such as a greater ability of the heart wall to contract.

The researchers then applied the approach to a 46-year-old woman with advanced heart failure. In this case the patches were made from human cells taken from a donor, and were sutured on to the patient’s beating heart with minimally invasive surgery.

Three months later the patient – who remained stable – had a heart transplant, allowing the team to analyse the removed heart. The researchers found the patches had survived and a blood supply had developed.

While use of cells from donors means immune suppression is required, the researchers say it would be too expensive and take too much time to create patches from the cells of a patient in urgent need, with donor cells also offering the chance for “off the shelf” patches and better safety testing.

The team say it takes three to six months for therapeutic effects of patches to be seen, meaning they would not be suitable for all patients. However, 15 patients have already received the patches.

“Our ongoing clinical trial will hopefully demonstrate whether this engineered heart muscle grafts will improve cardiac function in our patients,” said Kutschka.

Zimmermann said the aim was not necessarily to replace heart transplants.

“It is offering a novel treatment to patients that are presently under palliative care and that have a mortality of 50% within 12 months,” he said.

Prof Sian Harding, of Imperial College London described the research as a groundbreaking study, but said further work was needed, not least as the heart muscle cells in the patch did not mature completely and the establishment of blood flow was slow.

Prof Ipsita Roy, of the University of Sheffield, also welcomed the work, noting the surgery involved would be less invasive than for a heart transplant.

“It is an excellent piece of work. I’m really impressed,” she said. “The concept is quite clear, you can patch up the heart wherever the heart is damaged.”