31-01-2025
New stem cell patch promises to cure severe heart problems
A German medical team has developed and tested a possible treatment for people with severe heart failure that could potentially help millions of cardiac patients around the world.
It is based on body cells that are converted into stem cells in the laboratory. These cells, known as induced pluripotent stem cells (iPS), can then develop into various body cells again. They serve to form a heart graft or patch that can help people with severe cardiac failure, according to a proof of concept document, published in the journal Nature, which tested the approach in humans for the first time under the leadership of the University Hospital of Göttingen.
Researchers say some 200,000 people in Germany alone would be eligible for the therapy, according to the researchers, while millions more around the world suffer from cardiovascular diseases.
This results when the heart's pumping ability gradually diminishes, usually as a result of other problems such as coronary heart disease, high blood pressure or myocarditis, an inflammation of the heart muscle. The main symptoms are a reduced ability to perform and shortness of breath. Until now, the only treatment has been medication, with doctors also advising regular exercise and a healthy diet.
Lab-grown heart muscle tissue
A team led by Wolfram-Hubertus Zimmermann from the Institute of Pharmacology and Toxicology at the University Hospital Göttingen, with the participation of the University Hospital Schleswig-Holstein in Lübeck, has now developed and tested the stem cell approach.
It takes about three months to make the patch, Zimmermann said. The implant, which is composed of several parts and, according to the researchers, is about 100 cubic centimetres in size, is applied to the weakened heart muscle and is intended to permanently increase its pumping capacity.
The heart patch was initially tested on rats and rhesus monkeys. These trials, which lasted between three and six months, confirmed that the implants, which consist of 40 to 200 million heart cells, improve heart function.
"We were able to show in the animal model that the implantation of heart patches is suitable for the long-term build-up of heart muscle in heart failure," Zimmermann is quoted in a statement from the University Hospital. Following these results, a German medical regulatory body authorized the world's first test of this patch on humans.
Implant increased heart pumping capacity
In Nature, the team describes a 46-year-old female patient with advanced heart failure with concomitant conditions such as type 2 diabetes and high blood pressure. She had a heart attack in 2016, then developed heart failure and in the summer of 2021 received the heart patch consisting of 400 million heart cells implanted.
When the woman underwent a heart transplant the following October, the team was able to examine the removed heart and the implant in detail. Even during these three months, the pumping capacity of the left ventricle – which, according to Zimmermann, is around 60% in healthy people – had increased from 35% to 39%.
The analysis proves for the first time "that heart muscle repair through heart muscle reconstruction is also possible in humans." In view of the results, the dose per patch has been increased from 400 million to 800 million heart cells.
Clinical study extended
In the meantime, the clinical study has been extended: According to the university hospital, 15 people have already received such an implant. A total of 53 people are expected to receive a heart patch. The first clinical data is therefore expected at the end of 2025.
The implant is actually intended to bridge the time until a heart transplant is available, as in the case of the 46-year-old, as an alternative to a mechanical pump. However, Zimmermann thinks the implant might also be a permanent solution.
Although the patient would have to take immunosuppressants for the rest of their life, Zimmermann sees no evidence of major side effects or even an increased risk of tumours. So far, follow-up periods have been up to almost four years.
The body cells used to produce the iPS cells did not come from the patients themselves, as researchers said doing so was too cumbersome. Also, experiments on monkeys in the study showed that even when using one's own body cells for the procedure, rejection responses still occurred.
A licensing study for the procedure is currently being planned, which could possibly start as early as 2026. In addition, an application is being made for an exceptional licence for hospitals, which would make it possible to treat further patients even before the procedure is officially approved.
Stem cell-based therapies could in future also help with other diseases, such as Parkinson's disease, type 1 diabetes or retinal diseases such as age-related macular degeneration (AMD).
