Researchers have demonstrated that lab-grown muscle patches derived from stem cells can aid in the repair of failing hearts. A clinical trial involving a 46-year-old woman with heart failure showed promising results, with the patches stabilizing her condition until she received a heart transplant.
The woman, who had a heart attack in 2016 and subsequently developed heart failure, underwent a procedure in 2021 to implant ten patches, each containing 400 million cells, onto the surface of her heart. Examination of her explanted heart revealed that the implanted muscle patches remained in place and formed new blood vessels.
Engineered Heart Patches: A Novel Approach
Worldwide, an estimated 60 million people live with heart failure, and over half of those with severe heart failure die within a year. The limited availability of donor hearts necessitates alternative treatments. Researchers have been exploring stem cell implantation or direct injection of stem cells or lab-grown muscles into the heart. However, these methods often lead to irregular heartbeats, tumor growth, or immune rejection.
Wolfram-Hubertus Zimmermann and his team engineered induced pluripotent stem cells (iPSCs) to grow into heart muscle and connective tissue. These cells were mixed with collagen gel to create patches and placed on the heart's surface using a minimally invasive procedure. The patches, containing approximately 200 million cells embedded in a collagen hydrogel, facilitated the growth of new muscle cells and improved heart pumping function. Imaging and tissue analysis confirmed cell survival with immune suppression to prevent rejection. No tumors were observed, addressing concerns from previous experiments.
Clinical Trial and Future Directions
The engineered cells in the patch require three to six months to adapt and support the heart, necessitating patient stability at the time of implantation. The ongoing clinical trial involves 15 patients with advanced heart failure, with the aim of determining whether the engineered heart patch can serve as more than just a bridge to transplant.
According to Ingo Kutschka, the procedure involves a small incision in the chest wall, making it less invasive than a transplant. The patch is not intended to replace heart transplants but to offer a novel treatment for patients under palliative care with a high mortality rate.
Richard Lee, a cardiologist at Brigham and Women's Hospital and professor at Harvard Medical School, noted the remarkable progress made over decades of research. He emphasized that while more work is needed, this represents an important step forward.
