Stem cells could be used to repair heart attack damage, according to reports in The Guardian , Financial Times and Daily Mail . Stem cells from human embryos had developed into healthy heart tissue when implanted into rats that had experienced a heart attack. The Guardian said that tests of the treatment were underway in sheep, and the Mail and Financial Times report that trials on humans could start in two years.
This was a study conducted in rats, using human embryonic stem cells. The study was well conducted and does have promising results. Further trials are needed to see if the treatment will work and be safe in people who have had heart attacks.
Human studies will ultimately be needed to determine if this treatment will be beneficial and safe for people. These studies will take time, so even if this treatment works, it will not be available for several years.
Where did the story come from?
Dr Michael Laflamme and colleagues from the University of Washington and the Geron Corporation, a biopharmaceutical company, carried out this research. The study was funded by the Geron Corporation.
The study was published in the peer-reviewed scientific journal Nature Biotechnology .
What kind of scientific study was this?
This was an experimental laboratory study in rats. The researchers extracted human embryonic stem cells and grew them in the laboratory. Different ways of growing and treating the cells were tested. The researchers' aim was to find the method that made the highest proportion of stem cells develop into heart cells, which survived when they were transplanted into the injured hearts of rats.
The cells were then transplanted into the hearts of rats that had had artificially-induced heart attacks. They also used some rats as controls that either had no cells transplanted, or had human embryonic stem cells that had not developed into heart cells.
Researchers studied the rats over a four-week period, using imaging techniques such as echocardiography and magnetic resonance imaging, and post-mortem examination to look at the rats’ hearts.
What were the results of the study?
Researchers found that the transplanted heart cells survived in all of the hearts that received them, while the non-heart cells transplanted into the control rats did not. The heart cells had grown into differing amounts of muscle tissue in the damaged areas. The hearts of the rats that received the human heart cells showed signs of functioning better than the hearts of the control rats.
What interpretations did the researchers draw from these results?
The researchers concluded that human heart cells could improve the structure and function of rat hearts that had experienced a heart attack, and that more studies are needed to look at this treatment.
What does the NHS Knowledge Service make of this study?
This study produces interesting and promising results in rats. Further studies are needed in larger animals. The Guardian reported that trials in sheep, whose heart rate and size are more similar to human hearts, are now taking place. Human studies will ultimately be needed to determine if this treatment will be beneficial and safe for people. These studies will take time, so even if this treatment works, it will not be available for several years.
Sir Muir Gray says...
Another promising development which emphasises the potential benefits of stem cell research.
Analysis by Bazian
Edited by NHS Website
Links to the headlines
Financial Times, 26 August 2007
The Guardian, 27 August 2007
Links to the science
Nat Biotechnol 2007, [Published online August 26 2007]