Belief in stem cell therapy is somewhat cyclical, with breakthroughs more often than not followed by unexpected side effects. But now, hope is on the rise again. According to a new paper in The Lancet, it might be possible to reinject cardiac stem cells into the patients they were harvested from in order to reverse the damage from heart failure.
The study, called SCIPIO (Stem Cell Infusion in Patients with Ischemic cardiOmyopathy – quite the mouthful) is a first-in-man study, representing the move from successful animal models to a bona fide phase 1 clinical trial in humans. The idea behind the treatment is theoretically pretty simple; the fundamental problem in heart failure is the loss of cardiac tissue, so put in stem cells and let them regenerate the dead myocardium, and that should solve the problem. Ischemic heart disease is the most common cause of heart failure in the west, reaching epidemic levels in industrialized nations, so if further research shows that this works, there’s a huge potential for an improved quality of life in thousands of patients.
Controversy-free stem cells to the rescue!
The stem cells used in this treatment are cardiac stem cells (CSCs), harvested directly from the adult patient, meaning that the treatment lacks the controversy found in certain other stem cell research. Patients were screened for the trial before their surgeries to treat the heart failure, and either placed in control or treatment groups. Enough cells were harvested from every patient tissue sample that it would be possible to do multiple treatments, but for the time being, the researchers intentionally choice a conservative number of cells (no more than 1 mill. per person) since this primarily was a safety trial.
After pre-surgery harvesting, the CSCs are then purified, stored frozen and finally reinjected directly to the damaged tissue by intracoronary infusion 4 months after the heart surgery. The waiting period was chosen in order ensure that the heart had stabilized after the surgery, so any changes would be due to the treatment. Although the primary objective of the study was testing the safety of the method, rather than determining its efficacy, the initial data still showed a surprisingly large benefit. The relative infarct size reduction was 24%, and absolute improvement in ejection fraction (a measure of the heart’s pumping capability) was 8% after 4 months. Not only did these benefits last, they even increased in the patients reexamined after a year. Perhaps most importantly, no bad side effects were reported.
A new hope?
According to the commentary that accompanies the paper, this pilot data “brings new momentum to cardiac stem cell therapy … against [a] background of waning enthusiasm about the potential of repair by use of cardiac cells.” Naturally more work needs to be done to confirm it, but the results are positive enough that a larger phase 2 trial seems likely to follow. A subsequent study should also be blind – that is, instead of having a control group that aren’t given any treatment at all (as was the case here), the control group should receive a placebo infusion to confirm that the positive effects actually come from the treatment.
Isn’t it fascinating? At CERG, we study different types of exercise as treatment for ischemic heart disease, but this represents a completely different approach that could turn out to be equally valid. If you’re also interested in the human-interest angle of the research, you can check out this extensive story on CNN, where reporters talked to patients that have undergone the treatment.
Written by Hanna Sofie Ellingsen at CERG.