For over a decade, cardiologists have been conducting trials in patients using cells extracted from the
bone marrow and infusing them into the blood vessels of the heart in patients who have suffered a heart attack, a procedure not without risks due to it involving multiple invasive procedures.
The hope is that the stem cells contained within the bone marrow are able to help regenerate the heart, either by turning into heart cells (cardiomyocytes), blood vessel cells (endothelial cells), or releasing factors that protect the heart and prevent the formation of a large scar. Unfortunately, there is very limited scientific evidence providing that bone marrow stem cells can actually turn into functional heart cells and trials that have been conducted so far have yielded mixed results.
The SWISS-AMI cell therapy trial, published in the world's leading cardiovascular research journal Circulation, addressed this question in a randomized, controlled trial, which enrolled 200 patients who had suffered a major heart attack.
The researchers assigned the patients to three groups: a) Standard heart attack treatment, b) Standard heart attack treatment and infusion of bone marrow cells 5-7 days after the heart attack or c) Standard heart attack treatment and infusion of bone marrow cells 3-4 weeks after the heart attack. They assessed heart function four months later using cardiac magnetic resonance imaging, one of the best tools available to determine heart function. The results were rather disappointing: Neither of the two cell treatment groups showed any improvement in their cardiac function.
Despite the study's limitations, the trial will dampen the general enthusiasm for injecting bone marrow cells into heart attack patients, although it’s not a set back for cardiac stem cell treatments. Regenerating heart tissue from adult stem cells requires priming or directing stem cells towards becoming heart cells and ensuring that the cells can attach and integrate into the heart, not just infusing or injecting them into the heart.
It is commendable that the journal published this negative study, because too many treatments are being marketed as "stem cell therapies" without clarifying whether the injected cells are truly efficacious.
Publications such as this lead to be more careful when performing "stem cell treatment" in patients without carefully defining the scientific characteristics and therapeutic potential of the cells that are being used.
Written by Dr. Belén Suárez for The All Results Journals.