A recent study has now established that stem cell therapy for heart attack may not be as effective as it is claimed to be, when tested under rigorous conditions. German researchers have stated that bone marrow transplantation may not improve cardiac function following heart attack.
Over the past few years, very few topics have had the potential to attract the attention of public and scientists alike. One such is the controversial area of stem cell research and therapy. Day by the day, a number of studies are being published, highlighting the promise of stem cell therapy in the treatment of neurodegenerative disorders, hematological malignancies, injury, and many others.
Evidence is accumulating on the importance of stem cells in regeneration of cardiac tissue. It is even believed to lead to the development of new blood vessels after a heart attack. Mobilization of bone marrow stem cells can be achieved through stimulation of a growth factor protein, called granulocyte colony-stimulating factor (G-CSF).
The researchers conducted a randomized, double blind, placebo-controlled study (REVIVAL-2) to assess effect of G-CSF treatment in a large study population (114 patients) following a heart attack. All the study participants were diagnosed to have a ST-segment elevation, characteristic of acute myocardial infarction.
The patients had undergone angioplasty and other similar percutaneous coronary intervention procedures for opening up a narrowed coronary artery. They were assigned to receive either G-CSF or a placebo for 5 days following treatment. A daily dose of 10 µg/kg of the growth factor was given in the form of an injection.
Although G-CSF protein produced a satisfactory mobilization of bone marrow stem cells, the size of the infarct or the left ventricular function remained unaltered following a heart attack. Furthermore, no increased risk of restenois or other adverse cardiac events could be documented with G-CSF treatment.
The results of this study can be found in the latest issue of JAMA. This study also highlights need for caution about the direct application of experimental results to clinical practice, without careful analysis, that may lead to complications, not foreseen at the moment.