Stem cells have been front and center in many scientific, medical, and yes, political circles for several years now. Proponents have argued that these undifferentiated cells have unlimited potential to cure a host of chronic diseases and conditions, while detractors say that no matter how useful these cells may be, harvesting them from human embryos or other remains is simply unethical and cannot be pursued. Enter more confusion with the discovery that there's more than one type of stem cell and they lurk around all over the human body, even in adults. Clearly there's nothing to prevent research on this variety, except disappointed hopes, as evidenced in this week's JAMA and as Rick and I discuss in PodMed.
Stem cells harvested from each study subject's own bone marrow, known as 'bone marrow mononuclear cells,' were processed and sterilized, then infused directly back into their hearts. Each of the study participants had congestive heart failure caused by coronary artery disease that wasn't suitable for surgery. The cells were withdrawn from the hip bone and infused back into the heart muscle via a number of injections. Assessments of heart function and anatomy were performed both previous to and after cell injection.
Disappointingly, injection of bone marrow mononuclear cells did not improve or ameliorate any of the parameters of congestive heart failure in this study at 6 months post-procedure. Does this mean we should throw out infusion of stem cells into a failing heart as one means of attempting treatment of this increasingly common condition? No, says Rick, and I, at least in principle, agree. There are just so many things we don't know: are these the appropriate population of cells to use, is this the best method of delivering them, did subjects in this study have disease that was too far advanced to respond? and so on.
There are many ongoing studies looking at the utility of stem cells to repair a damaged heart muscle, and while this trial was certainly disappointing, it seems premature at this point to abandon the strategy. What should we do in the mean time, as the number of people who are developing heart failure increases each year? I have to go back to beating my same old drum: prevention if possible, including management of risk factors like high blood pressure, smoking cessation, weight management, regular exercise and consumption of a heart-healthy diet. The best case scenario is, as always, prevention.
Other topics this week include Botox for migraine headaches and infection of implanted cardiac devices, also in JAMA, and two forms of abdominal CT for diagnosing acute appendicitis in NEJM. Until next week, y'all live well.