| Congestive heart failure (CHF) is a serious and | | | | autologous stem cell transplantation in the |
| life-threatening illness that is associated with | | | | treatment of CHF, and may represent a major |
| premature death. If one thinks of the heart as a | | | | advancement towards finding an enduring |
| pump, progressive damage to this pump's muscle | | | | treatment, if not an eventual cure, for this |
| fibers results in decreased "pump efficiency," | | | | increasingly common and disabling disease. |
| which causes blood to, essentially, back-up within | | | | In this prospective interventional clinical study, 124 |
| the vascular system under increased pressure. | | | | patients who had just experienced an acute |
| This increased back-pressure causes swelling of | | | | myocardial infarction were evaluated with |
| the entire body (edema), and particularly the | | | | coronary angiograms, treadmill EKGs, 24-hour |
| lower extremities, the lungs, the liver, as well as | | | | EKGs, and echocardiograms, among other cardiac |
| within the heart itself. In more severe cases, CHF | | | | studies. Half of this cohort of patient volunteers |
| is associated with generalized weakness and | | | | also underwent collection of their own |
| profound shortness of breath. | | | | (autologous) bone marrow cells, and injection of |
| The American Heart Association estimates that | | | | these bone marrow cells into the blocked |
| there are already more than 5 million Americans | | | | coronary arteries that had caused these patients' |
| living with CHF, and that more than 550,000 new | | | | heart attacks. Both groups of patients were |
| cases of CHF are diagnosed each year. Although | | | | matched with each other in terms of baseline |
| mortality rates associated with CHF have | | | | cardiac function and the extent of their |
| improved dramatically over the past 30 years, | | | | myocardial infarctions. All 124 patients were then |
| the 5-year death rate associated with clinically | | | | closely followed, at regular intervals, for 5 years. |
| significant CHF still approaches 50 percent. | | | | The results of this study were rather dramatic. |
| As our population continues to grow older, on | | | | Within 3 months of bone marrow cell injection, |
| average, the incidence of CHF is expected to | | | | significant improvement was noted in cardiac |
| continue to rise. Although precise estimates are | | | | pumping efficiency (ejection fraction) of the bone |
| difficult to arrive at, the cost of caring for CHF is | | | | marrow cell transplant patients, when compared |
| thought to be at least $33 billion per year in the | | | | to the patients who did not receive autologous |
| United States alone. | | | | intracardiac bone marrow cell transfusions. |
| There are several known major risk factors for | | | | Moreover, on average, the total area of heart |
| CHF, including coronary artery disease and heart | | | | muscle death (infarction) following heart attack |
| attack (myocardial infarction), uncontrolled high | | | | was 8 percent smaller in the patients who |
| blood pressure (hypertension), diabetes, obesity, | | | | received the bone marrow cell transplants, when |
| diseased heart valves, elevated cholesterol, and | | | | compared to the "control group" patients. |
| smoking. In most countries, coronary artery | | | | In the area of the "infarction zone" of the heart, a |
| disease and myocardial infarction are the leading | | | | very significant 31 percent increase in cardiac |
| causes of CHF, and these two related risk factors | | | | contractility was observed in the patients who had |
| account for approximately two-thirds of all CHF | | | | undergone bone marrow cell transplant, suggesting |
| cases in the United States. | | | | that the infused bone marrow stem cells had |
| In adults, heart muscle fibers (cardiac myocytes) | | | | actually incorporated themselves into the infarcted |
| that have become damaged by chronic oxygen | | | | heart muscle, and had successfully transformed |
| deprivation (myocardial ischemia) or oxygen loss | | | | themselves into functional cardiac myocytes. |
| (myocardial infarction) are essentially unable to | | | | When compared to the control group patients, |
| regenerate themselves, and are gradually replaced | | | | the patients who had undergone autologous |
| by scar tissue that interferes with the heart's | | | | intracardiac bone marrow cell transplantation also |
| pumping action. At the present time, the standard | | | | experienced significantly improved exercise |
| clinical management of heart injury due to | | | | tolerance and a decreased risk of death |
| ischemia or infarction includes the use of | | | | throughout the 5-year observation period within |
| medications such as aspirin, ACE inhibitors, | | | | this study. Furthermore, these highly significant |
| aldosterone antagonists, beta-blockers and | | | | improvements in cardiac function continued to |
| nitrates. So-called "reperfusion strategies," including | | | | remain stable and durable throughout the 5-year |
| coronary artery stent placement and coronary | | | | period of post-transplant observation of these |
| artery bypass graft (CABG) surgery may also be | | | | patients. As the "treatment group" patients were |
| required in some patients. However, once the | | | | infused with their own bone marrow cells, there |
| heart's blood-pumping muscle fibers have become | | | | were no episodes of rejection, and no major |
| extensively replaced with non-contractile scar | | | | complications were reported with this novel |
| tissue (fibrosis), irreversible CHF develops, and | | | | treatment. |
| only symptomatic management is possible at this | | | | This small prospective pilot study strongly |
| point. | | | | suggests that autotransplantation with stem cells |
| Recent animal studies, and limited clinical research | | | | contained in the bone marrow can significantly |
| studies in humans, have looked at the use of | | | | reduce the risk and extent of CHF following acute |
| stem cell auto-transplantation into damaged hearts | | | | myocardial infarction. Not only does this therapy |
| afflicted with CHF. Although mature cardiac | | | | appear to be clinically effective, but it appears to |
| myocytes cannot regenerate or reproduce | | | | be associated with a very low risk of |
| following severe ischemia or infarction, primitive | | | | complications, and it also side-steps the ongoing |
| "pluropotential" stem cells in the bone marrow are | | | | ethical debate that surrounds the use of more |
| thought to be potentially capable, under certain | | | | versatile, but more controversial, fetal stem cells. |
| conditions, of metamorphosing, or differentiating, | | | | Based upon the rather remarkable findings of this |
| themselves into almost any type of specialized cell | | | | small clinical study, much larger multi-institution, |
| of the body, including cardiac myocytes. However, | | | | prospective, randomized, controlled studies of |
| this transformation, from undifferentiated bone | | | | autologous intracardiac bone marrow cell |
| marrow stem cell into a highly differentiated and | | | | transplantation, following acute myocardial |
| specialized cardiac muscle cell, does not occur | | | | infarction, need to be performed. Fortunately, |
| naturally in the human body, at least not to any | | | | several such studies are already underway in the |
| clinically significant degree. Therefore, as is also | | | | United States and Europe. I look forward to the |
| the case in other areas of stem cell research, the | | | | long-term results of such studies, as I believe that |
| greatest challenge in this type of clinical research | | | | they may have the potential to radically |
| is in coaxing undifferentiated stem cells to morph | | | | transform the management of coronary artery |
| into functional cardiac myocytes and to find a | | | | disease and acute myocardial infarction, and offer |
| way to incorporate these new heart muscle cells | | | | the best and most practical hope of reducing both |
| into the damaged heart in such a way that they | | | | the incidence of CHF and the mortality rate |
| actually improve the damaged heart's | | | | associated with CHF. |
| compromised pumping function. (These two | | | | The information in this column is intended for |
| challenges continue to vex clinical research into | | | | informational purposes only, and does not |
| stem cell therapy, and particularly research into | | | | constitute medical advice or recommendations by |
| the use of adult patients' own stem cells.) | | | | the author. Please consult with your physician |
| Now, newly published clinical research in the Journal | | | | before making any lifestyle or medication |
| of the American College of Cardiology appears to | | | | changes, or if you have any other concerns |
| have pushed the existing boundaries of so-called | | | | regarding your health. |