Is the use of stem cells in heart attack exaggerated?
Stem cells have shown their uselessness
The introduction of stem cells to patients is a safe, but ineffective method of treatmentVera Krysanova, "Newspaper.
These are the results of a clinical study conducted with the support of the US National Institutes of Health: Therapy with bone marrow-derived stem cells does not improve short-term recovery after heart attack.
The study, which is called "Transplantation In Myocardial Infarction Evaluation" (TIME), includes earlier work on this topic — the LateTIME project. These studies also show the ineffectiveness of the introduction of stem cells, but already 2-3 weeks after a myocardial infarction.
Both studies were conducted by the Cardiovascular Cell Therapy Research Network. — CCTRN) with the support of the National Heart, Lung, and Blood Institute (NHLBI). The scientists presented their results at the next congress of the American Heart Association (AHA) in Los Angeles, and a publication is also being prepared in the Journal of the American Medical Association.
The normal functioning of the heart is always disrupted after a myocardial infarction, which is expressed in a decrease in the contractile activity of a section of cardiac tissue that has undergone necrosis (necrosis) due to a heart attack, that is, the amount of blood ejected by the heart decreases. To restore this site, scientists use stem cells, which, according to their assumption, should create a new tissue capable of contractions at the site of necrosis.
It is believed that to obtain stem cells intended for such therapy, it is best to use a natural source that is located directly in the patient's body, namely bone marrow. This also simplifies the process of finding stem cell donors for the patient.
"In previous studies, ambiguous data were obtained, which was influenced by both the different number of injected stem cells and the methods of their delivery," says Dr. Sonia Skarlatos, deputy director of the Department of Cardiovascular Diseases at NHLBI. — In the course of two major studies, TIME and LateTIME, we established the safety of such a treatment method and developed a common standard for further research. This will determine the next steps in the study of the restoration of a damaged heart by stem cells."
Another advantage of the study is that doctors have preserved stem cell samples. This will establish a link between patients with clinical improvements and the properties of their stem cells.
From July 2008 to February 2011, 120 volunteers (87.5% of them were men) suffering from left ventricular dysfunction took part in the TIME project. The participants were divided into four groups depending on the day after the infarction, on which the stem cells were injected: on the third or seventh day. The other two groups were controls, and their participants were given a placebo on the same days. Researchers have developed a technique to obtain and purify stem cells so that each patient receives 150 million pieces at a time. This was done to get homogeneous data.
Six months after the manipulation, the researchers measured the ejection fraction of the left ventricle, that is, the amount of blood that the left ventricle throws out with each contraction. The scientists did not see any differences in the results obtained: there was the same improvement in the indicator in all groups.
"Our study, without a doubt, carries very important information, despite the lack of positive results of stem cell therapy after 6 months of follow—up," says Sonya Skarlatos. "The use of stem cells to restore heart function is just beginning to develop as a treatment method."
Meanwhile, last month, an article by German researchers from the Asklepios Clinic St. Georg Cardiology Department in Hamburg (Heeger et al., Percutaneous, transendocardial injection of bone marrow-derived mononuclear cells in heart failure patients following acute ST-elevation myocardial infarction: ALSTER-Stem Cell trial) was published in the journal Eurointervention. They received positive results after the administration of stem cells to patients suffering from a form of heart failure other than myocardial infarction. (In fact, as it is easy to see from the title of the article, German researchers examined their study on patients who had suffered one of the forms of myocardial infarction, with an increase in the ST segment of the electrocardiogram — VM.) Doctors revealed an improvement in the left ventricular ejection fraction compared to the control group taking placebo.
So, although stem cell therapy for restoring cardiac function has been studied for several years, the data on it is still quite contradictory.
Portal "Eternal youth" http://vechnayamolodost.ru20.11.2012