Acute myocardial infarction is a sudden occlusion of the coronary artery supplying blood to the heart, interrupting blood flow and causing local necrosis of part of the heart muscle due to severe and persistent ischemia, resulting in serious damage to heart function and a high mortality rate. According to statistics 1/3/-1/2 of patients die before they are brought to the hospital. When myocardial infarction occurs, at the moment of sudden drop in myocardial perfusion, myocardial contractile function and metabolic level at the ischemic site also drop sharply, and irreversible myocardial damage occurs 15-20 minutes after coronary artery blockage. In recent years, direct and rapid opening of occluded vessels by coronary interventions and pharmacological thrombolytic therapy have significantly reduced the early mortality of acute myocardial infarction. However, evidence-based medical studies now show that even in patients with myocardial infarction treated successfully with revascularization, more than 30% of patients still experience ventricular remodeling with wall thinning and chamber enlargement after myocardial infarction and develop chronic ischemic heart failure (CIHF), because early revascularization can only save the hibernating myocardium, while the already necrotic myocardium will definitely be replaced by fibrous connective tissue and form scars This is the leading cause of death from coronary artery disease, which eventually leads to ischemic cardiomyopathy. This is the main cause of death from coronary artery occlusion, myocardial infarction, scar formation, ventricular wall thinning, and ischemic cardiomyopathy. formation, ventricular wall thinning, ventricular chamber enlargement, heart failure How to stop this vicious circle? This is the bottleneck in the treatment of acute myocardial infarction in coronary heart disease. In November 1998, American biologists such as Thomson and Gearhart isolated human pluripotent stem cells for the first time, which has heralded its great theoretical significance and application prospect in medical biology and has been called by the world Scientists call it the forefront of contemporary biomedical development. It is this discovery that has promoted the rapid development of cell biology in the 21st world. The concept of repairing myocardium by transplantation of adult stem cells with multi-directional differentiation and self-renewal was born, which is a milestone breakthrough in the history of myocardial infarction treatment. Stem cells are undifferentiated cells or primitive cells, which are early undifferentiated cells with self-replicating ability and can differentiate into at least one functional cell. Under certain conditions, stem cells can be directed to differentiate into functional cells in the body and form any type of tissues and organs, i.e. they are “plastic”. Stem cells can be divided into embryonic stem cell (ESC) and adult stern cell according to the order of their appearance during the development of an individual. When the fertilized egg divides and develops into a blastocyst, the cells in the inner cell mass are embryonic stem cells. Adult stem cells are those stem cells with tissue or organ specificity, which are highly plastic and have a very wide range of tissue types. Among them are bone marrow hematopoietic stem cells, peripheral blood stem cells, umbilical cord blood stem cells, bone marrow mesenchymal stem cells and skeletal muscle stem cells associated with cardiac myocytes. Cell transplantation therapy of the heart, i.e., transplantation of cells isolated directly or with cells purified, cultured and proliferated in vitro into ischemic necrotic areas, improves myocardial systolic and diastolic functions by replacing fibrous tissue with newborn muscle cells, thus providing a brand new therapeutic approach for the treatment of myocardial infarction and severe heart failure. In 2008, JAMA published worldwide clinical reports on cell transplantation for coronary artery disease, including 17 clinical studies on cell transplantation for AMI and 16 clinical studies on cell transplantation for heart failure. Numerous clinical studies have found that stem cell transplantation helps improve clinical symptoms of acute myocardial infarction, old myocardial infarction and post-myocardial infarction heart failure as well as post-infarction cardiac systolic and diastolic functions, stop left ventricular remodeling, and improve prognosis. The consensus is that either autologous bone marrow mononuclear cells, bone marrow mesenchymal stem cells, or endothelial progenitor cells or bone marrow collateral cells transplantation can improve cardiac systolic function to varying degrees, can increase left ventricular ejection fraction by 5-6% on average, and is safe and beneficial in the treatment of acute myocardial infarction, old myocardial infarction and post-myocardial infarction heart failure. Although the mechanism of action of stem cells is still not well understood, it is possible that: 1. the transplanted stem cells differentiate into cardiomyocyte-like cells with cardiomyocyte phenotypic characteristics, increasing the thickness of the infarcted myocardial wall and limiting ventricular remodeling; 2. promoting vascular regeneration, anti-apoptosis, mobilization of cardiomyogenic stem cells and promoting their proliferation; 3. stem cells may be cells with differentiation potential that are widely present in various tissues of the body and can produce a variety of bioactive factors. Stem cells can express, synthesize and secrete a variety of growth factors, cytokines, regulatory peptides, gas signaling molecules and other bioactive factors, such as: ① Growth factors: vascular endothelial growth factor (VGF), placental growth factor (PGF), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), epidermal growth factor (EGF), transforming growth factor-derived growth factor (TGF), and other growth factors. EGF), transforming growth factor-ß (TGF-ß); (ii) cytokines: interleukin (L-1-12), tumor necrosis factor (TNF), stem cell factor (SCF), stem cell-derived factor (SDF-1); (iii) regulatory peptides: brain natriuretic factor (BNP), cardiac natriuretic factor (ANP), endothelin (ET), adrenomedullin (AM) These growth factors, cytokines, chemotactic factors, regulatory peptides, etc. enter the surrounding tissue from the transplanted stem cells, and their paracrine/autocrine factors directly alter the myocardial healing process, including multiple effects on vascular neovascularization, mobilization and migration of myocardial-derived stem cells, anti-apoptosis, inflammation, myocardial fibrosis, myocardial bioenergetics and endogenous repair, etc. effects to achieve myocardial repair and improve cardiac function effects. Therefore, the best solution for the treatment of acute myocardial infarction is to open the occluded coronary artery and seed the myocardium with seed cells, which is a multiplier of 1+1 over 2. Stenting of an occluded coronary artery and transcatheter transplantation of stem cells into the necrotic myocardium. As pictured
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