The development of emergency interventional techniques has saved countless lives, however, studies have shown that even if the infarct-related vessels are opened within 4 hours after the infarction, the incidence of heart failure still tends to increase 1 year after the infarction. The reason for this is that current drugs and interventions can only save myocardium that has escaped or is on the verge of necrosis, but cannot regenerate myocardial cells that have already died. The more cells are lost, the greater the chance of heart failure later. The prevention and treatment of post-infarction heart failure has become a major medical problem. In the last 20 years, neither pharmacological nor interventional treatments have made a breakthrough in heart failure. The discovery of stem cells has given hope for the regeneration of heart muscle tissue. After more than 10 years of research, thousands of clinical trials of stem cell use in humans for acute myocardial infarction at home and abroad have accumulated and found that intracoronary transplantation of stem cells is a highly promising method to repair myocardial tissue 4-7 days after infarction. Autologous bone marrow mesenchymal stem cells were the first stem cells to be used in humans. However, studies have shown that the amount of stem cells in autologous bone marrow is less than 1 in 10,000, the long period of culture in vitro and the large cell size do not meet the optimal time window for transplantation in patients with acute heart attack, and transcoronary transplantation may bring complications such as microembolism. Since then, a variety of stem cells such as adipose stem cells, skeletal muscle stem cells, umbilical cord stem cells, amniotic stem cells, and amniotic fluid stem cells have been studied in the laboratory. Umbilical cord Huatong gum was discovered by foreign scholars to be derived from the connective tissue around the arteries and veins of the umbilical cord, and after isolation and culture of the cells, it was found to express both embryonic stem cell surface markers and adult mesenchymal stem cell surface markers. It is considered to be a more primitive and differentiated stem cell than any adult stem cell. It is a true multipotential stem cell. It can be induced to differentiate into three germ layers in vitro, and has been confirmed to be non-immunogenic and non-tumorigenic in a series of studies such as tumorigenicity and immunity tests in animal studies. This has made allogeneic stem cell transplantation possible. After in vitro culture, umbilical cord Huatong gum-derived MSCs are smaller in size, faster in proliferation and more stable in karyotype than human bone marrow MSCs. The above study brings new hope for regenerative treatment of cardiac muscle tissue. This is the first international clinical study of this cell in the treatment of acute myocardial infarction. Patients aged 38-83 years were enrolled, and all were patients with acute ST-segment elevation myocardial infarction. All patients underwent emergency or elective interventional procedures to open the infarct-related vessels to TIMI class 3 flow and underwent transcoronary stem cell transplantation within 14 days after the infarction. All patients were given close monitoring during and after transplantation. No serious adverse effects were observed in any of them. The patients were all discharged 3 days after transplantation. There was no case of rehematologic reconstruction, reinfarction or readmission due to heart failure, and all patients achieved class I cardiac function. Biochemical indexes, immune indexes, and tumor markers were tested normal. Preliminary studies have confirmed that intracoronary transplantation of stem cells is safe. This also signifies that the research of stem cells has entered the clinical stage, and in the near future, stem cells will become a new technology popularized in the clinic for the benefit of human beings!