Early onset coronary artery disease refers to the younger age of onset of coronary artery disease, <55 years for men and <65 years for women, and there is a trend toward a younger age of onset of acute myocardial infarction. 2004 Saleheen et al. found that the age of onset of first acute myocardial infarction is gradually advancing, with AMI patients under 45 years of age accounting for 16% of all AMI patients, with the youngest being 18 years old when acute myocardial infarction occurred. The youngest was an acute myocardial infarction in an 18-year-old, and sudden death from coronary heart disease occurred in a 33-year-old. In these early-onset coronary heart disease patients, about 70% to 90% of young AMI patients have a history of smoking. Smoking is a very important and controllable risk factor for cardiovascular disease, therefore, strengthening the education of smokers to quit or control smoking has a positive effect on the early prevention and treatment of coronary heart disease. The INTERItEAItT study showed that the risk of myocardial infarction in former smokers decreased year by year after quitting, and the risk was still high in light smokers 1 year after quitting, but decreased significantly after 2 years, and the risk disappeared about 3-5 years after quitting. The risk disappears after about 3-5 years of quitting. Moderate to heavy smokers still have a risk of disease 20 years or more after quitting, but the risk of death is reduced compared to continued smokers. Given that smoking is an independently important risk factor for patients with early-onset coronary heart disease, strengthening education on smoking cessation and control in patients with early-onset coronary heart disease is important for primary and secondary prevention of the disease.