What is atrial fibrillation? Atrial fibrillation, referred to as atrial fibrillation, is the most common persistent arrhythmia, and the incidence of atrial fibrillation in people aged 30-85 years old in China is 0.77%. In normal people, the heartbeat is between 60-100 beats per minute and the rhythm is regular, while atrial fibrillation is an abnormal and rapid discharge of abnormal atrial foci, causing an abnormal heartbeat frequency, which can reach 350-600 beats per minute, and the heartbeat frequency is often fast and irregular, and the atria lose their normal contraction function, which is similar to creeping. Some patients with atrial fibrillation experience panic, dizziness, shortness of breath, and chest discomfort, while others do not feel it. What is the relationship between atrial fibrillation and stroke? According to information from China, the prevalence of atrial fibrillation in China is about 0.61%, and it is estimated that there are about 10 million patients with atrial fibrillation in China. Atrial fibrillation is not only common in normal times, but also a more serious hazard, affecting the quality of life of patients in severe cases, while greatly increasing the mortality rate and the incidence of strokes. Thrombosis and embolism are the most serious hazards of atrial fibrillation. In atrial fibrillation, as the atria lose their contractile function, blood is easily stagnated in the atria and thrombus is formed. The incidence of thromboembolic events in patients with atrial fibrillation is 5-7 times higher than in the normal sinus rhythm population. The annual stroke rate in patients with non-valvular atrial fibrillation without anticoagulation is 5.3%, and at least 35% of patients have had at least one stroke in their lifetime. Atrial fibrillation is more harmful to the human body and must be taken seriously. Our national cause of death survey shows that cardiovascular disease has now become the first cause of death, of which stroke accounts for about half. Atrial fibrillation, as the most common arrhythmia phenomenon, increases the risk of stroke for patients by five times. About 20% of stroke incidence is attributed to atrial fibrillation. It is important to note that only 6% of strokes associated with atrial fibrillation are routinely diagnosed in clinical practice, and a large proportion of patients are undiagnosed, becoming a potential stroke “reservoir”. The risk of death in these people can be up to five times higher than in the general stroke population. Stroke is the most serious complication of atrial fibrillation, with a higher rate of disability and death than other causes of stroke. What about warfarin, a commonly used anticoagulant in clinical practice? The most clinically used oral anticoagulant is warfarin, which has the advantage of high bioavailability and monitorable duration of action and maintenance. Warfarin has been in clinical use for nearly 60 years as an important oral anticoagulant and is currently the only widely used oral anticoagulant in clinical practice. The results of a study on primary prevention of thromboembolism in patients with non-valvular atrial fibrillation showed that warfarin reduced the incidence of ischemic stroke by 68%, with significant efficacy. Secondary prevention studies of atrial fibrillation-associated stroke have shown that warfarin can reduce the annual incidence of stroke by 8%. However, the use of warfarin is generally low in China, with only 9% of inpatients with atrial fibrillation using warfarin, which is related to the limitations and deficiencies of warfarin itself. The main problems in the application of warfarin include: interaction with food and drugs, metabolic genetic variability, narrow therapeutic window, the need for frequent monitoring and dose adjustment; in addition, warfarin is slow to take effect and needs to be applied simultaneously with other non-oral drugs when starting to take the drug; this affects the long-term compliance of patients with the drug, and the clinical dosage of warfarin is often insufficient. At the same time, anticoagulation therapy inevitably brings the risk of bleeding, and the incidence of serious bleeding complications from warfarin anticoagulation is 1.3% to 7.2% per year, the most dangerous of which is cerebral hemorrhage. Therefore, the INR must be monitored regularly with warfarin to keep it at 2.0-3.0, with an increased risk of stroke if the INR is <2.0 and an increased risk of bleeding if it is >3.0. However, with the development of science, our clinical practice has demonstrated that following pharmacogenetic models through genotyping can guide clinical warfarin application very accurately and effectively, which can greatly reduce the INR check and reduce the risk due to dosing problems (overdose or underdose). What is the place of new anticoagulants in the pharmacological treatment of atrial fibrillation? In clinical practice, anticoagulation has always been the core of atrial fibrillation treatment, but considering the many limitations of the traditional anticoagulant warfarin, experts in the field have been working for the past 10 years to develop new anticoagulant drugs that are safer, more effective, and more economical and convenient. Four new oral anticoagulants, including dabigatranate and rivaroxaban, apixaban and edoxaban, have been introduced and will bring new hope for stroke prevention in atrial fibrillation. Compared with warfarin, the new anticoagulants are more effective in reducing the risk of stroke, with the main advantages of better safety and convenience, fixed doses, rapid onset of action, fewer bleeding complications, less need for frequent monitoring of coagulation indicators, and fewer interactions with food and drugs. The disadvantages are that they mainly work in non-valvular AF, but not in valvular AF. In addition, the clinical data of new anticoagulant drugs are all from Europe and the United States, and there is a lack of data on the efficacy and safety of treatment in Chinese people, and attention should still be paid to the observation of bleeding complications and other adverse reactions during the drug administration. Although the new anticoagulants cannot replace warfarin as the main player in the prevention of thromboembolism in atrial fibrillation at this stage, a large sample size of phase III clinical trials has demonstrated that the new oral anticoagulants can significantly reduce the incidence of atrial fibrillation-related stroke and the risk of bleeding compared with warfarin, and are expected to become a new choice of anticoagulation therapy for patients with atrial fibrillation.