Abstract: Abstract：Objective To investigate the application of ivabradine (Iva) in chronic heart failure with reduced ejection fraction (HFrEF) in vulnerable stage and the influencing factors for readmission in vulnerable stage. Methods A total of 402 patients with chronic HFrEF in vulnerable stage were divided into control group (n=142) and observation group (n=260) according to whether they took Iva. The control group was given anti-heart failure treatment according to the guidelines, and the observation group was given treatment with Iva on the basis of the control group. The curative effect, cardiac adverse events, cardiac function indexes and inflammatory factors were compared between the two groups. Multivariate Logistic regression was used to analyze the influencing factors of readmission of patients with chronic HFrEF in vulnerable stage. Results The curative effect was better in the observation group than that of the control group (P＜0.05). The proportion of rehospitalization was significantly lower in the observation group than that in the control group (P＜0.05). After treatment, the 24-hour mean heart rate was significantly decreased in the observation group compared with that of the control group. LVEF was significantly higher, LVEDd was significantly smaller, 6MWD was significantly longer, and the concentrations of NT proBNP, TNF-α, IL-6 and hs-CRP were significantly lower in the observation group compared with those of the control group (P＜0.05 or P＜0.01). Logistic regression analysis showed that not taking medicine on time and living alone were independent risk factors for readmission of patients with chronic HFrEF in vulnerable stage, and weekly follow-up visit was an independent protective factor. Conclusion Iva can improve the efficacy of chronic HFrEF in the vulnerable period, reduce the readmission rate and the concentration of inflammatory factors in the vulnerable period, and improve the cardiac function index. Patients with chronic HFrEF who do not take medicine on time and lived alone are more likely to be readmitted during the vulnerable stage, while those who weekly return visit can reduce the readmission rate. 

Key words: heart failure, ivabradine, heart failure with reduced ejection fraction, vulnerable stage, readmission, influencing factors