Abstract: Objective To explore the correlation between heart rate changes at admission and discharge and prognosis in patients with acute heart failure. Methods One hundred and sixty-nine patients diagnosed with acute heart failure at Qilu Hospital of Shandong University were included from January 2018 to November 2021, then a one-year follow-up was conducted. Using the median value of 11 beats/min as the cutoff for the difference in heart rate at admission and discharge, patients were divided into the heart rate difference <11 beats/min group(n=84)and the heart rate difference ≥11 beats/min group(n=85). The baseline demographic characteristics, physical examination, history of underlying diseases, and laboratory test results between the two groups were compared. Log-rank test was used to compare the difference in one-year survival rates between the two groups, and Kaplan-Meier survival curves were plotted. For the primary outcome, multivariate Cox regression analysis was conducted to explore the relationship between changes in heart rate at admission and discharge and survival status during the vulnerable period as well as at one-year follow-up. For the secondary outcomes, multivariate Cox regression analysis was conducted to investigate the relationship between changes in heart rate at admission and discharge and the recurrence during the vulnerable period and one year follow-up. Binary Logistic regression analyzed the relationship between changes in heart rate at admission and discharge and the 6-minute walk distance. Additionally, multiple linear regression explored the relationship between patients heart rate changes at admission and discharge and quality of life among patients. Results The results of Log-rank analysis indicated that the patients in the heart rate difference <11 beats/min group had higher risk of death compared to the patients in the heart rate difference ≥11 beats/min group, with a statistically significant difference in one-year all-cause mortality(Log-rank P=0.002). Multivariate Cox regression indicated that the patients in the heart rate difference <11 beats/min group had higher risk of death(vulnerable period: HR=2.939, 95%CI: 1.038-8.321; one-year follow-up: HR=3.837, 95%CI: 1.383-10.644), with statistically significant differences(P<0.05). Older age(HR=1.046, 95%CI: 1.008-1.085, P=0.017), history of atrial fibrillation(HR=2.530, 95%CI: 1.019-6.278, P=0.045), heart rate difference <11 beats/min(HR=3.837, 95%CI:1.383-10.644, P=0.010), and NT-proBNP reduction <30%(HR=4.269, 95%CI: 1.809-10.074, P=0.001)were independent risk factors for all-cause mortality in acute heart failure patients. Cox regression analysis showed that the patients in the heart rate difference <11 beats/min group had higher risks of disease(one-year follow-up: HR=1.794, 95%CI: 1.150-2.799)compared to the patients in the heart rate difference ≥11 beats/min group, with a statistically significant difference in one-year rehospitalization rate(P<0.05). The results of binary Logistic regression indicated that patients in the heart rate difference <11 beats/min group had significantly higher risk(OR=4.593, 95%CI: 2.184-9.661)of a 6-minute walking distance less than 450 meters compared to the patients in the heart rate ≥ 11 beats/min group(P<0.05). Conclusion Changes of heart rate between admission and discharge in patients with acute heart failure are associated with mortality within one year. A smaller heart rate difference is associated with a higher risk of death within one year after discharge. Patients with a greater heart rate differential at admission and discharge have a significantly greater benefit than patients with a smaller heart rate differential in terms of 1-year rehospitalization and 6-minute walk distance.

Key words: Acute heart failure, Heart rate, Rehospitalization, Mortality, Risk factors