Effect of metoprolol tartrate sustained release tablets on cardiac function and autonomic tone of elderly patients with chronic heart failure

Objective To explore the effect of metoprolol tartrate sustained release tablets on cardiac function and autonomic tone o elderly patients with chronic heart failure (CHF). Methods One hundred and ten patients over 75 years with CHF who were admitted to Chinese PLA General Hospital from June 2014 to June 2015 were randomly divided into two groups: treatment group (n=55) and control group (n=55). Patients in control group received conventional treatment of heart failure and patients in treatment group received additional metoprolol succinate sustained-release tablet on the basis of conventional treatment and the dose of it was added gradually to achieve the resting heart rate of 55 to 60 beats/min. After 3 months, the changes of left ventricular eject fraction (LVEF), brain natriuretic peptide (BNP), 6-minute walk test distance and heart rate variability (HRV) before and after treatment were compared in the two groups. Results LVEF and 6-minute walk test distance in treatment group were higher than those in control group (54.1±8.8)% vs (49.2±7.6)%, (394.4±69.7) m vs (364.3±67.9) m, P ＜ 0.01, while, the BNP was lower than control group (954.6±115.6) pg/ml vs (1 445.2±129.4) pg/ml, P ＜ 0.01, and the HRV indexes, including standard deviation of NN intervals (SDNN), standard deviation of the average NN intervals (SDANN), root mean square of successive differences between adjacent normal RR interval (RMSSD) and percentage of differences exceeding 50 ms between adjacent NN intervals (PNN50) improved obviously in comparison to control group (135.5±30.4) ms vs (78.6±31.6) ms, (85.6±28.1) ms vs (70.6±27.6)ms, (41.6±15.6) vs (34.6±17.4), (7.1±2.9)% vs (5.7±3.1)%, P ＜ 0.01. Conclusion Additional metoprolol succinate sustained-release tablet on the basis of conventional treatment of heart failure and gradually adding the dose to achieve the target heart rate can obviously improve cardiac function in heart failure patients over 75 years.