Abstract: Objectives To investigate the improvement of cardiac function by continuous hemodiafiltration in patients with refractory heart failure. Methods Forty patients with refractory heart failure treated in Shihezi People’s Hospital from March 2013 to February 2015 were enrolled in this study. They were assigned into continuous venous- venous hemodiafiltration (CVVHDF) combined with conventional treatment group (experiment group, n=20) or conventional treatment group (control group, n=20) based on patient's preference. Urinary output before and after treatment was measured. Body weight (BW), plasma C-reactive protein
(CRP), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor alpha (TNF-α), and left ventricular ejection fraction (LVEF) were determined before treatment and after the treatment for 48 hours. Changes of these indicators (ΔCRP, ΔIL-6, ΔIL-8, ΔTNF-α, ΔBW, ΔLVEF) were then calculated. Multivariate linear regression model for predicting ΔLVEF was established. Results After the treatment for 48 hours, total fluid output (urine and ultrafiltration volume) was higher in experiment group than in control group (P＜0.001), and the levels of CRP, IL-6, IL-8 and TNF-α decreased significantly (P＜0.05) in experiment group but not in control group (P＞0.05) as compared with those before the treatment. BW became lower and LVEF became higher in both groups (P＜0.05) as compared with those before the treatment. Levels of CRP, IL-6, IL-8 and TNF-α were lower in experiment group than in control group (P＜0.05). BW was lower and LVEF was higher in experiment group than in control group but without statistical significance (P＞0.05). However, the increase of ΔLVEF and decrease of ΔBW were more in experiment group than in control group (P＜0.001). In experiment group, significantly positive correlations were found among ΔBW, ΔCRP, ΔIL-6, ΔIL-8, ΔTNF-αand ΔLVEF (P＜0.05); multiple linear regression analyses showed that ΔBW and ΔTNF-α were the independent factors for ΔLVEF, and ΔBW was the main independent factor for ΔLVEF. In control group, ΔLVEF was positively correlated with ΔBW (P＜0.001) but had no correlation with ΔCRP, ΔIL-6, ΔIL-8 and ΔTNF-α (P＜ 0.05); multiple linear regression analyses showed that only ΔBW was the independent factor for ΔLVEF. Conclusions Continuous hemodiafiltration increases LVEF in patients with refractory heart failure mainly through the clearance of inflammatory factors and especially through the removal of retained fluid.

Key words: Continuous venovenous hemodiafiltration, Refractory heart failure, Left ventricular ejection fraction, Multiple linear regression model