Analysis of clinical features of heart failure in children with cardiomyopathy and improved ejection fraction.

Background: The prognosis of children with heart failure varies considerably. After treatment, left ventricular ejection fraction (LVEF) can be improved in some children. The aim of this study was to analyze the clinical features of children with heart failure accompanied by cardiomyopathy and recovered ejection fraction [heart failure with recovered ejection fraction (HFrecEF)] and to identify the predictors of improved LVEF.

Methods: Children diagnosed with heart failure in Beijing Anzhen Hospital Affiliated to Capital Medical University from 2018 to 2021 were retrospectively enrolled. According to the baseline and change of LVEF, the patients were divided into two groups: a reduced ejection fraction (HFrEF) group and an HFrecEF group. The -test was used to evaluate the difference between the two groups. The predictive factors of ejection fraction improvement were analyzed with a logistic regression model.

Results: A total of 72 children were included in this study, including 31 (43.1%) in the HFrEF group and 41 (56.9%) in the HFrecEF group. Compared with children in the HFrEF group, children in the HFrecEF group were younger and had faster resting heart rates, lower creatinine, lower suppression of tumorigenicity 2 (ST2) expression, a lower platelet-to-lymphocyte (PLT:LYM) ratio, and smaller left atrial diameter. After a mean follow-up of 35.87 months, 26 cases returned to normal ejection fraction. In the HFrEF group, sudden cardiac death occurred in two cases, and four cases received heart transplantation. Logistic analysis showed that virus infection [odds ratio (OR) =1.279; 95% confidence interval (CI): 0.374-4.379; P=0.007], low ST2 expression (cutoff value =1.89 ng/mL: OR =1.042; 95% CI: 1.007-1.082; P=0.032), and treatment with intravenous immunoglobulin (IVIG) (OR =5.077; 95% CI: 1.458-17.684; P=0.011) were predictors of improvement in LVEF in patients with heart failure after treatment.

Conclusions: In some patients with HFrecEF, LVEF eventually returned to normal. The combination of viral infection, low ST2 expression, and the application of IVIG therapy were found to be independent predictors of LVEF improvement in patients with heart failure after treatment.