Abstract
BACKGROUND: There have been few large-scale studies on the outcomes of cardiomyopathy-associated heart failure (HF) in infants aged <1 year. This study aimed to assess longitudinal echocardiographic outcomes of infants with HF secondary to cardiomyopathy who survived for >1 year. METHODS AND RESULTS: A prospective observational study following 327 infant patients up to 5 years in 2 large pediatric heart centers in Northern China between January 2010 and December 2018. A total of 236 (72.2%) patients had reduced left ventricular ejection fraction (LVEF) (HF with reduced ejection fraction group; LVEF <40%), 91 (27.8%) patients had midrange LVEF (HF with midrange ejection fraction group; LVEF ≥40% but <55%). LVEF improved significantly within the first year and remained stable in years 2 through 5 for both groups. The HF with midrange ejection fraction group had a higher rate of LVEF normalization (hazard ratio, 1.65; P<0.001). Baseline LVEF ≥40%, baseline left ventricular end-diastolic diameter Z score <7.8, the absence of left bundle-branch block, and the absence of β-blocker use were 4 independent favorable predictors for future LVEF normalization. A total of 62.4% of enrolled patients were diagnosed with left ventricular noncompaction. No significant difference in LVEF normalization was found among the different types of cardiomyopathy studied. CONCLUSIONS: A significant number of infants with cardiomyopathy who survived >1 year were found to improve with medical therapies during the first year of diagnosis. Poorer outcomes were associated with decreased LVEF and increased heart size at diagnosis baseline, the presence of left bundle-branch block and use of β blockers. The Northern Chinese pediatric population may have a high proportion of left ventricular noncompaction.