AbstractBackgroundIn patients with heart failure, left atrial remodeling often occurs to varying degrees. Left atrial enlargement has been proved to be an important predictor of cardiovascular‐related adverse events. However, the relationship between left atrial diameter (LAD) with heart failure (HF) with preserved ejection fraction (HFpEF), reduced ejection fraction (HFrEF) and mid‐range ejection fraction (HFmrEF) remains unclear.HypothesisWe want to explore the correlation between left atrial diameter and HFpEF, HFmrEF, and HFrEF.MethodsA total of 210 patients with heart failure who underwent hospitalization in Ningbo Medical Center Lihuili Hospital, Zhejiang, China, from January 1, 2020, to June 31, 2021, were reviewed. The basic demographic characteristics, blood test, and the related indexes of echocardiography of the subjects were collected and analyzed.ResultsThere is a significant difference between HFpEF and HFrEF group in LAD (p = .007), and LAD is negatively correlated with left ventricular ejection fraction (LVEF) (p = .002, r = −.209).ConclusionLAD is negatively correlated with LVEF, which may predict the prevalence of HFrEF.