Abstract
OBJECTIVES: A new classification of heart failure based on the effects of medication has recently come into use. According to this classification, heart failure is divided into heart failure with normal ejection fraction (HFnEF; defined as an EF ≥55% for men and ≥60% for women) and non-HFnEF. However, the characteristics of patients with HFnEF are still unclear. Accordingly, in this study, we sought to identify the background characteristics, including non-cardiac factors, of patients with HFnEF. METHODS: We retrospectively divided 304 eligible patients who were hospitalized for worsening heart failure at our institution between December 2020 and December 2022 into an HFnEF group (n=37) and a non-HFnEF group (n=267) and compared their demographic and clinical characteristics. RESULTS: There were more elderly patients in the non-HFnEF group, along with fewer patients with coronary artery disease and low serum hemoglobin and NT-proBNP levels and a higher proportion of patients with a low skeletal muscle index (<7.0 kg/m(2) for men and <5.7 kg/m(2) for women). Multivariate analysis with addition of patient sex identified a low skeletal muscle index (odds ratio 2.96, p<0.01) to be an independent determinant of HFnEF along with older age and low NT-proBNP. CONCLUSIONS: A low skeletal muscle index was significantly more common in patients with HFnEF than in those with non-HFnEF. Intensive nutrition and exercise therapy to increase skeletal muscle mass may improve the prognosis in patients with HFnEF who respond poorly to standard pharmacological treatment.