Relationship between changes in cardiac function (HFrecEF, HFworEF) and physical function characteristics in heart failure patients

Introduction Recent research has categorised changes in LVEF in response to treatment into three distinct groups: improvement, worsening, and maintenance 1). Nevertheless, the relationship between the degree of EF change (ΔLVEF) and physical function remains unclear. Therefore, this study assessed the association between physical characteristics and Δleft ventricular ejection fraction(ΔLVEF) and physical function in two distinct categories: HF with recovered EF (HFrecEF) characterised by improved EF and HF with worsened EF (HFworEF) marked by worsened EF. Methods This retrospective cohort analysis included heart failure patients aged 65 years or older who underwent cardiopulmonary exercise testing between April 2016 and December 2022, called the pre-old age group starting at age 65, as the pre-older age group. LVEF (%) was measured using the modified Simpson method. Patients were assigned to two categories based (HFrecEF and HFworEF) on improvement (Δ) in LVEF. The relationship between ΔLVEF and physical function was analysed using the Spearman rank correlation. Multiple regression analysis was performed with ΔLVEF as the dependent variable for variables significantly related to ΔLVEF (P<0.05). The study subjects were classified into three groups based on LVEF, according to the JCS/JHFS 2021 guidelines 1). Among two, improvements and deteriorations were extracted. Results A total of 229 heart failure patients aged 65 years and older were included, with 40 patients who did not undergo follow-up echocardiography were excluded; HFuncEF excluded 144 patients, 45 patients, age 76.0 (67.5–79.5) years [HFrecEF 71.5(95% CI:66.0–78.5) vs HFworEF 78.0(72.5–81.5):P<0.01], were incorporated. Peak oxygen uptake (peak VO2) was significantly different between the two groups [HFrecEF 13.6(95% CI:11.9–15.4) vs HFworEF 10.1(7.8–11.8):P<0.01], and (peak ETCO2) was also significantly different, with lower values in HFworEF [HFrecEF 5. 36(5.02–5.96) vs HFworEF 4.7(4.5–5.2):P<0.05], (peak VE/CO2) was also significantly different and higher in HFworEF [HFrecEF 36.2(30.3–39.8) vs HFworEF 42.0(36.3–45.8):P<0.05] (minimum VE/CO2) was also significantly higher in HFworEF [HFrecEF 34.2(29.2–39.4) vs HFworEF 40.7(34.2–44.7):P<0.05]. Peak oxygen uptake/watt (peak VO2/w) was correlated with (ρ=0.547, P<0.01). In addition, peak oxygen uptake (peak VO2) (ρ=0.512, P<0.01) and peak carbon dioxide output (peak VCO2) (ρ=0.512, P<0.01) were also correlated. Peak VO2/w (β=0.492, P<0.01) was an independent predictor (R=0.492, F=13.72, P<0.01). Conclusion Patients with HF and recovered EF tended to be younger and more physically functional than those with worsened EF. In addition, peak VO2/w was an independent determinant of ΔLVEF.