ABSTRACT
PURPOSE: This study examined the influence of the maximal aerobic capacity on the two-year cardiac-related re-hospitalization in patients with heart failure with a reduced ejection fraction (HFrEF) in Korean society.METHODS: The maximal aerobic capacity of the study population (n=95, male 63%) was evaluated using a cardiopulmonary exercise (CPX) testing system. Each patient was followed up for two years to divide the HFrEF patients into two groups according to cardiac-related re-hospitalization: re-hospitalization (RH) group (n=29, 30%) and no re-hospitalization (NRH) group (n=66, 70%).RESULTS: The relative peak VO₂ (mL/kg/min, p<0.001), exercise duration (p<0.001), respiratory exchange ratio (VCO₂/VO₂, p=0.001), systolic blood pressure (SBP) reserve (p=0.004), heart rate (HR) reserve (p=0.007), SBP max (p=0.02), and HR max (p=0.039) were significantly lower in the RH group than the NRH group during the CPX test. On the other hand, the ventilatory efficiency (VE/VCO₂ slope, p=0.02) and age (p=0.022) were significantly higher in the RH group than in the NRH group. In binary logistic regression analysis, the relative peak VO₂ (p=0.001, Wald Chi-square 10.137) was the strongest predictive factor on cardiac-related re-hospitalization, which was followed by VCO₂/VO₂ (p=0.019, Wald Chi-square 5.54). On the other hand, age (p=0.063, Wald Chi-square 3.445) did not have a significant influence on cardiac related re-hospitalization.CONCLUSION: The maximal aerobic capacity, especially the relative peak VO₂, is the strongest factor on cardiac-related re-hospitalization within two years in patients with HFrEF in Korean society.