Method: We investigated pts with HFrEF (EF =45%) who underwent cardiopulmonary exercise test (CPET). All CPET was performed VO2RD was defined as time until post-exercise VO2 falls permanently below peak VO2. We defined impaired RLVF as decreased EF or improvement in EF <10 %, RLVF as improvement in EF =10 % during follow-up period (median 16.5 months).
Result: Total 55 pts with HFrEF (mean 55.0 years old, 78.2% male, 20.0% ischemic) were included. We found 30 pts (54.5%) of impaired RLVF. In terms of baseline characteristics, there were no differences in age, sex, NT-proBNP level, NYHA class and baseline EF between 2 groups. There was significantly different in VO2RD between 2 groups (14.5±11.4 for RLVF group vs. 24.4±19.8 sec for impaired RLVF group, p=0.031). Multivariate regression analysis revealed VO2RD was an independent predictor for impaired RLVF (OR=1.055, p=0.021) when controlled for age, ischemic heart disease and EF. And the cut-off value of VO2RD > 30 sec was associated with impaired RLVF with sensitivity 30.0 % and specificity 96.0 % (ROC area under curve of 0.653, p=0.038).
Conclusion: Post-exercise VO2RD, reflecting impaired cardiac output augmentation may be a useful parameter to predict impaired RLVF in patients with HFrEF.