Purpose: The study aimed to investigate the differences in oxygen uptake ((Equation is included in full-text article.)O2) and heart rate (HR) (at rest, submaximal exercise, peak exercise, and recovery) in patients with heart failure with preserved ejection fraction (HFpEF) with β-blockers (BB) or without BB treatment (NBB) and to analyze the relationship between HR reserve (HRresv) and peak (Equation is included in full-text article.)O2 ((Equation is included in full-text article.)O2peak) in BB and NBB.
Methods: A total of 174 HFpEF patients (>65 yr; BB, n = 59; NBB, n = 115) were assessed with a cardiopulmonary exercise test to peak exertion using an incremental protocol. After 5 min of supine rest, HR and (Equation is included in full-text article.)O2 (HRrest, (Equation is included in full-text article.)O2rest) at submaximal exercise (HRsubmax, (Equation is included in full-text article.)O2submax), at peak exercise (HRpeak, (Equation is included in full-text article.)O2peak), at 1 min of passive recovery (HRrec1), HRresv (HRpeak- HRrest), and HR recovery (HRrecov = HRpeak- HRrec1) were evaluated.
Results: Analysis showed that HRrest (66.0 ± 12.2 vs 69.7 ± 10.6 bpm), HRsubmax (91.7 ± 16.2 vs 98.6 ± 15.2 bpm), and HRrec1 (102.9 ± 18.9 vs 109.4 ± 16.9 bpm) were significantly lower (P ≤ .05) in BB than in NBB, respectively. However, there were no significant differences (P > .05) between the BB and the NBB for HRpeak, HRresv, HRrecov, (Equation is included in full-text article.)O2rest, (Equation is included in full-text article.)O2submax, and (Equation is included in full-text article.)O2peak. A significant relationship was found between HRresv and (Equation is included in full-text article.)O2peak values in both groups (BB, r = 0.52; NBB, r = 0.49, P < .001).
Conclusions: The nonsignificant differences in HRpeak, HRresv, HRrecov, or (Equation is included in full-text article.)O2 values between BB and NBB HFpEF patients, along with significant correlation between HRresv and (Equation is included in full-text article.)O2peak, suggest that these measures may have equal utility in prognostic and functional assessment as well as clinical applications, including the prescription of exercise, in elderly HFpEF patients.