Impact of β-Blockers on Heart Rate and Oxygen Uptake During Exercise and Recovery in Older Patients With Heart Failure With Preserved Ejection Fraction

摘要

The nonsignificant differences in heart rate or oxygen uptake values in elderly patients with heart failure with preserved ejection fraction (HFpEF) with β-blockers or without β-blockers treatment suggest that these measures may have equal utility in functional assessment, including the prescription and design of exercise, in elderly HFpEF patients. Purpose: The study aimed to investigate the differences in oxygen uptake ( o _(2)) 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 (HR_(resv)) and peak o _(2)( o _(2peak)) 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 o _(2)(HR_(rest), o _(2rest)) at submaximal exercise (HR_(submax), o _(2submax)), at peak exercise (HR_(peak), o _(2peak)), at 1 min of passive recovery (HR_(rec1)), HR_(resv)(HR_(peak)? HR_(rest)), and HR recovery (HR_(recov)= HR_(peak)? HR_(rec1)) were evaluated. Results: Analysis showed that HR_(rest)(66.0 ± 12.2 vs 69.7 ± 10.6 bpm), HR_(submax)(91.7 ± 16.2 vs 98.6 ± 15.2 bpm), and HR_(rec1)(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 HR_(peak), HR_(resv), HR_(recov), o _(2rest), o _(2submax), and o _(2peak). A significant relationship was found between HR_(resv)and o _(2peak)values in both groups (BB, r = 0.52; NBB, r = 0.49, P < .001). Conclusions: The nonsignificant differences in HR_(peak), HR_(resv), HR_(recov), or o _(2)values between BB and NBB HFpEF patients, along with significant correlation between HR_(resv)and o _(2peak), 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.