Background:

Beta blockers (BB) reduce chronotropic response and exercise capacity in heart failure with preserved ejection fraction (HFpEF). We aimed to analyze the influence of BB on exercise performance and O₂ pulse increase as a surrogate for stroke volume in HFpEF.

Methods:

We retrospectively analyzed the influence of BB intake (yes: n=48/no: n=51) on peak oxygen uptake (VO_2peak), oxygen uptake efficiency slope (OUES), O₂ equivalent at the first ventilatory threshold (EqO₂ at VT1), and increase of O₂ pulse during exercise in HFpEF patients undergoing cardiopulmonary exercise testing (CPET). Associations of outcome variables and risk category of the algorithm of the Heart Failure Association of the European Society of Cardiology (HFA-PEFF score; points: 0-1 low: n=23; 2-4 intermediate: n= 58; 5-6 high risk: n= 18) were calculated.

Results:

Patients on BB showed lower VO_2peak (17.7±4.7ml/kg/min vs. 22.0±7.4ml/kg/min, p=0.003) and OUES (1.6±0.5 vs. 2.0±0.7, p=0.002), with a dominant effect in the high- (p=0.020; 0.002), but not in the low risk-group (p=0.434; p=0.499). In the intermediate group BB showed a trend towards lower VO_2peak (p=0.078) and lower values for OUES (p=0.020). Patients on BB also demonstrated a lower increase of O₂ pulse during exercise (p=0.002), without differences between HFA-PEFF groups (low: p=0.322, intermediate: p=0.269, high: p=0.313). EqO₂ at VT1 did not differ in patients with and without BB intake (p=0.339).

Conclusions:

BB reduce exercise capacity and may be avoided in selected HFpEF patients. Direct quantification of O₂ pulse increase may have the potential to elucidate BB- associated exercise limitations in patients with HFpEF and may help to improve the discrimination of HFpEF.