Background: Equations to predict maximum heart rate (HR(max)) in heart failure (HF) patients receiving β-adrenergic blocking (BB) agents do not consider the cause of HF. We determined equations to predict HR(max) in patients with ischemic and nonischemic HF receiving BB therapy.
Methods and results: Using treadmill cardiopulmonary exercise testing, we studied HF patients receiving BB therapy being considered for transplantation from 1999 to 2010. Exclusions were pacemaker and/or implantable defibrillator, left ventricle ejection fraction (LVEF) >50%, peak respiratory exchange ratio (RER) <1.00, and Chagas disease. We used linear regression equations to predict HR(max) based on age in ischemic and nonischemic patients. We analyzed 278 patients, aged 47 ± 10 years, with ischemic (n = 75) and nonischemic (n = 203) HF. LVEF was 30.8 ± 9.4% and 28.6 ± 8.2% (P = .04), peak VO(2) 16.9 ± 4.7 and 16.9 ± 5.2 mL kg(-1) min(-1) (P = NS), and the HR(max) 130.8 ± 23.3 and 125.3 ± 25.3 beats/min (P = .051) in ischemic and nonischemic patients, respectively. We devised the equation HR(max) = 168 - 0.76 × age (R(2) = 0.095; P = .007) for ischemic HF patients, but there was no significant relationship between age and HR(max) in nonischemic HF patients (R(2) = 0.006; P = NS).
Conclusions: Our study suggests that equations to estimate HR(max) should consider the cause of HF.
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