Age-Related Maximum Heart Rate Among Ischemic and Nonischemic Heart Failure Patients Receiving β-Blockade Therapy

Abstract

BackgroundEquations to predict maximum heart rate (HRmax) in heart failure (HF) patients receiving β-adrenergic blocking (BB) agents do not consider the cause of HF. We determined equations to predict HRmax in patients with ischemic and nonischemic HF receiving BB therapy. Methods and ResultsUsing 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 HRmax 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 VO2 16.9 ± 4.7 and 16.9 ± 5.2 mL kg−1 min−1 (P = NS), and the HRmax 130.8 ± 23.3 and 125.3 ± 25.3 beats/min (P = .051) in ischemic and nonischemic patients, respectively. We devised the equation HRmax = 168 − 0.76 × age (R2 = 0.095; P = .007) for ischemic HF patients, but there was no significant relationship between age and HRmax in nonischemic HF patients (R2 = 0.006; P = NS). ConclusionsOur study suggests that equations to estimate HRmax should consider the cause of HF.