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

Alternatives to Aerobic Exercise Prescription in Patients with Chronic Heart Failure

Background

Exercise is essential for patients with heart failure as it leads to a reduction in morbidity and mortality as well as improved functional capacity and oxygen uptake (⩒O₂). However, the need for an experienced physiologist and the cost of the exam may render the cardiopulmonary exercise test (CPET) unfeasible. Thus, the six-minute walk test (6MWT) and step test (ST) may be alternatives for exercise prescription.

Objective

The aim was to correlate heart rate (HR) during the 6MWT and ST with HR at the anaerobic threshold (HR_AT) and peak HR (HR_P) obtained on the CPET.

Methods

Eighty-three patients (58 ± 11 years) with heart failure (NYHA class II) were included and all subjects had optimized medication for at least 3 months. Evaluations involved CPET (⩒O₂, HR_AT, HR_P), 6MWT (HR_6MWT) and ST (HR_ST).

Results

The participants exhibited severe ventricular dysfunction (ejection fraction: 31 ± 7%) and low peak ⩒O2 (15.2 ± 3.1 mL.kg_-1.min_-1). HR_P (113 ± 19 bpm) was higher than HR_AT (92 ± 14 bpm; p < 0.05) and HR_6MWT (94 ± 13 bpm; p < 0.05). No significant difference was found between HR_P and HR_ST. Moreover, a strong correlation was found between HR_AT and HR_6MWT (r = 0.81; p < 0.0001), and between HR_P and HR_ST (r = 0.89; p < 0.0001).

Conclusion

These findings suggest that, in the absence of CPET, exercise prescription can be performed by use of 6MWT and ST, based on HR_6MWT and HR_ST