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 (⩒O(2)). 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 (⩒O(2), 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)