Abstract
OBJECTIVES: To test the hypothesis that exercise training (ET) improves exercise capacity and other clinical outcomes in older persons with heart failure with reduced ejection fraction (HfrEF). DESIGN: Randomized, controlled, single-blind trial. SETTING: Outpatient cardiac rehabilitation program. PARTICIPANTS: Fifty-nine patients aged 60 and older with HFrEF recruited from hospital records and referring physicians were randomly assigned to a 16-week supervised ET program (n=30) or an attention-control, nonexercise, usual care control group (n=29). INTERVENTION: Sixteen-week supervised ET program of endurance exercise (walking and stationary cycling) three times per week for 30 to 40 minutes at moderate intensity regulated according to heart rate and perceived exertion. MEASUREMENTS: Individuals blinded to group assignment assessed four domains pivotal to HFrEF pathophysiology: exercise performance, left ventricular (LV) function, neuroendocrine activation, and health-related quality of life (QOL). RESULTS: At follow-up, the ET group had significantly greater exercise time and workload than the control group, but there were no significant differences between the groups for the primary outcomes: peak exercise oxygen consumption (VO(2) peak), ventilatory anaerobic threshold (VAT), 6-minute walk distance, QOL, LV volumes, EF, or diastolic filling. Other than serum aldosterone, there were no significant differences after ET in other neuroendocrine measurements. Despite a lack of a group "training" effect, a subset (26%) of individuals increased VO(2) peak by 10% or more and improved other clinical variables as well. CONCLUSION: In older patients with HFrEF, ET failed to produce consistent benefits in any of the four pivotal domains of HF that were examined, although the heterogeneous response of older patients with HFrEF to ET requires further investigation to better determine which patients with HFrEF will respond favorably to ET.