10-Year Exercise Training in Chronic Heart Failure: A Randomized Controlled Trial
Does long-term exercise training in heart failure (HF) lead to improved outcomes?
Stable patients (n = 135) with systolic HF (left ventricular ejection fraction [LVEF] <40%) were randomized to exercise training (ET) versus usual care (UC). The ET group (n = 63) underwent supervised bicycle ergonometry to 60% peak oxygen consumption (pVO2) 3 times weekly for 2 months, then twice weekly to 70% pVO2 until the end of the study. UC patients did not receive a formal exercise program and were encouraged not to participate in supervised exercise training. Patients were followed for 10 years with a primary endpoint of change in pVO2 and change in quality of life, as assessed by Kansas City Cardiomyopathy questionnaire (KCCQ). Secondary endpoints included mortality, cardiovascular readmission, and Ve/VCO2 slope.
There were 123 (91%) patients who completed the study, 63 of whom were in the ET group. The mean patient age was 59 ± 14 years, LVEF 37 ± 8%, and 59% and 41% were New York Heart Association (NYHA) class II and III, respectively. The ET and UC groups were similar. In the ET group, adherence to exercise was 88% and ET patients exercised significantly more than UC patients (2 ± 3 times weekly vs. 39 ± 13 sessions per year). While pVO2 was similar between the groups at baseline (~16.3 ml/kg/min), pVO2 was 3.6 ml/kg/min (between group Δ21%, p < 0.01) higher in the ET group after 10 years compared with the UC group. Likewise, Ve/VCO2 slope was lower in the ET group (35 ± 9 vs. 42 ± 11, p < 0.01). For secondary endpoints, ET patients had higher EFs after 10 years (41% vs. 34%, p < 0.01), higher KCCQ scores (p < 0.05), lower mortality (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.30-0.82), and fewer hospital readmissions (HR, 0.64; 95% CI, 0.34-0.81).
The authors concluded that patients with HF undergoing twice weekly exercise training for 10 years had better outcome than unsupervised HF patients.
In contrast to the HF-ACTION trial, this study of exercise training in systolic HF showed improvements in hospital readmission and survival. This study differed from HF-ACTION in size (HF-ACTION enrolled 2,331 patients), duration of follow-up (HF-ACTION ended at 1 year), and exercise training structure (HF-ACTION was unsupervised while the above study was supervised). The increased supervision in this study appeared to have led to improved adherence to exercise training. This study was underpowered to demonstrate an improvement in hard endpoints of mortality (n = 14 total) and readmission (n = 33). However, this study and HF-ACTION demonstrated improvements in pVO2, which translates to improvements in metabolic equivalents achieved. In patients with HF, this suggests a marked gain in morbidity with exercise training. Now, we just need to get insurance to cover supervised exercise training in HF….
Keywords: Kansas, Exercise, Heart Failure, Surveys and Questionnaires
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