Aerobic exercise training appears safe for patients with heart failure and was associated with a modest reduction in the risk of death and hospitalisation, with some improvement in quality of life, according to two articles in the 8 April, 2009 issue of JAMA.
Many patients treated with drug and device therapies often still have breathing difficulties and fatigue, diminished exercise tolerance, reduced quality of life, recurrent hospitalisations and premature death, according to background information in the article. Guidelines recommend that exercise training be considered for medically stable outpatients with heart failure, but there have remained concerns regarding safety and uncertainty about clinical outcomes.
Dr Christopher M O’Connor, Duke University School of Medicine, Durham, USA, and colleagues working with HF-ACTION (Heart failure: A controlled trial investigating outcomes of exercise training) examined whether aerobic-type exercise training reduces all-cause death or all-cause hospitalisation in patients with medically stable chronic heart failure due to systolic dysfunction. Patients in the study (n=2,331; median [midpoint] age, 59 years) were randomised to usual care plus aerobic exercise training (that consisted of 36 sessions of supervised aerobic exercise training [walking, treadmill or stationary cycling] three times per week followed by prescribed home-based training at the same intensity five times per week) or usual care alone (that included optimal medical therapy and a recommendation for regular physical activity). Exercise adherence decreased from a median of 95 minutes per week during months four through six of follow-up to 74 minutes per week during months 10 through 12. Median follow-up was 30 months.
During follow-up, 759 patients in the exercise training group (65%) and 796 patients in the usual care group (68%) died or were hospitalized. In the primary analysis, exercise training resulted in a nonsignificant reduction in the primary end point of all-cause death or hospitalisation. There was no significant difference in the number of deaths in the exercise training group (16%) vs. in the usual care group (17%). Exercise training had a nonsignificant reduction in the combined end point of cardiovascular death or cardiovascular hospitalisation in the main analysis in the exercise training group (55%) vs. in the usual care group (58%). There was a nonsignificant reduction in cardiovascular death or heart failure hospitalisation in the exercise training group vs. in the usual care group.
After adjusting for highly prognostic predictors of the primary endpoint, exercise training was found to significantly reduce the incidence of all-cause death or all-cause hospitalisation by 11% and cardiovascular death or heart failure hospitalisation by 15%. Other adverse events were similar between the groups.
“The change from a nonsignificant to a significant result after adjustment for strongly predictive factors is unusual in large clinical trials, but can occur when the treatment differences are close to significance. The overall interpretation of the results, then, is that this structured exercise training intervention had at best a modest effect on clinical end points in a large cohort of patients,” the authors wrote. “Based on the safety of exercise training and the modest reductions in clinical events…, the HF-ACTION results support a prescribed exercise training program for patients with reduced left ventricular function and heart failure symptoms in addition to evidence-based therapy,” the researchers concluded.
