Conflicting data on the value of exercise in heart failure

Results from the HF-ACTION study were reported during the American Heart Association meeting in New Orleans. And now in JAMA here.

In both cases, the results were negative  before the data were adjusted.

First the details.

• 2,331 adults with NYHA Class II-IV heart failure participated.
• NYHA Class II-IV includes patients with slight discomfort from activity to those requiring complete bed rest.
• Patients had a left ventricular ejection fraction (LEVF) of 35% or less and were capable of exercising.
• LEVF is a measure of the extent of heart dysfunction and a patient’s capacity for exercise, with normal being at least 50%.
• Usual care patients were told once that moderate intensity exercise for 30 minutes could be beneficial.
• The exercise group was given supervised training for 30 minutes, 3 times a week for 18 sessions.
• They moved on to home exercise with either a treadmill or stationary bicycle, with a goal of 120 minutes per week.
• Participants recorded their exercise times and heart rates over about 2.5 years.

And, the results based on the initial study objective endpoints.

• 68% of the usual care group died or were hospitalized vs 65% in the exercise group — not a significant difference.
• Deaths were reported in 17% of patients in the usual care group vs 16% in the exercise group — not a significant difference.

However, after adjusting for characteristics that are strongly predictive of complications and death, the authors reported significant benefits.

• Exercise led to an 11% reduction in risk of hospitalization or death for those in the exercise group.
• In addition, the exercise group had a significant, 15% lower risk of death from cardiovascular disease and hospitalization due to complications of heart failure.
• Predictive characteristics included atrial fibrillation, depression, and left ventricular ejection fraction (LVEF) status.

The bottom line?
Medpage Today reports that the adjustment of the data to achieve significant findings was controversial among attendees of the meeting.

But a bigger problem for these patients might be the difficulty in maintaining an exercise program. According to Dr. Christopher O’Connor from Duke Medical College in Durham, North Carolina, after 2.5 years, patients were only exercising for about 50 minutes a week, compared to the goal of 120 minutes.

12/1/08 21:05 JR