HF Action Trial Summary

Introduction

• Speakers: Chris Okconor (Professor of Medicine, Duke University) and Dr. David Whan (Associate Professor of Medicine, Jefferson Medical College)
• Location: Duke Clinical Research Institute
• Objective: Discuss results of the HF Action Trial, a major study on exercise training in heart failure.

Background

• Focus: Efficacy and safety of exercise training for chronic heart failure.
• Exercise training has shown benefits in functional capacity, quality of life, and biomarkers in previous studies.
• Previous studies were limited by size, single-center focus, lack of control groups, and safety data.

HF Action Study Design

• Hypothesis: Exercise training + usual care results in 20% lower rate of all-cause mortality or hospitalization over two years compared to usual care alone.
• Participants: Patients with chronic heart failure, NYHA class 2-4, and left ventricular ejection fraction ≤ 35%.
• Exclusion Criteria: Recent cardiovascular events, inability to exercise, or active training prior to randomization.
• Randomization: Stratified by center and heart failure etiology.
• Follow-up: Median of 2.5 years.

Intervention

• Usual Care: Optimal medical therapy and 30 minutes of recommended physical activity.
• Exercise Training: 36 supervised sessions, followed by home training with equipment provided.
• Intensity: 70% heart rate reserve, exercise 5 times per week for 40 minutes.

Study Organization

• Involved 82 participating centers in the US, Canada, and France.
• Coordinated by the Duke Clinical Research Institute.
• Supported by NIH and had independent data safety monitoring.

Results

• Primary Outcome: All-cause mortality or hospitalization.
  • Modest improvement in exercise group (HR 0.93 unadjusted, HR 0.89 adjusted - significant).
• Secondary Outcomes:
  • Cardiovascular mortality/hospitalization: Modest improvement, not significant.
  • Heart failure hospitalization: Significant improvement in adjusted analysis (HR 0.85).
  • No significant difference in all-cause mortality between groups.

Safety

• Exercise training was safe, with low rates of cardiovascular events and adverse events.

Limitations

• Adherence: Suboptimal adherence in exercise group.
• Blinding: Not possible due to nature of intervention.

Conclusion

• Regular exercise is safe for heart failure patients.
• Provides modest improvement in functional status and quality of life.
• Adjusted analyses showed statistically significant benefits.
• Supports prescription of exercise training for heart failure patients with reduced LV function.

Discussion

• Conducting such a trial is complex due to challenges with adherence and control.
• Importance of large-scale validation beyond small, single-center studies.
• Safety and efficacy data support exercise training despite initial doubts.

Final Thoughts

• The trial sets a standard for future research in behavioral interventions.
• Reinforces the need for cautious interpretation of single-center studies without large-scale validation.