Exercise Therapy to Reduce Heart Failure Symptoms; Sorting Mechanisms of Benefit

Study Summary

The purpose of this research study is to better understand how exercise training in older adults (≥65 years) with heart failure (HF) affects skeletal muscle both intrinsically and in respect to its impact on functional capacity. While many conceptualize HF as a pathophysiology that exclusively affects the heart, skeletal muscle atrophy and weakening are also elemental to the disease. While reduced exercise capacity is typically associated with HF, this may be related more to disease effects in skeletal muscle than the heart. This is a clinical study that focuses on exercise training which compares functional endpoints before and after training. Patients are randomized to one of three exercise training interventions (aerobic vs. aerobic and strength vs. inspiratory muscle training) for 12 weeks and are assessed pre- and post-training to determine if any differences occur in their skeletal muscle and functional capacity. Skeletal muscle biopsies before and after the exercise training intervention in order to study changes in skeletal muscle histology and biology. Functional endpoints in this study include ventilatory gas indices from cardiopulmonary exercise testing, lower body strength testing, grip strength, sit-to-stand, six-minute-walk distance, gait speed, inspiratory muscle strength, and quality of life and physical activity-oriented questionnaires, including the Kansas City Cardiomyopathy Questionnaire, Duke Activity Status Index, and CHAMPS Physical Activity Questionnaire for Older Adults. Body composition is measured with Dual Energy X-ray (DXA) scanning. Skeletal muscle biopsies are completed in the vastus lateralis of the non-dominant leg to assess histology and biologic endpoints.

Interventions

• BEHAVIORAL Aerobic Exercise Intervention
• BEHAVIORAL Combined Aerobic and Strength Exercise Intervention
• BEHAVIORAL Inspiratory Muscle Training Exercise Intervention