Effects of home-based inspiratory muscle training on cardiac function, exercise capacity, and quality of life in patients with cardiac resynchronization therapy: A randomized controlled trial.

BACKGROUND

Inspiratory muscle weakness is common among patients with chronic heart failure undergoing cardiac resynchronization therapy (CRT). Home-based inspiratory muscle training (IMT) could be a vital therapeutic strategy, particularly for those with limited access to cardiac rehabilitation programs.

OBJECTIVES

This study aimed to investigate the effects of a 12-week home-based IMT program on inspiratory muscle strength, cardiac function, NT-proBNP levels, exercise capacity, quality of life, and daily activities. It examined the relationships between changes in NT-proBNP levels, walking distance, maximal inspiratory pressure (MIP), and left ventricular ejection fraction (LVEF) in patients with heart failure at least one year after CRT implantation.

METHODS

In this randomized controlled trial, 32 patients with CRT devices were assigned to either the IMT group (n = 19) or the control group (n = 13). Outcome measures included MIP, LVEF, NT-proBNP levels, the 6-minute walk test, performance of activities of daily living (PMADL-8), and quality of life (Nottingham Health Profile-NHP).

RESULTS

Compared to the control group, the IMT group showed statistically significant improvements in MIP (p < 0.001), LVEF (p = 0.025), NT-proBNP levels (p = 0.003), walk distance (p < 0.001), PMADL-8 score (p < 0.001), and NHP total score. Significant correlations were observed among the changes in NT-proBNP, MIP, LVEF, and walk distance.

CONCLUSION

In this small-sample study home-based IMT was associated with improvements in respiratory strength, cardiac function, functional capacity, patient-reported functionality, and quality of life. This confirms the role of home-based IMT as a supportive preventive strategy for CRT patients who lack access to rehabilitation. Larger-scale, long-term studies are needed to confirm its effects on remodeling and clinical outcomes.