Effects of inspiratory muscle training on NT-proBNP level, functional exercises capacity and quality of life in patients with cardiac resynchronization therapy: a pilot study

It is known that cardiac rehabilitation has improvement effects on exercise capacity and healthy quality of life in patients receiving Cardiac Resynchronization Therapy. However, we did not find a study examining the effect of inspiratory muscle strength training (IMT) on NT-ProBNP, exercise capacity, and health-related quality of life in patients with CRT. Therefore, we planned this study as a pilot study.

To test the effectiveness of inspiratory muscle training (IMT) on NT-ProBNP level, functional exercise capacity, and quality of life in patients with cardiac resynchronization therapy (CRT).

Ten individuals with CRT (age: 62.5±12.7; man 60%; NYHA:2; LVEF: 43.5±11.3) were included in this study. The patients underwent a 12-week inspiratory muscle training program (30% of their maximal inspiratory pressures, MIP) using a threshold loading device for 30 minutes per day, seven days per week at home. All patients underwent echocardiographycal examination, assessement of NT-proBNP level, assessed of functional exercises capacity by a 6-minute walk test, and evaluation of quality of life by the Nottingham Health Profile (NHP) questionnaire.

After the IMT, there was no significantly improvement in the LVEF levels (p>0,005). There was a significant decrease in the NT-ProBNP level of 777.6 ng/L ( 1801 to 1103 ng/L, p=0.005) and a significant increase in the 6MWT of 64.21meters (408.5 to 472.7, p=0.005), total NHP score of -121.55 points (244.31 to 122.76, p=0.009).

The 12-week IMT program was able to improve the NT-ProBNP level, functional exercise capacity, and quality of life levels in patients with CRT. The results suggest that IMT can be added to CRT patients' CR program. Randomized controlled studies are needed to investigate the effects of IMT.