Effect of inspiratory muscle training in patients with chronic heart failure: a systematic review and meta-analysis of randomized controlled trials

Background: The effect of inspiratory muscle training (IMT) in chronic heart failure (CHF) patients remains unclear now. This study aimed to comprehensively identify the therapeutic effects of IMT among CHF patients based on current evidence of randomized controlled trials (RCTs). Methods: Several databases were searched up to January 2, 2024 for RCTs investigating the clinical application of IMT in CHF patients. Primary outcomes were maximal inspiratory pressure (MIP) and pulmonary function. Secondary outcomes were exercise performance, including the six-minute walk test (6MWT) and Borg dyspnea index, quality of life evaluated by the Minnesota Living with Heart Failure Questionnaire (MLWHF) and N terminal-pro brain natriuretic peptide (NT-proBNP). Statistical analyses were conducted by the RevMan 5.3 software. Results: peak (MD =1.66 mL/kg/min, 95% CI: 0.27 to 3.05, P=0.02). Besides, patients receiving the IMT showed increased 6MWT (MD =37.40 m, 95% CI: 16.46 to 58.35, P<0.001) and decreased Borg dyspnea index (MD =-0.63, 95% CI: -0.83 to -0.44, P<0.001), MLWHF (MD =-8.51, 95% CI: -13.60 to -3.42, P=0.001) and NT-proBNP (MD =-81.67 pg/mL, 95% CI: -124.88 to -38.45, P<0.001). Conclusions: IMT plays a role in improving the clinical outcomes including the inspiratory muscle function, exercise performance, quality of life and NT-proBNP among CHF patients.