The efficacy of inspiratory muscle training in improving clinical outcomes in heart failure patients: An updated systematic review and meta-analysis.

BACKGROUND

Inspiratory muscle training (IMT) has shown improvements in clinical variables for heart failure (HF) patients. We conducted a meta-analysis to investigate if IMT can enhance respiratory muscle strength, quality of life (QoL), and reduce cardiac biomarker levels in HF patients.

METHODS

PubMed, Cochrane Library, and Google Scholar databases were systematically searched up to July 8, 2024. Randomized controlled trials of IMT in HF patients were included. A random effects model was used to calculate weighted mean differences (WMDs) and 95 % confidence intervals. Outcomes analyzed included minute ventilation to carbon dioxide output slope (VE/VCO2), QoL, six-minute walk distance (6MWD), maximum expiratory pressure, maximum inspiratory pressure (MIP), N-terminal pro B-type natriuretic peptide (NT-pro-BNP), forced vital capacity, forced expiratory volume in one second, and metabolic equivalents.

RESULTS

Seventeen studies involving 510 patients (252 in IMT group, 258 in control) were included. IMT significantly improved 6MWD [WMD: 72.72; 95 % CI: (16.65 to 128.78); p = 0.01], QoL [WMD: -15.27; 95 % CI: (-21.01 to -9.53); p < 0.00001], VE/VCO2 [WMD: -5.09; 95 % CI: (-7.36 to -2.83); p < 0.0001], MIP [WMD: 13.77; 95 % CI: (7.51 to 20.03); p < 0.0001], and NT-pro-BNP levels [WMD: -659.66; 95 % CI: (-1212.87 to -106.46); p = 0.02].

CONCLUSION

IMT significantly improved respiratory muscle strength, QoL, and reduced cardiac biomarker levels in patients with both heart failure with preserved ejection fraction and heart failure with reduced ejection fraction. These findings suggest that IMT may be a promising exercise-based strategy for treating HF.