Inspiratory Muscle Training in Patients With Heart Failure With Preserved Ejection Fraction: A Meta-Analysis.

Objectives To explore the role of inspiratory muscle training (IMT) in improving cardiorespiratory fitness of stable heart failure with preserved ejection fraction (HFpEF) patients. Background There is a paucity of data on the role of IMT in patients with HFpEF. HFpEF is a growing problem in the developed world, especially in the aging population. Methods We conducted a systematic literature search for English studies in PubMed, EMBASE, and Cochrane Central Register of Controlled Trials. We searched databases using terms relating to or describing breathing exercise, IMT, and HFpEF. RevMan 5.4 (The Cochrane Collaboration, 2020) was used for data analysis, and two independent investigators performed literature retrieval and data extraction. Results We identified three randomized controlled trials (RCTs) and one prospective study on the role of IMT in HFpEF. We calculated the pooled mean difference of peak oxygen consumption (Peak VO2) and six-min walk distance (6MWD) between the IMT and standard care (SC) groups. Our meta-analysis showed that compared with SC, IMT could significantly improve peak VO2 with a mean difference (MD) of 2.82 ml/kg/min, 95% CI [1.90, 3.74] P < 0.00001 and improve 6MWD with MD of 83.97 meters, 95% CI [59.18, 108.76] P< 0.00001 to improve cardiorespiratory fitness at 12 weeks of IMT and improve peak VO2 with MD of 2.18 ml/kg/min, 95% CI [0.38, 3.99] P < 0.00001 at 24 weeks of therapy. Conclusion IMT should be further studied as a possible treatment option to improve cardiorespiratory fitness for patients with stable HFpEF.