The results of inspiratory muscle training on cardiac, respiratory, musculoskeletal, and psychological status in patients with stable angina: a randomized controlled trial

Purpose To determine the effect of inspiratory muscle training (IMT) on respiratory and peripheral muscle strength, functional exercise capacity, health-related quality of life (HRQoL), fatigue, depression, and cardiac functions in patients with stable angina. Methods A randomized, controlled, single-blinded study. Twenty patients (59.95 +/- 7.35 y, LVEF = 58.77 +/- 7.49) with stable angina received IMT at the lowest load (10 cmH(2)O), and 20 patients (55.85 +/- 7.60 y, LVEF = 62.26 +/- 7.75) received training at 30% of maximal inspiratory pressure (MIP) seven days/8 weeks. Respiratory muscle strength (MIP; maximal expiratory pressure, MEP), peripheral muscle strength, pulmonary functions, functional exercise capacity (6-min walking test; exercise test), fatigue, HRQoL, depression, and cardiac functions were evaluated before and after. Results A statistical difference was found between groups in terms of respiratory and peripheral muscle strength, pulmonary functions, functional exercise capacity (p < 0.05). The results of fatigue, depression, HRQoL, and cardiac functions were similar between the groups (p > 0.05). Conclusions This study is the first to demonstrate the positive effects of IMT in patients with stable angina. IMT is a safe and effective method and is recommended to be added to cardiopulmonary rehabilitation programs and guidelines, as it results in increased peripheral muscle strength and functional exercise capacity in stable angina patients.