Effects of High-Intensity Inspiratory Muscle Training Associated with Aerobic Exercise in Patients Undergoing CABG: Randomized Clinical Trial

Abstract Objective: Evaluate the interaction between high-intensity inspiratory muscle training (IMT) and aerobic exercise on physical capacity, respiratory muscle strength, peripheral muscle strength, and quality of life of patients who underwent coronary artery bypass grafting (CABG). Methods: Twenty-four patients underwent CABG were randomized into two groups. During 36 sessions, one group received IMT associated with aerobic exercise and the other group received only aerobic exercise. Primary outcome was the distance in the six-minute walk distance (6MWD) test. Secondary outcomes included respiratory muscle strength, peripheral muscle strength, and quality of life. Measures were taken at the baseline, at the 12th session, the 24th session, and 36th session. Results: Baseline characteristics were similar between the groups. There was no statistically significant difference between the two groups in any outcome [6MWD - P=0.935; peak oxygen consumption (PeakVO2) - P=0.853; maximal inspiratory pressure (MIP) - P=0.243; maximal expiratory pressure (MEP) - P=0.268; sitting-rising test (SRT) - P=0.212], but there was interaction in MIP (P=0.000) and all outcomes improved in the two groups (6MWD - P=0.000; PeakVO2 - P=0.000; MIP - P=0.000; MEP - P=0.000; SRT - P=0.000). Conclusion: There was an improvement of all outcomes in both groups, but IMT was not able to provide additional benefits. The use of this combination should be used with caution to not generate higher costs in the rehabilitation process of these patients.

### 摘要
**目的**：评估高强度吸气肌训练（high-intensity inspiratory muscle training, IMT）与有氧运动联合对冠状动脉旁路移植术（coronary artery bypass grafting, CABG）后患者的体能、呼吸肌肌力、外周肌肌力及生活质量的交互影响。
**方法**：将24例行冠状动脉旁路移植术的患者随机分为两组。在共计36次的训练疗程中，一组接受IMT联合有氧运动，另一组仅接受有氧运动。主要结局指标为6分钟步行距离（six-minute walk distance, 6MWD）测试结果。次要结局指标包括呼吸肌肌力、外周肌肌力及生活质量。分别于基线、第12次疗程、第24次疗程及第36次疗程时完成评估。
**结果**：两组基线特征无统计学差异。各项结局指标在两组间均无显著统计学差异[6MWD - P=0.935; 峰值摄氧量（peak oxygen consumption, PeakVO2） - P=0.853; 最大吸气压力（maximal inspiratory pressure, MIP） - P=0.243; 最大呼气压力（maximal expiratory pressure, MEP） - P=0.268; 坐-立测试（sitting-rising test, SRT） - P=0.212]，但MIP存在显著交互效应（P=0.000）；且两组各项结局指标均较基线改善[6MWD - P=0.000; PeakVO2 - P=0.000; MIP - P=0.000; MEP - P=0.000; SRT - P=0.000]。
**结论**：两组各项结局指标均得到显著改善，但IMT未能为患者带来额外获益。在该类患者的康复过程中，采用该联合训练方案需谨慎，以避免不必要的康复成本增加。