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**：
**研究目的**：评估高强度吸气肌训练（high-intensity inspiratory muscle training, IMT）联合有氧运动对冠状动脉旁路移植术（coronary artery bypass grafting, CABG）后患者的躯体功能、呼吸肌肌力、外周肌肌力及生活质量的交互影响。
**研究方法**：纳入24例行冠状动脉旁路移植术的患者，将其随机分为两组。在为期36次的干预疗程中，一组接受高强度吸气肌训练联合有氧运动，另一组仅接受有氧运动。本研究的主要结局指标为6分钟步行试验（six-minute walk distance, 6MWD）的步行距离；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次干预、第24次干预及第36次干预时完成指标评估。
**研究结果**：两组患者的基线特征无显著差异。两组间各项结局指标均未观察到统计学显著性差异[6分钟步行距离（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；坐立试验（sitting-rising test, SRT）：P=0.212]，但在最大吸气压力指标存在显著交互效应（P=0.000）；且两组各项结局指标均得到显著改善（6MWD：P=0.000；PeakVO2：P=0.000；MIP：P=0.000；MEP：P=0.000；SRT：P=0.000）。
**研究结论**：两组患者的各项结局指标均得到显著改善，但高强度吸气肌训练未为该类患者带来额外获益。在这类患者的康复治疗中，采用该联合干预方案需谨慎，以防增加康复相关成本。