Effects of preoperative inspiratory muscle training intensity on cardiopulmonary function and exercise capacity after open-heart valve surgery:a randomized controlled trial
WU Haoyun
SUN Xiaolong
XU Zhaodi
ZHANG Jinyu
JU Fen
DING Haifeng
WANG Zhao
LIU Jincheng
YUAN Hua
Abstract：Objective To investigate the effects of preoperative inspiratory muscle training(IMT)with different intensities on the postoperative recovery of cardiopulmonary function and exercise capacity in patients undergoing open-heart valve surgery,so as to provide evidence-based basis for optimizing the cardiac rehabilitation program.Methods A single-blind,randomized controlled trial was conducted.Ninety patients scheduled for open-heart valve surgery in Department of Cardiovascular Surgery,Xijing Hospital,Air Force Medical University from December 2024 to October 2025 were randomly assigned to a high-intensity IMT(HI-IMT)group(n=30),a low-intensityIMT(LI-IMT)group(n=30),or a control group(n=30).All groups received routine preoperative prehabilitation.Additionally,the HI-IMT and LI-IMT groups underwent 7-day daily IMT at≥50%and 30%-50%of maximum inspiratory pressure(MIP),respectively.On day1 of admission and before discharge,the three groups of patients were assessed and compared in terms of 6-minute walk test(6MWT)distance,pulmonary function parameters,and diaphragmatic ultrasound parameters,and the incidence of postoperative complications was also recorded.The Duke Activity Status Index(DASI)was recorded at 1-month follow-up.Results All patients completed the postoperative assessment.(1)Exercise capacity:Postoperatively,the 6MWT distance decreased in all three groups compared with preoperative values,but the reductions in both the HI-IMT and LI-IMT groups were significantly smaller than that in the control group(P<0.05).One month after discharge,the reduction in DASI score in the HI-IMT group was smaller than that in the control group(P<0.05).(2)Pulmonary and diaphragmatic function:The HI-IMT group exhibited significantly smaller reductions in MIP and maximum voluntary ventilation(MVV)compared to the control group after surgery(P<0.01).Reductions in peak expiratory flow(PEF)and diaphragmatic excursion(DE)were also smaller in the HI-IMT group than in the LI-IMT and control groups(P<0.05).(3)Postoperative complications:The incidence of postoperative pulmonary complications(PPCs)was significantly higher in the control group(33.3%)than in the HI-IMT(10.0%)and LI-IMT(13.3%)groups(P=0.044).Conclusion Adding short-term preoperative IMT to conventional prehabilitation can mitigate postoperative declines in exercise capacity and pulmonary function,reduce the risk of PPCs,and promote recovery of postoperative motor function in patients undergoing open-heart valve surgery.HI-IMT demonstrates superior benefits in preserving postoperative PEF,DE,and short-term functional status,suggesting its preference for optimizing prehabilitation strategy of cardiac valve surgery.
Keywords：cardiac valve surgeryrespiratory muscle trainingrehabilitationcardiopulmonary functionultrasonographyexercise tolerancethoracotomypostoperative complications
Publication Date：2026-05-31
Online Publishing Date：2026-08-26(First online date of this platform, not the publication date of the document)
Pages：10( 722-731 )