Circulation Reports · Apr 21, 2026

Inspiratory Muscle Training in Older Patients With Acute Heart Failure: Design and Rationale of a Multi-Arm Parallel-Group Randomized Controlled Trial

By Takahashi R, Yokota J, Tsushima E

BACKGROUND: Approximately 70% of older patients with acute heart failure (AHF) exhibit inspiratory muscle weakness (IMW). Inspiratory muscle training (IMT) may improve respiratory function and functional capacity, yet evidence regarding its efficacy, safety, and optimal dosing in this population remains limited. The IMT-AHF trial aims to verify the efficacy and safety of IMT in older patients with AHF. METHODS AND RESULTS: The IMT-AHF trial is a single-center, multi-arm, parallel-group randomized controlled trial enrolling older patients aged ≥65 years with AHF who have IMW and can ambulate independently. Participants are stratified by age (<85 vs. ≥85 years), sex, and baseline 2-min walk distance (2MWD; <70 vs. ≥70 m) and are randomized to high-intensity IMT (HI-IMT), low-intensity IMT (LI-IMT), or sham IMT. Training intensities for HI-IMT, LI-IMT, and sham IMT are set at 60%, 30%, and 0% of maximum inspiratory mouth pressure, respectively. The intervention is performed 5 times per week and consists of 3 sets of 15 repetitions per day. The primary endpoint is change in 2MWD from baseline to discharge. CONCLUSIONS: The findings of the IMT-AHF trial are expected to strengthen evidence for cardiac rehabilitation and inform IMT prescription in older patients with AHF.

doi.org/10.1253/circrep.cr-25-0313 Open access PubMed 42273317 Interventions