What is the clinical evidence from this study?

Study design: RCT. Population: Acute heart failure. Intervention: Inspiratory muscle training (IMT). Primary outcome: Efficacy and safety.

What question did this study set out to answer?

To describe the design and rationale of the IMT-AHF trial evaluating the efficacy, safety, and optimal intensity of inspiratory muscle training in older patients hospitalized with acute heart failure.

April 23, 2026Circulation ReportsOpen Access

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

Q: What are the key findings of this study?

The IMT-AHF trial is designed to verify the efficacy and safety of inspiratory muscle training in older patients with acute heart failure.

View Full Paper

Ask AI

Bookmark

Key result

IMT-AHF trial evaluates inspiratory muscle training in older patients with acute heart failure.

Why the study?

Evidence regarding the efficacy, safety, and optimal dosing of inspiratory muscle training in older patients with acute heart failure and inspiratory muscle weakness remains limited.

Does high-intensity or low-intensity inspiratory muscle training improve 2-minute walk distance in older patients hospitalized with acute heart failure and inspiratory muscle weakness?

Key Points

To describe the design and rationale of the IMT-AHF trial evaluating the efficacy, safety, and optimal intensity of inspiratory muscle training in older patients hospitalized with acute heart failure.
Single-center, multi-arm, parallel-group, single-blind randomized controlled trial conducted at Sendai Medical Center in Japan (UMIN000055454).
Hospitalized patients aged ≥65 years with acute heart failure and inspiratory muscle weakness are stratified by age (<85 vs. ≥85 years), sex, and baseline 2-min walk distance (<70 vs. ≥70 m).
Participants are randomized 1:1:1 to high-intensity (60% maximum inspiratory mouth pressure), low-intensity (30%), or sham (0%) training performed 5 times per week (3 sets of 15 repetitions daily).
The primary endpoint is change in 2-min walk distance from baseline to hospital discharge.
High-intensity inspiratory muscle training is hypothesized to yield greater improvements in exercise tolerance and 2-min walk distance than low-intensity training.
Safety analyses track adverse event frequencies and vital sign changes pre- and post-session to determine acute-phase feasibility.

Study Design

Type

RCT

Randomization

Multi-arm parallel-group

Structured PICO

Does high-intensity or low-intensity inspiratory muscle training improve 2-minute walk distance in older patients hospitalized with acute heart failure and inspiratory muscle weakness?

Population

Older patients aged ≥65 years hospitalized with acute heart failure (AHF) who have inspiratory muscle weakness (%PImax <70%) and can ambulate independently (n=66).

Intervention

High-intensity inspiratory muscle training (HI-IMT) at 60% of maximum inspiratory mouth pressure, or low-intensity IMT (LI-IMT) at 30%, performed 5 times per week (3 sets of 15 repetitions per day) until discharge, added to conventional cardiac rehabilitation.

Comparator

Sham IMT at 0% of maximum inspiratory mouth pressure, performed 5 times per week (3 sets of 15 repetitions per day) until discharge, added to conventional cardiac rehabilitation.

Outcome

Change or rate of change in the 2-min walk distance (2MWD) from baseline (start of cardiac rehabilitation) to discharge.surrogate

The IMT-AHF trial is designed to evaluate whether high-intensity inspiratory muscle training improves exercise tolerance in older patients hospitalized with acute heart failure.

Limitations

Single-center design
Numerous exclusion criteria
Short follow up
Completely blinded assessment of the 2MWD assessment was not feasible

Implication

IMT lacks evidence in older AHF; this RCT leaves open efficacy and safety for exercise tolerance in inspiratory muscle weakness.

Abstract

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.

Discussion

No takes yet. Share an insight, caveat, or question.

Figures from the paper

Published by Circulation Reports · CC BY-NC-ND

Cite This Study

Takahashi et al. (2026) conducted an RCT in Acute heart failure. Inspiratory muscle training (IMT) was evaluated on Efficacy and safety. The IMT-AHF trial is designed to verify the efficacy and safety of inspiratory muscle training in older patients with acute heart failure.

synapsesocial.com/papers/69e9b62685696592c86eae70 https://doi.org/10.1253/circrep.cr-25-0313

Topics

HFrEF treatment

Heart failure

View Full Paper

Ask AI

Bookmark

Implication

IMT lacks evidence in older AHF; this RCT leaves open efficacy and safety for exercise tolerance in inspiratory muscle weakness.

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

Key Points

Study Design

Structured PICO

Limitations

Implication

Abstract

Discussion

Figures from the paper

Cite This Study

Topics

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

Key Points

Study Design

Structured PICO

Limitations

Implication

Abstract

Discussion

Figures from the paper

Cite This Study

Keep reading

Topics

Keep reading

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

Key Points

Study Design

Structured PICO

Limitations

Implication

Abstract

Discussion

Cite This Study

Topics

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

Key Points

Study Design

Structured PICO

Limitations

Implication

Abstract

Discussion

Cite This Study

Keep reading

Topics

Keep reading

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

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