Inspiratory Muscle Training for Breathless Patients With Chronic Obstructive Pulmonary Disease and Heart Failure


The purpose of this study is to determine whether inspiratory muscle training is effective to improve breathless and exercise intolerance in symptomatic patients with chronic obstructive pulmonary disease (COPD) plus chronic heart failure (HF).

Full Title of Study: “Inspiratory Muscle Training for Dyspneic Patients With COPD-HF Overlap: a Multicenter, Randomized Controlled Trial”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Treatment
    • Masking: Single (Outcomes Assessor)
  • Study Primary Completion Date: June 2017

Detailed Description

Chronic obstructive pulmonary disease (COPD) and heart failure with reduced left ventricular ejection fraction (HF) are leading causes of disability and death worldwide. Unfortunately, COPD and HF coexist in up to a third of elderly patients making the so-called COPD-HF overlap (CHO) a major challenge to Health Care Systems. In addition, population ageing anticipates that CHO prevalence will further increase in the next decades.

Intolerance to exertion due to disabling breathlessness is the hallmark of COPD and HF and these abnormalities are notoriously potentiated by diseases coexistence.

The inspiratory muscles are centrally related to the pathophysiology of exertional dyspnea in COPD and HF. In both populations a higher central motor command output is required to maintain adequate force generation in the face of weaker inspiratory muscles. This information is interpreted as "shortness of breath".

There is well established evidence gained from recent meta-analyses indicating that inspiratory muscle training (IMT), as a standalone therapy, significantly improves inspiratory muscle function (strength and endurance), dyspnea during daily activities, and functional exercise capacity in COPD and HF. Previous findings indicate that reduced pressure-generating capacity reflecting inspiratory muscle weakness is frequently observed in patients with COPD-HF and related to a clinically-relevant outcome: exertional dyspnea. These findings set the scene for a randomized controlled trial to investigate the potential role of IMT in dyspnea palliation in CHO patients.


To determine the effects of IMT on:

1. Dyspnea on daily life

2. Inspiratory muscle strength and endurance

3. Dyspnea on exertion and time to exercise intolerance


  • Device: POWERbreathe®KHA (IMT group)
    • 2 training sessions/day consisting of 30 breaths (~50% maximal inspiratory pressure; Pi,max), 7 days/week (once/week supervised at research center), for 8 weeks using an electronic tapered flow resistive loading (TFRL) device (POWERbreathe®KH2, HaB International Ltd., Southam, UK). Measurements of PImax will be performed every week and training loads will be increased continuously to maintain the actual ~50% Pimax values.
  • Device: POWERbreathe®KH2 (sham group)
    • 2 training sessions/day of 30 breaths at an inspiratory load of no more than 10% of their initial Pi,max (POWERbreathe®KH2, HaB International Ltd., Southam, UK). This training load will not be changed during the entire study period.

Arms, Groups and Cohorts

  • Active Comparator: Inspiratory Muscle Training (IMT)
    • POWERbreathe®KHA (IMT group)
  • Sham Comparator: Sham Training
    • POWERbreathe®KH2 (sham group)

Clinical Trial Outcome Measures

Primary Measures

  • Dyspnea on daily life
    • Time Frame: 8 weeks
    • Measured by the Baseline Dyspnea Index (BDI)

Secondary Measures

  • Inspiratory muscle strength as measured by spirometry
    • Time Frame: 8 weeks
    • Measured by Maximal Static Inspiratory Pressures (Pi,max)
  • Inspiratory muscle endurance as measured by a PowerBreathe device
    • Time Frame: 8 weeks
    • Assessed by Endurance Respiratory Muscle Protocol (Patients will breathe against 60% of Pi,max inspiratory load until task failure)
  • Dyspnea on exertion
    • Time Frame: 8 weeks
    • Measured by Borg score during high intensity constant load cycling exercise test
  • Time to exercise intolerance (Tlim)
    • Time Frame: 8 weeks
    • Evaluated by high intensity constant load cycling exercise test

Participating in This Clinical Trial

Inclusion Criteria

  • Previous diagnoses of COPD and HF under optimized clinical treatment as judged by the accompanying physician
  • Reduced left ventricular ejection fraction (<50%)
  • Non-reversible airway obstruction (post-bronchodilator FEV1/FVC < 0.7 and FEV1 < 80 %)
  • Respiratory muscle weakness (Pi,max < 70cmH2O)
  • Persistent dyspnea on daily life (Baseline Dyspnea Index focal score <or= 8).

Exclusion Criteria

  • Inability to perform exercise tests
  • Diagnosed psychiatric or cognitive disorders
  • Progressive neurological or neuromuscular disorders having a major impact on exercise capacity

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 90 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Queen’s University
  • Collaborator
    • KU Leuven
  • Provider of Information About this Clinical Study
    • Principal Investigator: Dr. J. Alberto Neder, Study Chair – Queen’s University
  • Overall Official(s)
    • J Alberto Neder, MD, PhD, Study Chair, Queen’s University
  • Overall Contact(s)
    • J Alberto Neder, MD, PhD, (+1) 613-549-6666,

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