High-intensity vs. Low-intensity Inspiratory Muscle Training in Patients With Heart Failure

Study Overview
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Brief Summary
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It is well-known that muscle weakness and deconditioning play an important role in low exercise capacity of patients with HF. Interestingly, not only peripheral muscles are impaired, but also respiratory muscles. Studies have shown that patients with HF may have, in addition to decreasing maximal inspiratory muscle strength and endurance, metabolic and structural impairments in diaphragm fibers. Moreover, exercise capacity and weakness of inspiratory muscles have been associated with low quality of life and poor prognosis, which make the addition of inspiratory muscle training (IMT) reasonable in cardiovascular rehabilitation.The specifications of the loads to be imposed during IMT is the main factor determining the outcome. Studies of IMT have highlighted the need for a fixed inspiratory workload during exercise. Thus, purpose of this report was to perform a randomized clinical trial of the effects of addition of high-intensity vs. low-intensity IMT to combined aerobic and resistance Exercise in patients with heart failure.

Official Title
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The Addition of High-intensity vs. Low-intensity Inspiratory Muscle Training to Combined Aerobic and Resistance Exercise in Patients With Heart Failure

Conditions
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Heart Failure

Intervention / Treatment
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* Other: High-intensity IMT + Aerobic/resistance exercise
* Other: Low-intensity IMT + Aerobic/resistance exercise
* Other: Sham IMT + Aerobic/resistance exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The target population consists of adults patients aged ≥ 18 years with heart failure and New York Heart Association (NYHA) class I-III. Exclusion Criteria: Unstable angina; coronary revascularization; Decompensated heart failure functional class IV (NYHA); Recent transplant or hospitalization (6 months <); Chronic Obstructive Pulmonary Disease; Neuromuscular, Orthopedic, Neurologic and Neoplastic Diseases; Recent myocardial infarction or cardiac surgery (less than 6 months); Atrial Fibrillation.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High-intensity IMT<br>High-intensity IMT + Aerobic/resistance exercise IMT: Training loads will be adjusted weekly to the maximal inspiratory pressure (MIP). In the first 2 weeks as adaptation, the protocol will be of 2 minutes warm-up with intensity 20% of MIP. The training will have 7 peaks of intensity with 70% of MIP for 30 sec, with 30-sec of passive rest between the peaks, finishing the training with 20% of MIP for 2 min, totaling 10 min and 30 sec. From the third week the protocol will be of 2 min warm-up with intensity 30% of MIP. The training will have 7 peaks of intensity with 70% of MIP for 60 sec, with 60-second of passive rest between the peaks, finishing the training with 20% of MIP for 2 min, totaling 17 min. Exercise: see group Combined aerobic/resistance exercise | Other: High-intensity IMT + Aerobic/resistance exercise<br>* High-intensity IMT<br>|
| Active Comparator: Low-intensity IMT<br>Low-intensity IMT + Aerobic/resistance exercise IMT:Training loads will be also adjusted weekly to the maximal inspiratory pressure (MIP). In the first two weeks as adaptation, the protocol will be of 2 minutes warm-up with intensity 20% of MIP. The training will be held with 3 sets of 15 repetitions, with 40% of MIP, finishing the training with 20% of MIP for 2 minutes. From the third week the protocol will be of 2 minutes warm-up with intensity 30% of MIP. The training will be held with 3 sets of 15 repetitions, with 60% of MIP, finishing the training with 30% of MIP for 2 minutes. Exercise: see group Combined aerobic/resistance exercise | Other: Low-intensity IMT + Aerobic/resistance exercise<br>* Low-intensity IMT<br>|
| Sham Comparator: Aerobic/resistance exercise<br>Sham IMT + Aerobic/resistance exercise Aerobic session will consist of a 4-min of warm-up, 20 minutes of exercise, and 4 min of cool-down. Intensity will set by the formula: Training HR = (maximum HR - resting HR) × intensity % + resting HR. Patients will exercise using 30 seconds, high-intensity work phases 0.7% followed by 1-minute recovery bouts 0.5%. Resistance exercise will consist of dynamic lower and upper limb exercise. Upper limb exercises will include 3 sets of exercises for each muscle group performed with 10 repetitions each. Lower limb exercises will include 3 sets of exercises for each muscle group performed with 12 repetitions each. Resistance exercises will be performed at 12-MR. | Other: Sham IMT + Aerobic/resistance exercise<br>* Aerobic and resistance exercise<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Aerobic Capacity | Six-minute walk test | 10 weeks | 
| Health-Related Quality of Life: MLHFQ | Health-Related Quality of Life will be measured by a questionnaire (Minnesota Living with Heart Failure questionnaire - MLHFQ) | 10 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Respiratory muscle strength | Maximal respiratory pressures | 10 weeks | 
| Disability | The World Health Organization Disability Assessment Schedule (WHODAS 2.0) | 10 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Heart Failure; Rehabilitation