Heart Failure NYHA Class II, Heart Failure NYHA Class III
Conditions
Keywords
Heart failure, inspiratory muscle training, physical activity
Brief summary
Individuals with chronic heart failure need a safe and effective exercise program that could enhance their quality of life. In this study, we examined whether an experimental exercise program of autonomous walking and high-intensity Inspiratory Muscle Training (IMT) could result in better effects on respiratory muscle strength (PImax), cardiovascular endurance, quality of life, and physical activity, when compared to autonomous walking and sham IMT program, in adults with chronic heart failure.
Detailed description
Participants were recruited from the outpatient heart failure transitional care clinic at the Presbyterian Hospital of Dallas and other local heart failure support groups. Flyers were distributed to cardiologists, nurse practitioners, and local heart failure support groups in the Dallas/Ft Worth area. Cardiologists and nurse practitioners were aware of the scope of the study and its inclusion and exclusion criteria of research participants. Potential research participants could then call the research team for further information. Participants came to our facility for the initial evaluation session, where a history interview was conducted to gather demographic data, such as age, gender, height, weight, race/ethnicity, and past medical/surgical history. The following baseline data were then collected: a) two trials of the six-minute walk test, b) respiratory muscle strength indicated by maximal inspiratory pressure (PImax), and two quality of life questionnaires. During the walk test, heart rate and heart rhythms were continuously monitored via a holter monitor. During the rest breaks, research participants filled out two quality of life questionnaires (SF-36, Minnesota Living with Heart Failure Questionnaire). Each participant was randomly assigned to one of the two groups: a) the autonomous walking program with a high-intensity Inspiratory Muscle Training (IMT) program, or b) the autonomous walking program with a sham IMT. The training threshold for the experimental IMT group was trained at 60%PImax which was reassessed at weekly follow ups. The frequency of training was 5x/week (1x/day preferred) for 6 interval levels at each session (6 inspiratory efforts in each level): (1) 60s rest interval; (2) 45s rest interval; (3) 30s rest interval; (4) 15s rest interval; (5)10s rest interval; (6) 5s rest interval, trained to exhaustion. The intensity of sham IMT was set at fixed 15% PImax. Research participants were blinded to the group assignment. The time commitment for IMT was about 15-20 minutes a session per day at home. Weekly follow up was conducted at the School of Physical Therapy in Dallas to reassess PImax, collect the log of daily step count, and discuss about the walking program. Every participant was given a breathing device for inspiratory muscle training. Each participant was given a pedometer and a heart rate monitor to track their daily step counts and heart rate during the walking session. The walking program consisted of walking daily at an intensity of somewhat hard to hard on the Borg's Rating of Perceived Exertion (RPE) scale. Participants were encouraged to walk 10 to 15 minutes, once to twice a day initially, then progressed to about 45-50 minutes a day by week six, if they could tolerate. At the end of 6 weeks, these participants returned to our facility for the final evaluation session.
Interventions
BEHAVIORALHigh-intensity IMT plus walking
The IMT intensity was set at 60% of PImax which was reassessed weekly. Frequency: 5x/week; 1x/day preferred. 6 Interval Levels: (6 efforts at each level): (1) 60s rest interval; (2) 45s rest interval; (3) 30s rest interval; (4) 15s rest interval; (5)10s rest interval; (6) 5s rest interval, trained to exhaustion. For the walking program, it was the same as the one for the control group.
BEHAVIORALLow-intensity IMT plus walking
The IMT training was 3 sets of 10 repetitions, or when the participant felt tired. Participants returned to our facility every week to reassess PImax. For the walking program, each participant was given a pedometer and a heart rate monitor to track daily step counts and heart rate. The walking program consisted of walking every day at an intensity of somewhat hard to hard on the Borg's Rating of Perceived Exertion scale. Participants began at least 10 to 15 minutes, once to twice a day, for 7 days a week, and eventually progressed to 45-50 minutes a day by the end of the six weeks, if they could tolerate.
Sponsors
Texas Health Resources
Texas Woman's University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 90 Years
Healthy volunteers
No
Inclusion criteria
* adults with chronic heart failure (NYHA Functional Class II-III) * BMI \< 35 kg/m\^2 * Age: 18 to 90 years * walk independently with or without an assisted device * hospital discharge for CHF within a year.
Exclusion criteria
* ECG with uncontrolled ventricular arrhythmia * bronchiectasis * limited walking ability due to neurologic or orthopedic impairments of the legs
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Mean Minnesota Living With Heart Failure Questionnaire Score | Baseline and 6 weeks | This questionnaire includes 21 questions which ask how much the heart condition affected the patient's life during the past month. Each question has 5 optional answers with the scores ranging from 0 to 5. A higher score indicates a worse outcome. The minimum overall score of the questionnaire is 0 and the maximum score is 105. A higher overall score on the Minnesota Living with Heart Failure Questionnaire indicates a worse outcome. |
| Change From Baseline in Mean Score of Physical Component of the SF-36 Questionnaire | Baseline and 6 weeks | The SF-36 quality of life questionnaire (short form) was used. A higher score of the SF-36 questionnaire indicates a better outcome (i.e., lower disability). The range of overall score on the SF-36 questionnaire is from 0 to 100. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Mean Daily Step Counts From Week 1 to Week 6 | Baseline and 6 weeks | Each subject was given a pedometer to record his/her step counts every day. |
| Respiratory Muscle Strength is Indicated by Maximal Inspiratory Pressure (PImax) | Baseline and 6 weeks | The inspiratory muscle strength will be measured in the unit of cmH2O by the Respiratory Muscle Pressure Meter (Micro Direct). A higher inspiratory pressure indicates a better inspiratory breathing strength. |
| Six-minute Walk Test Distance | Baseline and 6 Weeks | The six-minute walk test is a measure of cardiovascular endurance which measures how far a person can walk in 6 minutes. This test was conducted twice respectively at pre-training and at post-training to account for potential learning effect. A longer distance walked on the six-minute walking test indicates a better cardiovascular endurance. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Low-intensity IMT Plus Walking Inspiratory Muscle Training (IMT) intensity is set at 15% PImax. The walking program will consist of walking every day at an intensity of hard to somewhat hard on the Rating of Perceived Exertion (RPE) scale. Participants will be instructed to walk at 15 minutes twice a day initially, then progress to 45-50 minutes a day by the end of the six weeks.
Low-intensity IMT plus walking: The IMT training is about 15-20 minutes. Both groups will need to come in once a week for 15 to 20 minutes to probably readjust the IMT training intensity on the breathing device.
For the walking program, each participant will be given a pedometer and a heart rate monitor so he/she can track daily step counts and walking heart rate during the study. The walking program will consist of walking every day at an intensity of hard to somewhat hard on the Rating of Perceived Exertion (RPE) scale. Participants will begin walking at least 15 minutes twice a day for 7 days a week and eventually pr | 9 |
| High-intensity IMT Plus Walking Inspiratory Muscle Training (IMT) intensity is set at 60% PImax. The walking program will consist of walking every day at an intensity of hard to somewhat hard on the Rating of Perceived Exertion (RPE) scale. Participants will be instructed to walk 15 minutes twice a day initially, then progress to 45-50 minutes a day by the end of six weeks.
High-intensity IMT plus walking: The IMT intensity will be set at 60% of PImax which will be adjusted weekly and nose clip will be used. Frequency: 5x/week; 1x/day preferred. 6 Interval Levels: (6 efforts at each level): (1) 60s rest interval; (2) 45s rest interval; (3) 30s rest interval; (4) 15s rest interval; (5)10s rest interval; (6) 5s rest interval, trained to exhaustion.
For the walking program, each participant will be given a pedometer and a heart rate monitor so he/she can track daily step counts and heart rate during the study. The walking program will consist of walking every day at an intensity of hard to somewhat har | 7 |
| Total | 16 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Lost to Follow-up | 1 | 0 |
| Overall Study | readmission to a hospital | 2 | 1 |
| Overall Study | relocation | 1 | 0 |
| Overall Study | transportation issues | 2 | 1 |
Baseline characteristics
| Characteristic | High-intensity IMT Plus Walking | Total | Low-intensity IMT Plus Walking |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 2 Participants | 2 Participants |
| Age, Categorical Between 18 and 65 years | 7 Participants | 14 Participants | 7 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 1 Participants | 1 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 6 Participants | 15 Participants | 9 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Sex: Female, Male Female | 1 Participants | 4 Participants | 3 Participants |
| Sex: Female, Male Male | 6 Participants | 12 Participants | 6 Participants |
| Six-Minute Walk Test Distance | 356.00 meters STANDARD_DEVIATION 85.3 | 388 meters STANDARD_DEVIATION 109 | 413.92 meters STANDARD_DEVIATION 85 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 9 | 0 / 7 |
| other Total, other adverse events | 6 / 9 | 2 / 7 |
| serious Total, serious adverse events | 2 / 9 | 1 / 7 |
Outcome results
Primary
Change From Baseline in Mean Minnesota Living With Heart Failure Questionnaire Score
This questionnaire includes 21 questions which ask how much the heart condition affected the patient's life during the past month. Each question has 5 optional answers with the scores ranging from 0 to 5. A higher score indicates a worse outcome. The minimum overall score of the questionnaire is 0 and the maximum score is 105. A higher overall score on the Minnesota Living with Heart Failure Questionnaire indicates a worse outcome.
Time frame: Baseline and 6 weeks
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Low-intensity IMT Plus Walking | Change From Baseline in Mean Minnesota Living With Heart Failure Questionnaire Score | MLHF score at baseline | 36 score on a scale |
| Low-intensity IMT Plus Walking | Change From Baseline in Mean Minnesota Living With Heart Failure Questionnaire Score | change from baseline at 6 weeks | 18.6 score on a scale |
| High-intensity IMT Plus Walking | Change From Baseline in Mean Minnesota Living With Heart Failure Questionnaire Score | MLHF score at baseline | 57.6 score on a scale |
| High-intensity IMT Plus Walking | Change From Baseline in Mean Minnesota Living With Heart Failure Questionnaire Score | change from baseline at 6 weeks | -20.6 score on a scale |
Primary
Change From Baseline in Mean Score of Physical Component of the SF-36 Questionnaire
The SF-36 quality of life questionnaire (short form) was used. A higher score of the SF-36 questionnaire indicates a better outcome (i.e., lower disability). The range of overall score on the SF-36 questionnaire is from 0 to 100.
Time frame: Baseline and 6 weeks
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Low-intensity IMT Plus Walking | Change From Baseline in Mean Score of Physical Component of the SF-36 Questionnaire | Baseline Physical SF-36 | 34.1 score on a scale |
| Low-intensity IMT Plus Walking | Change From Baseline in Mean Score of Physical Component of the SF-36 Questionnaire | Change from baseline physical SF-36 | 0.82 score on a scale |
| High-intensity IMT Plus Walking | Change From Baseline in Mean Score of Physical Component of the SF-36 Questionnaire | Baseline Physical SF-36 | 30.7 score on a scale |
| High-intensity IMT Plus Walking | Change From Baseline in Mean Score of Physical Component of the SF-36 Questionnaire | Change from baseline physical SF-36 | 7.08 score on a scale |
Secondary
Mean Daily Step Counts From Week 1 to Week 6
Each subject was given a pedometer to record his/her step counts every day.
Time frame: Baseline and 6 weeks
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Low-intensity IMT Plus Walking | Mean Daily Step Counts From Week 1 to Week 6 | Baseline daily step count at Week 1 | 3512 steps/day |
| Low-intensity IMT Plus Walking | Mean Daily Step Counts From Week 1 to Week 6 | Daily step counts at week 6 | 4434 steps/day |
| High-intensity IMT Plus Walking | Mean Daily Step Counts From Week 1 to Week 6 | Baseline daily step count at Week 1 | 7002 steps/day |
| High-intensity IMT Plus Walking | Mean Daily Step Counts From Week 1 to Week 6 | Daily step counts at week 6 | 9255 steps/day |
Secondary
Respiratory Muscle Strength is Indicated by Maximal Inspiratory Pressure (PImax)
The inspiratory muscle strength will be measured in the unit of cmH2O by the Respiratory Muscle Pressure Meter (Micro Direct). A higher inspiratory pressure indicates a better inspiratory breathing strength.
Time frame: Baseline and 6 weeks
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Low-intensity IMT Plus Walking | Respiratory Muscle Strength is Indicated by Maximal Inspiratory Pressure (PImax) | Baseline PImax at week 1 | 51.44 cm H2O |
| Low-intensity IMT Plus Walking | Respiratory Muscle Strength is Indicated by Maximal Inspiratory Pressure (PImax) | PImax at week 6 | 57.22 cm H2O |
| High-intensity IMT Plus Walking | Respiratory Muscle Strength is Indicated by Maximal Inspiratory Pressure (PImax) | Baseline PImax at week 1 | 43.53 cm H2O |
| High-intensity IMT Plus Walking | Respiratory Muscle Strength is Indicated by Maximal Inspiratory Pressure (PImax) | PImax at week 6 | 58.13 cm H2O |
Secondary
Six-minute Walk Test Distance
The six-minute walk test is a measure of cardiovascular endurance which measures how far a person can walk in 6 minutes. This test was conducted twice respectively at pre-training and at post-training to account for potential learning effect. A longer distance walked on the six-minute walking test indicates a better cardiovascular endurance.
Time frame: Baseline and 6 Weeks
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Low-intensity IMT Plus Walking | Six-minute Walk Test Distance | six-minute walk distance at week 1 | 356.16 meters |
| Low-intensity IMT Plus Walking | Six-minute Walk Test Distance | Six-minute walk distance at week 6 | 375.78 meters |
| High-intensity IMT Plus Walking | Six-minute Walk Test Distance | six-minute walk distance at week 1 | 378.04 meters |
| High-intensity IMT Plus Walking | Six-minute Walk Test Distance | Six-minute walk distance at week 6 | 419.71 meters |