Intermittent Claudication, Peripheral Arterial Disease
Conditions
Keywords
rehabilitation, exercise training
Brief summary
Peripheral artery disease (PAD) results in blockages of arteries (blood vessels) and decreased blood flow to the legs. This may cause difficulty or pain with walking or other activities that use leg muscles. Exercise may help improve blood flow in the legs and improve the ability to walk. This research project will be conducted patients with PAD that require revascularization. The goal is to examine the effects of 3 months of exercise rehabilitation or neuromuscular stimulation on leg blood flow, physical function, quality of life and general health.
Detailed description
Peripheral artery disease (PAD) and its associated declines in physical function impair quality of life (QOL) in nearly 20% of older Veterans and result in substantial VA health care costs. Revascularization addresses the anatomical pathology, but does not restore mobility function and QOL. Optimal therapy may require post-revascularization rehabilitation to address lingering defects in skeletal muscle that limit function; however, the current standard of care after revascularization does not include rehabilitation. Exercise training and neuromuscular electrical stimulation (NMES) may enhance function by increasing muscle perfusion to improve outcomes in older Veterans with PAD after revascularization. The investigators will enroll Veterans (50-80 years of age) with PAD who are planned for percutaneous revascularization. Participants will complete research testing consisting of: a) Assessment of mobility function and QOL; and b) Treadmill tests to assess ambulatory capacity, and calf muscle perfusion. Participants will undergo screening prior to revascularization and will have baseline testing 2-3 weeks after revascularization. After post-revascularization testing, patients will be randomized to Exercise-only or NMES-only. After completion of the 3-month intervention, participants will repeat all tests to determine the effects of the interventions.
Interventions
OTHERExercise training
The exercise program includes supervised and home-based walking and strength exercise.
OTHERNMES
This intervention consists of using neuromuscular electrical stimulation (NMES) as a form of passive exercise for muscles in the legs.
Sponsors
VA Office of Research and Development
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
50 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
* Diagnosis of peripheral arterial disease; or ankle-brachial index \<0.9. * Planned to undergo endovascular revascularization within 6 months.
Exclusion criteria
* Cancer under active treatment * Planned for lower extremity bypass surgery * Body mass index \> 45 kg/m2 * Critical limb ischemia or lower extremity gangrene
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Modified Physical Performance Test | 3 months | Test of Mobility Function (minimum score = 0; maximum score = 36; higher score associated with better outcome) |
| Six-minute Walk Distance | 3 months | Test of ambulatory capacity |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Muscle Perfusion Measured by Ultrasound Scan | 3 months | Calf Muscle Perfusion assessed as digital video intensity from recorded ultrasound scans. Units are scale data with a minimum = 0 and no predetermined maximum. Higher score = more perfusion. |
Countries
United States
Participant flow
Pre-assignment details
56 participants enrolled; only 35 participants completed baseline testing and were randomized.
Participants by arm
| Arm | Count |
|---|---|
| Exercise Exercise Training
Exercise training: The exercise program includes supervised treadmill walking and home-based walking exercise. | 22 |
| NMES Neuromuscular Electrical Stimulation
NMES: This intervention consists of using neuromuscular electrical stimulation (NMES) as a form of passive exercise for muscles in the legs. | 13 |
| Total | 35 |
Baseline characteristics
| Characteristic | NMES | Total | Exercise |
|---|---|---|---|
| Age, Continuous | 69.7 years STANDARD_DEVIATION 7.5 | 67.8 years STANDARD_DEVIATION 6.4 | 66.3 years STANDARD_DEVIATION 5.3 |
| Modified Physical Performance Test | 30.7 scores on a scale STANDARD_DEVIATION 3 | 30.8 scores on a scale STANDARD_DEVIATION 3.2 | 30.8 scores on a scale STANDARD_DEVIATION 3.5 |
| Muscle Perfusion Measured by Ultrasound Scan | 3.90 units on a scale STANDARD_DEVIATION 2.01 | 4.28 units on a scale STANDARD_DEVIATION 1.9 | 4.57 units on a scale STANDARD_DEVIATION 1.98 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 7 Participants | 19 Participants | 12 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 6 Participants | 16 Participants | 10 Participants |
| Region of Enrollment United States | 12 Participants | 34 Participants | 22 Participants |
| Sex: Female, Male Female | 1 Participants | 2 Participants | 1 Participants |
| Sex: Female, Male Male | 12 Participants | 33 Participants | 21 Participants |
| Six-minute Walk Distance | 1070 feet STANDARD_DEVIATION 325 | 1164 feet STANDARD_DEVIATION 330 | 1237 feet STANDARD_DEVIATION 328 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 22 | 0 / 13 |
| other Total, other adverse events | 4 / 22 | 1 / 13 |
| serious Total, serious adverse events | 1 / 22 | 0 / 13 |
Outcome results
Primary
Modified Physical Performance Test
Test of Mobility Function (minimum score = 0; maximum score = 36; higher score associated with better outcome)
Time frame: 3 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Exercise | Modified Physical Performance Test | 31.8 scores on a scale | Standard Deviation 5.2 |
| NMES | Modified Physical Performance Test | 32.3 scores on a scale | Standard Deviation 3 |
Primary
Six-minute Walk Distance
Test of ambulatory capacity
Time frame: 3 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Exercise | Six-minute Walk Distance | 1295 feet | Standard Deviation 287 |
| NMES | Six-minute Walk Distance | 1193 feet | Standard Deviation 191 |
Secondary
Muscle Perfusion Measured by Ultrasound Scan
Calf Muscle Perfusion assessed as digital video intensity from recorded ultrasound scans. Units are scale data with a minimum = 0 and no predetermined maximum. Higher score = more perfusion.
Time frame: 3 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Exercise | Muscle Perfusion Measured by Ultrasound Scan | 6.13 units on a scale | Standard Deviation 4.75 |
| NMES | Muscle Perfusion Measured by Ultrasound Scan | 4.59 units on a scale | Standard Deviation 2.49 |