Peripheral Arterial Disease
Conditions
Keywords
peripheral arterial disease, walking time, lifestyle modification, cardiovascular risk reduction, exercise, diet, claudication
Brief summary
Patients with peripheral arterial disease (PAD) experience significant functional limitations due to ischemic symptoms (claudication) and are at high risk for CVD morbidity and mortality resulting from untreated cardiovascular disease (CVD) risk factors and aggressive atherosclerosis. The overall Goal of this randomized controlled clinical trial is to examine the synergistic effect of a multifactor risk reduction on walking distance, blood flow and quality of life in 300 patients with PAD. Specifically, we will compare the effects of 24 months of a novel, yet well-tested multiple risk factor reduction program, the Health Education and Risk Reduction Training (HEAR2T) Program for PAD versus enhanced standard care on: 1) symptom limited walking distance as assessed by treadmill exercise testing and walking impairment questionnaire; 2) endothelial function as measured by flow mediated vasodilation (FMVD) via brachial artery ultrasound. We will also explore the association between FMVD and decreased oxidative stress (as measured by oxygen radical absorbance capacity and urinary isoprostanes) and reduced degradation of nitric oxide (NO) and/or increased NO biosynthesis (as measured by urine nitrogen oxide, plasma nitrogen oxide, plasma asymmetric dimethylarginine, plasma, urine and platelet cyclic GMP). Secondary hypotheses examine the association between reducing CVD risk factors, improved endothelial function, increased walking distance, improved quality of life and number of metabolic syndrome abnormalities in PAD patients. Significance. This study will contribute to evidence on the efficacy of multiple risk factor reduction on improving physical function and quality of life in the understudied, elderly PAD patient. This study will also provide preliminary evidence for the biological basis for the efficacy of multifactor risk reduction in restoring vascular homeostasis, critical because of its role in antiatherogenesis and maintaining vasoreactivity, both necessary for slowing the progression of atherosclerosis.
Detailed description
closed to recruitment
Interventions
BEHAVIORALexercise
tailored multifactor CVD risk reduction
Sponsors
Stanford University
University of California, San Francisco
Palo Alto Veterans Institute for Research
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Intervention model description
Home-based exercise
Eligibility
Sex/Gender
ALL
Age
50 Years to 90 Years
Healthy volunteers
No
Inclusion criteria
Subjects eligible for this study include: 1. Age 50 years or older with one or more CVD risk factor 2. PAD secondary to atherosclerosis with significant claudication 3. Claudication is defined as pain, ache, cramp, numbness or severe fatigue of muscles of one or both lower extremities, reproducibly provoked by walking causing the patient to slow or stop walking pace 4. Ankle-brachial index (ABI) \< 0.90 5. In diabetics ABI is inaccurate, in which case, we will substitute toe pressures \< 60 mmHg 6. ABI one minute after exercise is at least 20% lower than index leg resting ABI 7. Capable of walking at least 50 feet 8. Primary limitation to walking is claudication, not coexisting conditions such as severe CAD, uncontrolled hypertension, pulmonary disease, severe arthritis, or orthopedic conditions 9. Difference of walking time between two consecutive (of four) baseline treadmill tests must be \< 25%.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| walking time | 24 months | determined by symptom limited walking time on treadmill exercise test |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| quality of life, biomarkers of CVD risk, endothelial function | 24 months | Quality of life per SF-36; biomarkers include: lipids, endothelial function per FMD |
Outcome results
None listed