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Multifactor Risk Reduction for Optimal Management of PAD (VIGOR2)

This study is ongoing, but not recruiting participants.
Stanford University
University of California, San Francisco
Information provided by (Responsible Party):
Roberta Oka, Palo Alto Veterans Institute for Research Identifier:
First received: September 27, 2007
Last updated: April 18, 2017
Last verified: April 2017

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.

Condition Intervention
Peripheral Arterial Disease
Behavioral: exercise

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Intervention Model Description:
Home-based exercise
Masking: Participant
Primary Purpose: Treatment
Official Title: Multifactor Risk Reduction for Optimal Management of PAD

Resource links provided by NLM:

Further study details as provided by Palo Alto Veterans Institute for Research:

Primary Outcome Measures:
  • walking time [ Time Frame: 24 months ]
    determined by symptom limited walking time on treadmill exercise test

Secondary Outcome Measures:
  • quality of life, biomarkers of CVD risk, endothelial function [ Time Frame: 24 months ]
    Quality of life per SF-36; biomarkers include: lipids, endothelial function per FMD

Enrollment: 300
Study Start Date: September 2006
Estimated Study Completion Date: June 2018
Estimated Primary Completion Date: June 2018 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: A-Exercise group
Home based exercise
Behavioral: exercise
tailored multifactor CVD risk reduction
No Intervention: B- Usual Care
Exercise as usually prescribed by provider

Detailed Description:
closed to recruitment

Ages Eligible for Study:   50 Years to 90 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts 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%.

Exclusion Criteria:

Exclusion criteria include:

  1. Active malignancy or tumor or other condition that would severely limit life expectancy
  2. Any type of major surgery during the last 3 months (i.e. aortic or lower extremity arterial surgery, angioplasty, or lumbar sympathectomy, leg amputation above the ankle)
  3. Residence in a long-term institutional setting
  4. Psychiatric disorders with currently active manifestations
  5. Uncontrolled metabolic disorders (renal failure, liver failure, thyrotoxicosis)
  6. Active symptoms suggestive of an acute coronary syndrome or decompensated heart failure
  7. Lack of phone access (either by self or through neighbors/family members)
  8. Other specified circumstances incompatible with case-management (i.e., plan to move away from area)
  9. Presence of another household member or first-degree relative already enrolled in the study
  10. Current enrollment in another clinical trial
  11. Regular participation in an exercise program for at least 3 months prior to study entry.
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Please refer to this study by its identifier: NCT00537225

Sponsors and Collaborators
Palo Alto Veterans Institute for Research
Stanford University
University of California, San Francisco
Principal Investigator: Roberta K Oka, ANP, DNSc PAIRE
  More Information

Responsible Party: Roberta Oka, Associate Chief Nurse, Research, Palo Alto Veterans Institute for Research Identifier: NCT00537225     History of Changes
Other Study ID Numbers: OKR0001AGG/SGG
Study First Received: September 27, 2007
Last Updated: April 18, 2017
Individual Participant Data  
Plan to Share IPD: No

Keywords provided by Palo Alto Veterans Institute for Research:
peripheral arterial disease
walking time
lifestyle modification
cardiovascular risk reduction

Additional relevant MeSH terms:
Peripheral Arterial Disease
Peripheral Vascular Diseases
Arterial Occlusive Diseases
Vascular Diseases
Cardiovascular Diseases processed this record on April 24, 2017