Home-based Walking Program With Smart Devices

Intermittent claudication (IC), the most common manifestation of peripheral artery disease (PAD), represents not only a significant detriment in quality of life, but also an increased risk for atherosclerotic cardiovascular disease (ASCVD), including progression of PAD, coronary artery disease (CAD) and cerebrovascular disease. Guideline directed therapy for IC includes supervised exercise, smoking cessation and optimal medical management to decrease overall risk of ASCVD. In the VA Health Care System, implementation of supervised exercise therapy through cardiac rehabilitation or physical therapy programs is limited by distances that patients must travel to VA facilities that provide these services. Furthermore, one of the most common failure points in exercise therapy programs is poor patient compliance. Improved patient participation and compliance in exercise programs for IC represents an unmet need, without which the majority of patients with life-style limiting PAD may not be receiving optimal medical management.

Small studies have demonstrated the effectiveness of home-based exercise programs as an alternative to supervised exercise therapy; however, the success of the home-based exercise programs require remote coaching and/or regular provider feedback. The wide-spread availability of smart phones and smart devices has accelerated the implementation of telehealth programs that may supplement or may eventually replace in-person encounters for health care delivery. The role of provider feedback in addition to real-time feedback from smart devices remains completely unexplored. Our central hypothesis is that in individuals with IC, regular provider feedback on smart-device-based remote health monitoring data, which is available to the patient in real time, will augment the benefits of home-based exercise programs. We propose a randomized trial in patients with IC to test the central hypothesis through two Specific Aims:

1. To determine the effect of provider feedback on smart-device-based remote health monitoring data during home-based exercise programs on walking distance in patients with IC.
2. To determine the effect of provider feedback on smart-device-based remote health monitoring data during home-based exercise programs on quality of life (QOL) in patients with IC.

Based on a sample size calculation to detect a 50% increase in walking distance between the 2 groups, we expect to enroll 30 patients (15 in each group). Patient participation in the study will be concluded after 12 weeks.

As an exploratory aim in the study, we will also (as an optional part of the study) collect plasma before and after the 12-weeks of exercise to investigate changes in lipid levels and plasma biomarkers associated with exercise therapy. This exploratory aim will generate preliminary data for future studies.

The study design is that of a prospective randomized study of patients presenting to the vascular surgery and cardiology clinics with symptoms of IC and enrolled in 12-week supervised exercise program. Upon enrollment, each patient will undergo a medical and surgical history, ascertainment of smoking status, review of medications, and 6-minute walk test (walking on a flat, pre-defined course(i.e. hallway) for 6 minutes and recording time and distance to claudication onset as well as total distance walked, and total number of steps taken). We will also collect data from the patient's CPRS notes through our institutional cardiac rehab/PAD rehab program, with a dedicated cardiac rehab nurse. Patients with IC who are enrolled in the study will also be asked to complete 2 QOL questionnaires: the VASCUQoL6 and the Walking Impairment Questionnaire (WIQ). Patients will undergo supervised exercise therapy (per cardiac rehab protocol) and will receive the LIVMOR health monitoring system with instructions on how to use it. Randomization and details of exercise therapy are described in the next section. Patients will be followed for up to 12 weeks to collect data regarding change in distance and time of claudication onset.

In the optional exploratory aim, we will analyze plasma from one blood draw at the beginning and at the end of exercise therapy for lipid levels, distribution of LDL particle size, and other biomarkers. We will perform metabolomics, proteomics, and lipidomics assays to examine small circulating molecules that are involved in the development of atherosclerotic plaque in peripheral arterial disease. All blood and plasma analysis performed outside of Pathology and the Clinical Core Lab will be performed in the PI's research laboratory at the Dallas VA Medical Center by members of the research staff, or by members of the PI's collaborating lab at UT Southwestern or in the UT Southwestern research Core Laboratories. Any plasma sent to UT Southwestern will be de-identified.

Data (including name, birth date, social security number, dates of procedures and studies) will be stored in an Excel spreadsheet. Each patient's data will be associated with a study ID and stripped of the 18 identifiers need to de-identify the data. Only study staff will have access to PHI. No PHI will be released outside the North Texas VA Health Care Systems.

For the LIVMOR system, only the patient's study ID will be entered into the system. De-identified health monitoring data (heart rate, steps taken, distance walked) will be transmitted and stored in the LIVMOR cloud server, as was done in the LIVMOR Data Collection Study (IRB# 17-106).

After enrollment, baseline data, including questionnaires, will be collected. Patients who have agreed to optional blood draw will have a fasting blood draw (up to 10 cc) at the next available time within 1 week of study enrollment. At the next supervised exercise therapy visit (occurs 3 times a week according to the cardiac rehab protocol), the patient will have baseline resting heart rate and blood pressure measurements, and will undergo a 6-minute walk test. The patient will be randomized to remote coaching (regular provider feedback based on LIVMOR data) vs. remote health monitoring without provider feedback. Each patient will be sent home with instructions for home-based supplemental exercise and a LIVMOR remote health monitoring system, which includes a wristwatch that records heart rate, steps taken, and distance traveled (pedometer function) and a tablet. Patients will be instructed to check a resting heart rate with the LIVMOR watch for 10 minutes before starting exercise. They will exercise while wearing the watch (heart rate monitor and pedometer), then check heart rate for 10 minutes after completion of the exercise session. Patients will not receive real time feedback from the smart-watch heart rate monitor, however they have the option to review their heart rate and pedometer data by logging into the tablet provided with the watch, after the exercise session. In patients randomized to the remote coaching arm, study staff will provide feedback on home-based supplemental exercise based on heart rate measurements and pedometer measurements from the LIVMOR health monitoring system, as well as heart rate and walking data collected from supervised exercise therapy sessions. Remote coaching will occur by telephone call, but the conversation will mirror conversations that occur during supervised exercise therapy, and will not be based solely on the surrogate measure of heart rate for walking effort. A member of the study team will call the patient 1-3 times a week, depending on the patient's preference, which may change over the course of the study. Therefore the remote coaching is adaptive to patient's needs. In patients randomized to no remote coaching, health monitoring data will be reviewed by study staff, but will not be used to adjust home-based supplemental exercise. Any abnormalities in health monitoring data will be alerted to appropriate clinical staff. All patients will keep a journal of their home-based supplemental exercise, including time of exercise, in order to correlate heart rate readings from the smart-watch.

For patients agreeing to the optional blood draw: Blood will be sent to the Dallas VA Medical Center clinical lab for a lipid panel. The remaining blood will be refrigerated, then transported to the PI's research lab at the Dallas VA Medical Center, where the research staff will centrifuge the blood to isolate plasma.

Plasma will be tested for the following:

* Metabolomics, proteomics, and lipidomics assays to study small circulating molecules that may be involved in the development of atherosclerosis in peripheral arterial disease, and may change with exercise therapy.
* Lipoprotein subfractions.
* Small molecules that can be assayed using ELISA. At the end of the 12-week program, an end-of-study 6 minute walk test will be performed as well as the questionnaires will be completed. All the LIVMOR devices will be returned to the investigators. If the patient is unable to complete the end-of study 6-min walk test or does not complete the 12-week exercise program, a phone follow- up will be done to complete the questionnaires. A final blood draw will be completed (within 1 week of completing the 12-week exercise program) for patients who have opted for the blood draw.

The LIVMOR system transmits data through wireless technology up to a cloud server. The data transmission is encrypted and FIPS-140-2 compliant.

Eligibility Criteria:
Inclusion Criteria:

* Presence of documented PAD by ABI \<0.90 at rest or ≥20% drop in claudication limited exercise ABI in either limb and one of the following criteria in the corresponding limb:

  i. Prior lower extremity revascularization ii. Known presence of flow-limiting stenosis (≥70%) by clinically indicated angiography, computed tomographic (CT) or magnetic resonance imaging (MRI), or Duplex ultrasonography (DUS)
* Documented diagnosis of intermittent claudication
* Enrollment in supervised exercise therapy through the institutional cardiac rehab program

Exclusion Criteria:

* Severe cardiac or pulmonary disease that precludes participation in an exercise-based study.
* Severe psychiatric or behavioral illness that precludes study participation
* Inability to provide informed consent