Microvascular Reactivity in Peripheral Artery Disease

May 28, 2024 updated by: Columbia University

Microvascular Reactivity in People With Peripheral Artery Disease: a Pilot Study to Determine Reliability, Validity, and Sensitivity to Change

Peripheral Artery Disease (PAD) is a major risk factor for lower limb amputation. Microvascular reactivity assessed with near-infrared spectrometry has been studied in people with PAD but not in people with limb loss (PLL) who have PAD. The purpose of this research is to explore whether near-infrared spectrometry measures can contribute to identifying people at risk for amputation. Specific aims include: 1) Determine the test-retest reliability of near-infrared spectrometry measures in people with peripheral artery disease with or without major unilateral amputation. 2) Determine construct validity of near-infrared spectrometry measures compared to 6-Minute Walk Test, and time to claudication onset; and self-reported prosthetic mobility in people with transtibial amputation.

This methodologic prospective study with repeated assessments and long term phone follow-up every year to identify any subjects that undergo revascularization or amputation will include 2 groups of subjects: a PAD group enrolled from an out-patient walking program, and a PLL+PAD group who receive no care but have their walking step counts monitored.

Study Overview

Detailed Description

Subjects: Subjects with peripheral artery disease (PAD) with or without lower limb amputation will be recruited from PAD rehabilitation programs or support groups for people with limb loss (PLL) in the Columbia University Irving Medical Center system and New York City metropolitan area. Equal numbers (n=10) will be assigned to the people with PAD group and the PLL plus PAD (PLL+PAD) group. All subjects will be 35-80 years old at risk for amputation as determined by meeting any of the following criteria. 1) People with peripheral artery disease diagnosed by ankle-brachial index (ABI) <0.9 or 1.4. 2) People who have a history of endovascular or surgical revascularization for critical ischemia, or 3) People with previous major or minor unilateral lower limb loss due to PAD, with or without diabetes. Once informed written consent has been obtained Assessment sessions will depend on group assignment.

The PLL+PAD group will attend 2 assessment sessions: initial and 1-month follow-up assessments only. The PLL+PAD group will receive no intervention. However, a monitor will be used to remotely assess their general walking activity. At the end of the initial assessment, PLL will have daily step count assessed with a StepWatch4 step activity monitor strapped just above the lateral prosthetic ankle. The average daily step count will be derived from the last full week of 24- hour/day data collection closest in time to the next assessment, at which time the StepWatch4 will be removed. Between sessions, subjects will be encouraged to continue their usual activities; no directions regarding exercise, physical activity, or walking will be given. Data from the two sessions will be used to determine test-retest reliability (Aim 1). Near infrared spectrometry measurement data from the 1st session will be used to determine associations with walking performance measures (Aim 2).

The PAD group will attend 3 assessment sessions: initial, 1-month, and 2-month follow-up assessments. The PAD group will already be enrolled in a PAD rehabilitation program-independent of this research program-that consists of 2-3 times per week 1-hour sessions. Sessions include progressive treadmill training for 30- minute-including rest breaks as needed-with inclination added if tolerated. Also included is 30-minutes of calf and hamstring stretching and general strengthening including free weights for the upper limbs, cuff weights for the lower limbs, and repeated sit-to-stand and step functional training. The rehabilitation program consists of 24 sessions over 2 months and the number of sessions attended will be counted. If subjects opt for an additional 1-month of training session, they will undergo a 3-month follow-up assessment. Repeated measures data from the PAD group will be used to determine effect size change of the primary outcome measures (Aim 3).

Measures: All subjects at each session will complete a questionnaire and undergo clinical assessments. Follow up calls every 6 months will be made to determine medical outcome.

Questionnaire data will include individual characteristics, medical history, and self-report claudication scale. General health perception will be assessed with SF-12.

Clinical assessment will occur at each session and include vital signs, ankle brachial index, near infrared spectrometry during strength and walking assessments. General lower extremity strength will be assessed with heel raises up to 25 repetitions and the 30-sec sit-to-stand. Walking performance will be assessed using the 6-Minute Walk Test using a standard 20m walkway with rests allowed as needed. Walking speed will be obtained from the first 20m. Clinical assessment of strength and walking are expected to be of moderate intensity.

Statistical analysis will include group descriptions, Intraclass Correlation Coefficients for test-retest reliability, and Pearson correlation coefficients for convergent or divergent validity between near infrared spectrometry and clinical outcome measures.

Study Type

Observational

Enrollment (Actual)

3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • New York
      • New York, New York, United States, 10032
        • Columbia University Irving Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

35 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Subjects with peripheral artery disease with or without lower limb amputation will be recruited from peripheral artery disease (PAD) rehabilitation programs or support groups for people with limb loss (PLL) in the Columbia University Irving Medical Center system and New York City metropolitan area. Equal numbers (n=10) will be assigned to the people with PAD group and the PLL plus PAD (PLL+PAD) group.

Description

Inclusion Criteria:

  • People of any sex or race/culture
  • Clinical diagnosed of peripheral artery disease
  • People with or without diabetes
  • People with or without past endovascular or vascular procedures for peripheral artery disease within the past year
  • People who have unilateral minor or major lower limb amputation

Exclusion Criteria:

  • People who cannot communicate in English
  • People judged unable to participate due to cognitive limitation or medical instability
  • People who cannot walk independently 50 feet, with or without walking aid

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
PAD: Peripheral Artery Disease
People with Peripheral Artery Disease (PAD). No intervention given, observation and assessment only
No Intervention. Clinical Assessments include: vital signs, near infrared spectrometry, general leg strength, and 6-minute walking test.
PLL+PAD: People with Limb Loss and Peripheral Artery Disease
People with Lower-Limb Loss (PLL) and Peripheral Artery Disease (PAD) No intervention given, observation and assessment only
No Intervention. Clinical Assessments include: vital signs, near infrared spectrometry, general leg strength, and 6-minute walking test.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Microvascular Reactivity
Time Frame: Monthly: from initial assessment each month for up to 2 months.
Near Infrared Spectrometry
Monthly: from initial assessment each month for up to 2 months.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
6-Minute Walk Test
Time Frame: Monthly: from initial assessment each month for up to 2 months.
Distance and speed
Monthly: from initial assessment each month for up to 2 months.
Claudication
Time Frame: Monthly: from initial assessment each month for up to 2 months.
Time to onset and severity
Monthly: from initial assessment each month for up to 2 months.
General Lower-Limb Strength
Time Frame: Monthly: from initial assessment each month for up to 2 months.
30s Sit-to-Stand test
Monthly: from initial assessment each month for up to 2 months.
Calf muscle strength
Time Frame: Monthly: from initial assessment each month for up to 2 months.
Repetitive heel raises (up to 25 max)
Monthly: from initial assessment each month for up to 2 months.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Christopher K Wong, PhD, PT, Columbia University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 9, 2021

Primary Completion (Actual)

April 24, 2023

Study Completion (Actual)

April 24, 2023

Study Registration Dates

First Submitted

September 9, 2021

First Submitted That Met QC Criteria

September 21, 2021

First Posted (Actual)

October 1, 2021

Study Record Updates

Last Update Posted (Actual)

May 30, 2024

Last Update Submitted That Met QC Criteria

May 28, 2024

Last Verified

May 1, 2024

More Information

Terms related to this study

Other Study ID Numbers

  • AAAT5119
  • R01HS025198 (U.S. AHRQ Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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