Using Near-Infrared Light to Better Understand Peripheral Artery Disease

Near-Infrared Diffuse Correlation Spectroscopy to Better Define the Pathophysiology of Peripheral Artery Disease

The goal of this study is to better understand how blood flows and how oxygen is utilized in the lower limbs of people who suffer from peripheral artery disease. This study will also assess how these factors affect treatment outcomes.

Specific aims include:

Aim 1: Utilize BB-NIR-DCS to differentiate PAD patients experiencing primary oxygen delivery limitations from those suffering from mitochondrial dysfunction.

Aim 2: Test the efficacy of BB-NIR-DCS at predicting individual responses to vascular intervention.

Study Overview

• Status: Recruiting
• Conditions: Peripheral Artery Disease (PAD)

Detailed Description

Subjects that do not have peripheral artery disease will complete the study procedures up to two times (baseline and follow-up at 1-2 months).

Subjects diagnosed with peripheral artery disease may be asked to complete the study procedures up to 4 separate times (baseline, follow-up at 1-2 weeks, 1-2 months, and 4-6 months). The investigators will work with them to schedule each visit.

All participants will provide informed consent prior to participating in the study. The screening procedures will include collecting information about health history, age, sex, race/ethnicity, height, weight, and reasons one should not undergo an MRI or exercise.

The laboratory procedures will include questionnaires about quality of life and walking ability, Ankle- Brachial Index, functional performance measures (treadmill walking and six minute walk distance), wearable activity monitor and activity log, and lower limb MRI with muscle perfusion and oxygenation measures at rest and in response to physiologic provocation (ischemia-reperfusion and exercise).

Investigators may ask subjects to return on a separate day to repeat part, or all, of the study procedures depending on image quality and/or equipment performance.

• Study Type: Observational
• Enrollment (Estimated): 120

Contacts and Locations

• Study Contact: Name: Michael Nelson, PhD; Phone Number: 8175130383; Email: michael.nelson3@uta.edu
• Study Contact Backup: Name: Rajvi Shah, MPH; Phone Number: 2147557343; Email: rajvi.shah@uta.edu

Study Locations

• United States
  • Texas
    • Arlington, Texas, United States, 76010
      • Recruiting
      • University of Texas at Arlington
      • Contact: Rajvi Shah; Phone Number: 2147557
    • Arlington, Texas, United States, 76019
      • Not yet recruiting
      • University of Texas Arlington
      • Principal Investigator: Michael Nelson, PhD
      • Contact: Rajvi Shah, MPH; Phone Number: 2147557343; Email: rajvi.shah@uta.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Cases- 80 individuals with PAD.

Controls- 40 healthy volunteers, of similar age, sex, and ethnicity as the PAD cases.

Description

Inclusion Criteria:

• Cases, Aim 1

  1. 18 or older
  2. willing to participate under the conditions described in the informed consent form (ICF)
  3. eligible to sign the ICF
  4. established diagnosis of PAD confirmed by a physician
  5. able to comply with the study requirements

• Cases, Aim 2

  1) completed Aim 1

• Controls 1) asymptomatic, with no history or diagnosis of peripheral artery disease

Exclusion Criteria:

• Cases, Aim 1

  1. Ankle-Brachial Index >0.9 or <0.4
  2. isolated disease in aorta/iliac vessels
  3. unstable angina or myocardial infarction in past 12 months
  4. orthopedic or other physical limitations which would prevent data collection
  5. contraindications to MRI, including presence of a Pacemaker, presence of bone growth/ bone fusion stimulators, presence of tissue expander, presence of cochlear implants, unable to ambulate for 10 feet, receiving continuous Oxygen therapy, pregnancy, permanent Jewelry (screened using MRI safety screening form and verbal screening by MRI operator

• Cases, Aim 2

  1. unstable angina or myocardial infarction in past 12 months
  2. orthopedic or other physical limitations which would prevent data collection
  3. contraindications to MRI, including presence of a pacemaker, presence of bone growth/ bone fusion stimulators, presence of tissue expander, presence of cochlear implants, unable to ambulate for 10 feet, receiving continuous Oxygen therapy, pregnancy, permanent Jewelry (screened using MRI safety screening form and verbal screening by MRI operator).
• Controls 1) history of peripheral artery disease 2) overt cardiovascular disease (e.g. heart failure) 3) known pulmonary disease (excluding mild asthma) 4) current tobacco use 5) orthopedic or other physical limitations which would prevent data collection, 6) BP >150/90 mmHg at screening 7) contraindications to MRI, including presence of a pacemaker, presence of bone growth/ bone fusion stimulators, presence of tissue expander, presence of cochlear implants, unable to ambulate for 10 feet, receiving continuous Oxygen therapy, pregnancy, permanent Jewelry (screened using MRI safety screening form and verbal screening by MRI operator).

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Healthy Controls; Individuals without PAD
Cases with PAD; Individuals with PAD

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Perceived Quality of life	Participants will complete a health questionnaire to gain a deeper understanding of their quality of life.	Baseline and up to 26 weeks
Ankle- Brachial Index	The Ankle Brachial Index will be noninvasively assessed using the Smartdop XT device (Koven Technology, Inc.)	Baseline and upto 26 weeks
Walking ability	Participants will complete a questionnaire to gain a deeper understanding of their walking ability	Baseline and upto 26 weeks
Functional performance	Participants will be asked to walk as much as they can for six minutes (up and down a long hallway). Then, they will be asked to walk on a treadmill at 2 mph (3.2 km/h) at a grade of 10% for all as long as they can, or for a maximum of 10 minutes.	Baseline and upto 26 weeks
Steps taken	Participants will be asked to wear an activity monitor on their wrist to track the number of steps they take each day for up to 6 months. A member of the study team will contact them by phone, email or text message each week to remind them to complete a log book of their daily activity.	Baseline and upto 26 weeks
Oxygen level of leg muscles	Participants will be asked to perform exercise with their lower leg (affected leg, if they have peripheral artery disease) while they are in an MRI. A small plastic device (about the size of a match box) will also be placed on their lower limb. This device will measure the oxygen level of their leg muscles using near-infrared light.	Baseline and upto 26 weeks
Body composition	An MRI will be performed across the upper and lower body to measure muscle size, muscle quality, adiposity and body structure.	Baseline and up to 26 weeks
Leg Exercise MRI	Participants will be asked to perform exercise with their lower leg (affected leg, if they have peripheral artery disease) while they are in an MRI. The MRI will be used to measure the blood flow in leg and the oxygen level of the blood in their veins.	Baseline and upto 26 weeks
Lower Leg Ischemia-Reperfusion	A blood pressure cuff will be inflated around the upper leg for 5 minutes before being released. Leg blood flow and vein oxygen saturation will be measured throughout.	Baseline and up to 26 weeks
Leg muscle size and quality	An MRI of the leg will be performed to measure muscle size and tissue characteristics.	Baseline and up to 26 weeks

Collaborators and Investigators

• Sponsor: The University of Texas at Arlington

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2025
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: August 18, 2025
• First Submitted That Met QC Criteria: December 16, 2025
• First Posted (Estimated): January 2, 2026

Study Record Updates

• Last Update Posted (Estimated): January 2, 2026
• Last Update Submitted That Met QC Criteria: December 16, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: MRI; Peripheral Artery Disease; Questionnaires; Functional Performance; Ankle-Brachial Index; Exercise MRI
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Atherosclerosis; Arteriosclerosis; Arterial Occlusive Diseases; Peripheral Vascular Diseases; Peripheral Arterial Disease
• Other Study ID Numbers: 2025-0414; 25CSA1432263 (Other Grant/Funding Number: AHA)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No