Functional MRI of the Lower Extremities

Stress-rest Calf Muscle Perfusion: a Functional Diagnostic Test for Peripheral Arterial Disease (PAD)

In this project, the investigators propose to use high-resolution magnetic resonance imaging (MRI) to measure blood perfusion in different groups of calf muscle. This imaging approach is standard of care for evaluation of coronary artery disease (CAD), and has never been successfully applied to PAD. Preliminary results show distinct patterns of muscle perfusion between healthy and PAD patients, and thus great promise of the technique. The investigators will first verify the reproducibility of the technique, and then compare the calf muscle perfusion measures in PAD patients against healthy age-matched controls. This comparison will test the feasibility of detecting functional abnormality in PAD patients. After the baseline scans, the PAD patients will opt to undergo a 12-week supervised exercise therapy, and then a post-therapy MRI scan. Comparison of the pre- and post-therapy measurements will indicate how the therapy improves the calf-muscle perfusion, and how this perfusion change correlates with increases in patient's walking ability.

The long term goals of this project are to develop an improved diagnostic test for patients with PAD to predict who will benefit from therapeutic intervention. The MRI perfusion studies of calf muscle can be performed in conjunction with routine peripheral MR angiography to assess the functional significance of vascular stenosis.

Study Overview

• Status: Unknown
• Conditions: Peripheral Arterial Disease
• Intervention / Treatment: Behavioral: Supervised exercise therapy

• Study Type: Interventional
• Enrollment (Anticipated): 90
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

PAD patients with

• Intermittent claudication
• Ankle-brachial blood-pressure index (ABI) < 0.9

Exclusion Criteria:

• Estimated glomerular filtration rate (eGFR) < 30 ml/min/1.73m2
• Chronic pulmonary diseases
• Arthritis or other joint ailments

Study Plan

How is the study designed?

Design Details

• Primary Purpose: DIAGNOSTIC
• Allocation: NON_RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
NO_INTERVENTION: Healthy Controls
NO_INTERVENTION: Age-Matched Controls; Subjects without PAD who have the same average age as the PAD patients
EXPERIMENTAL: PAD Patients; Patients with PAD. Approximately 75% of PAD patients will be enrolled in the 12-week exercise therapy program.	Behavioral: Supervised exercise therapy; The therapy will be conducted three times each week for 12 weeks. Each session takes 1 hour, consisting of 5 minutes of warmup activities, 50 minutes of intermittent exercise, and 5 minutes of cool-down activities. Exercise consists of walking on a treadmill initiated at 2 mph and 0% grade, until claudication pain becomes moderately severe. After claudication pain subsides, the subject will restart the walk. At the end of the session, the total exercise duration will be recorded. After a patient is able to walk 8-10 minutes at the initial workload, the grade is increased by 1-2%, or the speed is increased by 0.5 mph as tolerated.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stress-rest calf-muscle perfusion	Perfusion in the different calf muscle groups following exercises of low (rest) and high (stress) intensities	Single visit (~90 minutes)
Perfusion changes following supervised exercise therapy	Change in stress-rest calf-muscle perfusion in PAD patients following the 12-week supervised exercise therapy	Before and after supervised exercise therapy (12 weeks)

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital

Study record dates

Study Major Dates

• Study Start (ANTICIPATED): October 31, 2020
• Primary Completion (ANTICIPATED): July 1, 2021
• Study Completion (ANTICIPATED): July 1, 2021

Study Registration Dates

• First Submitted: January 23, 2018
• First Submitted That Met QC Criteria: January 30, 2018
• First Posted (ACTUAL): February 6, 2018

Study Record Updates

• Last Update Posted (ACTUAL): September 16, 2020
• Last Update Submitted That Met QC Criteria: September 11, 2020
• Last Verified: September 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Atherosclerosis; Peripheral Arterial Disease; Peripheral Vascular Diseases
• Other Study ID Numbers: 2019P001781

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