Functional MRI of the Lower Extremities

NCT03423316 | Unknown

• 1 other identifier: 2019P001781
• Study Type: interventional
• Target: 90
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Peripheral Arterial Disease

Outcome Measures

Primary Outcomes (2)

• 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)

Study Arms (3)

Healthy Controls

NO INTERVENTION

Age-Matched Controls

NO INTERVENTION

Subjects without PAD who have the same average age as the PAD patients

PAD Patients

EXPERIMENTAL

Patients with PAD. Approximately 75% of PAD patients will be enrolled in the 12-week exercise therapy program.

Behavioral: Supervised exercise therapy

Interventions

Supervised exercise therapy BEHAVIORAL

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.

PAD Patients

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• PAD patients with
• Intermittent claudication
• Ankle-brachial blood-pressure index (ABI) \< 0.9

You may not qualify if:

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

Sponsors & Collaborators

• Massachusetts General Hospital: lead

Study Sites (1)

Massachusetts General Hospital

Boston, Massachusetts, 02114, United States

Location

MeSH Terms

Conditions

Peripheral Arterial Disease

Condition Hierarchy (Ancestors)

Atherosclerosis; Arteriosclerosis; Arterial Occlusive Diseases; Vascular Diseases; Cardiovascular Diseases; Peripheral Vascular Diseases

Central Study Contacts

Lei Zhang

CONTACT

6177268627; jeff.zhang@mgh.harvard.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: January 23, 2018
• First Posted: February 6, 2018
• Study Start: October 31, 2020
• Primary Completion: July 1, 2021
• Study Completion: July 1, 2021
• Last Updated: September 16, 2020

Record last verified: 2020-09

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)