Functional MRI of the Lower Extremities

NCT ID: NCT03423316

Last Updated: 2020-09-16

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 90 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2020-10-31
• Study Completion Date: 2021-07-31

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

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: DIAGNOSTIC
• Blinding Strategy: NONE

Study Groups

Healthy Controls

Group Type: NO_INTERVENTION

No interventions assigned to this group

Age-Matched Controls

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

Group Type: NO_INTERVENTION

No interventions assigned to this group

PAD Patients

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

Group Type: EXPERIMENTAL

Supervised exercise therapy

Intervention Type: 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.

Interventions

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.

Intervention Type: BEHAVIORAL

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Massachusetts General Hospital

OTHER

Sponsor Role: lead

Responsible Party

Jeff L. Zhang, PhD

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Massachusetts General Hospital

Boston, Massachusetts, United States

Countries

United States

Central Contacts

Lei Zhang

Role: CONTACT

jeff.zhang@mgh.harvard.edu

6177268627

Facility Contacts

Christopher Conlin

Role: primary

Other Identifiers

2019P001781

Identifier Type: -

Identifier Source: org_study_id