Effect of Intermittent Pressure in Patients With PAD

August 5, 2021 updated by: University of Dundee

Mechanistic Insights Into Changes in Blood Flow Following Application of Intermittent Negative Pressure

The study will evaluate the effect of intermittent negative pressure (INP) on peripheral arterial disease (PAD) patient vascular function and blood flow. Patients will be given either -40mmHg INP or -10mmHg INP which will act as a placebo. Healthy volunteers will be given -40mmHg INP to evaluate changes in vascular function and blood flow with INP in healthy physiology.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Atherosclerosis occurs when blood supply to the lower limbs is restricted upon accumulation of fat in the arteries. Atheroslerosis in the lower limbs is termed peripheral arterial disease (PAD). The initial symptom is pain in the lower limbs followed by ulceration and gangrene. The literature has indicated that intermittent negative pressure (INP) can be used to reduce pain and facilitate wound healing. INP is a non-invasive technique that aims to increase arterial and skin blood flow in lower limbs and foot. This study aims to investigate the underlying mechanisms that are involved in changes in blood flow following application of INP. The Flow-Ox 'boot' will be used to apply INP for periods ranging from 4-8 weeks, for an hour twice per day, to the lower limb to determine the effects of INP on vascular function and blood flow. Specifically, vascular tests such as assessments of endothelial function, arterial stiffness, ankle-brachial pressure index (ABPI) and blood borne metabolic and inflammatory markers will be performed before and after INP application. A pain chart will be employed before and after INP application to determine whether there is any change in perception of pain felt by individuals who suffer from pain associated with lower limb arterial disease.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
65

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

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

  • United Kingdom
      • Dundee, United Kingdom
        • School of Medicine, University of Dundee, Ninewells Hospital & Medical School

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria

PAD Patients:

  • Age ≥ 18 years
  • Attending vascular outpatient clinics or admitted in ward with PAD.
  • ABPI <0.9

Healthy Volunteers:

  • Age ≥ 18 years
  • No current or previous significant cardiovascular illness
  • Able to give written informed consent

Exclusion criteria

PAD Patients:

  • Unable to give written informed consent
  • Patients with deep venous thrombosis
  • Pregnant women

Healthy Volunteers:

  • Positive medical history of: Vascular diseases such as PAD, stroke, IHD, hypertension... etc.
  • Haematological conditions such as hypercoagulability, deep venous thrombosis... etc.,
  • Alcohol excess
  • Unable to give written informed consent
  • Pregnant women

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

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Active PAD group
-40mmHg of Intermittent Negative Pressure (INP) for 4-8 weeks.
Device: Active Intermittent Negative Pressure (INP)
Application of -40mmHg negative pressure on the lower limb
Experimental: Placebo PAD group
-10mmHg of Intermittent Negative Pressure (INP) for 4-8 weeks.
Device: Placebo Intermittent Negative Pressure (INP)
Application of -10mmHg negative pressure on the lower limb
Experimental: Healthy Volunteers
-40 mmHg of Intermittent Negative Pressure (INP) for 5 days
Device: Active Intermittent Negative Pressure (INP)
Application of -40mmHg negative pressure on the lower limb

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in microvascular blood flow
Time Frame: Baseline, 1 day and 4-8 weeks
Microvascular blood flow measurement in foot using laser Dopper imaging.
Baseline, 1 day and 4-8 weeks
Change in microvascular endothelial function
Time Frame: Baseline, 1 day and 4-8 weeks
Peak blood perfusion response to acetylcholine (ACh) delivered by iontophoresis will be measured using a laser Doppler imager.
Baseline, 1 day and 4-8 weeks
Change in arterial stiffness
Time Frame: Baseline, 1 day and 4-8 weeks
Brachial pulse wave analysis (PWA) augmentation index (Ax) and carotid-femoral pulse wave velocity (m/s) (PWV) as an indication of arterial stiffness.
Baseline, 1 day and 4-8 weeks
Change in macrovascular endothelial function
Time Frame: Baseline, 1 day and 4-8 weeks
Brachial endothelial function measured as change in brachial blood vessel diameter (%) upon shear stress.
Baseline, 1 day and 4-8 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in pain score
Time Frame: Baseline, 1 day and 4-8 weeks
Self-scoring of pain felt by patient on a visual analogue scale with 0 being no pain at all to 10 being the worst pain ever felt.
Baseline, 1 day and 4-8 weeks
Change in concentration of blood borne inflammatory and oxidative stress biomarkers
Time Frame: Baseline, 1 day and 4-8 weeks
Concentration of inflammatory and oxidative stress markers of endothelial activation/damage (including IL-1a, IL-6, IL-10, TNF-a, CRP, E-selectin and sICAM-1) measured in serum and plasma collected from patient blood samples.
Baseline, 1 day and 4-8 weeks
Change in Ankle-Brachial Pressure Index (ABPI)
Time Frame: Baseline, 1 day and 4-8 weeks

Brachial systolic pressure and ankle (dorsalis pedis) systolic pressure (mmHg) measured using Doppler probe. ABPI calculated as ankle systolic pressure divided by brachial systolic pressure.

ABPI <0.9 = PAD, ABPI =>1.0 Normal.
Baseline, 1 day and 4-8 weeks

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Dundee

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Jody McIntosh, PhD student

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 16, 2019

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 5, 2021

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 5, 2021

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 19, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 22, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 26, 2019

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 6, 2021

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 5, 2021

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 1-014-18

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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