Effect of Intermittent Pressure in Patients With PAD

Not Applicable

Completed

• Conditions: Peripheral Arterial Disease
• Interventions: Device: Active Intermittent Negative Pressure (INP); Device: Placebo Intermittent Negative Pressure (INP)

• Registration Number: NCT03854097
• Lead Sponsor: University of Dundee

Brief Summary

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.

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 Timeline

• Study Start: 2019-02-16
• Study First Submitted: 2019-02-19
• Study First Submitted QC: 2019-02-22
• Study First Posted: 2019-02-26
• Primary Completion: 2021-06-05
• Study Completion: 2021-06-05
• Status Verified: 2021-08
• Last Update Submitted: 2021-08-05
• Last Update Posted: 2021-08-06

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 65

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Active PAD group	Active Intermittent Negative Pressure (INP)	-40mmHg of Intermittent Negative Pressure (INP) for 4-8 weeks.
Healthy Volunteers	Active Intermittent Negative Pressure (INP)	-40 mmHg of Intermittent Negative Pressure (INP) for 5 days
Placebo PAD group	Placebo Intermittent Negative Pressure (INP)	-10mmHg of Intermittent Negative Pressure (INP) for 4-8 weeks.

Primary Outcome Measures

Name	Time	Method
Change in microvascular endothelial function	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.
Change in microvascular blood flow	Baseline, 1 day and 4-8 weeks	Microvascular blood flow measurement in foot using laser Dopper imaging.
Change in macrovascular endothelial function	Baseline, 1 day and 4-8 weeks	Brachial endothelial function measured as change in brachial blood vessel diameter (%) upon shear stress.
Change in arterial stiffness	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.

Secondary Outcome Measures

Name	Time	Method
Change in pain score	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.
Change in concentration of blood borne inflammatory and oxidative stress biomarkers	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.
Change in Ankle-Brachial Pressure Index (ABPI)	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.

Trial Locations

Locations (1)

School of Medicine, University of Dundee, Ninewells Hospital & Medical School; 🇬🇧 Dundee, United Kingdom