Clinical trial NCT03854097: Effect of Intermittent Pressure in Patients With PAD
Official title: Mechanistic Insights Into Changes in Blood Flow Following Application of Intermittent Negative Pressure
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Peripheral Arterial Disease
Keywords: PAD
Lead sponsor: University of Dundee
Sponsor class: OTHER
First posted: 2019-02-26
Enrollment: 65
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

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.

Eligibility criteria: 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

Primary outcomes:
measure: Change in microvascular blood flow
timeFrame: Baseline, 1 day and 4-8 weeks
measure: Change in microvascular endothelial function
timeFrame: Baseline, 1 day and 4-8 weeks
measure: Change in arterial stiffness
timeFrame: Baseline, 1 day and 4-8 weeks
measure: Change in macrovascular endothelial function
timeFrame: Baseline, 1 day and 4-8 weeks
Secondary outcomes:
measure: Change in pain score
timeFrame: Baseline, 1 day and 4-8 weeks
measure: Change in concentration of blood borne inflammatory and oxidative stress biomarkers
timeFrame: Baseline, 1 day and 4-8 weeks
measure: Change in Ankle-Brachial Pressure Index (ABPI)
timeFrame: Baseline, 1 day and 4-8 weeks
Other outcomes:
Locations:
city: Dundee
country: United Kingdom
facility: School of Medicine, University of Dundee, Ninewells Hospital & Medical School
Study officials:
affiliation: PhD student
name: Jody McIntosh
role: PRINCIPAL_INVESTIGATOR
References: