Heat Therapy and Peripheral Artery Disease

Maximal walking distance a participant can walk, through a graded treadmill test.

Maximum distance participant can walk without pain (IC)

Amount of time able to walk pain free before reaching claudication

Quality of life was assessed using the Vascular Quality of Life Questionnaire (VacQoL), a disease-specific instrument comprised of 25 items rated on a 7-point Likert scale. When scored as a mean across items, the VacQoL has a range from 1 to 7, where 1 indicates the poorest quality of life and 7 the best. Alternatively, when summed, the total score ranges from 25 (worst) to 175 (best).

The Short Form 36 Health Survey Questionnaire (SF-36) is used to indicate the health status of particular populations, to help with service planning and to measure the impact of clinical and social interventions.

The EQ-5D-5L is a brief, multi-attribute, generic, health status measure composed of 5 questions with Likert response options (descriptive system) and a visual analogue scale. The latter asks patients to rate their own health from 0 to 100 (the worst and best imaginable health, respectively).

Investigators will compare blood sample measures of TNF-α, CRP, MCP-1, IL-1Ra, IL-4, IL-6, IL-8, IL-10, and eHSP70.

Investigators will compare blood sample measures of HIF-1α, VEGF, endothelin-1, MMP-9, MMP-10 and nitrite.

Superficial tissue oxygen saturation and muscle oxygen consumption will be measured throughout the protocol by a NIRS probe placed on the skin surface of the medial gastrocnemius on the most affected leg. Measurements will be recorded during the graded treadmill test.

Vascular ultrasound images of the carotid, brachial and superficial femoral artery will be obtained using a high-resolution duplex machine (Terason, Burlington, MA) and subsequently used to calculate wall thickness, changes in arterial blood flow and shear stress.

Flow-mediated dilation (FMD) of the brachial artery will be measured after 10 min of supine rest via reactive hyperemia in response to transient ischemia of the lower arm according to international guidelines.

Ankle brachial pressure index (ABPI): ABPI will be determined at rest and following a treadmill test by using standardised methodologies

Following a 10-minute period of supine rest in a quiet room, blood pressure will be measured (in duplicate) using an automated sphygmomanometer.

Pulse wave velocity will be measured using central (carotid-femoral) and peripheral (carotid-radial) via a handheld tonometer following standard guidelines. This will be used with a SphygmoCor XCEL.

Physical activity will be measured using a wrist-worn accelerometer. Physical activity will be monitored for 7 days at a time. This including 7 days pre-trial, 7 days pre heat intervention, 7 days post heat intervention, and 7 days post trial (Dependent on what group randomisation was first).

The investigators will record the number of eligible participants, as well as the number who enrol onto the study.

The investigators will examine adherence on visits to the lab for the heat therapy intervention. I.e. How many sessions were completed throughout the 8 weeks.

Workshop interviews will be held between an investigator and participants who has either completed the intervention, withdrawn or declined participation, to ask questions regarding the intervention protocol.

The investigators will examine participant thermal comfort/discomfort throughout each intervention day. This will be done through recording of time spent in tub and thermal comfort scales.