Active clinical trials for "Intermittent Claudication"

Specific Aim 1: To test the hypothesis that subjects with PAD and intermittent claudication have altered expression of genes that regulate skeletal muscle metabolism. Specific Aim 2: To test the hypothesis that exercise training improves calf skeletal muscle insulin resistance and genes that regulate skeletal muscle metabolic function in PAD patients with intermittent claudication.

The study investigates the incidence of remote ischemic conditioning in mild cognitive impairment and dementia patients

This study will test how well a new contrast agent (dye) used in magnetic resonance imaging (MRI) can help visualize totally blocked arteries that normally supply blood to the neck, arms or legs. Currently used agents work well in visualizing normal or partly blocked arteries (arteries that have some blood flowing through them), but only poorly in totally blocked arteries. This study will see if a contrast agent called gadofosveset can better brighten images of completely blocked arteries. Gadofosveset is approved in Europe for use in MRI scans, but is still considered experimental in the United States. People 18 years of age or older with known or suspected total blockage of an artery to the neck, arm or leg may be eligible for this study. Participants undergo MRI scanning with gadofosveset contrast dye. MRI uses a magnetic field and radio waves to produce images of body tissues and organs. For this procedure, the subject lies on a table that can slide in and out of the tubular scanner, wearing earplugs to muffle loud noises that occur during the scanning process. The procedure lasts about 1.5 to 2 hours, during which the subject may be asked to hold his or her breath several times for as long as 5 to 20 seconds. During the procedure, gadofosveset is injected and several kinds of MRI pictures are taken to understand better how the new agent works. Subjects may be asked to undergo a second scan using conventional MRI contrast dye

Exercise training improves walking capacity and regional perfusion in patients with Intermittent Claudication (IC). Endothelial Progenitor Cells (EPCs) and Endothelial Microparticles (EMPs) could play an important role in this process, promoting the healing of the diseased endothelium. The investigators are going to measure EPCs and EMPs in a group of patients with IC and in a control group of healthy individuals before a treadmill test and 2, 24, and 48 hours after the test. Subsequently, a group of IC patients will be randomly assigned to perform a 12-week home-based exercise training program. The investigators expect a significant increase of EMPs and EPCs after acute and chronic physical activity. We expect also a correlation between the increase of EMPs and EPCs and the improvement in walking capacity. Aim of the study is to demonstrate that acutely performed aerobic exercise could be able to promote the mobilization of EMPs and EPCs in patients with IC and that endothelial progenitor cells mobilization could play a pivotal role in exercise induced improvement of walking performance and endothelial function in subjects with IC.

Background: Peripheral arterial disease is a result of atherosclerotic occlusion in the major arteries supplying the lower limbs and is associated with an increased risk of mortality and morbidity. It results in restricted blood flow to the skeletal muscles causing intermittent claudication (IC). IC presents as cramp like pain affecting 5% of the population >50 years and is associated with a substantial reduction in walking capacity, quality of life and diminished physical function. Supervised exercise programmes have been demonstrated to improve maximum walking distances and NICE recommends group-based supervised exercise for treating patients with IC. However, there is significant variability in the impact of treatment across studies and little agreement on the underlying mechanism whereby exercise increases functional outcomes. Potential mechanisms include skeletal muscle metabolism, VO2 max, anaerobic threshold and endothelial function. Studies are needed to better understand how exercise improves outcome and in whom, so as to better refine and target the treatment. The participation of patients with IC in exercise programmes is low. The investigators need to understand factors influencing participation so that we can improve the number of patients with IC benefiting from the programme The research consists of two workstreams: Workstream one Objective: Assess the extent to which patient baseline characteristics and candidate physiological mechanisms are associated with clinical improvement in IC patients participating in an exercise programme Patients: Patients with documented IC referred from a Vascular Consultant. Eligible patients will be invited to participate in a 12 week supervised exercise programme. Testing Schedule: Measurements will be recorded at baseline (prior to exercise), immediately after the completion of the exercise programme and then three months after. Measurements include: Baseline characteristics that might predict outcome: Quality of life using the VascuQol questionnaire Clinical indicators of lower limb function: Ankle brachial pressure index (ABPI), intermittent claudication distance (ICD), Maximum walking distance (MWD). Candidate physiological mechanisms Aerobic capacity (VO2 max & AT) Muscular strength and endurance Muscle morphology (including muscle thickness, pennation angle, fascicle length and elastography) Endothelial function (sheer stress response as measured by flow mediated dilation) Analysis: Regression analysis will be used to explain variation in patient maximum walking distance at 3 months. The regression will use 9 candidate measures of physiological response and 3 baseline measures to explore what mechanism and patient factors may be associated with clinical improvements. 100 patients recruited over 2 years will give a 90% power to detect an additional increase in variability in MWD explained by each candidate measure of around 5% at the a 0.05 significance level. This research will be used to identify which types of exercise may be most influential in improving outcome and in which patients. Workstream two Objective: Explore the reasons behind patients' participation, non-participation in, experience of and adherence to the exercise programme. Study Design: An interview study of patients with IC routinely referred for supervised exercise. Three groups of patients will be invited to participate. Those who: Choose not to participate in the exercise programme (Group A) Agree to participate in the exercise programme (Group B). Agree to participate but discontinue after at least one session (Group C). Semi-structured face-to-face interviews with 20 patients per group, interviews will be conducted using a topic guide to ensure consistency. The format will be flexible to allow participants to generate naturalistic data on what they consider as important and / or successful in terms of outcome. Data will be analysed thematically and managed using Nvivo software - the approach will be inductive and iterative. This research will be used to redesign the current exercise programme to improve participation and so the impact of exercise in patients with IC.

Title: How does exercise improve the calf muscle in patients with poor blood supply to their leg? Purpose of the project: Patients with peripheral arterial disease have a poor blood supply to their lower leg. The reduced inflow prevents the leg from utilising nutrients and oxygen as easily as a healthy leg would. This causes pain when walking (intermittent claudication), which often occurs after a reproducible distance e.g. every 50 yards. These patients have a reduction in their quality of life as they feel embarrassed in social situations e.g. walking around town requires multiple breaks, so they tend to avoid this and isolate themselves more. One treatment for claudication is exercising until the pain comes on; which most are reluctant to do. Walking up to three times a week for an hour, can double most people's walking distances, but doesn't always. The reason why some improve with exercise and others do not remains unknown. This project will be the first randomised controlled trial of exercise in claudicants that focuses on the adaptations that occur in the muscle at a cellular level. We wish to compare muscle cells from a group that have exercised and group that have not. We will focus on the change in muscle cell size and function at present, and later progress to why and how this happens. Methods: We will take measurements at the start of the study (baseline), after 6 weeks and then 3, 6 and 12 months. These measurements will be of a patient's fitness, actual walking distances and blood samples. At the time of surgery, muscle from the calf will be taken from the affected leg. This will be processed at the University's biomedical science department to look at the different types of muscle fibre and how efficiently they are working.

The purpose of this study is to determine whether 12 weeks of daily home use of the FM220 in the most affected leg of patients with PAD and claudication, will improve peak walking time (PWT) at three months as compared with a non-treated control group.

To perform an observational analysis to determine if mean translesional gradient measurements (TLG) are associated with differences in clinical outcomes in patients with femoropopliteal arterial disease and claudication. Hypothesis: Patients stratified by a residual translesional gradient </= 11 mmHg after peripheral revascularization or angiography alone will have better clinical outcomes than patients with TLG > 11 mmHg as assessed by six minute walk (6MW), walking impairment questionnaire scores (WIQ), ankle brachial index and need for repeat procedure at 6 months.

The medical device being examined in this study is the Bard® LifeStent® 5F Vascular Stent System. It is intended for use in patients who suffer from peripheral artery disease (PAD). PAD is generally associated with blocked arteries of the legs. The superficial femoral artery (SFA) and popliteal artery are common locations for this problem to develop. The patient may experience pain or discomfort in the leg that occurs when walking or have other complications associated with wound healing. The purpose of this study is to collect information to assess the deliverability, clinical utility, safety and effectiveness of the Bard® LifeStent® 5F Vascular Stent System.

Current evidence cannot explain the clinical features of peripheral arterial disease only from the principle of reduced blood flow. Explanations have therefore in addition been linked to mitochondrial dysfunction of skeletal muscles. This study will elucidate whether there is a relation between clinical variables of the different levels of arterial insufficiency in peripheral arterial disease and mitochondrial respiratory capacity.