Clinical Research Directory

Improve PAD PERformance With METformin

The PERMET trial will determine whether metformin daily for six months improves six-minute walk performance in individuals with peripheral artery disease compared to placebo.

Vascular Regenerative Cell Exhaustion in Adults With Peripheral Artery Disease (PAD-VRCE)

PAD-VRCE is an observational, cross-sectional, two arm study aimed at determining if the presence of peripheral artery disease (PAD) can influence the number of circulating regenerative cells in blood. From peripheral blood samples, circulating progenitor cell content will be assessed via flow cytometry and compared between individuals with PAD and individuals without PAD. Ultimately, this study plans to evaluate the relationship between PAD, vascular regenerative cell exhaustion and overall cardiovascular health.

Leg Exercise Assistive Paddling (LEAP) Therapy for Peripheral Artery Disease

The purpose of this study is to test the effects of leg exercise assistive paddling (LEAP) therapy during prolonged sitting (PS) on vascular and functional performance in those with peripheral artery disease (PAD) and age-matched controls. LEAP therapy is a novel application of passive limb movement to enhance blood flow through the legs without muscular contractions. Specifically, LEAP therapy is the rotational passive movement of the lower leg about the knee from 90 to 180 degrees of rotation at a cadence of 1Hz. Previous literature has indicated that this movement pattern can produce robust increases in blood flow in the passively moved limb in healthy individuals, and passive limb movement may protect vascular function during PS. However, the impact of LEAP therapy to improve blood flow in the legs of those with PAD during PS is unknown. Participants will participate in a randomized cross-over design study with 2 visits (LEAP therapy and no LEAP therapy). For the first visit, participants will be randomly allocated to receive LEAP therapy during 2.5 hours of PS or not. For the second visit, participants will sit for 2.5 hours and will receive the condition that they did not previously receive. Before and after PS, the following measurements will be made: flow-mediated dilation of the popliteal and brachial arteries, arterial stiffness with tonometry techniques, microvascular vasodilatory capacity and skeletal muscle metabolic rate with near-infrared spectroscopy, autonomic nervous system function, and there will be blood drawn from the antecubital vein. After PS, participants will participate in a graded exercise test to assess functional walking capacity. Finally, during PS, near-infrared spectroscopy on the calf muscles and electrocardiogram will be collected continuously to monitor muscle oxygen availability and autonomic activity, respectively.

IV-X Medical First-in-Human Peripheral Intravascular Lithotripsy Study for PAD

To evaluate the safety and performance of the IV-X Medical Intravascular Lithotripsy (IVL) System in adults in order to demonstrate the ability of the IV-X Medical IVL System to safely and effectively deliver IVL treatment calcified peripheral arteries (iliac, femoral, ilio-femoral, popliteal, and infra-popliteal arteries).

Observational GORE® VIABAHN® Endoprosthesis With PROPATEN Bioactive Surface Global Registry

Collect real-world post-market clinical follow-up data on patients treated with the GORE® VIABAHN® Endoprosthesis with PROPATEN Bioactive Surface (VSX)

Leg Heat Therapy in Peripheral Artery Disease

The goal of this randomized, double-blind, sham-controlled clinical trial is to evaluate the benefits of home-based, leg heat therapy (HT) on lower-extremity functioning and quality of life in patients who suffer from lower-extremity peripheral artery disease (PAD). We will randomize 106 patients to one of two groups that either receive leg HT or a sham intervention. The primary study outcome is the change in 6-minute walk distance between baseline and the 12-week follow up. Secondary outcomes include changes in the short physical performance battery score, handgrip strength, quality of life (measured by the Walking Impairment Questionnaire and Short-Form (SF)-36 Questionnaire), calf muscle strength (measured using a calf ergometer), size (measured by magnetic resonance imaging) and bioenergetics (assessed using phosphorus-31 magnetic resonance spectroscopy), and physical activity (measured by accelerometer).

Women's Health Initiative Strong and Healthy Study

The WHISH trial applies state-of-the science behavioral principles and currently available technologies to deliver a physical activity intervention without face-to-face contact to \~25,000 older U.S. women expected to consent. It includes the National Institute of Aging (NIA) Go4Life® Exercise \& Physical Activity materials 3 and WHISH developed targeted materials based on Go4Life® to provide inspirational tips and recommendations about how to achieve nationally recommended levels of PA and overcome barriers to exercise, with a means for self-monitoring and setting personal goals. The intervention builds upon evidence-based behavioral science principles and intervention components that have proven to be effective in increasing PA in older women, with innovative adaptive approaches to tailoring the delivery to meet individual (personal) needs.

Response to Exercise and Nitric Oxide in PAD

RESIST PAD is a randomized trial of 200 PAD patients to establish: 1) whether a 12-week exercise intervention significantly increases Δ nitrite at 12-week follow-up, compared to control; 2) whether exercise "responders" have greater Δ nitrite increases compared to "non-responders"; 3) among non-responders, whether supplementing exercise with nitrate-rich beetroot juice between weeks 13-24 increases Δ nitrite and improves 6-minute walk at 24-week follow-up.

Prevalence of Obstructive Sleep Apnea in Patients With Peripheral Arterial Occlusive Disease

Obstructive sleep apnea syndrome (OSAS) is characterized by partial (hypopnea) or complete (apnea) obstruction of the upper airways, leading to intermittent hypoxemia and sleep fragmentation. Peripheral arterial occlusive disease (PAOD) is a chronic condition defined by the narrowing or occlusion of arteries in the lower limbs, often resulting in ischemia of downstream tissues. This disease is a common complication of atherosclerosis and affects approximately 1.2% of the general French population. OSAS is a well-established risk factor for atherosclerotic disease, particularly for coronary and neurovascular events. Although a relationship between OSAS and PAOD has been investigated in recent years, the link has not been definitively established and requires further study. Therefore, this preliminary cohort study aims to observe the prevalence of OSAS among patients diagnosed with PAOD, regardless of the disease stage.

The Value of Screening for HPR in Patients Undergoing Lower Extremity Arterial Endovascular Interventions

This is a randomized controlled trial designed to evaluate the role of screening for and intervening on patients with high on treatment platelet reactivity undergoing lower extremity arterial endovascular interventions.

Home-based Exercise Therapy in Patients With Moderate to Severe Peripheral Artery Disease

Peripheral arterial disease (PAD) is a chronic atherosclerotic condition associated with impaired mobility, reduced quality of life, cardiovascular events, and risk of lower limb amputation. Although supervised exercise therapy (SET) is recommended for symptomatic PAD, access and adherence remain limited, particularly among patients with moderate-to-severe disease or chronic limb-threatening ischemia (CLTI). The PILOT-PAD-CYCLE study is a prospective, single-center, pilot randomized controlled trial designed to evaluate the feasibility, acceptability, and preliminary efficacy of a 12-week home-based exercise therapy (HET) program using a portable pedal exerciser in adults with moderate-to-severe PAD, including CLTI, with or without foot wounds. Twelve participants will be randomized 1:1 to either HET plus standard care or standard care alone. The intervention includes individualized exercise prescription, remote supervision by a kinesiologist, cardiovascular education, and follow-up over 12 weeks. Outcomes include feasibility and acceptability metrics, 6-minute walk test distance, vascular perfusion indices, quality of life, and cardiovascular events up to 6 months. This pilot trial aims to generate feasibility data and preliminary efficacy estimates to support the development of a future multicenter randomized controlled trial.

Impact of Nrf2 Activation on Macrovascular, Microvascular & Leg Function & Walking Capacity in Peripheral Artery Disease

Peripheral artery disease (PAD) is associated with elevated oxidative stress, and oxidative stress has been implicated as the cause of reduced endothelial reactivity in individuals with PAD. Endothelial function is important because the endothelium contributes to the dilation of arteries during exercise, thereby implicating impaired endothelial function as a mechanism contributing to exacerbated exercise-induced ischemia. Therefore, the purpose of this study is to test the hypothesis that acute exogenous diroximel fumarate (Vumerity) intake will improve antioxidant capacity, thereby reducing oxidative stress and improving vascular function and walking capacity in those with PAD. During this study, participants will be administered diroximel fumarate or a placebo, and the acute effects of diroximel fumarate on vascular function and walking capacity will be assessed. Vascular function and walking capacity will be assessed with flow-mediated dilation, arterial stiffness, head-up tilt test, blood biomarkers, near-infrared spectroscopy, and a treadmill test. There will be a follow-up visit to assess blood work after diroximel fumarate.

Randomized Controlled Trial of Alert-Based Computerized Decision Support for Patients With Peripheral Artery Disease Not Prescribed Lipid-Lowering Therapy

This single-center, 400-patient, randomized controlled trial assesses the impact of a patient- and provider-facing EPIC Best Practice Advisory (BPA; alert-based computerized decision support tool) to increase guideline-directed utilization of statin and statin-alternative oral LDL-C lowering therapies in patients with PAD who are not being prescribed LDL-C-lowering therapy.

Predictive Value of Systolic Rise Time of the Plantar Arch on the Risk of Major Adverse Limb Events (MALE) and Major Adverse Cardiovascular Events (MACE) in Peripheral Artery Disease (PAD) at Critical Ischaemia Stage

Peripheral artery disease (PAD), vascular disease of atheromatous origin, is a frequent pathology, with a steady and significant increase in prevalence over the last decades. It has various symptoms ranging from mild arterial claudication to critical limb ischemia. The critical ischaemia stage in PAD is defined by rest pain or trophic disorders and is a special situation because of the number of cardiovascular deaths at 1 year (25%), 60% at 5 years and acute ischaemic recurrence at 1 year (25%). It is a medico-surgical pathology. A haemodynamic marker is needed to monitor patients, as it is predictive of limb progression, cardiovascular events and mortality. The Systolic Rise Time (SRT) of the plantar footpad is a recently described haemodynamic measurement of proven value in the diagnosis of PAD. The aim of this study is to show the prognostic value of the Systolic Rise Time on Major Adverse Limb Events (MALE).

The THOR IDE Study

The goal of this clinical trial is to test the Thor system in adult (≥ 18 year old) patients with de novo (new, never treated) calcified lesions in infrainguinal (leg) arteries (peripheral artery disease or PAD). The main question\[s\] it aims to answer are: * Is the Thor system safe in treating these lesions * Does the Thor system work to treat these lesions Participants will: * Receive treatment with the Thor system * Have follow-up visits at Discharge, 30 days, 6 months, and 12 months

Intermittent Pneumatic Compression With and Without Exercise to Improve Functioning in Peripheral Artery Disease

The INTERCEDE randomized trial will establish whether six-months of intermittent pneumatic compression combined with walking exercise improves walking endurance at six-month follow-up, compared to walking exercise + sham compression therapy, in people with lower extremity peripheral artery disease (PAD). The INTERCEDE trial will also determine whether intermittent pneumatic compression therapy improves walking endurance at 6-month follow-up, compared to a sham compression therapy. The trial will also determine whether benefits of intermittent pneumatic compression persist after intermittent pneumatic compression treatment is completed.

Far Red Light to Improve Functioning in PAD

The LIGHT PAD Trial is a Phase II multi-centered randomized clinical trial to collect preliminary data to test whether daily far red light treatment of the lower extremities in people with PAD improves six-minute walk distance, lower extremity perfusion, and ischemia-related damage in gastrocnemius muscle at four-month follow-up, compared to a sham control. Participants will complete 10 minutes of twice daily home treatment with either far red light or a sham light for four months.

Chronical Illness-related Limitations of the Ability to Cope With Rising Temperatures, Third Wave

The CLIMATE-III Observational Study examines to what extent chronically ill patients experience adverse health effects because of heat and whether the patients' specific health behavior, somatosensory amplification, risk and benefit perception, self-efficacy, health literacy, and the degree of urbanisation of the patients' administration district are associated with these effects. Study participants from Germany and Italy will be included in the sample.

The Effects of a Novel, Non-ischemic and Pain-free Exercise Intervention in Peripheral Artery Disease

This study is a 3-month, prospective, randomized controlled clinical trial designed to address the efficacy of the Non-Ischemic Exercise (NICE) program to improve exercise and vascular outcome measures in patients with peripheral artery disease (PAD).

The COCOA-PAD II Trial

Among people with peripheral artery disease (PAD) age 55 and older, the investigators will test the hypothesis that PAD participants randomized to cocoa flavanols will have greater improvement or less decline in six-minute walk distance at six-month follow-up, compared to those randomized to placebo. The study will randomize 190 participants with PAD age 55 and older to one of two groups for six months: cocoa flavanols vs placebo. Our primary outcome is change in six-minute walk distance at six-month follow-up. Secondary outcomes are Actigraph-measured physical activity, brachial artery flow-mediated dilation (FMD), gastrocnemius muscle biopsy measures of endothelial nitric oxide synthase (eNOS) and phosphorylated eNOS, gastrocnemius muscle perfusion (measured by magnetic resonance imaging (MRI)) and gastrocnemius muscle characteristics (measured by muscle biopsy). To achieve the specific aims, the study will randomize 190 participants age 55 and older with PAD to one of two groups: cocoa flavanols vs placebo. Participants will be followed for six months.

The Value of Super-resolution Ultrasound Imaging for Peripheral Artery Disease

Peripheral artery disease (PAD) is a chronic atherosclerotic disorder characterized by stenosis or occlusion of the extracranial arteries distal to the aortic arch, most commonly affecting the lower extremities. This vascular compromise leads to tissue hypoperfusion, resulting in a spectrum of clinical manifestations ranging from asymptomatic disease to intermittent claudication, critical limb ischemia, and limb loss. The microvascular system comprises arterioles, capillaries, and post-capillary venules with diameters less than or equal to 100 micrometers. Emerging evidence underscores that microvascular dysfunction (MVD)-defined as structural and functional impairment of this microcirculatory network-plays a pivotal pathophysiological role in PAD progression, contributing to impaired perfusion reserve, endothelial dysfunction, inflammation, and tissue fibrosis, independent of macrovascular stenosis severity. Super-resolution ultrasound microvascular imaging (SRUMI) is an advanced contrast-enhanced ultrasound technique that leverages the nonlinear acoustic signatures of intravascular microbubble contrast agents (e.g., SonoVue) under ultra-low mechanical index (MI) pulsing schemes. Implemented on the Verasonics Vantage 256 research platform (Verasonics, Inc., Kirkland, WA, USA), SRUMI achieves in vivo visualization of microvascular architecture at sub-diffraction resolution (approximately 10-20 micrometers), surpassing conventional Doppler and contrast-enhanced ultrasound. Key advantages include absence of ionizing radiation, negligible thermal and mechanical bioeffects, real-time capability, portability, and cost-effectiveness. As such, SRUMI represents a promising noninvasive tool to probe microvascular integrity in PAD, enabling mechanistic investigation of MVD's contribution to disease initiation, progression, and therapeutic response. This study aims to evaluate the diagnostic and prognostic utility of SRUMI for assessing microvascular dysfunction in patients with PAD. The investigators prospectively enrolled patients diagnosed with PAD and admitted to the Department of Interventional Vascular Surgery at Peking University First Hospital. Primary objectives include: Characterizing lower-limb microvascular density, morphology, and perfusion patterns via SRUMI across PAD subgroups stratified by comorbidities-including diabetes mellitus, current or former smoking, hypertension, and chronic kidney disease; Assessing the concordance between SRUMI-derived microvascular parameters and established clinical and paraclinical markers, including symptom severity (Rutherford classification), ankle-brachial index (ABI), urinary albumin-to-creatinine ratio (UACR), and retinal microvascular findings on fundoscopy; Determining the sensitivity, specificity, and predictive value of baseline SRUMI metrics for major adverse limb events (MALE) and cardiovascular outcomes during longitudinal follow-up; and Comparing the incremental prognostic value of SRUMI against conventional modalities-including ABI, duplex ultrasonography, and clinical risk scores-using multivariable Cox regression and time-dependent receiver operating characteristic (ROC) analyses. Collectively, this research seeks to establish SRUMI as a quantitative, translatable biomarker of microvascular health in PAD, thereby advancing precision phenotyping, risk stratification, and monitoring of therapeutic efficacy in this high-morbidity population.

Revascularization With Modification Using Definitive IVL and Serration Remodeling for Optimal Lumen

The objective of this first-in-human study is to assess the safety and effectiveness of the Serranator Sonic Intravascular Lithotripsy (IVL) System™ for the treatment of peripheral artery disease.

Promote Weight Loss in Obese Peripheral Artery Disease (PAD) Patients to Prevent Mobility Loss

The PROVE Trial is a randomized clinical trial that will determine whether a weight loss intervention combined with walking exercise achieves greater improvement or less decline in six-minute walk distance at 12 month follow-up than walking exercise alone in people with PAD and BMI\>25 kg/m2. The intervention uses a Group Mediated Cognitive Behavioral framework, connective mobile technology, remote monitoring by a coach, and a calorie restricted Dietary Approaches to Stop Hypertension (DASH)-derived Optimal Macronutrient Intake Trial for Heart Health (OMNIHeart) diet. 212 participants with PAD and BMI \> 25 kg/m2 will be randomized to one of two groups: weight loss + exercise (WL+EX) vs. exercise alone (EX). Participants will be randomized at Northwestern, Tulane University, and University of Minnesota. Our primary outcome is change in six-minute walk distance at 12-month follow-up. Secondary outcomes are change in 6-minute walk distance at 6-month follow-up and change in exercise adherence, physical activity, patient-reported walking ability (measured by the Walking Impairment Questionnaire (WIQ) distance score), and mobility (measured by the Patient-Reported Outcomes Measurement Information System \[PROMIS\] mobility questionnaire) at 12-month follow-up. Tertiary outcomes are perceived exertional effort (measured by the Borg scale at the end of the 6-minute walk at 12-month follow-up), and diet quality. Exploratory outcomes consist of change in the short physical performance battery (SPPB), the WIQ stair climbing and walking speed scores, and calf muscle biopsy measures at 12-month follow-up. Study investigators will perform calf muscle biopsies in 50 participants to compare changes in mitochondrial biogenesis and activity, capillary density, and inflammation between WL+EX vs. EX.

Telehealth Delivered Home-based Walking for Vets With Peripheral Artery Disease

Walking is beneficial for adults with peripheral arterial disease. Benefits include the ability to walk for longer periods and general well being (quality of life). This study will look at two types of delivery methods for a home-based walking program. The walking program includes step count goals, information on healthy walking and motivational messages. The two delivery methods include a web-based delivery and an telehealth delivery. Participants are randomized to either one of the delivery methods or usual care. After 12 weeks participants in the web based or telehealth based groups maybe re-randomized to receive a combination of both web-based and telehealth for a second 12 week period. After 24 weeks, everyone is followed for an additional 12 weeks, so the total time a participant is in the study is 36 weeks. At baseline, 12, 24 and 36 weeks the investigators ask participant to walk (slowly) on a treadmill, perform a six-minute walk test, and several questionnaires on quality of life. Vouchers are provided at each study visit. All participants who complete the study also keep their pedometer.