Red Light Therapy for Peripheral Artery Disease

Overseen By Nicole L Lohr, MD,PHD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Alabama at Birmingham

Disqualifiers: Pregnancy, Pulmonary hypertension, Sickle cell, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 1

Duration: 1 day

40 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests red light therapy to determine if it can improve blood flow in individuals with peripheral artery disease, a condition where narrowed arteries reduce blood flow to the limbs. Participants will receive a single 5-minute exposure to red light. Researchers will measure blood flow changes using ultrasound and assess changes in blood chemistry. Individuals diagnosed with peripheral artery disease and experiencing reduced blood flow to their limbs may be suitable for this trial. As an unphased trial, this study offers participants the chance to contribute to groundbreaking research that could lead to new treatments for peripheral artery disease.

Do I need to stop my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What prior data suggests that this red light therapy is safe for peripheral artery disease?

Research has shown that red light therapy might improve blood flow in people with peripheral artery disease. In these studies, the therapy involved shining a specific type of red light (670 nm) on the skin briefly. This process can widen blood vessels by releasing nitric oxide, which relaxes the vessels and enhances circulation.

Previous studies suggest that red light therapy is generally safe. For instance, one study found that using the light repeatedly over two weeks increased blood flow without serious side effects. Another study, involving just one session of red light therapy, also demonstrated improved blood flow and no major negative effects. While these findings are encouraging, more research is needed to fully understand the therapy's safety. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Unlike the standard treatments for Peripheral Artery Disease, which often involve medications to improve blood flow or surgical interventions, red light therapy is unique because it uses specific wavelengths of light to potentially enhance blood circulation and reduce symptoms. Researchers are excited about this therapy because it offers a non-invasive alternative that might stimulate cellular energy production and repair. This innovative approach could provide a safer, more convenient option for patients, with the potential for fewer side effects compared to traditional treatments.

What evidence suggests that Red Light Treatment might be an effective treatment for peripheral artery disease?

Research has shown that red light therapy, which participants in this trial will receive, can improve blood flow in individuals with peripheral artery disease. One study found that a single session of this therapy increased nitrosothiols in the blood, substances that help widen blood vessels. This widening can enhance blood flow in the legs. Another study demonstrated that repeated therapy over two weeks led to a steady increase in blood flow in the affected areas. Early findings suggest that 670 nm red light can release nitric oxide, a compound that relaxes blood vessels and improves circulation. These results indicate that red light therapy could be a promising method to enhance blood flow in peripheral artery disease. ^{1 2 3 4 6}

Who Is on the Research Team?

Nicole L Lohr, MD,PHD

Principal Investigator

Medical College of Wisconsin

Are You a Good Fit for This Trial?

This trial is for adults aged 18-85 with peripheral artery disease, indicated by an ankle brachial index outside the normal range. It's open to all ethnicities. Excluded are those under 18 or over 85, pregnant women, individuals sensitive to perflutren contrast agents, those with uncontrolled medical conditions like high blood pressure or sickle cell disease, and people who can't understand the consent process.

Inclusion Criteria

I have been diagnosed with peripheral artery disease.

I am eligible regardless of my gender or ethnicity.

Exclusion Criteria

I have a neurological condition like spinal stenosis or a pain disorder.

I have high blood pressure in the lungs.

Your blood pressure is higher than 160/95 and you are not receiving treatment for it.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Treatment

Participants undergo a single 5-minute exposure to 670 nm light, with blood flow measured by ultrasound and blood samples collected for nitric oxide metabolites

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

1 week

What Are the Treatments Tested in This Trial?

Interventions

• Red Light Treatment

Trial Overview The study tests a single five-minute exposure of red light therapy on the lower leg muscle in patients with peripheral artery disease. The aim is to see if this treatment improves blood flow as measured by ultrasound after injecting a special contrast agent. Blood samples will also be taken to check for changes in nitric oxide levels.

How Is the Trial Designed?

Group I: Red Light treatment Experimental Treatment 2 Interventions

This is a single arm design. All subjects will be enrolled to have peripheral blood flow measured before, during, and after red light exposure.

Who Is Running the Clinical Trial?

University of Alabama at Birmingham

Lead Sponsor

Trials

1,677

Recruited

2,458,000+

Medical College of Wisconsin

Lead Sponsor

Trials

645

Recruited

1,180,000+

Published Research Related to This Trial

Both low-level laser therapy and LED light sources can effectively induce vasodilation in porcine coronary arteries, with maximum relaxation observed at an energy density of 10 J/cm², achieving comparable results between the two light sources.

The vasodilation effect is mediated by a nitric oxide-dependent mechanism, suggesting that these light therapies could be beneficial in clinical settings, such as during coronary artery bypass surgery, to facilitate easier suturing of blood vessels.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Light-induced vasodilation of coronary arteries and its possible clinical implication. Plass, CA., Loew, HG., Podesser, BK., et al.[2015]

Irradiating the hind limb of mice with red light (670 nm) for 5-10 minutes significantly increased blood flow by promoting the release of a nitric oxide precursor, demonstrating its potential for enhancing vasodilation in ischemic tissues.

In a model simulating human peripheral artery disease, repeated light treatment over 14 days led to a sustained increase in blood flow in the affected limb, suggesting that this therapy could be a simple and effective home-based treatment for individuals with impaired blood circulation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

In Vivo Characterization of a Red Light-Activated Vasodilation: A Photobiomodulation Study. Keszler, A., Lindemer, B., Broeckel, G., et al.[2023]

The xenon-hydrogen chloride excimer laser is highly effective for treating peripheral artery disease, achieving an 86% procedural success rate and a 93% limb salvage rate at 6 months in a study of 145 patients.

This laser operates using a nonthermal mechanism to ablate plaque, making it particularly beneficial for complex cases, although careful patient selection is necessary, especially for those with diabetes and renal failure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Excimer laser-assisted angioplasty for infrainguinal artery disease. Das, TS.[2022]

Recent advancements in laser technology have significantly improved our ability to treat vascular diseases, leading to various clinical applications such as laser endarterectomy and laser angioplasty.

These laser techniques enhance the effectiveness of traditional procedures by targeting blood vessels more precisely, which may improve patient outcomes in cardiovascular disease management.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Vascular applications of lasers. Faught, WE., Lawrence, PF.[2019]

Vascular photodynamic therapy (PDT) significantly increases the bursting pressure of rat iliac arteries shortly after treatment, indicating improved arterial wall strength compared to control groups.

However, after one year, while the bursting pressure remained stable in the lower energy PDT group, the higher energy group (100 J/cm) showed signs of aneurysmal dilatation, suggesting potential long-term risks associated with higher energy PDT.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Arterial wall strength after endovascular photodynamic therapy. Gabeler, EE., van Hillegersberg, R., Sluiter, W., et al.[2013]

Laser technology has shown promise in treating completely blocked blood vessels, particularly in peripheral vascular disease, but concerns remain about potential damage to the arterial walls, including perforation.

The presentation discusses the initial experiences with a new hybrid laser probe used in angioscopically guided laser-assisted angioplasty, indicating advancements in laser treatment methods for lower extremity vascular issues.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The role of lasers in the management of peripheral vascular disease. Sanfelippo, PM.[2017]

In a study involving 22 patients with angina pectoris, intravascular red light therapy (IRLT) using a diode laser was found to be safe and successfully performed without any procedural complications.

At 6 months follow-up, the mean minimal lumen diameter was 2.57 mm, and only 4 patients developed angiographic restenosis, indicating that IRLT may effectively reduce the risk of restenosis after coronary stenting.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Intravascular Red Light Therapy after Coronary Stenting Ñ Angiographic and Clinical Follow-up Study in Humans. Kaul, U., Singh, B., Sudan, D., et al.[2019]

Laser energy can effectively recanalize totally blocked peripheral arteries, improving blood flow in patients with peripheral vascular disease, which is less invasive than traditional surgery.

While laser-assisted balloon angioplasty shows promise for treating certain types of arterial blockages, its effectiveness is currently limited for long occlusions or below-the-knee disease compared to standard surgical methods.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Current status of laser angioplasty. Seeger, J., Abela, GS.[2007]

Recent advancements in laser technology have improved its potential for treating peripheral vascular disease through percutaneous revascularization, but its effectiveness is still under investigation.

Current use of lasers in vascular disease treatment is considered experimental, highlighting the need for more clinical studies to establish their safety and efficacy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Vascular applications of laser. Cragg, AH., Gardiner, GA., Smith, TP.[2007]

In a study involving 27 patients with chronic femoropopliteal occlusions, the Nd-YAG laser system achieved initial clinical success in 69% of cases, significantly improving blood flow as indicated by the ankle-brachial pressure ratio.

However, the long-term results were disappointing, with a 1-year primary patency rate of only 12%, and a high incidence of complications such as vessel perforation (28%) and wall dissection (25%), suggesting that the current technique requires significant improvements.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Percutaneous laser recanalisation of femoropopliteal occlusions using continuous wave Nd-YAG laser and sapphire contact probe delivery system. Ashley, S., Brooks, SG., Gehani, AA., et al.[2019]

Direct laser light combined with percutaneous transluminal angioplasty (PTA) successfully recanalized atherosclerotic peripheral arteries in 92% of cases (33 out of 36 procedures), indicating high efficacy for this treatment method.

While there were some complications, including emboli and hematomas, the preliminary results suggest that direct laser angioplasty could be a valuable addition to standard PTA for treating blocked arteries, with a mean follow-up of 3 months.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Direct argon laser exposure for recanalization of peripheral arteries: early results. Nordstrom, LA., Castaneda-Zuniga, WR., Young, EG., et al.[2007]

In a study involving 13 juvenile pigs, photodynamic therapy (PDT) using red light significantly improved the lumen size and reduced neointimal hyperplasia in balloon-injured coronary arteries compared to control, suggesting its efficacy in preventing artery narrowing after injury.

The results indicate that PDT not only minimizes neointimal growth but also maintains the lumen size of treated arteries similar to healthy segments, highlighting its potential as a safe and effective treatment for restenosis following endovascular procedures.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Reduction in the response to coronary and iliac artery injury with photodynamic therapy using 5-aminolaevulinic acid. Jenkins, MP., Buonaccorsi, GA., Mansfield, R., et al.[2019]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9108481/

In Vivo Characterization of a Red Light-Activated Vasodilation Our results strongly support 670 nm light can regulate dilation of conduit vessel by releasing a vasoactive nitric oxide precursor species.

2. scholars.northwestern.edu scholars.northwestern.edu/en/projects/proprioception-and-joint-stability-across-planes-in-knee-asteoart-7

Far Red Light to Improve Functioning in PAD A single dose of far red light therapy increased plasma nitrosothiols, improved lower extremity blood flow, and meaningfully improved functional performance in ...

3. clinicaltrials.gov clinicaltrials.gov/study/NCT03203239

Red Light Treatment in Peripheral Artery Disease Subjects with a known diagnosis of peripheral artery disease as measured by an abnormal ankle brachial index (<.9 or >1.1) will undergo a single 5 min exposure ...

4. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0891584917307578

Original article Red/near infrared light stimulates release of ... Original article. Red/near infrared light stimulates release of an endothelium dependent vasodilator and rescues vascular dysfunction in a diabetes model.

5. withpower.com withpower.com/trial/phase-2-walking-difficulty-2024-a26a0

Far Red Light Therapy for Peripheral Arterial Disease In a model simulating human peripheral artery disease, repeated light treatment over 14 days led to a sustained increase in blood flow in the affected limb, ...

6. sciencedirect.com sciencedirect.com/science/article/pii/S0026286225000834

Pilot study on near-infrared spectroscopy in peripheral ... This pilot study evaluated NIRS for differentiating between non-ischemic upper limbs and ischemic lower limbs, and assessed NIRS correlation with ABI. To do ...