Update on the pathophysiology and medical treatment of peripheral artery disease

Toe-brachial index and toe systolic blood pressure for the diagnosis of peripheral arterial disease

BACKGROUND

Peripheral arterial disease (PAD) of the lower limbs is caused by atherosclerotic occlusive disease in which narrowing of arteries reduces blood flow to the lower limbs. PAD is common; it is estimated to affect 236 million individuals worldwide. Advanced age, smoking, hypertension, diabetes and concomitant cardiovascular disease are common factors associated with increased risk of PAD. Complications of PAD can include claudication pain, rest pain, wounds, gangrene, amputation and increased cardiovascular morbidity and mortality. It is therefore clinically important to use diagnostic tests that accurately identify PAD. Accurate and timely detection of PAD allows clinicians to implement appropriate risk management strategies to prevent complications, slow progression or intervene when indicated. Toe-brachial index (TBI) and toe systolic blood pressure (TSBP) are amongst a suite of non-invasive bedside tests used to detect PAD. Both TBI and TSBP are commonly utilised by a variety of clinicians in different settings, therefore a systematic review and meta-analysis of their diagnostic accuracy is warranted and highly relevant to inform clinical practice.

OBJECTIVES

To (1) estimate the accuracy of TSBP and TBI for the diagnosis of PAD in the lower extremities at different cut-off values for test positivity in populations at risk of PAD, and (2) compare the accuracy of TBI and TSBP for the diagnosis of PAD in the lower extremities. Secondary objectives were to investigate several possible sources of heterogeneity in test accuracy, including the following: patient group tested (people with type 1 or type 2 diabetes, people with renal disease and general population), type of equipment used, positivity threshold and type of reference standard.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the MEDLINE, Embase, CINAHL, Web of Science, LILACS, Zetoc and DARE databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 27 February 2024.

SELECTION CRITERIA

We included diagnostic case-control, cross-sectional, prospective and retrospective studies in which all participants had either a TSBP or TBI measurement plus a validated method of vascular diagnostic imaging for PAD. We needed to be able to cross-tabulate (2 x 2 table) results of the index test and the reference standard to include a study. To be included, study populations had to be adults aged 18 years and over. We included studies of symptomatic and asymptomatic participants. Studies had to use TSBP and TBI (also called toe-brachial pressure index (TBPI)), either individually, or in addition to other non-invasive tests as index tests to diagnose PAD in individuals with suspected disease. We included data collected by photoplethysmography, laser Doppler, continuous wave Doppler, sphygmomanometers (both manual and aneroid) and manual or automated digital equipment.

DATA COLLECTION AND ANALYSIS

Two review authors independently completed data extraction using a standardised form. We extracted data to populate 2 x 2 contingency tables when available (true positives, true negatives, false positives, false negatives). Where data were not available to enable statistical analysis, we contacted study authors directly. Two review authors working independently undertook quality assessment using QUADAS-2, with disagreements resolved by a third review author. We incorporated two additional questions into the quality appraisal to aid our understanding of the conduct of studies and make appropriate judgements about risk of bias and applicability.

MAIN RESULTS

Eighteen studies met the inclusion criteria; 13 evaluated TBI only, one evaluated TSBP only and four evaluated both TBI and TSBP. Thirteen of the studies used colour duplex ultrasound (CDU) as a reference standard, two used computed tomography angiography (CTA), one used multi-detector row tomography (MDCT), one used angiography and one used a combination of CDU, CTA and angiography. TBI was investigated in 1927 participants and 2550 limbs. TSBP was investigated in 701 participants, of which 701 limbs had TSBP measured. Studies were generally of low methodological quality, with poor reporting of participant recruitment in regard to consecutive or random sampling, and poor reporting of blinding between index test and reference standard, as well as timing between index test and reference standard. The certainty of evidence according to GRADE for most studies was very low.

AUTHORS' CONCLUSIONS

Whilst a small number of diagnostic test accuracy studies have been completed for TBI and TSBP to identify PAD, the overall methodological quality was low, with most studies providing a very low certainty of evidence. The evidence base to support the use of TBI and TSBP to identify PAD is therefore limited. Whilst both TBI and TSBP are used extensively clinically, the overall diagnostic performance of these tests remains uncertain. Future research using robust methods and clear reporting is warranted to comprehensively determine the diagnostic test accuracy of the TBI and TSBP for identification of PAD with greater certainty. However, conducting such research where some of the reference tests are invasive and only clinically indicated in populations with known PAD is challenging.

Interaction and combined effect of triglyceride-glucose index and hypertension on type 2 diabetes individuals' peripheral arterial disease risk

BACKGROUND

The interaction and combined effect of the triglyceride-glucose (TyG) index, an alternative parameter of insulin resistance, along with hypertension (HT), on the risk of peripheral arterial disease (PAD), a specific type of atherosclerotic cardiovascular disease, in individuals with type 2 diabetes (T2D) seems straightforward. However, specific research on this topic remains scarce.

METHODS

In this cross-sectional study, 2027 adult participants with T2D were devided into four groups based on the mean values of TyG index and various blood pressure parameters along with its category. Binary logistic regression, interaction analysis, combined effect size, and goodness-of-fit of the constructed models were performed.

RESULTS

The TyG index's individual effect and it's combined effect with HT, or higher systolic blood pressure (SBP) or higher mean arterial pressure in patients with T2D correlated with a higher PAD risk respectively (odds ratio [OR], 0.50, [95% confidence interval {CI} 0.28-0.89]; OR, 0.32, [95% CI 0.12-0.90]; OR, 0.35, [95% CI 0.13-0.94]; OR, 0.35, [95% CI 0.12-0.98], respectively). Only an interaction effect exists between the TyG index and SBP (multiplicative interaction{INTM}: 1.02 [1.002, 1.038]). Combining them can significantly improve the accuracy of predicting PAD (area under the receiver operating characteristic curve {AUC}MAX = 0.7, AUCModel3 + TyG index + SBP-AUCModel3 = 0.027). All P values were < 0.05.

CONCLUSION

This study suggested that TyG index and hypertension, as well as their combined and interaction effect were significantly correlated with the risk of PAD in T2D individuals.

Netrin1-Enriched Exosomes From Genetically Modified ADSCs as a Novel Treatment for Diabetic Limb Ischemia

Diabetic limb ischemia (DLI) is a frequent complication of diabetes and the leading cause of non-traumatic amputation. Traditional treatments like stent placement and bypass surgery may not suit all patients. Exosome transplantation has emerged as a promising therapy. Netrin1, a protective cardiovascular factor, has an unclear role in DLI. This study investigates the role of Netrin1 in DLI patients and evaluates the therapeutic potential of exosomes derived from Netrin1-overexpressing adipose-derived stem cells (N-ADSCs). The expression of Netrin1 is significantly decreased in both endothelial cells and serum of DLI patients, highlighting its potential as a biomarker or therapeutic target. In vitro, Netrin1-enriched exosomes (N-Exos) promoted human umbilical vein endothelial cell (HUVEC) proliferation, migration, tube formation, and increased resistance to apoptosis under high glucose conditions. These protective effects are mediated through PI3K/AKT/eNOS and MEK/ERK pathways, and N-Exos further facilitated macrophage polarization from M1 to M2. In vivo, N-Exos demonstrates superior therapeutic effects over ADSC exosomes (Exos), including enhanced angiogenesis, improved collateral artery remodeling, reduced inflammation, and muscle protection. Collectively, these findings identify Netrin1 as a critical factor in DLI and underscore its significance in disease progression and therapeutic strategies. N-Exos offers a promising non-cellular therapeutic approach for the treatment of DLI.

Mesenchymal stromal cell therapy (REGENACIP®), a promising treatment option in chronic limb threatening ischemia - a narrative review

Chronic Limb Threatening Ischemia (CLTI) is a challenging clinical problem associated with high morbidity and mortality. Endovascular interventions have been the cornerstone of treatment whenever possible. It is estimated that CLTI represents < 10% of all Peripheral Artery Disease patients, yet 50% of the patients end up either with a major amputation of the lower limbs or die of cardiovascular causes within one year period, especially in those with unsuccessful revascularization or "no-option" CLTI. Cell-based therapeutics, especially bone marrow-derived mesenchymal stromal cells have emerged as a potential, promising, and novel alternate therapeutic modality in the management of CLTI, bolstered with positive results in numerous research, including randomized and nonrandomized trials. REGENACIP® is one such BM-MSC therapy approved by Central Drugs Standard Control Organization in India for the management of "no-option" Atherosclerotic Peripheral Arterial disease / Buerger's disease patients with established critical limb ischemia in Rutherford Grade III-5 or III-6, not eligible for or have failed traditional revascularization treatment, with rest pain and / or ulcers in the affected limb. The current review aims to deliberate upon the various aspects of CLTI and clinical benefits of REGENACIP® therein.

LncRNA H19/miR-107 regulates endothelial progenitor cell pyroptosis and promotes flow recovery of lower extremity ischemia through targeting FADD

BACKGROUND

Peripheral artery disease (PAD) is an ischemic disease with a rising incidence worldwide. The lncRNA H19 (H19) is enriched in endothelial progenitor cells (EPCs), and transplantation of pyroptosis-resistant H19-overexpressed EPCs (oe-H19-EPCs) may promote vasculogenesis and blood flow recovery in PAD, especially with critical limb ischemia (CLI).

METHODS

EPCs isolated from human peripheral blood was characterized using immunofluorescence and flow cytometry. Cell proliferation was determined with CCK8 and EdU assays. Cell migration was assessed by Transwell and wound healing assays. The angiogenic potential was evaluated using tube formation assay. The pyroptosis pathway-related protein in EPCs was detected by western blot. The binding sites of H19 and FADD on miR-107 were analyzed using Luciferase assays. In vivo, oe-H19-EPCs were transplanted into a mouse ischemic limb model, and blood flow was detected by laser Doppler imaging. The transcriptional landscape behind the therapeutic effects of oe-H19-EPCs on ischemic limbs were examined with whole transcriptome sequencing.

RESULTS

Overexpression of H19 in EPCs led to an increase in proliferation, migration, and tube formation abilities. These effects were mediated through pyroptosis pathway, which is regulated by the H19/miR-107/FADD axis. Transplantation of oe-H19-EPCs in a mouse ischemic limb model promoted vasculogenesis and blood flow recovery. Whole transcriptome sequencing indicated significant activation of vasculogenesis pathway in the ischemic limbs following treatment with oe-H19-EPCs.

CONCLUSIONS

Overexpression of H19 increases FADD level by competitively binding to miR-107, leading to enhanced proliferation, migration, vasculogenesis, and inhibition of pyroptosis in EPCs. These effects ultimately promote the recovery of blood flow in CLI.

The Use of Autologous Cell Therapy in Diabetic Patients with Chronic Limb-Threatening Ischemia

Autologous cell therapy (ACT) is primarily used in diabetic patients with chronic limb-threatening ischemia (CLTI) who are not candidates for standard revascularization. According to current research, this therapy has been shown in some studies to be effective in improving ischemia parameters, decreasing the major amputation rate, and in foot ulcer healing. This review critically evaluates the efficacy of ACT in patients with no-option CLTI, discusses the use of mononuclear and mesenchymal stem cells, and compares the route of delivery of ACT. In addition to ACT, we also describe the use of new revascularization strategies, e.g., nanodiscs, microbeads, and epigenetics, that could enhance the therapeutic effect. The main aim is to summarize new findings on subcellular and molecular levels with the clinical aspects of ACT.

Immune and inflammatory insights in atherosclerosis: development of a risk prediction model through single-cell and bulk transcriptomic analyses

Background

Investigation into the immune heterogeneity linked with atherosclerosis remains understudied. This knowledge gap hinders the creation of a robust theoretical framework essential for devising personalized immunotherapies aimed at combating this disease.

Methods

Single-cell RNA sequencing (scRNA-seq) analysis was employed to delineate the immune cell-type landscape within atherosclerotic plaques, followed by assessments of cell-cell interactions and phenotype characteristics using scRNA-seq datasets. Subsequently, pseudotime trajectory analysis was utilized to elucidate the heterogeneity in cell fate and differentiation among macrophages. Through integrated approaches, including single-cell sequencing, Weighted Gene Co-expression Network Analysis (WGCNA), and machine learning techniques, we identified hallmark genes. A risk score model and a corresponding nomogram were developed and validated using these genes, confirmed through Receiver Operating Characteristic (ROC) curve analysis. Additionally, enrichment and immune characteristic analyses were conducted based on the risk score model. The model's applicability was further corroborated by in vitro and in vivo validation of specific genes implicated in atherosclerosis.

Result

This comprehensive scRNA-seq analysis has shed new light on the intricate immune landscape and the role of macrophages in atherosclerotic plaques. The presence of diverse immune cell populations, with a particularly enriched macrophage population, was highlighted by the results. Macrophage heterogeneity was intricately characterized, revealing four distinct subtypes with varying functional attributes that underscore their complex roles in atherosclerotic pathology. Intercellular communication analysis revealed robust macrophage interactions with multiple cell types and detailed pathways differing between proximal adjacent and atherosclerotic core groups. Furthermore, pseudotime trajectories charted the developmental course of macrophage subpopulations, offering insights into their differentiation fates within the plaque microenvironment. The use of machine learning identified potential diagnostic markers, culminating in the identification of RNASE1 and CD14. The risk score model based on these biomarkers exhibited high accuracy in diagnosing atherosclerosis. Immune characteristic analysis validated the risk score model's efficacy in defining patient profiles, distinguishing high-risk individuals with pronounced immune cell activities. Finally, experimental validation affirmed RNASE1's involvement in atherosclerotic progression, suggesting its potential as a therapeutic target.

Conclusion

Our findings have advanced our understanding of atherosclerosis immunopathology and paved the way for novel diagnostic and therapeutic strategies.

MicroRNAs in diabetic macroangiopathy

Diabetic macroangiopathy is a leading cause of diabetes-related mortality worldwide. Both genetic and environmental factors, through a multitude of underlying molecular mechanisms, contribute to the pathogenesis of diabetic macroangiopathy. MicroRNAs (miRNAs), a class of non-coding RNAs known for their functional diversity and expression specificity, are increasingly recognized for their roles in the initiation and progression of diabetes and diabetic macroangiopathy. In this review, we will describe the biogenesis of miRNAs, and summarize their functions in diabetic macroangiopathy, including atherosclerosis, peripheral artery disease, coronary artery disease, and cerebrovascular disease, which are anticipated to provide new insights into future perspectives of miRNAs in basic, translational and clinical research, ultimately advancing the diagnosis, prevention, and treatment of diabetic macroangiopathy.

Vascular Impairment, Muscle Atrophy, and Cognitive Decline: Critical Age-Related Conditions

The triad of vascular impairment, muscle atrophy, and cognitive decline represents critical age-related conditions that significantly impact health. Vascular impairment disrupts blood flow, precipitating the muscle mass reduction seen in sarcopenia and the decline in neuronal function characteristic of neurodegeneration. Our limited understanding of the intricate relationships within this triad hinders accurate diagnosis and effective treatment strategies. This review analyzes the interrelated mechanisms that contribute to these conditions, with a specific focus on oxidative stress, chronic inflammation, and impaired nutrient delivery. The aim is to understand the common pathways involved and to suggest comprehensive therapeutic approaches. Vascular dysfunctions hinder the circulation of blood and the transportation of nutrients, resulting in sarcopenia characterized by muscle atrophy and weakness. Vascular dysfunction and sarcopenia have a negative impact on physical function and quality of life. Neurodegenerative diseases exhibit comparable pathophysiological mechanisms that affect cognitive and motor functions. Preventive and therapeutic approaches encompass lifestyle adjustments, addressing oxidative stress, inflammation, and integrated therapies that focus on improving vascular and muscular well-being. Better understanding of these links can refine therapeutic strategies and yield better patient outcomes. This study emphasizes the complex interplay between vascular dysfunction, muscle degeneration, and cognitive decline, highlighting the necessity for multidisciplinary treatment approaches. Advances in this domain promise improved diagnostic accuracy, more effective therapeutic options, and enhanced preventive measures, all contributing to a higher quality of life for the elderly population.

Management of Pain in People Living With Chronic Limb Threatening Ischemia: Highlights From a Rapid Umbrella Review

Peripheral artery disease is a complex health condition. It is associated with atherosclerotic occlusive lesions in the arteries limiting normal blood flow, mostly involving the lower extremities, leading to chronic limb-threatening ischemia (CLTI). Chronic unrelenting ischemic leg pain can be debilitating and distressing, contributing to poor health-related quality of life. Comprehensive management of pain associated with CLTI requires multimodal approaches that draw on a range of strategies and specialist treatments delivered by an interdisciplinary team across various health care settings. We recognized a significant gap in evidence-based strategies that are accessible, appropriate, acceptable, effective, and safe for the elderly with CLTI-associated pain. We therefore conducted an umbrella review or overview of multiple existing reviews that employ a rigorous and transparent method to comprehensively identify and synthesize relevant literature including systematic, scoping, and narrative reviews. The purpose of this umbrella review was to aggregate and compare various management options to inform best practices and quality indicators for the management of ischemic pain in older patients with peripheral artery disease.

Oxidative stress and vascular dysfunction: Potential therapeutic targets and therapies in peripheral artery disease

Peripheral artery disease (PAD) is the manifestation of atherosclerosis characterized by the accumulation of plaques in the arteries of the lower limbs. Interestingly, growing evidence suggests that the pathology of PAD is multifaceted and encompasses both vascular and skeletal muscle dysfunctions, which contributes to blunted physical capabilities and diminished quality of life. Importantly, it has been suggested that many of these pathological impairments may stem from blunted reduction-oxidation (redox) handling. Of note, in those with PAD, excessive production of reactive oxygen species (ROS) outweighs antioxidant capabilities resulting in oxidative damage, which may have systemic consequences. It has been suggested that antioxidant supplementation may be able to assist in handling ROS. However, the activation of various ROS production sites makes it difficult to determine the efficacy of these antioxidant supplements. Therefore, this review focuses on the common cellular mechanisms that facilitate ROS production and discusses how excessive ROS may impair vascular and skeletal muscle function in PAD. Furthermore, we provide insight for current and potential antioxidant therapies, specifically highlighting activation of the Kelch-like ECH-associated protein 1 (Keap1) - Nuclear Factor Erythroid 2-related factor 2 (Nrf2) pathway as a potential pharmacological therapy to combat ROS accumulation and aid in vascular function, and physical performance in patients with PAD. Altogether, this review provides a better understanding of excessive ROS in the pathophysiology of PAD and enhances our perception of potential therapeutic targets that may improve vascular function, skeletal muscle function, walking capacity, and quality of life in patients with PAD.

Counseling Intervention and Cardiovascular Events in People With Peripheral Artery Disease: A Post Hoc Analysis of the BIP Randomized Clinical Trial

Importance

It is unclear whether counseling to promote walking reduces the risk of major adverse cardiovascular events (MACE) in people with peripheral artery disease (PAD).

Objective

To test whether a counseling intervention designed to increase walking reduced the risk of MACE in patients with PAD.

Design, Setting, and Participants

The BIP trial was a randomized clinical trial, with recruitment performed between January 2015 and July 2018 and follow-up concluded in August 2023. Participants with walking impairment due to PAD from vascular departments in the Australian cities of Brisbane, Sydney, and Townsville were randomly allocated 1:1 to the intervention or control group. Data were originally analyzed in March 2024.

Intervention

Four brief counseling sessions aimed to help patients with the challenges of increasing physical activity.

Main Outcomes and Measures

The primary outcome was the between-group difference in risk of MACE, which included myocardial infarction (MI), stroke, and cardiovascular death. The relationship between Intermittent Claudication Questionnaire (ICQ) scores, PAD Quality of Life (PADQOL) scores, and MACE was examined with Cox proportional hazard regression analyses.

Results

A total of 200 participants were included, with 102 allocated to the counseling intervention (51.0%) and 98 to the control group (49.0%).Participants were followed up for a mean (SD) duration of 3.5 (2.6) years. Median (IQR) participant age was 70 (63-76) years, and 56 of 200 participants (28.0%) were female. A total of 31 individuals had a MACE (composed of 19 MIs, 4 strokes, and 8 cardiovascular deaths). Participants allocated to the intervention were significantly less likely to have a MACE than participants in the control group (10 of 102 participants [9.8%] vs 21 of 98 [21.4%]; hazard ratio [HR], 0.43; 95% CI, 0.20-0.91; P = .03). Greater disease-specific quality of life (QOL) scores at 4 months (ICQ: HR per 1-percentage point increase, 0.97; 95% CI, 0.95-0.99; P < .001; PADQOL factor 3 [symptoms and limitations in physical functioning]: HR per 1-unit increase, 0.91; 95% CI, 0.84-0.98; P = .01) and at 12 months (ICQ: HR per 1-percentage point increase, 0.97; 95% CI, 0.95-0.99; P = .003; PADQOL factor 3: HR per 1-unit increase, 0.91; 95% CI, 0.84-0.98; P = .02) were associated with a lower risk of MACE. In analyses adjusted for ICQ or PADQOL factor 3 scores at either 4 or 12 months, allocation to the counseling intervention was no longer significantly associated with a lower risk of MACE.

Conclusions and Relevance

This post hoc exploratory analysis of the BIP randomized clinical trial suggested that the brief counseling intervention designed to increase walking may reduce the risk of MACE, possibly due to improvement in QOL.

Trial Registration

anzctr.org.au Identifier: ACTRN12614000592640.

Association between dietary fiber intake and peripheral artery disease in hypertensive patients

BACKGROUND

At present, no studies explored whether dietary fiber intake was associated with the risk of peripheral artery disease (PAD) in hypertensive patients. This study assessed the association between dietary fiber intake and PAD in hypertensive patients.

METHODS

This cross-sectional study collected the data of 4628 participants with the measurement of ankle-brachial pressure index in the National Health and Nutrition Examination Surveys database. Univariate logistic regression analysis was applied to identify variables associated with PAD as confounding factors. Univariate and multivariable logistic regression analyses were used to explore the association between dietary fiber intake and PAD in hypertensive patients. Subgroup analysis was stratified by age, cardiovascular disease, dyslipidemia, diabetes, smoking, and physical activity.

RESULTS

After adjusting for confounding factors, decreased risk of PAD was observed in hypertensive patients with dietary fiber intake > 21 g [odds ratio (OR) = 0.67, 95% confidence interval (CI) 0.46-0.99]. Compared with people with dietary fiber intake ≤ 21 g, those with dietary fiber intake > 21 g were associated with decreased risk of PAD in hypertensive patients < 60 years (OR = 0.23, 95%CI 0.08-0.66). In hypertensive patients without dyslipidemia, dietary fiber intake > 21 g were associated with reduced risk of PAD (OR = 0.33, 95%CI 0.12-0.95). Decreased risk of PAD was also found in hypertensive patients without diabetes in dietary fiber intake > 21 g group (OR = 0.50, 95%CI 0.31-0.78). Dietary fiber intake > 21 g was linked with reduced risk of PAD in hypertensive patients in never smoke group (OR = 0.46, 95%CI 0.24-0.86).

CONCLUSION

Higher dietary fiber intake was associated with reduced risk of PAD in hypertensive patients, suggesting the importance of increase the daily dietary quality especially fiber intake in hypertensive people.

Effects of L-Ornithine-L-Aspartate on Angiogenesis and Perfusion in Subacute Hind Limb Ischemia: Preliminary Study

The current treatment options for peripheral arterial disease (PAD) are limited due to a lack of significant high-level evidence to inform clinical decisions and unfavorable outcomes in terms of cost-effectiveness and amputation rates. In order to suggest the use of the commercially available L-Ornithine-L-Aspartate (LOLA) for treating PAD, we induced hind limb ischemia (HLI) by unilaterally ligating the femoral artery in a rat model. The rats were randomly divided into three groups, with seven rats assigned to each group: group 1 (control), group 2 (sorbitol), and group 3 (LOLA). Intraperitoneal injections were administered five times on post-operative days (PODs) 3, 5, 7, 10, and 12. Perfusion imaging was conducted on PODs 7 and 14 and compared to pre-operative perfusion imaging. Immunohistochemistry staining and Western blotting were performed after the final perfusion imaging. Group 3 showed a significant increase in perfusion, high CD31-positive capillary lumen density, and substantial overexpression of VEGF in the ischemic limb during the subacute phase of HLI. In conclusion, this study provides the first documented evidence of angiogenesis and perfusion recovery in the subacute phase of the HLI model following the administration of LOLA. With LOLA readily available on the commercial market, the implementation of LOLA treatment for PAD in humans can be expedited compared to other therapies still in the developmental stage.

Endothelial ELABELA improves post-ischemic angiogenesis by upregulating VEGFR2 expression

BACKGROUND

Post-ischemic angiogenesis is critical for perfusion recovery and tissue repair. ELABELA (ELA) plays an essential role in embryonic heart development and vasculogenesis. However, the mechanism of ELA on post-ischemic angiogenesis is poorly characterized.

METHODS

We first assessed ELA expression after hind limb ischemia (HLI) in mice. We then established a HLI model in tamoxifen-inducible endothelial-ELA-specific knockout mice (ELAECKO) and assessed the rate of perfusion recovery, capillary density, and VEGFR2 pathway. Knockdown of ELA with lentivirus or siRNA and exogenous addition of ELA peptides were employed to analyze the effects of ELA on angiogenic capacity and VEGFR2 pathway in endothelial cells in vitro. The serum levels of ELA in healthy people and patients with type 2 diabetes mellitus (T2DM) and diabetic foot ulcer (DFU) were detected by a commercial ELISA kit.

RESULTS

In murine HLI models, ELA was significantly up-regulated in the ischemic hindlimb. Endothelial-specific deletion of ELA impaired perfusion recovery and angiogenesis. In physiologic conditions, no significant difference in VEGFR2 expression was found between ELAECKO mice and ELAWT mice. After ischemia, the expression of VEGFR2, p-VEGFR2, and p-AKT was significantly lower in ELAECKO mice than in ELAWT mice. In cellular experiments, the knockdown of ELA inhibited endothelial cell proliferation and tube formation, and the addition of ELA peptides promoted proliferation and tube formation. Mechanistically, ELA upregulated the expression of VEGFR2, p-VEGFR2, and p-AKT in endothelial cells under hypoxic conditions. In clinical investigations, DFU patients had significantly lower serum levels of ELA compared to T2DM patients.

CONCLUSION

Our results indicated that endothelial ELA is a positive regulator of post-ischemic angiogenesis via upregulating VEGFR2 expression. Targeting ELA may be a potential therapeutic option for peripheral arterial diseases.

Current Opinion on Diagnosis of Peripheral Artery Disease in Diabetic Patients

Peripheral arterial disease (PAD) prevalence and diabetes mellitus (DM) prevalence are continuously increasing worldwide. The strong relationship between DM and PAD is highlighted by recent evidence. PAD diagnosis in diabetic patients is very important, particularly in patients with diabetic foot disease (DFD); however, it is often made difficult by the characteristics of such diseases. Diagnosing PAD makes it possible to identify patients at a very high cardiovascular risk who require intensive treatment in terms of risk factor modification and medical therapy. The purpose of this review is to discuss the diagnostic methods that allow for a diagnosis of PAD in diabetic patients. Non-invasive tests that address PAD diagnosis will be discussed, such as the ankle-brachial index (ABI), toe pressure (TP), and transcutaneous oxygen pressure (TcPO2). Furthermore, imaging methods, such as duplex ultrasound (DUS), computed tomography angiography (CTA), magnetic resonance angiography (MRA), and digital subtraction angiography (DSA), are described because they allow for diagnosing the anatomical localization and severity of artery stenosis or occlusion in PAD. Non-invasive tests will also be discussed in terms of their ability to assess foot perfusion. Foot perfusion assessment is crucial in the diagnosis of critical limb ischemia (CLI), the most advanced PAD stage, particularly in DFD patients. The impacts of PAD diagnosis and CLI identification in diabetic patients are clinically relevant to prevent amputation and mortality.

Oral Nanoformulations in Cardiovascular Medicine: Advances in Atherosclerosis Treatment

Atherosclerosis (AS) is the formation of atherosclerotic plaques on the walls of the arteries, causing them to narrow. If this occurs in the coronary arteries, the blood vessels may be completely blocked, resulting in myocardial infarction; if it occurs in the blood vessels of the brain, the blood vessels may be blocked, resulting in cerebral infarction, i.e., stroke. Studies have shown that the pathogenesis of atherosclerosis involves the processes of inflammation, lipid infiltration, oxidative stress, and endothelial damage, etc. SIRT, as a key factor regulating the molecular mechanisms of oxidative stress, inflammation, and aging, has an important impact on the pathogenesis of plaque formation, progression, and vulnerability. Statistics show that AS accounts for about 50 per cent of deaths in Western countries. Currently, oral medication is the mainstay of AS treatment, but its development is limited by side effects, low bioavailability and other unfavourable factors. In recent years, with the rapid development of nano-preparations, researchers have combined statins and natural product drugs within nanopreparations to improve their bioavailability. Based on this, this paper summarises the main pathogenesis of AS and also proposes new oral nanoformulations such as liposomes, nanoparticles, nanoemulsions, and nanocapsules to improve their application in the treatment of AS.

Challenges and opportunities in the management of type 2 diabetes in patients with lower extremity peripheral artery disease: a tailored diagnosis and treatment review

Lower extremity peripheral artery disease (PAD) often results from atherosclerosis, and is highly prevalent in patients with type 2 diabetes mellitus (T2DM). Individuals with T2DM exhibit a more severe manifestation and a more distal distribution of PAD compared to those without diabetes, adding complexity to the therapeutic management of PAD in this particular patient population. Indeed, the management of PAD in patients with T2DM requires a multidisciplinary and individualized approach that addresses both the systemic effects of diabetes and the specific vascular complications of PAD. Hence, cardiovascular prevention is of the utmost importance in patients with T2DM and PAD, and encompasses smoking cessation, a healthy diet, structured exercise, careful foot monitoring, and adherence to routine preventive treatments such as statins, antiplatelet agents, and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. It is also recommended to incorporate glucagon-like peptide-1 receptor agonists (GLP-1RA) and sodium-glucose cotransporter-2 inhibitors (SGLT2i) in the medical management of patients with T2DM and PAD, due to their demonstrated cardiovascular benefits. However, the specific impact of these novel glucose-lowering agents for individuals with PAD remains obscured within the background of cardiovascular outcome trials (CVOTs). In this review article, we distil evidence, through a comprehensive literature search of CVOTs and clinical guidelines, to offer key directions for the optimal medical management of individuals with T2DM and lower extremity PAD in the era of GLP-1RA and SGLT2i.

Outcomes of Revascularisation for Treating Lifestyle-Limiting Intermittent Claudication in Aboriginal and Torres Strait Islander People and Non-Indigenous Patients from North Queensland: A Retrospective Cohort Study

Background: This retrospective analysis of an ongoing prospective cohort study aimed to assess the outcome of revascularisation for treating lifestyle-limiting intermittent claudication caused by peripheral artery disease (PAD) in Aboriginal and Torres Strait Islander Peoples and non-Indigenous North Queenslanders. Methods: Consenting patients with PAD who underwent endovascular or open revascularisation procedures for treating lifestyle-limiting intermittent claudication were included. The primary outcome measure was major adverse limb events (MALEs), defined as major amputation or the requirement for repeat open or endovascular revascularisation. Results: Of the 378 included patients, 18 (4.8%) identified as Aboriginal and/or Torres Strait Islander Peoples. During a mean follow-up (standard deviation) of 6.0 (3.9) years, the incidence of MALE was similar in the Aboriginal and Torres Strait Islander People and non-Indigenous Australians (absolute percentage: 50.0% vs. 40.6%, log rank p = 0.59). In both unadjusted and adjusted analyses, Aboriginal and Torres Strait Islander Peoples and non-Indigenous Australians had similar risks of MALE (unadjusted hazard ratio, HR, 1.20, 95% confidence interval, CI, 0.61, 2.36; adjusted HR 1.02, 95%CI 0.50, 2.06). Conclusions: This study suggests that Aboriginal and Torres Strait Islander People are under-represented in the population of patients undergoing revascularisation to treat intermittent claudication. Due to small numbers it cannot be reliably concluded that Aboriginal and Torres Strait Islander People and non-Indigenous Australians have similar rates of MALE.

Hypertension in Patients With Peripheral Artery Disease: An Updated Literature Review

Peripheral artery disease (PAD), a condition where there is reduced blood flow due to narrowing or blockage of the arteries of the peripheral vasculature, is an epidemic that currently affects eight million people in the United States alone and is a major risk equivalent to having active coronary artery disease (CAD). However, it is commonly underdiagnosed in the general population. Hypertension is a common cardiovascular condition characterized by elevated blood pressure levels. There are several mitigating risk factors that can reduce the risk of complications of PAD, with hypertension playing a major role. This literature review aims to explore the relationship between hypertension and PAD, including their shared risk factors, pathophysiological mechanisms, and management strategies. In addition, we will analyze how this impacts major cardiovascular outcomes, such as critical limb ischemia, vascular amputation, myocardial infarction (MI), ischemic stroke, and cardiovascular-related death by examining relevant studies, current guidelines, and evidence. This literature review is intended to guide practitioners on ideal blood pressure parameters and evidence-based anti-hypertensives that provide overall cardiovascular benefit in both the primary care and hospital-based setting. By understanding the association between hypertension and PAD and the underlying pathophysiological mechanisms, healthcare professionals can improve diagnosis, treatment, and management strategies for affected individuals.

Quality of Life Outcomes Following Aortofemoral and Iliofemoral Bypass Surgery in Patients With Peripheral Arterial Disease: A Two-Year Follow-Up Study

INTRODUCTION

Peripheral arterial disease is a circulatory disorder characterized by reduced blood flow to the extremities, predominantly affecting the lower limbs. This study aims to evaluate the impact of aortofemoral and iliofemoral bypass surgeries on patients' quality of life two years post operation and identify predictors of quality-of-life improvements.

METHODS

This cross-sectional study included adult patients with aortoiliac disease who underwent bypass surgery (aortofemoral or iliofemoral) at East Jeddah General Hospital from January 2020 to December 2022. Quality of life was assessed using the Arabic version of the Short Form Health Survey 12 (SF-12) preoperatively and two years postoperatively. Data on sociodemographic factors (age, sex, education, income) and medical factors (smoking, BMI, comorbidities) were collected. Statistical analyses included descriptive statistics, t-tests, one-way ANOVA, and regression analyses using IBM SPSS version 25.0 (IBM Corp., Armonk, NY).

RESULTS

The study included 275 patients. Significant improvements in both physical and mental SF-12 scores were observed postoperatively across all patient groups (P < 0.001). Older age, unemployment, and lower income were associated with lower SF-12 scores. Males had higher postoperative mental scores (P = 0.036). Higher BMI and smoking pack-years negatively correlated with SF-12 scores. Patients with comorbidities had significantly lower preoperative and postoperative SF-12 scores (P < 0.05) but showed significant improvements postoperatively (P < 0.001).

CONCLUSION

Aortofemoral and iliofemoral bypass surgeries significantly improve the quality of life in peripheral arterial disease patients two years post operation. Key predictors of lower quality of life include older age, unemployment, lower income, high BMI, smoking, and comorbidities. Targeted interventions, such as smoking cessation programs, weight management, and comprehensive medical care, are essential for optimizing postoperative outcomes and enhancing patients' physical and mental well-being.

Evaluating the between-day reliability and likelihood of change of a test battery incorporating vastus lateralis muscle thickness, ankle-brachial pressure index, maximal voluntary torque, and six-minute walk test in patients with claudication

OBJECTIVE

The study aims to evaluate the between-day reliability of a proposed test battery for patients with claudication that can be used for monitoring the effectiveness of exercise interventions and other therapeutic strategies tailored to this patient population.

METHODS

Twenty-five men with claudication were recruited. The test battery consisted of the Vastus Lateralis muscle thickness (VL-MT), ankle-brachial pressure index (ABI), unilateral isometric knee extension maximal voluntary torque (MVT) and 6-minute walk test (6MWT). A single investigator conducted the tests for each patient on two separate testing sessions (T1 and T2) 5-7 days apart.

RESULTS

Good to excellent reliability was observed for VL-MT (ICC = 0.95, 95% LOA = ±3.10 mm, SEM = 0.81 mm), ABI (ICC = 0.97, 95% LOA = ±0.10, SEM = 0.02), MVT (ICC = 0.97, 95% LOA = ±24.0 N·m, SEM = 6.31 N·m), 6MWT distance (ICC = 0.99, 95% LOA = ±39.6 m, SEM = 11.0 m), 6MWT time to claudication (ICC = 0.99, 95% LOA = ±30.8 s, SEM = 7.8 s), and 6MWT ratings of pain (ICC = 0.87, 95% LOA = ±2.4 CR-10+, SEM = 0.7 CR-10+ ). Analysis derived from reliability data indicates a change of 1.4 mm for VL-MT, 0.14 for ABI, 12 N·m for MVT, 25 m for 6MWT distance, 15 s for 6MWT time to claudication and 1 CR-10+ for 6MWT ratings of pain is required to be interpreted as the minimum 'likely' change (76% chance).

CONCLUSIONS

The test battery provides a reliable assessment of patients with claudication and can be widely used to evaluate the effects of exercise programmes and other therapeutic interventions. For the individual, changes in VL-MT, ABI, MVT, and 6MWT greater than the minimum likely change as a result of an exercise programme or an intervention are likely changes and less influenced by error associated with the test.

Validation of a New Ankle Brachial Index Measurement System Using Pulse Wave Velocity

Peripheral artery disease (PAD) is a common circulatory disorder characterized by the accumulation of fats, cholesterol, and other substances in the arteries that restrict blood flow to the extremities, especially the legs. The ankle brachial index (ABI) is a highly reliable and valid non-invasive test for diagnosing PAD. However, the traditional method has limitations. These include the time required, the need for Doppler equipment, the training of clinical staff, and patient discomfort. PWV refers to the speed at which an arterial pressure wave propagates along the arteries, and this speed is conditioned by arterial elasticity and stiffness. To address these limitations, we have developed a system that uses electrocardiogram (ECG) and photoplethysmography (PPG) signals to calculate pulse wave velocity (PWV). We propose determining the ABI based on this calculation. Validation was performed on 22 diabetic patients, and the results demonstrate the accuracy of the system, maintaining a margin of ±0.1 compared with the traditional method. This confirms the correlation between PWV and ABI and positions this technique as a promising alternative to overcome some of the limitations of the conventional method.

Effects of additional exercise therapy after a successful vascular intervention for people with symptomatic peripheral arterial disease

BACKGROUND

Peripheral arterial disease (PAD) is characterised by obstruction or narrowing of the large arteries of the lower limbs, usually caused by atheromatous plaques. Most people with PAD who experience intermittent leg pain (intermittent claudication) are typically treated with secondary prevention strategies, including medical management and exercise therapy. Lower limb revascularisation may be suitable for people with significant disability and those who do not show satisfactory improvement after conservative treatment. Some studies have suggested that lower limb revascularisation for PAD may not confer significantly more benefits than supervised exercise alone for improved physical function and quality of life. It is proposed that supervised exercise therapy as adjunctive treatment after successful lower limb revascularisation may confer additional benefits, surpassing the effects conferred by either treatment alone.

OBJECTIVES

To assess the effects of a supervised exercise programme versus standard care following successful lower limb revascularisation in people with PAD.

SEARCH METHODS

We searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, two other databases, and two trial registers, most recently on 14 March 2023.

SELECTION CRITERIA

We included randomised controlled trials which compared supervised exercise training following lower limb revascularisation with standard care following lower limb revascularisation in adults (18 years and older) with PAD.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were maximum walking distance or time (MWD/T) on the treadmill, six-minute walk test (6MWT) total distance, and pain-free walking distance or time (PFWD/T) on the treadmill. Our secondary outcomes were changes in the ankle-brachial index, all-cause mortality, changes in health-related quality-of-life scores, reintervention rates, and changes in subjective measures of physical function. We analysed continuous data by determining the mean difference (MD) and 95% confidence interval (CI), and dichotomous data by determining the odds ratio (OR) with corresponding 95% CI. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We identified seven studies involving 376 participants. All studies involved participants who received either additional supervised exercise or standard care after lower limb revascularisation. The studies' exercise programmes varied, and included supervised treadmill walking, combined exercise, and circuit training. The duration of exercise therapy ranged from six weeks to six months; follow-up time ranged from six weeks to five years. Standard care also varied between studies, including no treatment or advice to stop smoking, lifestyle modifications, or best medical treatment. We classified all studies as having some risk of bias concerns. The certainty of the evidence was very low due to the risk of bias, inconsistency, and imprecision. The meta-analysis included only a subset of studies due to concerns regarding data reporting, heterogeneity, and bias in most published research. The evidence was of very low certainty for all the review outcomes. Meta-analysis comparing changes in maximum walking distance from baseline to end of follow-up showed no improvement (MD 159.47 m, 95% CI -36.43 to 355.38; I2 = 0 %; 2 studies, 89 participants). In contrast, exercise may improve the absolute maximum walking distance at the end of follow-up compared to standard care (MD 301.89 m, 95% CI 138.13 to 465.65; I2 = 0 %; 2 studies, 108 participants). Moreover, we are very uncertain if there are differences in the changes in the six-minute walk test total distance from baseline to treatment end between exercise and standard care (MD 32.6 m, 95% CI -17.7 to 82.3; 1 study, 49 participants), and in the absolute values at the end of follow-up (MD 55.6 m, 95% CI -2.6 to 113.8; 1 study, 49 participants). Regarding pain-free walking distance, we are also very uncertain if there are differences in the mean changes in PFWD from baseline to treatment end between exercise and standard care (MD 167.41 m, 95% CI -11 to 345.83; I2 = 0%; 2 studies, 87 participants). We are very uncertain if there are differences in the absolute values of ankle-brachial index at the end of follow-up between the intervention and standard care (MD 0.01, 95% CI -0.11 to 0.12; I2 = 62%; 2 studies, 110 participants), in mortality rates at the end of follow-up (OR 0.92, 95% CI 0.42 to 2.00; I2 = 0%; 6 studies, 346 participants), health-related quality of life at the end of follow-up for the physical (MD 0.73, 95% CI -5.87 to 7.33; I2 = 64%; 2 studies, 105 participants) and mental component (MD 1.04, 95% CI -6.88 to 8.95; I2 = 70%; 2 studies, 105 participants) of the 36-item Short Form Health Survey. Finally, there may be little to no difference in reintervention rates at the end of follow-up between the intervention and standard care (OR 0.91, 95% CI 0.23 to 3.65; I2 = 65%; 5 studies, 252 participants).

AUTHORS' CONCLUSIONS

There is very uncertain evidence that additional exercise therapy after successful lower limb revascularisation may improve absolute maximal walking distance at the end of follow-up compared to standard care. Evidence is also very uncertain about the effects of exercise on pain-free walking distance, six-minute walk test distance, quality of life, ankle-brachial index, mortality, and reintervention rates. Although it is not possible to confirm the effectiveness of supervised exercise compared to standard care for all outcomes, studies did not report any harm to participants from this intervention after lower limb revascularisation. Overall, the evidence incorporated into this review was very uncertain, and additional evidence is needed from large, well-designed, randomised controlled studies to more conclusively demonstrate the role additional exercise therapy has after lower limb revascularisation in people with PAD.

Pedal medial arterial calcification in diabetic foot ulcers: A significant risk factor of amputation and mortality

AIMS

Pedal medial arterial calcification (MAC) is frequently observed in individuals with diabetic foot ulcers (DFUs). However, the impact of pedal MAC on individuals with DFUs remains uncertain. The main aim of this study was to evaluate the association between pedal MAC with amputation and mortality outcomes.

METHODS

A prospective, observational cohort study was conducted at West China Hospital from January 2012 to December 2021. Logistic regression analyses, Kaplan-Meier survival method, and Cox proportional hazards models were employed to evaluate the relationship between pedal MAC and amputation as well as mortality.

RESULTS

A total of 979 patients were enrolled in the study. Peripheral artery disease (PAD) was observed in 53% of patients with DFUs, and pedal MAC was found in 8%. Over a median follow-up of 46 (23-72) months, foot amputation was performed on 190 patients, and mortality occurred in 246 patients. Pedal MAC showed a significant association with amputation both in unadjusted analysis (odds ratio [OR] = 2.98, 95% confidence interval [CI] = 1.86-4.76, p < .001) and after adjusting sex, age, albumin levels, hemoglobin levels, and diabetic retinopathy status (OR 2.29, 95% CI 1.33-3.93, p = .003). The risk of amputation was found to be twofold higher in individuals with PAD and pedal MAC compared to those with PAD alone (OR 2.05, 95% CI 1.10-3.82, p = .024). Furthermore, the presence of pedal MAC was significantly associated with an increased risk of mortality (p = .005), particularly among individuals with DFUs but without PAD (HR 4.26, 95% CI 1.90-9.52, p < .001), rather than in individuals presenting with both DFUs and PAD.

CONCLUSION

The presence of pedal MAC is significantly associated with both amputation and mortality in individuals with DFUs. Moreover, pedal MAC could provide additional value to predict amputation other than PAD.

Efficacy and Safety of Covered Stents Versus Bare-Metal Stents for Aortoiliac Occlusive Disease: A Systematic Review and Meta-Analysis

PURPOSE

This study aimed to assess the efficacy and safety outcome of covered stents (CSs), as compared with bare-metal stents (BMSs), for the treatment of patients with aortoiliac occlusive disease (AIOD).

MATERIALS AND METHODS

A systematic literature search was conducted in PubMed, Embase, and Cochrane Library up to August 2023 to identify all studies comparing efficacy and safety outcomes of CSs versus BMSs for treating AIOD. Our outcome was primary patency, secondary patency, technical success, ankle-brachial index (ABI) variation, target lesion revascularization (TLR), limb salvage, complications, and long-term survival. Dichotomous outcomes were pooled as relative risks (RR) or hazard ratio with the 95% confidence interval (CI). Continuous outcomes were pooled as weighted mean differences and 95% CI. Model selection was based on the heterogeneity of the included studies.

RESULTS

There were 10 studies (2 randomized controlled trials, 8 retrospective cohort studies), comprising 1676 sample size. Compared with BMSs, CSs use was associated with better primary patency of patients with a Trans-Atlantic Inter-Society Consensus II (TASC) D lesion (RR, 1.15, 95% CI, 1.04 to 1.27, p=0.007), TLR (RR, 0.39, 95% CI, 0.27 to 0.56, p<0.001), technical success (RR, 1.01, 95% CI, 1.00 to 1.02, p=0.010), and long-term survival (RR, 1.06, 95% CI, 1.01 to 1.11, p=0.020). There is no difference between CSs and BMSs regarding primary patency of all patients, secondary patency, variation in ABI, limb salvage, and complications.

CONCLUSIONS

Compared with BMSs, CSs used in AIOD was associated with more favorable primary patency in patients with TASC D lesions, TLR, technical success rates, and patient long-term survival. These results provide evidence of the advantages of using CSs for AIOD treatment. Future studies focusing on long-term variations in ABI, primary patency of different degrees of calcification, vascular segments, and TASC classification are warranted.

CLINICAL IMPACT

Although several studies evaluated the clinical efficacy of CS in the context of AIOD treatment, the significance and consistency of these findings were not determined to date. We found that CS was used in AIOD associated with better technical success rate, long-term patient survival, lower target lesion revascularization, and higher primary patency of patients with a Trans-Atlantic Inter-Society Consensus II D lesion when compared with BMSs. Our study provides evidence supporting the superiority of CSs over BMSs in the treatment of AIOD, and furnishing clinicians with guidance for treatment decisions.

Promoting collateral formation in type 2 diabetes mellitus using ultra-small nanodots with autophagy activation and ROS scavenging

BACKGROUND

Impaired collateral formation is a major factor contributing to poor prognosis in type 2 diabetes mellitus (T2DM) patients with atherosclerotic cardiovascular disease. However, the current pharmacological treatments for improving collateral formation remain unsatisfactory. The induction of endothelial autophagy and the elimination of reactive oxygen species (ROS) represent potential therapeutic targets for enhancing endothelial angiogenesis and facilitating collateral formation. This study investigates the potential of molybdenum disulfide nanodots (MoS2 NDs) for enhancing collateral formation and improving prognosis.

RESULTS

Our study shows that MoS2 NDs significantly enhance collateral formation in ischemic tissues of diabetic mice, improving effective blood resupply. Additionally, MoS2 NDs boost the proliferation, migration, and tube formation of endothelial cells under high glucose/hypoxia conditions in vitro. Mechanistically, the beneficial effects of MoS2 NDs on collateral formation not only depend on their known scavenging properties of ROS (H2O2, •O2-, and •OH) but also primarily involve a molecular pathway, cAMP/PKA-NR4A2, which promotes autophagy and contributes to mitigating damage in diabetic endothelial cells.

CONCLUSIONS

Overall, this study investigated the specific mechanism by which MoS2 NDs mediated autophagy activation and highlighted the synergy between autophagy activation and antioxidation, thus suggesting that an economic and biocompatible nano-agent with dual therapeutic functions is highly preferable for promoting collateral formation in a diabetic context, thus, highlighting their therapeutic potential.

NIR-II fluorescence imaging without intended excitation light

Nowadays, second near-infrared window (NIR-II) dyes are almost excited by laser diodes, but none of the white light (400-700 nm) excited NIR-II imaging has been studied because of the lack of suitable optical probes. Herein, a novel blue-shifted NIR-II dye, TPA-TQT, has been selected for use in multi-wavelength white light emitting diode (LED) excited NIR-II imaging. This white LED barely caused photo-quenching of the dyes, especially indocyanine green (ICG), whereas the ICG's brightness decreased by 90% under continuous 808 nm laser irradiation. Compared to single-wavelength LED, multi-wavelength LED showed a lower background and similar signal-to-background ratios. This system provided high image resolution to identify blood vessels (103 μm), lymphatic capillaries (129.8 μm), and to monitor hindlimb ischemia-reperfusion and lymphatic inflammation. Furthermore, white LED excited NIR-II fluorescence imaging-guided surgery (FIGS) was successfully performed in 4T1 tumor-bearing mice. Impressively, the lighting LED-based NIR-II FIGS was found to clearly delineate small lesions of metastatic tumors of about ∼350 μm diameter and further was able to guide surgical removal. Overall, multi-wavelength LED-based NIR-II imaging is a promising imaging strategy for tumor delineation and other biomedical applications.

The Role of Cilostazol, a Phosphodiesterase-3 Inhibitor, in the Development of Atherosclerosis and Vascular Biology: A Review with Meta-Analysis

Atherosclerotic cardiovascular disease (ASCVD) stands as the leading global cause of mortality. Addressing this vital and pervasive condition requires a multifaceted approach, in which antiplatelet intervention plays a pivotal role, together with antihypertensive, antidiabetic, and lipid-lowering therapies. Among the antiplatelet agents available currently, cilostazol, a phosphodiesterase-3 inhibitor, offers a spectrum of pharmacological effects. These encompass vasodilation, the impediment of platelet activation and aggregation, thrombosis inhibition, limb blood flow augmentation, lipid profile enhancement through triglyceride reduction and high-density lipoprotein cholesterol elevation, and the suppression of vascular smooth muscle cell proliferation. However, the role of cilostazol has not been clearly documented in many guidelines for ASCVD. We comprehensively reviewed the cardiovascular effects of cilostazol within randomized clinical trials that compared it to control or active agents and involved individuals with previous coronary artery disease or stroke, as well as those with no previous history of such conditions. Our approach demonstrated that the administration of cilostazol effectively reduced adverse cardiovascular events, although there was less evidence regarding its impact on myocardial infarction. Most studies have consistently reported its favorable effects in reducing intermittent claudication and enhancing ambulatory capacity in patients with peripheral arterial disease. Furthermore, cilostazol has shown promise in mitigating restenosis following coronary stent implantation in patients with acute coronary syndrome. While research from more diverse regions is still needed, our findings shed light on the broader implications of cilostazol in the context of atherosclerosis and vascular biology, particularly for individuals at high risk of ASCVD.

Primary results of the brazilian registry of atherothrombotic disease (NEAT)

There is limited contemporary prospective real-world evidence of patients with chronic arterial disease in Latin America. The Network to control atherothrombosis (NEAT) registry is a national prospective observational study of patients with known coronary (CAD) and/or peripheral arterial disease (PAD) in Brazil. A total of 2,005 patients were enrolled among 25 sites from September 2020 to March 2022. Patient characteristics, medications and laboratorial data were collected. Primary objective was to assess the proportion of patients who, at the initial visit, were in accordance with good medical practices (domains) for reducing cardiovascular risk in atherothrombotic disease. From the total of patients enrolled, 2 were excluded since they did not meet eligibility criteria. Among the 2,003 subjects included in the analysis, 55.6% had isolated CAD, 28.7% exclusive PAD and 15.7% had both diagnoses. Overall mean age was 66.3 (± 10.5) years and 65.7% were male patients. Regarding evidence-based therapies (EBTs), 4% were not using any antithrombotic drug and only 1.5% were using vascular dose of rivaroxaban (2.5 mg bid). Only 0.3% of the patients satisfied all the domains of secondary prevention, including prescription of EBTs and targets of body-mass index, blood pressure, LDL-cholesterol, and adherence of lifestyle recommendations. The main barrier for prescription of EBTs was medical judgement. Our findings highlight that the contemporary practice does not reflect a comprehensive approach for secondary prevention and had very low incorporation of new therapies in Brazil. Large-scale populational interventions addressing these gaps are warranted to improve the use of evidence-based therapies and reduce the burden of atherothrombotic disease.ClinicalTrials.gov NCT04677725.

Heparin-Mediated Extracorporeal Low-Density Lipoprotein Precipitation Apheresis for Treating Peripheral Arterial Disease in Patients with Chronic Kidney Disease

Patients with chronic kidney disease (CKD), particularly those with end-stage renal disease (ESRD), have a high prevalence of cardiovascular disease and peripheral arterial disease (PAD). Medical treatment is mainly based on risk factor management, and the surgical approach remains the gold standard treatment in specific conditions. Heparin-mediated extracorporeal low-density lipoprotein precipitation (H.E.L.P.) apheresis is effective in reducing circulating lipoprotein, fibrinogen, inflammatory mediators and procoagulant factors, thereby reducing cardiovascular risk in patients with familial hypercholesterolemia and hypertriglyceridemia. These activities may be effective in reducing symptoms and ischemic vascular lesions even in patients with severe PAD. We reported the application of a treatment protocol with H.E.L.P. apheresis in an ESRD patient with severe PAD without clinical improvement after severe revascularization who was not suitable for further surgical approaches, despite normal LDL cholesterol and lipoprotein (a). The H.E.L.P. protocol was characterized by an intensive first phase with weekly treatments followed by a single session every 10-15 days for 6 months of treatment. The overall clinical condition, foot lesions and walking distance improved significantly after the first 2 months of treatment, and foot amputation was avoided. Here, we review the main pathogenetic mechanisms through which LDL apheresis improves microcirculation and clinical outcomes. Its wider application may represent an optimal therapeutic option for patients unresponsive to standard treatment.

Prevalence and Associations of Peripheral Arterial Disease in China: The Beijing Eye Study

PURPOSE

To explore the prevalence and associations of peripheral arterial disease (PAD) in China.

DESIGN

Population-based incidence estimate and cross-sectional study.

METHODS

The participants (n=3468) of the Beijing Eye Study underwent a detailed ophthalmologic and systemic examination including assessment of the ankle-brachial index (ABI). PAD was defined by an ABI of less than 0.9.

RESULTS

Blood pressure measurements of both arms and ankles were available for 1078 (31.1%) individuals. An ABI (mean: 1.09±0.11; median: 1.10; range: 0.25, 1.36) of <0.9 and <0.95 was found in 32 of 1078 participants (3.0%, 95% CI 2.0, 4.0) and 70 of 1078 individuals (6.5%, 95% CI 5.0, 8.0), respectively. Higher PAD prevalence (multivariable analysis) was associated with older age (odds ratio [OR] 1.08, 95% CI 1.02, 1.15; P = .009), lower level of education (OR 0.62, 95% CI 0.43, 0.90; P = .01), lower quality of life (OR 0.67, 95% CI 1.11, 2.32), higher glucose serum concentration (OR 1.36, 95% CI 1.09, 1.58; P = .006), lower estimated glomerular filtration rate (OR 0.98, 95% CI 0.96, 0.99; P = .04), and higher prevalence of retinal vein occlusions (OR 7.30, 95% CI 1.63, 32.6; P = .009). PAD prevalence was not associated with the prevalence of glaucoma (P = .53) (open-angle glaucoma: P = .42; angle-closure glaucoma: P = .57) and age-related macular degeneration (any AMD: P = .39; early AMD: P = .31; intermediate AMD: P = .92; late AMD: P = .99), prevalence (P = .26) and stage (P = .07) of diabetic retinopathy, prevalence (P = .38) and degree (P = .68) of nuclear cataract, prevalence (P = .39) and degree (P = .72) of cortical cataract, prevalence of subcapsular cataract (P = .86), prevalence of pseudoexfoliation (P = .65), intraocular pressure (P = .50), axial length (P = .56), and peripapillary retinal nerve fiber layer thickness (P = .68).

CONCLUSIONS

The PAD prevalence (3.0%, 95% CI 2.0%, 4.0%) was relatively low in this cohort from rural and urban Beijing, with older age, lower educational level, lower quality of life, higher glucose serum concentration, lower estimated glomerular filtration rate, and higher prevalence of retinal vein occlusions as main associated factors.

Translational Relevance of Advanced Age and Atherosclerosis in Preclinical Trials of Biotherapies for Peripheral Artery Disease

Approximately 6% of adults worldwide suffer from peripheral artery disease (PAD), primarily caused by atherosclerosis of lower limb arteries. Despite optimal medical care and revascularization, many PAD patients remain symptomatic and progress to critical limb ischemia (CLI) and risk major amputation. Delivery of pro-angiogenic factors as proteins or DNA, stem, or progenitor cells confers vascular regeneration and functional recovery in animal models of CLI, but the effects are not well replicated in patients and no pro-angiogenic biopharmacological procedures are approved in the US, EU, or China. The reasons are unclear, but animal models that do not represent clinical PAD/CLI are implicated. Consequently, it is unclear whether the obstacles to clinical success lie in the toxic biochemical milieu of human CLI, or in procedures that were optimized on inappropriate models. The question is significant because the former case requires abandonment of current strategies, while the latter encourages continued optimization. These issues are discussed in the context of relevant preclinical and clinical data, and it is concluded that preclinical mouse models that include age and atherosclerosis as the only comorbidities that are consistently present and active in clinical trial patients are necessary to predict clinical success. Of the reviewed materials, no biopharmacological procedure that failed in clinical trials had been tested in animal models that included advanced age and atherosclerosis relevant to PAD/CLI.

Human ESC-derived vascular cells promote vascular regeneration in a HIF-1α dependent manner

Hypoxia-inducible factor (HIF-1α), a core transcription factor responding to changes in cellular oxygen levels, is closely associated with a wide range of physiological and pathological conditions. However, its differential impacts on vascular cell types and molecular programs modulating human vascular homeostasis and regeneration remain largely elusive. Here, we applied CRISPR/Cas9-mediated gene editing of human embryonic stem cells and directed differentiation to generate HIF-1α-deficient human vascular cells including vascular endothelial cells, vascular smooth muscle cells, and mesenchymal stem cells (MSCs), as a platform for discovering cell type-specific hypoxia-induced response mechanisms. Through comparative molecular profiling across cell types under normoxic and hypoxic conditions, we provide insight into the indispensable role of HIF-1α in the promotion of ischemic vascular regeneration. We found human MSCs to be the vascular cell type most susceptible to HIF-1α deficiency, and that transcriptional inactivation of ANKZF1, an effector of HIF-1α, impaired pro-angiogenic processes. Altogether, our findings deepen the understanding of HIF-1α in human angiogenesis and support further explorations of novel therapeutic strategies of vascular regeneration against ischemic damage.

Nanotechnology translation in vascular diseases: From design to the bench

Atherosclerosis is a systemic pathophysiological condition contributing to the development of majority of polyvascular diseases. Nanomedicine is a novel and rapidly developing science. Due to their small size, nanoparticles are freely transported in vasculature, and have been widely employed as tools in analytical imaging techniques. Furthermore, the application of nanoparticles also allows target intervention, such as drug delivery and tissue engineering regenerative methods, in the management of major vascular diseases. Therefore, by summarizing the physical and chemical characteristics of common nanoparticles used in diagnosis and treatment of vascular diseases, we discuss the details of these applications from cellular, molecular, and in vivo perspectives in this review. Furthermore, we also summarize the status and challenges of the application of nanoparticles in clinical translation. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Cardiovascular Disease Implantable Materials and Surgical Technologies > Nanomaterials and Implants Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Anatomical Distribution Patterns of Peripheral Arterial Disease in the Upper Extremities According to Patient Characteristics: A Retrospective Cohort Study

Purpose

Peripheral arterial disease (PAD) greatly affects the patients' quality of life. We aimed to investigate the affected anatomical sites and distribution patterns in upper extremity PAD using computed tomography angiography (CTA). Furthermore, we sought to identify the correlations between patient characteristics and the identified patterns.

Patients and Methods

This was a retrospective chart review of upper limb CTA findings from patients with symptomatic PAD aged >18 years. Significant variables from univariate logistic regression analysis were further tested using multivariate logistic regression analysis. Statistical significance was set at p < 0.05, with confidence intervals of 95%.

Results

The mean age of the 102 included patients with upper extremity PAD was 55.45 years. Laterality analysis revealed that the upper left limb segments were more affected than the upper right limb segments (42 vs 63; left-to-right ratio, 3:2). The forearm was the segment most affected by stenotic PAD (62 segments, 3.37%). The arm was the segment most affected by occlusive PAD (14 segments, 0.76%). Diabetes mellitus (DM) and hypertension (HTN) were significant predictors of PAD (p = 0.046). In patients with DM, the occlusive form of PAD was dominant in the arm (18.18%); however, the stenotic form prevailed in the forearm (72.72%). In patients with HTN, the occlusive form of PAD was predominant in the arm (45.45%); however, the stenotic form tended to occur in the arm and forearm (90.90%).

Conclusion

The distribution patterns of upper extremity PAD are linked to its underlying pathophysiology. HTN and DM are the most frequent comorbidities in patients with upper extremity PAD. Angiographically, PAD in these patients is likely to present as stenosis rather than as occlusion. This is vital for interventionists who deviate from radial arterial access in patients with PAD. Therefore, targeted screening standards are required, and further studies on PAD are warranted.

Co-Delivery of Bioengineered Exosomes and Oxygen for Treating Critical Limb Ischemia in Diabetic Mice

Diabetic patients with critical limb ischemia face a high rate of limb amputation. Regeneration of the vasculature and skeletal muscles can salvage diseased limbs. Therapy using stem cell-derived exosomes that contain multiple proangiogenic and promyogenic factors represents a promising strategy. Yet the therapeutic efficacy is not optimal because exosomes alone cannot efficiently rescue and recruit endothelial and skeletal muscle cells and restore their functions under hyperglycemic and ischemic conditions. To address these limitations, we fabricated ischemic-limb-targeting stem cell-derived exosomes and oxygen-releasing nanoparticles and codelivered them in order to recruit endothelial and skeletal muscle cells, improve cell survival under ischemia before vasculature is established, and restore cell morphogenic function under high glucose and ischemic conditions. The exosomes and oxygen-releasing nanoparticles, delivered by intravenous injection, specifically accumulated in the ischemic limbs. Following 4 weeks of delivery, the exosomes and released oxygen synergistically stimulated angiogenesis and muscle regeneration without inducing substantial inflammation and reactive oxygen species overproduction. Our work demonstrates that codelivery of exosomes and oxygen is a promising treatment solution for saving diabetic ischemic limbs.

Exercise and Ischemia-Activated Pathways in Limb Muscle Angiogenesis and Vascular Regeneration

Exercise has a profound effect on cardiovascular disease, particularly through vascular remodeling and regeneration. Peripheral artery disease (PAD) is one such cardiovascular condition that benefits from regular exercise or rehabilitative physical therapy in terms of slowing the progression of disease and delaying amputations. Various rodent pre-clinical studies using models of PAD and exercise have shed light on molecular pathways of vascular regeneration. Here, I review key exercise-activated signaling pathways (nuclear receptors, kinases, and hypoxia inducible factors) in the skeletal muscle that drive paracrine regenerative angiogenesis. The rationale for highlighting the skeletal muscle is that it is the largest organ recruited during exercise. During exercise, skeletal muscle releases several myokines, including angiogenic factors and cytokines that drive tissue vascular regeneration via activation of endothelial cells, as well as by recruiting immune and endothelial progenitor cells. Some of these core exercise-activated pathways can be extrapolated to vascular regeneration in other organs. I also highlight future areas of exercise research (including metabolomics, single cell transcriptomics, and extracellular vesicle biology) to advance our understanding of how exercise induces vascular regeneration at the molecular level, and propose the idea of "exercise-mimicking" therapeutics for vascular recovery.

The Influence of Individualized Three-Dimensional Holographic Models on Patients' Knowledge Qualified for Intervention in the Treatment of Peripheral Arterial Disease (PAD)

We sought to determine the role of the patient-specific, three-dimensional (3D) holographic vascular model in patient medical knowledge and its influence on obtaining a more conscious informed consent process for percutaneous balloon angioplasty (PTA). Patients with peripheral arterial disease who had been scheduled for PTA were enrolled in the study. Information regarding the primary disease, planned procedure, and informed consent was recorded in typical fashion. Subsequently, the disease and procedure details were presented to the patient, showing the patients their individual model. A patient and medical supervisor equipped with mixed reality headsets could both simultaneously manipulate the hologram using gestures. The holographic 3D model had been created on a scale of 1:1 based on computed tomography scans. The patient's knowledge was tested by the completion of a questionnaire before and after the interaction in a mixed reality environment. Seventy-nine patients manipulated arterial holograms in mixed reality head-mounted devices. Before the 3D holographic artery model interaction, the mean ± standard deviation score of the knowledge test was 2.95 ± 1.21 points. After the presentation, the score had increased to 4.39 ± 0.82, with a statistically significant difference (p = 0.0000) between the two scores. Using a Likert scale from 1 to 5, the patients had scored the use of the 3D holographic model at 3.90 points regarding its usefulness in comprehending their medical condition; at 4.04 points regarding the evaluation of the holograms as helpful in understanding the course of surgery; and rated the model at 1.99 points in reducing procedure-related stress. Using a nominal scale (know or don't know), the patients had self-assessed their knowledge of the procedure before and after the 3D model presentation, with a score of 6.29 ± 2.01 and 8.39 ± 1.54, respectively. The study group tolerated the use of head-mounted devices. Only one patient had nausea and dizziness, while four patients experienced transient eye pain. The 3D holographic arterial model aided in the understanding of patients' knowledge regarding the disease and procedure, making the informed consent process more conscious. The holograms improved the patient's self-consciousness. Mixed reality headset-related complications were rare and within acceptable rates.

Current Medical Therapy and Revascularization in Peripheral Artery Disease of the Lower Limbs: Impacts on Subclinical Chronic Inflammation

Peripheral artery disease (PAD), coronary artery disease (CAD), and cerebrovascular disease (CeVD) are characterized by atherosclerosis and inflammation as their underlying mechanisms. This paper aims to conduct a literature review on pharmacotherapy for PAD, specifically focusing on how different drug classes target pro-inflammatory pathways. The goal is to enhance the choice of therapeutic plans by considering their impact on the chronic subclinical inflammation that is associated with PAD development and progression. We conducted a comprehensive review of currently published original articles, narratives, systematic reviews, and meta-analyses. The aim was to explore the relationship between PAD and inflammation and evaluate the influence of current pharmacological and nonpharmacological interventions on the underlying chronic subclinical inflammation. Our findings indicate that the existing treatments have added anti-inflammatory properties that can potentially delay or prevent PAD progression and improve outcomes, independent of their effects on traditional risk factors. Although inflammation-targeted therapy in PAD shows promising potential, its benefits have not been definitively proven yet. However, it is crucial not to overlook the pleiotropic properties of the currently available treatments, as they may provide valuable insights for therapeutic strategies. Further studies focusing on the anti-inflammatory and immunomodulatory effects of these treatments could enhance our understanding of the mechanisms contributing to the residual risk in PAD and pave the way for the development of novel therapies.

Contemporary Medical Management of Peripheral Arterial Disease

PURPOSE

Peripheral arterial disease (PAD) is characterized by atherosclerotic arterial occlusive disease of the lower extremities and is associated with an increased risk of major adverse cardiovascular events (MACE) in addition to disabling clinical sequelae, including intermittent claudication and chronic limb-threatening ischemia (CLTI). Given the growing burden of disease, knowledge of modern practices to prevent MACE and major adverse limb events (MALE) is essential. This review article examines evidence for medical management of PAD and its associated risk factors, as well as wound prevention and care.

METHODS

A thorough review of the literature was performed, with attention to evidence for the management of modifiable atherosclerotic risk factors, claudication symptoms, wound prevention, and wound care.

RESULTS

Contemporary management of PAD requires a multi-faceted approach to care, with medical optimization of smoking, hypertension, hyperlipidemia, and diabetes mellitus. The use of supervised exercise therapy for intermittent claudication is highlighted. The anatomic disease patterns of smoking and diabetes mellitus are discussed further, and best practices for diabetic foot ulcer prevention, including offloading footwear, are described. Quality wound care is essential in this patient population and involves strategic use of debridement, wound-healing adjuncts, and skin substitutes, when appropriate.

CONCLUSION

The objective of medical management of PAD is to reduce the risk of MACE and MALE. Atherosclerotic risk factor optimization, appropriate wound care, and management of diabetic foot ulcers, foot infections, gangrene, and chronic, non-healing wounds are critical components of PAD care. Interdisciplinary care is essential to coordinate care, leverage expertise, and improve outcomes.

Pathology, Progression, and Emerging Treatments of Peripheral Artery Disease-Related Limb Ischemia

PURPOSE

This narrative review summarizes recent research examining treatment targets for peripheral artery disease (PAD)-related limb ischemia.

METHODS

Targeted searches of the PubMed and clinical trial registry databases were performed to identify recent findings from animal models of limb ischemia and clinical studies examining PAD progression and treatment. Ongoing clinical trials testing new treatments for PAD were also reviewed. Relevant full-text articles were retrieved and critically reviewed. Where indicated, data were tabulated and summarized in the text.

FINDINGS

Most people with PAD need treatment to improve their walking and function and limit leg pain. Currently, the available treatments of cilostazol, exercise therapy, and revascularization have several deficiencies, including limited access, poor uptake, limited efficacy, and risk of complications. Severe PAD threatens limb viability and is treated by endovascular or open surgical revascularization but is not always successful in achieving limb salvage. Research is ongoing to develop and test new therapies, including new exercise programs, drugs, stem cell treatments and RNA therapeutics, so that new and adjunctive PAD treatments can be offered. Results from multiple clinical trials are expected within the next 5 years.

IMPLICATIONS

It is envisaged that a range of new therapies for PAD will be available in the future.

The intersocietal IWGDF, ESVS, SVS guidelines on peripheral artery disease in people with diabetes mellitus and a foot ulcer

Diabetes related foot complications have become a major cause of morbidity and are implicated in most major and minor amputations globally. Approximately 50% of people with diabetes and a foot ulcer have peripheral artery disease (PAD) and the presence of PAD significantly increases the risk of adverse limb and cardiovascular events. The International Working Group on the Diabetic Foot (IWGDF) has published evidence based guidelines on the management and prevention of diabetes related foot complications since 1999. This guideline is an update of the 2019 IWGDF guideline on the diagnosis, prognosis, and management of peripheral artery disease in people with diabetes mellitus and a foot ulcer. For this updated guideline, the IWGDF, the European Society for Vascular Surgery, and the Society for Vascular Surgery decided to collaborate to develop a consistent suite of recommendations relevant to clinicians in all countries. This guideline is based on three new systematic reviews. Using the Grading of Recommendations, Assessment, Development and Evaluation framework clinically relevant questions were formulated, and the literature was systematically reviewed. After assessing the certainty of the evidence, recommendations were formulated which were weighed against the balance of benefits and harms, patient values, feasibility, acceptability, equity, resources required, and when available, costs. Through this process five recommendations were developed for diagnosing PAD in a person with diabetes, with and without a foot ulcer or gangrene. Five recommendations were developed for prognosis relating to estimating likelihood of healing and amputation outcomes in a person with diabetes and a foot ulcer or gangrene. Fifteen recommendations were developed related to PAD treatment encompassing prioritisation of people for revascularisation, the choice of a procedure and post-surgical care. In addition, the Writing Committee has highlighted key research questions where current evidence is lacking. The Writing Committee believes that following these recommendations will help healthcare professionals to provide better care and will reduce the burden of diabetes related foot complications.

Peripheral Artery Disease: Underappreciated Impact and Residual Cardiovascular Risk Despite Revascularization

This Commentary highlights the under-recognized prevalence and heavy burden of peripheral artery disease (PAD) and its important role as a harbinger of complications of atherosclerotic cardiovascular disease. Although increasing in prevalence globally, PAD is being further accelerated with diabetes, and patients with advanced PAD are at high risk for chronic limb-threatening ischemia. The need for (repeated) revascularization and amputation places a heavy social burden on patients and family, and a heavy financial burden on the health care system, exceeding the cost of coronary artery and cerebrovascular diseases. Clinical trial research in PAD will be enhanced by widely agreed-upon definitions of major adverse cardiovascular events and major adverse limb events. Antithrombotic and lipid-lowering therapies are recommended but underutilized, while the optimal peri-interventional antithrombotic regimen is still under debate. Additional antiinflammatory treatment is currently an unaddressed strategy in the management of patients with PAD, and there is a strong case for the evaluation of widely available antiinflammatory agents such as colchicine.

Nuclear receptors as potential therapeutic targets in peripheral arterial disease and related myopathy

Peripheral arterial disease (PAD) is a prevalent cardiovascular complication of limb vascular insufficiency, causing ischemic injury, mitochondrial metabolic damage and functional impairment in the skeletal muscle, and ultimately leading to immobility and mortality. While potential therapies have been mostly focussed on revascularization, none of the currently available pharmacological treatments are fully effective in PAD, often leading to amputations, particularly in chronic metabolic diseases. One major limitation of focussed angiogenesis and revascularization as a therapeutic strategy is a limited effect on metabolic restoration and muscle regeneration in the affected limb. Therefore, additional preclinical investigations are needed to discover novel treatment options for PAD preferably targeting multiple aspects of muscle recovery. In this review, we propose nuclear receptors expressed in the skeletal muscle as potential candidates for ischemic muscle repair in PAD. We review classic steroid and orphan receptors that have been reported to be involved in the regulation of paracrine muscle angiogenesis, oxidative metabolism, mitochondrial biogenesis and muscle regeneration, and discuss how these receptors could be critical for recovery from ischemic muscle damage. Furthermore, we identify existing gaps in our understanding of nuclear receptor signalling in the skeletal muscle and propose future areas of research that could be instrumental in exploring nuclear receptors as therapeutic candidates for treating PAD.

Plasma protein signatures for high on-treatment platelet reactivity to aspirin and clopidogrel in peripheral artery disease

BACKGROUND

A significant proportion of patients with peripheral artery disease (PAD) displays a poor response to aspirin and/or the platelet P2Y12 receptor antagonist clopidogrel. This phenomenon is reflected by high on-treatment platelet reactivity (HTPR) in platelet function assays in vitro and is associated with an increased risk of adverse cardiovascular events.

OBJECTIVE

This study aimed to elucidate specific plasma protein signatures associated with HTPR to aspirin and clopidogrel in PAD patients.

METHODS AND RESULTS

Based on targeted plasma proteomics, 184 proteins from two cardiovascular Olink panels were measured in 105 PAD patients. VerifyNow ASPI- and P2Y12-test values were transformed to a continuous variable representing HTPR as a spectrum instead of cut-off level-defined HTPR. Using the Boruta random forest algorithm, the importance of 3 plasma proteins for HTPR in the aspirin, six in clopidogrel and 10 in the pooled group (clopidogrel or aspirin) was confirmed. Network analysis demonstrated clusters with CD84, SLAMF7, IL1RN and THBD for clopidogrel and with F2R, SELPLG, HAVCR1, THBD, PECAM1, TNFRSF10B, MERTK and ADM for the pooled group. F2R, TNFRSF10B and ADM were higher expressed in Fontaine III patients compared to Fontaine II, suggesting their relation with PAD severity.

CONCLUSIONS

A plasma protein signature, including eight targets involved in proatherogenic dysfunction of blood cell-vasculature interaction, coagulation and cell death, is associated with HTPR (aspirin and/or clopidogrel) in PAD. This may serve as important systems-based determinants of poor platelet responsiveness to aspirin and/or clopidogrel in PAD and other cardiovascular diseases and may contribute to identify novel treatment strategies.

The Intersocietal IWGDF, ESVS, SVS Guidelines on Peripheral Artery Disease in People With Diabetes Mellitus and a Foot Ulcer

Diabetes related foot complications have become a major cause of morbidity and are implicated in most major and minor amputations globally. Approximately 50% of people with diabetes and a foot ulcer have peripheral artery disease (PAD) and the presence of PAD significantly increases the risk of adverse limb and cardiovascular events. The International Working Group on the Diabetic Foot (IWGDF) has published evidence based guidelines on the management and prevention of diabetes related foot complications since 1999. This guideline is an update of the 2019 IWGDF guideline on the diagnosis, prognosis, and management of peripheral artery disease in people with diabetes mellitus and a foot ulcer. For this updated guideline, the IWGDF, the European Society for Vascular Surgery, and the Society for Vascular Surgery decided to collaborate to develop a consistent suite of recommendations relevant to clinicians in all countries. This guideline is based on three new systematic reviews. Using the Grading of Recommendations, Assessment, Development and Evaluation framework clinically relevant questions were formulated, and the literature was systematically reviewed. After assessing the certainty of the evidence, recommendations were formulated which were weighed against the balance of benefits and harms, patient values, feasibility, acceptability, equity, resources required, and when available, costs. Through this process five recommendations were developed for diagnosing PAD in a person with diabetes, with and without a foot ulcer or gangrene. Five recommendations were developed for prognosis relating to estimating likelihood of healing and amputation outcomes in a person with diabetes and a foot ulcer or gangrene. Fifteen recommendations were developed related to PAD treatment encompassing prioritisation of people for revascularisation, the choice of a procedure and post-surgical care. In addition, the Writing Committee has highlighted key research questions where current evidence is lacking. The Writing Committee believes that following these recommendations will help healthcare professionals to provide better care and will reduce the burden of diabetes related foot complications.

Unveiling the Genetic Footprint: Exploring Somatic Mutations in Peripheral Arterial Disease Progression

Peripheral arterial diseases (PADs) are complex cardiovascular conditions influenced by environmental factors and somatic mutations in multiple genes involved in hematopoiesis and inflammation. While traditional risk factors, such as smoking, hypercholesterolemia, and hypertension, have been extensively studied, the role of somatic mutations in PAD progression remains underexplored. The present article intends to provide a comprehensive commentary of the molecular mechanisms, genetic landscape, prognostic significance, and clinical implications of somatic mutations in PADs. The expansion of clonal hematopoiesis of indeterminate potential (CHIP) clones in the circulating blood, named clonal hematopoiesis (CH), leads to the infiltration of these clones into atherosclerotic plaques and the production of inflammatory cytokines, increasing the risk of cardiovascular diseases, including PADs. Furthermore, recent experimental evidence has demonstrated the involvement of somatically mutated TP53 genes with a high variant allele frequency (VAF) in PAD development and prognosis. This review delves into the relationship between CH and PADs, elucidating the prevalence, impact, and underlying mechanisms of this association. This understanding paves the way for novel therapeutic approaches targeting CHIP to promote tissue regeneration and improve outcomes in PAD patients. It emphasizes the need for further research to fully unravel the genetic footprint of the disease and highlights potential clinical implications. The findings presented in this article lay the foundation for personalized medicine approaches and open avenues for the development of targeted therapies based on somatic mutation profiling.

Estrogen-Related Receptor Gamma Gene Therapy Promotes Therapeutic Angiogenesis and Muscle Recovery in Preclinical Model of PAD

Background Peripheral arterial disease and critical limb ischemia are cardiovascular complications associated with vascular insufficiency, oxidative metabolic dysfunction, and myopathy in the limbs. Estrogen-related receptor gamma (ERRγ) has emerged as a dual regulator of paracrine angiogenesis and oxidative metabolism through transgenic mouse studies. Here our objective was to investigate whether postischemic intramuscular targeting of ERRγ via gene therapy promotes ischemic recovery in a preclinical model of peripheral arterial disease/critical limb ischemia. Methods and Results Adeno-associated virus 9 (AAV9) Esrrg gene delivery vector was developed and first tested via intramuscular injection in murine skeletal muscle. AAV9-Esrrg robustly increased ERRγ protein expression, induced angiogenic and oxidative genes, and boosted capillary density and succinate dehydrogenase oxidative metabolic activity in skeletal muscles of C57Bl/6J mice. Next, hindlimb ischemia was induced via unilateral femoral vessel ligation in mice, followed by intramuscular AAV9-Esrrg (or AAV9-green fluorescent protein) gene delivery 24 hours after injury. ERRγ overexpression increased ischemic neoangiogenesis and markers of endothelial activation, and significantly improved ischemic revascularization measured using laser Doppler flowmetry. Moreover, ERRγ overexpression restored succinate dehydrogenase oxidative metabolic capacity in ischemic muscle, which correlated with increased mitochondrial respiratory complex protein expression. Most importantly, myofiber size to number quantification revealed that AAV9-Esrrg restores myofibrillar size and mitigates ischemia-induced myopathy. Conclusions These results demonstrate that intramuscular AAV9-Esrrg delivery rescues ischemic pathology after hindlimb ischemia, underscoring that Esrrg gene therapy or pharmacological activation could be a promising strategy for the management of peripheral arterial disease/critical limb ischemia.