Peripheral Arterial Disease and the Diabetic Foot Syndrome: Neuropathy Makes the Difference! A Narrative Review

Background: In vascular medicine, peripheral arterial disease (PAD) and diabetic foot syndrome (DFS) are often considered synonymous with respect to the need for revascularization. In PAD patients, clinical symptoms reflect the degree of atherosclerotic disease, since peripheral innervation, including pain sensation, is not usually compromised. In DFS patients, however, symptoms of relevant foot ischemia are often absent and progression of ischemia goes unnoticed owing to diabetic polyneuropathy, the loss of nociception being the main trigger for foot ulcers. This review analyzes the fundamental differences between PAD and DFS against the background of polyneuropathy. Methods: The literature research for the 2014 revision of the German evidence-based S3-PAD-guidelines was extended to 2023. Results: Vascular examination is imperative for both, PAD and DFS. Stage-dependent revascularization is of utmost importance in PAD patients, especially those suffering from critical limb-threatening ischemia (CLTI). Successful therapy of DFS goes further, including infection and metabolic control, wound management, offloading the foot and lifelong prophylaxis in the course of a multidisciplinary treatment concept. Revascularization is not needed in all cases of DFS. Conclusions: There are fundamental differences between PAD and DFS with respect to pathophysiology, the anatomical distribution of arterial occlusive processes, the clinical symptoms, the value of diagnostic tools such as the ankle-brachial index, and classification. Also, therapeutic concepts differ substantially between the two patient populations.

Mitochondrial respiration in peripheral arterial disease depends on stage severity

Peripheral arterial disease (PAD) is an increasing cause of morbidity and its severity is graded based on clinical manifestation. To investigate the influence of the different stages on myopathy of ischemic muscle we analysed severity-dependent effects of mitochondrial respiration in PAD. Eighteen patients with severe PAD, defined as chronic limb-threatening ischemia, 47 patients with intermittent claudication (IC) and 22 non-ischemic controls were analysed. High-resolution respirometry (HRR) was performed on muscle biopsies of gastrocnemius and vastus lateralis muscle of patients in different PAD stages to investigate different respiratory states. Results from HRR are given as median and interquartile range and were normalized to citrate synthase activity (CSA), a marker for mitochondrial content. In order to account for inter-individual differences between patients and controls, we calculated the ratio of O₂-flux in gastrocnemius muscle over vastus muscle ('GV ratio'). CSA of the gastrocnemius muscle as a proxy for mitochondrial content was significantly lower in critical ischemia compared to controls. Mitochondrial respiration normalized to CSA was higher in IC compared to controls. Likewise, the GV ratio was significantly higher in IC compared to control. Mitochondrial respiration and CSA of PAD patients showed stage-dependent modifications with greater changes in the mild PAD stage group (IC).

Lifestyle Approach and Medical Therapy of Lower Extremity Peripheral Artery Disease

Lower extremity peripheral artery disease (PAD) is common among patients with several risk factors, such as elderly, smoking, hypertension, and diabetes mellitus. Notably, PAD is associated with a higher risk of cardiovascular complications. Non-invasive interventions are beneficial to improve morbidity and mortality among patients with PAD. Traditional risk factors like smoking, diabetes mellitus, hypertension, and dyslipidemia play a significant role in the development of PAD. Still, additional factors such as mental health, glycemic control, diet, exercise, obesity management, lipid-lowering therapy, and antiplatelet therapy have emerged as important considerations. Managing these factors can help improve outcomes and reduce complications in PAD patients. Antiplatelet therapy with aspirin or clopidogrel is recommended in PAD patients, with clopidogrel showing more significant benefits in symptomatic PAD individuals. Managing several risk factors is crucial for improving outcomes and reducing complications in patients with PAD. Further research is also needed to explore the potential benefits of novel therapies. Ultimately, a comprehensive approach to PAD management is essential for improving morbidity and mortality among patients with this condition.

Use of Rotational Atherectomy-Assisted Balloon Angioplasty in the Treatment of Isolated Below-the-Knee Atherosclerotic Lesions in Patients with Chronic Limb-Threatening Ischemia

The aim of the study is to evaluate the safety and effectiveness of rotational atherectomy-assisted balloon angioplasty (BTK-RA) for the treatment of isolated below the knee (BTK) atherosclerotic lesions and to compare the outcomes to plain old balloon angioplasty (POBA). Between January 2020 and September 2023, 96 consecutive patients with chronic limb threatening ischemia (CTLI) and isolated BTK-lesions underwent POBA (group A) or BTK-RA (group B). The primary outcome measures were: periprocedural technical success, primary patency, postoperative increase of the ankle branchial index (ABI), target lesion revascularization (TLR), limb salvage, minor amputation and death. Both techniques had similar technical success, operative time, intraprocedural complications and bailout stent implantations, independently of the operator's experience. Group B had significantly higher primary patency rates (93.5% vs. 72.0%, respectively, p = 0.006), TLR (2.1% vs. 24%, p = 0.057), lower in-hospital stay (2.0-3.0 vs. 4.0-6.0 days, respectively, p < 0.001) and higher postoperative ABI (0.8-0.2 vs. 0.7-0.1, respectively, p = 0.008), compared to group A. Significant differences (POBA n: 20, 40%, BTK-RA n = 3, 6.5%) were found in minor amputation rates between the two groups (p < 0.001), while the respective limb salvage rates were similar in both groups (94.0% vs. 97.8%, p = 0.35). The use of BTK-RA for the treatment of BTK-lesions in patients with CTLI showed significant clinical advantages in comparison to POBA.

Efficacy analysis following polymer coated drug eluting stent and bare metal stent deployment for femoropopliteal arterial disease

OBJECTIVES

The objective is to assess the performance of the Eluvia polymer coated drug eluting stent (DES) compared to a bare metal stent (BMS) platform in patients with femoropopliteal arterial disease.

METHODS

This is a retrospective, single-center analysis. Patients treated with the Eluvia DES (group Eluvia) or the EverFlex BMS (group BMS) for femoropopliteal disease between January 2013 and December 2019 were included. Primary measure outcome of this analysis was the overall mortality. The PTX specific mortality, the primary patency, the amputation free survival (AFS), and the target lesion revascularization (TLR) rates were additionally evaluated.

RESULTS

A total of 124 patients were treated by BMS deployment, while the Eluvia platform was preferred in 75 subjects. In both groups the majority presented with lifestyle limiting claudication (BMS: 84% vs Eluvia: 73%, p = 0.73). Chronic total occlusions were more frequent in patients treated by BMS (BMS: 71% vs Eluvia: 84%, p = 0.027), whereas the calcification burden (BMS: 81% vs Eluvia: 76%, p = 0.43) and the median lesion length (in mm, IQR) (BMS: 160 (100 to 240) vs Eluvia: 140 (80 to 229), p = 0.17) were comparable. At 24 months, the overall survival (BMS: 93% vs Eluvia: 89%, hazard ratio (HR): 1.20, 95% confidence interval (CI): 0.55 to 2.64, p = 0.64) and the PTX specific survival (BMS: 95% vs Eluvia: 95%, HR: 1.28, 95% CI: 0.41 to 4.02, p = 0.67) did not differ significantly between the two platforms. No significant difference was observed regarding the 24 months primary patency rate (BMS: 66% vs Eluvia: 78%, HR: 0.65, 95% CI: 0.37 to 1.15, p = 0.18), the freedom from TLR (BMS: 83% vs Eluvia: 89%, HR: 0.81, 95% CI: 0.39 to 1.68, p = 0.572), and the AFS (BMS: 93 vs Eluvia: 89%, HR: 1.20, 95% CI: 0.55 to 2.64). The Cox regression analysis revealed a higher mortality risk among patients with chronic limb-threatening ischemia (CLTI) (HR: 3.14, 95% CI: 1.61 to 6.14, p = 0.008), chronic obstructive pulmonary disease (COPD) (HR: 4.65, 95% CI: 2.14 to 10.09, p = 0.001), in octagenerians (HR: 4.40, 95% CI: 1.92 to 10.44, p = 0.005), and in patients not on statins at baseline (HR: 2.44, 95% CI: 1.19 to 4.99, p=0.014).

CONCLUSIONS

In this cohort, the use of the Eluvia DES did not increase the risk for mortality compared to BMS deployment. CLTI, COPD, advanced age, and the lack of statin therapy at baseline were associated with a higher risk for death.

Long-Term Follow-up and Mortality Rate of Patients of the Randomized Freeway Stent Study

PURPOSE

This follow-up study was designed as a reopen of the completed Freeway Stent Study and collected mortality and clinical outcome data for at least 5 years after enrollment to evaluate long-term patient safety and treatment efficacy. The primary study enrolled 204 patients with stenosis or occlusion in the superficial femoral artery and proximal popliteal artery. Patients were randomized to primary nitinol stenting followed by standard PTA or primary nitinol stenting followed by FREEWAY™ paclitaxel-eluting balloon PTA.

METHODS

Previous patients were recontacted by phone or during a routine hospital visit, and medical records were reviewed. Vital and clinical status information was collected.

RESULTS

No increased late mortality was observed at 5 years, with an all-cause mortality rate of 12.0% in the FREEWAY drug-eluting balloon group versus 15.0% in the non-paclitaxel PTA group. No accumulation of any cause of death was observed in either group, nor was there any correlation with the dose of paclitaxel used. Freedom from clinically driven target lesion revascularization at 5 years was significantly higher in the FREEWAY drug eluting balloon group (85.3%) compared to standard PTA group (72.7%) Log-rank p = 0.032.

CONCLUSION

The safety results presented support the recent conclusions that the use of paclitaxel technology does not lead to an increase in mortality. At the same time, the efficacy results clearly demonstrate that the potential benefits of drug-eluting balloon treatment are maintained over a 5-year period.

Omega-3 Polyunsaturated Fatty Acids are not associated with Peripheral Artery Disease in a Meta-Analysis from the Multi-Ethnic Study of Atherosclerosis and Atherosclerosis Risk in Communities Study Cohorts

BACKGROUND

Research suggests omega-3 polyunsaturated fatty acids (PUFAs) exert favorable effects on several biological processes involved in the development and progression of atherosclerotic cardiovascular disease (ASCVD). However, studies examining the relationship between omega-3 PUFAs and peripheral artery disease (PAD) are scarce.

OBJECTIVES

We evaluated the associations between omega-3 PUFAs and incident PAD in a meta-analysis of the Multi-Ethnic Study of Atherosclerosis (MESA) and Atherosclerosis Risk in Communities (ARIC) study cohorts.

METHODS

Omega-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were measured at baseline for all MESA (n = 6495) and Minnesota ARIC participants (n = 3612). Incident clinical PAD events (MESA n = 106; ARIC n = 149) identified primarily through ICD discharge codes were assessed through follow-up of each cohort. Associations between omega-3 PUFAs (EPA, DHA, and EPA+DHA) and incident PAD were modeled in MESA and ARIC as quartiles and continuously using Cox proportional hazards regression, respectively. A fixed-effects meta-analysis was conducted to evaluate associations in the 2 cohorts combined.

RESULTS

In the fully adjusted model, in 10,107 participants, no significant associations were observed between EPA, DHA, or EPA+DHA, and incident PAD modeled as quartiles or continuously for either MESA or ARIC cohorts separately or in the meta-analysis after a follow-up of approximately 15 y.

CONCLUSION

This study is consistent with previous literature indicating that the beneficial effects of omega-3 PUFAs on the markers of ASCVD may not translate to a clinically meaningful decrease in PAD risk.

In-patient characteristics of peripheral artery disease in Germany

Background: Peripheral artery disease (PAD) frequently leads to hospital admission. Sex related differences in in-patient care are a current matter of debate. Patients and methods: Data were provided from the German national in-patient sample provided by the Federal Bureau of Statistics (DESTATIS). Trends on risk profiles, therapeutic procedures, and outcomes were evaluated from 2014 until 2019 stratified by sex and PAD severity. Results: Two-thirds of an annual >191,000 PAD in-patient cases applied to male sex. Chronic limb-threatening ischemia (CLTI) was recorded in 49.6% of male and 55.2% of female cases (2019). CLTI was as a major risk factor of in-hospital amputation (OR 229) and death (OR 10.5), whereas endovascular revascularisation (EVR) with drug-coated devices were associated with decreased risk of in-hospital amputation (OR 0.52; all p<0.001). EVR applied in 47% of CLTI cases compared to 71% in intermittent claudication (IC) irrespective of sex. In-hospital mortality was 4.3% in male vs. 4.8% in female CLTI cases, minor amputations 18.4% vs. 10.9%, and major amputation 7.5% vs. 6.0%, respectively (data 2019; all p<0.001). After adjustment, female sex was associated with lower risk of amputation (OR 0.63) and death (OR 0.96) during in-patient stay. Conclusions: Male PAD patients were twice as likely to be admitted for in-patient treatment despite equal PAD prevalence in the general population. Among in-patient cases, supply with invasive therapy did not relevantly differ by sex, however is strongly reduced in CLTI. CLTI is a major risk factor of adverse short-term outcomes, whereas female sex was associated with lower risk of in-patient amputation and/or death.

A PAD-Based Unmanned Aerial Vehichle Route Planning Scheme for Remote Sensing in Huge Regions

Unmanned aerial vehicles (UAVs) have been employed extensively for remote-sensing missions. However, due to their energy limitations, UAVs have a restricted flight operating time and spatial coverage, which makes remote sensing over huge regions that are out of UAV flight endurance and range challenging. PAD is an autonomous wireless charging station that might significantly increase the flying time of UAVs by recharging them in the air. In this work, we introduce PADs to simplify UAV-based remote sensing over a huge region, and then we explore the UAV route planning problem once PADs have been predeployed throughout a huge remote sensing region. A route planning scheme, named PAD-based remote sensing (PBRS), is proposed to solve the problem. The PBRS scheme first plans the UAV's round-trip routes based on the location of the PADs and divides the whole target region into multiple PAD-based subregions. Between adjacent subregions, the UAV flight subroute is planned by determining piggyback points to minimize the total time for remote sensing. We demonstrate the effectiveness of the proposed scheme by conducting several sets of simulation experiments based on the digital orthophoto model of Hutou Village in Beibei District, Chongqing, China. The results show that the PBRS scheme can achieve excellent performance in three metrics of remote sensing duration, the number of trips to charging stations, and the data-storage rate in UAV remote-sensing missions over huge regions with predeployed PADs through effective planning of UAVs.

Primary Afferent Depolarization and the Gate Control Theory of Pain: A Tutorial Simulation

The gate control theory of pain postulates that the sensation of pain can be reduced or blocked by closing a "gate" at the earliest synaptic level in the spinal cord, where nociceptive (pain) afferents excite the ascending interneurons that transmit the signal to the brain. Furthermore, the gate can be induced to close by stimulating touch afferents with receptive fields in the same general area as the trauma that is generating the pain (the "rub it to make it better" effect). A considerable volume of research has substantiated the theory and shown that a key mechanism mediating the gate is pre-synaptic inhibition, and that this inhibition is generated by depolarizing IPSPs in the nociceptor central terminals (primary afferent depolarization; PAD). Both pre-synaptic inhibition and depolarizing IPSPs are topics that students often regard as matters of secondary importance (if they are aware of them at all), and yet they are crucial to a matter of primary importance to us all - pain control. This report describes some simple computer simulations that illustrate pre-synaptic inhibition and explore the importance of the depolarizing aspect of the IPSPs. These concepts are then built into a model of the gate control of pain itself. Finally, the simulations show how a small change in chloride homeostasis can generate the dorsal root reflex, in which nociceptor afferents generate antidromic spikes which may increase neurogenic inflammation and actually exacerbate pain. The hope is that the simulations will increase awareness and understanding of a topic that is important in both basic neuroscience and medical neurology.

Peptidyl Arginine Deiminases in Chronic Diseases: A Focus on Rheumatoid Arthritis and Interstitial Lung Disease

Protein citrullination is accomplished by a broad enzyme family named Peptidyl Arginine Deiminases (PADs), which makes this post-translational modification in many proteins that perform physiological and pathologic mechanisms in the body. Due to these modifications, citrullination has become a significant topic in the study of pathological processes. It has been related to some chronic and autoimmune diseases, including rheumatoid arthritis (RA), interstitial lung diseases (ILD), multiple sclerosis (MS), and certain types of cancer, among others. Antibody production against different targets, including filaggrin, vimentin, and collagen, results in an immune response if they are citrullinated, which triggers a continuous inflammatory process characteristic of autoimmune and certain chronic diseases. PAD coding genes (PADI1 to PADI4 and PADI6) harbor variations that can be important in these enzymes' folding, activity, function, and half-life. However, few studies have considered these genetic factors in the context of chronic diseases. Exploring PAD pathways and their role in autoimmune and chronic diseases is a major topic in developing new pharmacological targets and valuable biomarkers to improve diagnosis and prevention. The present review addresses and highlights genetic, molecular, biochemical, and physiopathological factors where PAD enzymes perform a major role in autoimmune and chronic diseases.

Disparities in Diagnosis, Treatment, and Outcomes of Peripheral Artery Disease: JACC Scientific Statement

Disparities by sex, race, socioeconomic status, and geography exist in diagnosis, treatment, and outcomes for people with lower extremity peripheral artery disease (PAD). PAD prevalence is similar in men and women, but women have more atypical symptoms and undergo lower extremity revascularization at older ages compared to men. People who are Black have an approximately 2-fold higher prevalence of PAD, compared to people who are White and have more atypical symptoms, greater mobility loss, less optimal medical care, and higher amputation rates. Although fewer data are available for other races, people with PAD who are Hispanic have higher amputation rates than White people. Rates of amputation also vary by geography in the United States, with the highest rates of amputation in the southeastern United States. To improve PAD outcomes, intentional actions to eliminate disparities are necessary, including clinician education, patient education with culturally appropriate messaging, improved access to high-quality health care, science focused on disparity elimination, and health policy changes.

Oscillometric measurement of the ankle-brachial index and the estimated carotid-femoral pulse wave velocity improves the sensitivity of an automated device in screening peripheral artery disease

Background and aims

To overcome the time and personnel constraints of the Doppler method, automated, four-limb blood pressure monitors were recently developed. Their additional functions, such as measuring the estimated carotid-femoral pulse wave velocity (ecfPWV), have been, thus far, less studied. We aimed to compare the sensitivity and specificity of different ankle-brachial index (ABI), toe-brachial index (TBI), and ecfPWV measurement methodologies to evaluate their contribution to peripheral artery disease (PAD) screening.

Methods

Among 230 patients (mean age 64 ± 14 years), ABI measurements were performed using a Doppler device and a manual sphygmomanometer. The Doppler ABI was calculated by taking the higher, while the modified Doppler ABI by taking the lower systolic blood pressure of the two ankle arteries as the numerator, and the higher systolic blood pressure of both brachial arteries as the denominator. The automated ABI measurement was carried out using an automatic BOSO ABI-system 100 PWV device, which also measured ecfPWV. TBI was obtained using a laser Doppler fluxmeter (Periflux 5000) and a photoplethysmographic device (SysToe). To assess atherosclerotic and definitive PAD lesions, vascular imaging techniques were used, including ultrasound in 160, digital subtraction angiography in 66, and CT angiography in four cases.

Results

ROC analysis exhibited a sensitivity/specificity of 70.6%/98.1% for the Doppler ABI (area under the curve, AUC = 0.873), 84.0%/94.4% for the modified Doppler ABI (AUC = 0.923), and 61.5%/97.8% for the BOSO ABI (AUC = 0.882) at a cutoff of 0.9. Raising the cutoff to 1.0 increased the sensitivity of BOSO to 80.7%, with the specificity decreasing to 79.1%. The ecfPWV measurement (AUC = 0.896) demonstrated a 63.2%/100% sensitivity/specificity in predicting atherosclerotic lesions at a cutoff of 10 m/s. Combining BOSO ABI and ecfPWV measurements recognized 89.5% of all PAD limbs.

Conclusion

The combined BOSO ABI and ecfPWV measurements may help select patients requiring further non-invasive diagnostic evaluation for PAD. The user-friendly feasibility may make it suitable for screening large populations.

Antithrombotic Therapy in Arterial Thrombosis and Thromboembolism in COVID-19: An American College of Chest Physicians Expert Panel Report

BACKGROUND

Evidence increasingly shows that the risk of thrombotic complications in COVID-19 is associated with a hypercoagulable state. Several organizations have released guidelines for the management of COVID-19-related coagulopathy and prevention of VTE. However, an urgent need exists for practical guidance on the management of arterial thrombosis and thromboembolism in this setting.

RESEARCH QUESTION

What is the current available evidence informing the prevention and management of arterial thrombosis and thromboembolism in patients with COVID-19?

STUDY DESIGN AND METHODS

A group of approved panelists developed key clinical questions by using the Population, Intervention, Comparator, and Outcome (PICO) format that address urgent clinical questions regarding prevention and management of arterial thrombosis and thromboembolism in patients with COVID-19. Using MEDLINE via PubMed, a literature search was conducted and references were screened for inclusion. Data from included studies were summarized and reviewed by the panel. Consensus for the direction and strength of recommendations was achieved using a modified Delphi survey.

RESULTS

The review and analysis of the literature based on 11 PICO questions resulted in 11 recommendations. Overall, a low quality of evidence specific to the population with COVID-19 was found. Consequently, many of the recommendations were based on indirect evidence and prior guidelines in similar populations without COVID-19.

INTERPRETATION

The existing evidence and panel consensus do not suggest a major departure from the management of arterial thrombosis according to recommendations predating the COVID-19 pandemic. Data on the optimal strategies for prevention and management of arterial thrombosis and thromboembolism in patients with COVID-19 are sparse. More high-quality evidence is needed to inform management strategies in these patients.

Potentially active compounds that improve PAD through angiogenesis: A review

Peripheral arterial disease (PAD) has been historically neglected, which has resulted in a lack of effective drugs in clinical practice. However, with the increasing prevalence of diseases like atherosclerosis and diabetes, the incidence of PAD is rising and cannot be ignored. Researchers are exploring the potential of promoting angiogenesis through exogenous compounds to improve PAD. This paper focuses on the therapeutic effect of natural products (Salidroside, Astragaloside IV, etc.) and synthetic compounds (Cilostazol, Dapagliflozin, etc.). Specifically, it examines how they can promote autocrine secretion of vascular endothelial cells, enhance cell paracrine interactions, and regulate endothelial progenitor cell function. The activation of these effects may be closely related to PI3K, AMPK, and other pathways. Overall, these exogenous compounds have promising therapeutic potential for PAD. This study aims to summarize the potential active compounds, provide a variety of options for the search for drugs for the treatment of PAD, and bring light to the treatment of patients.

Chronic Limb-Threatening Ischemia Is Associated With Higher Mortality and Limb Revascularization After Transcatheter Aortic Valve Replacement

Peripheral arterial disease (PAD) is common in patients with symptomatic aortic stenosis. PAD exists as a spectrum, and patients with chronic limb-threatening ischemia (CLTI), the most severe form of PAD, are at high risk for limb loss and death. We seek to determine patient characteristics and clinical outcomes among patients who underwent TAVR with or without CLTI. We identified all hospitalizations for TAVR from October 2015 to December 2018 using the National Inpatient Sample database. Patients with any diagnosis of CLTI were identified using the International Classification of Diseases 10th Revision codes. The primary outcome was in-hospital mortality, and secondary outcomes were major complications, open revascularization, and endovascular revascularization after TAVR. During the study period, a total of 31,335 hospitalizations for TAVR procedures were included, including 7,048 (22.5%) in patients with CLTI. CLTI was associated with higher in-hospital mortality (odds ratio [OR] 1.4, 95% confidence interval [CI] 1.13 to 1.74, p = 0.002) and major complications (OR 1.2, 95% CI 1.09 to 1.25, p <0.001). CLTI was also associated with a significantly higher rate of open limb revascularization (OR 5.1, 95% CI 3.94 to 6.48, p <0.001) and endovascular revascularization (OR 4.0, 95% CI 3.54 to 4.59, p <0.001). CLTI among patients who underwent TAVR is associated with higher in-hospital mortality, major complications, and longer lengths of stay compared with patients without CLTI. However, the overall rates of adverse events remain low. Further studies are needed to optimize the multidisciplinary care of these patients before TAVR with a focus on shared decision-making.

Improving Monocular Facial Presentation-Attack-Detection Robustness with Synthetic Noise Augmentations

We present a synthetic augmentation approach towards improving monocular face presentation-attack-detection (PAD) robustness to real-world noise additions. Face PAD algorithms secure authentication systems against spoofing attacks, such as pictures, videos, and 2D-inspired masks. Best-in-class PAD methods typically use 3D imagery, but these can be expensive. To reduce application cost, there is a growing field investigating monocular algorithms that detect facial artifacts. These approaches work well in laboratory conditions, but can be sensitive to the imaging environment (e.g., sensor noise, dynamic lighting, etc.). The ideal solution for noise robustness is training under all expected conditions; however, this is time consuming and expensive. Instead, we propose that physics-informed noise-augmentations can pragmatically achieve robustness. Our toolbox contains twelve sensor and lighting effect generators. We demonstrate that our toolbox generates more robust PAD features than popular augmentation methods in noisy test-evaluations. We also observe that the toolbox improves accuracy on clean test data, suggesting that it inherently helps discern spoof artifacts from imaging artifacts. We validate this hypothesis through an ablation study, where we remove liveliness pairs (e.g., live or spoof imagery only for participants) to identify how much real data can be replaced with synthetic augmentations. We demonstrate that using these noise augmentations allows us to achieve better test accuracy while only requiring 30% of participants to be fully imaged under all conditions. These findings indicate that synthetic noise augmentations are a great way to improve PAD, addressing noise robustness while simplifying data collection.

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.

Consensus minimum core data elements adapted to peripheral vascular intervention in the drug-eluting era: Consensus report from the Registry Assessment of Peripheral Interventional Devices (RAPID) Pathways "LEAN" working group

Registry Assessment of Peripheral Interventional Devices (RAPID) initiated the Pathways Program to provide a transparent, collaborative forum in which to pursue insights into multiple unresolved questions on benefit-risk of paclitaxel-coated devices, including understanding the basis of the mortality signal, without a demonstrable potential biological mechanism, and whether the late mortality signal could be artifact intrinsic to multiple independent prospective randomized data sources that did not prespecify death as a long-term end point. In response to the directive, the LEAN-Case Report Form working group focused on enhancements to the RAPID Phase I Minimum Core Data set through the addition of key clinical modifiers that would be more strongly linked to longer-term mortality outcomes after peripheral arterial disease intervention in the drug-eluting device era, with the goal to have future mortality signals more accurately examined.

Underutilization of guideline-recommended therapy in patients 80 years and older with peripheral artery diseases

Background: Ageing is a major cardiovascular risk factor with detrimental changes that culminate in a high atherosclerotic burden. Peripheral artery disease (PAD) is a major manifestation of atherosclerosis with high mortality. Guideline-recommended treatment is essential, however implementation is inadequate. With an ageing society, age-related inequalities are important and have not been elucidated in a high-risk PAD population on a nation-wide scale. We sought to analyse outpatient treatment structures and guideline adherence in treatment of PAD patients older than 80 years. Patients and methods: The study is based on ambulatory claims data comprising 70.1 million statutorily insured patients per year in Germany from 2009 to 2018. We analysed age-related differences in prevalence, pharmacotherapy and specialized outpatient care in PAD patients. Results: Of 17,633,970 PAD patients included, 28% were older than 80 years. PAD prevalence increased between 2008 and 2018 (1.85% vs. 3.14%), with the proportion of older patients increasing by a third (24.4% vs. 31.2%). Octogenarians were undertreated regarding guideline-recommended statin pharmacotherapy compared to younger patients while antiplatelets were prescribed more often (statins 2016: 46.5% vs. 52.4%; antiplatelets 2016 30.6% vs. 29.3%; p<.05). Furthermore, octogenarians received less specialized outpatient care (angiology: 6.4% vs. 9.5%, vascular surgery: 8.1% vs. 11.8%, cardiology: 25.2% vs. 29.2%, p<.05). Conclusions: Our results demonstrate that age-related differences in pharmacotherapy and specialized outpatient care of PAD patients are evident. While overall guideline-recommended outpatient treatment is low, patients 80 years and older are less likely to receive both, leaving age-related health inequalities a challenge of our future.

SWAT 84: effects of same-day consent vs delayed consent on the recruitment and retention of trial participants-an observational SWAT

BACKGROUND AND AIM

The recruitment process in a randomized trial can be challenging. Poor recruitment can have a negative impact on the allocated budget and estimated completion date of the study and may result in an underpowered study. We aimed to perform a Study Within A Trial (SWAT) to evaluate the impact of same-day consent or delayed consent on recruitment and retention in the host trial.

METHODS

This SWAT is designed as a prospective cohort design. The host trial was a randomized controlled trial evaluating the effectiveness of an intensive lifestyle modification programme in participants with peripheral arterial disease. Researchers screened the participants for inclusion and exclusion criteria. Informed consents were obtained from the participants who were willing to participate in the study on a standardized consent form. Participants were given the option to consent on the same day or to delay their consent. Following the consent, the participants were allocated to two groups (same-day consent vs. delayed consent) based on pre-determined criteria for SWAT. One hundred sixteen participants were consented to take part in the host trial. Seventy-five participants were randomized to the host trial. The primary outcome was the proportion of participants who withdrew consent at the recruitment phase. Secondary outcomes were reasons for consent withdrawal and dropout, attrition rate, and adherence with the host trial intervention.

RESULTS

There was a significantly lower consent-withdrawal rate in same-day consent (17.4%, n = 8/46), compared to the delayed consent group (47.1%, n = 33/70), p = 0.001. There was a significantly lower dropout rate in participants randomized following same-day consent (10.5%, n = 4/38), compared to those randomized after delayed consent (29.7%, n = 11/37), p = 0.038. Transport was the main reason mentioned for consent withdrawal and dropout. In participants randomized to the host trial intervention arm, there was a significant difference in adherence (percentage of the 12-week programme completed) between same-day consent (96.7% ± 4.9) and delayed consent participants (86.4% ± 11.2), p = 0.003, as well as number of weeks completed (mean difference =  - 1.547, 95% confidence intervals (- 2.237 to - 0.85)), p = 0.02.

CONCLUSION

This SWAT found evidence that participants who gave consent on the same day seemed to have better adherence and fewer-withdrawal and dropout rates.

SWAT REGISTRATION

The SWAT was registered on the Northern Ireland Network for Trials Methodology Research, SWAT 84.

Cellular immune response to SARS-CoV-2 in patients with primary antibody deficiencies

Introduction

Primary antibody deficiencies (PAD) are inborn defects of the immune system that result in increased susceptibility to infections. Despite the reduced response to vaccination, PAD patients still benefit from it by reducing the risk of severe infections and complications. SARS-CoV-2 vaccines are recommended in PAD patients, but their immune effects are poorly studied. Here, we analyze virus-specific T-cell responses in PAD patients after booster vaccination against SARS-CoV-2.

Patients and methods

The study included 57 adult PAD patients on long-term immunoglobulin replacement therapy (IgRT) diagnosed with X-linked agammaglobulinemia (XLA; n = 4), common variable immunodeficiency (CVID; n = 33), isotype defects or IgG subclass deficiency (n = 6), and unclassified IgG deficiency (n = 14). Of those, 49 patients (86%) received vaccination against SARS-CoV-2 using mRNA vaccine (Pfizer-BioNTech). T-cell responses were assessed at a median of 21 (13 - 30) weeks after the booster dose (mainly the third dose) using commercially available interferon-gamma release assay (IGRA) with recombinant SARS-CoV-2 spike S1 protein.

Results

Vaccinated PAD patients showed an increased (3.8-fold, p = 0.004) release of IFN-γ upon S1 stimulation. In this group, we also documented higher serum levels of anti-SARS-CoV-2 IgG (4.1-fold, p = 0.01), although they were not associated with IGRA results. Further subgroup analysis revealed very similar IGRA responses in CVID and unclassified IgG deficiencies that were 2.4-fold increased compared to XLA and 5.4-fold increased compared to patients with isotype defects or IgG subclass deficiencies (e.g., vs. CVID: p = 0.016). As expected, CVID and XLA patients showed decreased serum titers of anti-SARS-CoV-2 antibodies compared to other studied groups (e.g., CVID vs. unclassified IgG deficiency: 4.4-fold, p = 0.006). The results did not depend directly on IgRT mode or dose, number of vaccine doses and time from the last booster dose, and clinical manifestations of PAD. Interestingly, anti-SARS-CoV-2 titers were positively correlated with serum immunoglobulin levels before IgRT (e.g., for IgA: r = 0.45, p<0.001; for IgG: r = 0.34, p = 0.009) and the percentage of peripheral blood NK cells (r = 0.48, p<0.001).

Conclusions

Our results documented satisfactory in vitro cellular immune response in PAD patients after booster SARS-CoV-2 vaccination. Therefore, even patients with agammaglobulinemia should benefit from vaccination due to the apparent induction of cell-mediated immunity, which, together with IgRT, grants comprehensive protection against the pathogen.

National Institutes of Health funding among vascular surgeons is rare

BACKGROUND

The National Institutes of Health (NIH) is an essential source of funding for vascular surgeons conducting research. NIH funding is frequently used to benchmark institutional and individual research productivity, help determine eligibility for academic promotion, and as a measure of scientific quality. We sought to appraise the current scope of NIH funding to vascular surgeons by appraising the characteristics of NIH-funded investigators and projects. In addition, we also sought to determine whether funded grants addressed recent Society for Vascular Surgery (SVS) research priorities.

METHODS

In April 2022, we queried the NIH Research Portfolio Online Reporting Tools Expenditures and Results (RePORTER) database for active projects. We only included projects that had a vascular surgeon as a principal investigator. Grant characteristics were extracted from the NIH Research Portfolio Online Reporting Tools Expenditures and Results database. Principal investigator demographics and academic background information were identified by searching institution profiles.

RESULTS

There were 55 active NIH awards given to 41 vascular surgeons. Only 1% (41/4037) of all vascular surgeons in the United States receive NIH funding. Funded vascular surgeons are an average of 16.3 years out of training; 37% (n = 15) are women. The majority of awards (58%; n = 32) were R01 grants. Among the active NIH-funded projects, 75% (n = 41) are basic or translational research projects, and 25% (n = 14) are clinical or health services research projects. Abdominal aortic aneurysm and peripheral arterial disease are the most commonly funded disease areas and together accounted for 54% (n = 30) of projects. Three SVS research priorities are not addressed by any of the current NIH-funded projects.

CONCLUSIONS

NIH funding of vascular surgeons is rare and predominantly consists of basic or translational science projects focused on abdominal aortic aneurysm and peripheral arterial disease research. Women are well-represented among funded vascular surgeons. Although the majority of SVS research priorities receive NIH funding, three SVS research priorities are yet to be addressed by NIH-funded projects. Future efforts should focus on increasing the number of vascular surgeons receiving NIH grants and ensuring all SVS research priorities receive NIH funding.

ZILVERPASS Study: ZILVER PTX Stent versus Prosthetic Above-the-Knee Bypass Surgery in Femoropopliteal Lesions, 5-year Results

PURPOSE

To report the 60-month safety and effectiveness results of a multicenter, prospective, randomized controlled trial comparing the ZILVER PTX paclitaxel-eluting stent to prosthetic above-the-knee bypass for the treatment of symptomatic TransAtlantic Inter-Society Consensus (TASC) C and D femoropopliteal lesions.

MATERIALS AND METHODS

Patients were enrolled between October 2013 and July 2017. One of the secondary outcomes was primary patency at 60 months, defined as no evidence of binary restenosis or occlusion within the target lesion or bypass graft based on a duplex ultrasound peak systolic velocity ratio < 2.4 and no clinically-driven target lesion revascularization (TLR) in endovascular cases or reintervention to restore flow in the bypass at 60 months. Survival rates after 5 years were also analyzed.

RESULTS

220 patients (mean age 68.6 ± 10.5 years; 159 men) were included and randomized to ZILVER PTX (n = 113, 51.40%) or BYPASS group (n = 107, 48.60%). The 60-month primary patency rate was 49.3% for the ZILVER PTX group versus 40.7% for the bypass group (p = 0.6915). Freedom from TLR was 63.8% for the ZILVER PTX group versus 52.8% for the bypass group (p = 0.2637). At 5 years, no significant difference in survival rate could be seen between the ZILVER PTX and the bypass group (69.1% vs. 71% respectively, p = 0.5503).

CONCLUSION

Even at 5 years, non-inferior safety and effectiveness results of the ZILVER PTX could be seen. These findings confirmed that the use of ZILVER PTX stents can be considered as a valid alternative for bypass surgery when treating long and complex femoropopliteal lesions.

Melatonin secretion patterns are associated with cognitive vulnerability and brain structure in bipolar depression

Circadian rhythm disruption is a core symptom of bipolar disorder (BD), also reflected in altered patterns of melatonin release. Reductions of grey matter (GM) volumes are well documented in BD. We hypothesized that levels and timing of melatonin secretion in bipolar depression could be associated with depressive psychopathology and brain GM integrity. The onset of melatonin secretion under dim light conditions (DLMO) and the amount of time between DLMO and midsleep (i.e. phase angle difference; PAD) were used as circadian rhythm markers. To study the time course of melatonin secretion, an exponential curve fitting the melatonin values was calculated, and the slope coefficients (SLP) were obtained for each participant. Significant differences were found between HC and BD in PAD measures and melatonin profiles. Correlations between PAD and depressive psychopathology were identified. Melatonin secretion patterns were found to be associated with GM volumes in the Striatum and Supramarginal Gyrus in BD. Our findings emphasized the role of melatonin secretion role as a biological marker of circadian synchronization in bipolar depression and provided a novel insight for a link between melatonin release and brain structure.

Protective Effects of Statins on Limb and Cardiovascular Outcomes in Patients with Peripheral Artery Disease and End-Stage Renal Disease

Background

Previous studies have reported that statins have inconsistent and marginal cardiovascular (CV) benefits in patients with end-stage renal disease (ESRD). However, whether statins play a secondary preventive role in patients with peripheral artery disease (PAD) and ESRD remains unclear.

Objectives

This study aimed to compare the long-term clinical outcomes between statin users and nonusers with PAD and ESRD.

Methods

This retrospective cohort study assessed the long-term protective effects of statins using data from the National Health Insurance Research Database in Taiwan. Propensity score matching was performed according to sex, age, index year, related comorbidities, and medications. The main outcomes were limb events and major adverse CV events (MACEs).

Results

The statin user group (n = 4,460) was compared with the propensity score-matched statin nonuser group (n = 4,460). The mean age of the matched patients was 64 years, and 40% of the patients were men. The baseline characteristics of the groups were well-balanced. The overall limb event and MACE rates were not different between the two groups. However, the statin user group had lower rates of limb amputation [adjusted hazard ratio (aHR): 0.85, 95% confidence interval (CI): 0.73-0.99], stroke (aHR: 0.71, 95% CI: 0.62-0.83), CV death (aHR: 0.46, 95% CI: 0.32-0.66), and all-cause death (aHR: 0.45, 95% CI: 0.42-0.48) despite having a higher rate of percutaneous transluminal angioplasty for PAD.

Conclusions

This population-based retrospective cohort study demonstrated that statin therapy was associated with a lower risk of limb amputation, nonfatal stroke, CV death, and all-cause death in patients with PAD and ESRD.

Utility of BeBack crossing catheter in fistula creation during percutaneous deep vein arterialization

For patients with "no-option" chronic limb-threatening ischemia, a final attempt can be made for limb salvage in the form of percutaneous deep vein arterialization (pDVA). In the present study, we describe five cases of pDVA using a BeBack crossing catheter (Bentley InnoMed GmbH; previously, the GoBack crossing catheter; Upstream Peripheral Technologies). From November 2021 to July 2022, five patients underwent pDVA using the BeBack crossing catheter. The demographic data, procedural details, and patient outcomes were recorded. Successful vascular crossing was achieved in all five cases using the BeBack device. No surgical complications were encountered. The limb salvage rate was 60%, and the wound closure rate was 40%. No mortalities occurred during the follow-up period. The findings from the present study demonstrate that the use of the BeBack crossing catheter for pDVA is safe and feasible.

Disparities in healthcare utilization by insurance status among patients with symptomatic peripheral artery disease

BACKGROUND

Peripheral artery disease (PAD) is a common circulatory disorder associated with increased hospitalizations and significant health care-related expenditures. Among patients with PAD, insurance status is an important determinant of health care utilization, treatment of disease, and treatment outcomes. However, little is known about PAD-costs differences across different insurance providers. In this study we examined possible disparities in length of stay and total charge of inpatient hospitalizations among patients with PAD by insurance type.

METHODS

We conducted a cross-sectional analysis of length of stay and total charge by insurance provider for all hospitalizations for individuals with PAD in South Carolina (2010-2018). Cross-classified multilevel modeling was applied to account for the non-nested hierarchical structure of the data, with county and hospital included as random effects. Analyses were adjusted for patient age, race/ethnicity, county, year of admission, admission type, all-patient refined diagnostic groups, and Charlson comorbidity index.

RESULTS

Among 385,018 hospitalizations for individuals with PAD in South Carolina, the median length of stay was 4 days (IQR: 5) and the median total charge of hospitalization was $43,232 (IQR: $52,405). Length of stay and total charge varied significantly by insurance provider. Medicare patients had increased length of stay (IRR = 1.08, 95 CI%: 1.07, 1.09) and higher total charges (β: 0.012, 95% CI: 0.007, 0.178) than patients with private insurance. Medicaid patients also had increased length of stay (IRR = 1.26, 95% CI: 1.24,1.28) but had lower total charges (β: -0.022, 95% CI: -0.003. -0.015) than patients with private insurance.

CONCLUSIONS

Insurance status was associated with inpatient length of stay and total charges in patients with PAD. It is essential that Medicare and Medicaid individuals with PAD receive proper management and care of their PAD, particularly in the primary care settings, to prevent hospitalizations and reduce the excess burden on these patients.

Revascularisation Options for Chronic Limb Threatening Ischaemia in Diabetes: Implications From Two Recent Trials

Chronic limb-threatening ischaemia (CLTI) is a severe form of peripheral arterial disease (PAD) and is associated with an increased risk of amputation, mortality, and significantly impaired quality of life. International guidelines recommend considering timely revascularisation and optimal medical therapy to improve limb perfusion in individuals with CLTI. The 2 primary revascularization approaches for CLTI are open bypass surgery (BS) and endovascular therapy (EV), however, there is currently no consensus on the best initial treatment strategy for CLTI, leading to uncertainty among clinicians. To shed light on this issue, 2 recent trials, namely best endovascular versus best surgical therapy in patients with CLI (BEST-CLI) and bypass versus angioplasty for severe ischaemia of the leg (BASIL-2), have tried to provide valuable insights. While a definitive conclusion on the optimal revascularisation approach is still pending, these trials offer immediate and clinically relevant information to the diabetic foot multidisciplinary team. The trials encompassed a distinct range of patient cohorts and included participants with varying degrees of medical and physical frailty. Taken together, their findings, highlight the need for an individualised revascularisation strategy which accounts for underlying comorbidities, risk factors, disease severity, availability of suitable bypass conduits, surgical risks, and timely access to procedures. Regardless of the chosen strategy, early referral of patients with diabetes and CLTI to a specialist team within a multidisciplinary environment is crucial. Comprehensive care should encompass essential elements such as adequate debridement, infection control, offloading, glycaemic control, smoking cessation, and patient education. By addressing these aspects, healthcare providers can optimise the management and outcomes for individuals with CLTI and diabetes.

Effectiveness of incisional negative pressure wound therapy after major lower extremity amputation: a randomised controlled trial

INTRODUCTION

The aim was to study the effect of incisional negative pressure wound therapy (iNPWT) in wound healing compared with standard sterile gauze dressings after major lower extremity amputation in patients with peripheral arterial disease (PAD).

METHODS

This prospective, randomised controlled trial included 50 patients undergoing major lower extremity amputations for PAD. Patients were randomised into iNPWT and standard dressing groups. The patency of blood vessels at the level of the stump was ensured with or without revascularisation. The primary outcome was wound-related complications such as surgical site infection (SSI), wound dehiscence, seroma/haematoma formation or the need for revision amputation. The secondary outcome was the time taken for the eligibility of prosthesis placement.

RESULTS

It was found that only 12% of the patients in the iNPWT group had SSI compared with 36% in the standard dressing group (p = 0.047). Rates of wound dehiscence, seroma/haematoma formation and revision amputation were decreased in the iNPWT group but this was not statistically significant (p > 0.05). There was a significant reduction in the time taken for eligibility of prosthesis placement in the iNPWT group (5.12 ± 1.53 vs 6.8 ± 1.95 weeks, p = 0.002).

CONCLUSIONS

iNPWT is effective in reducing the incidence of SSI and the time taken for rehabilitation in patients undergoing major lower limb amputation due to PAD.

Treatment of Peripheral Artery Disease Using Injectable Biomaterials and Drug-Coated Balloons: Safety and Efficacy Perspective

The possibility of injectable biomaterials being used in the therapy of peripheral artery disease (PAD) is investigated in this article. We conducted a thorough review of the literature on the use and efficacy of biomaterials (BMs) and drug-coated balloons (DCBs). These BMs included hydrogels, collagen scaffolds, and nanoparticles. These BMs could be used alone or in combination with growth factors, stem cells, or gene therapy. The treatment of peripheral artery disease with DCBs is increasingly common in the field of interventional angiology. Studies have been carried out to examine the effectiveness of paclitaxel-coated balloons such as PaccocathTM in lowering the frequency with which further revascularization operations are required. PCB angioplasty and angioplasty without paclitaxel did not significantly vary in terms of mortality, according to the findings of a recent meta-analysis that included the results of four randomized controlled studies. On the other hand, age was found to be a factor that predicted mortality. There was a correlation between the routine utilization of scoring balloon angioplasty along with DCBs and improved clinical outcomes in de novo lesions. In both preclinical and clinical testing, the SelutionTM DCB has demonstrated efficacy and safety, but further research is required to determine whether or not it is effective and safe over the long term. In addition, we reviewed the difficulties involved in bringing injectable BMs-based medicines to clinical trials, including the approval processes required by regulatory bodies. Injectable BMs have a significant amount of therapeutic promise for PAD, which highlights the need for more research and clinical studies to be conducted in this field. In conclusion, this research focuses on the potential of injectable BMs and DCBs in the treatment of PAD as well as the hurdles that must be overcome in order to translate these treatments into clinical trials. In this particular field, there is a demand for further research as well as clinical trials.

Citrullination of C1-inhibitor as a mechanism of impaired complement regulation in rheumatoid arthritis

Background

Dysregulated complement activation, increased protein citrullination, and production of autoantibodies against citrullinated proteins are hallmarks of rheumatoid arthritis (RA). Citrullination is induced by immune cell-derived peptidyl-Arg deiminases (PADs), which are overactivated in the inflamed synovium. We characterized the effect of PAD2- and PAD4-induced citrullination on the ability of the plasma-derived serpin C1-inhibitor (C1-INH) to inhibit complement and contact system activation.

Methods

Citrullination of the C1-INH was confirmed by ELISA and Western blotting using a biotinylated phenylglyoxal probe. C1-INH-mediated inhibition of complement activation was analyzed by C1-esterase activity assay. Downstream inhibition of complement was studied by C4b deposition on heat-aggregated IgGs by ELISA, using pooled normal human serum as a complement source. Inhibition of the contact system was investigated by chromogenic activity assays for factor XIIa, plasma kallikrein, and factor XIa. In addition, autoantibody reactivity to native and citrullinated C1-INH was measured by ELISA in 101 RA patient samples.

Results

C1-INH was efficiently citrullinated by PAD2 and PAD4. Citrullinated C1-INH was not able to bind the serine protease C1s and inhibit its activity. Citrullination of the C1-INH abrogated its ability to dissociate the C1-complex and thus inhibit complement activation. Consequently, citrullinated C1-INH had a decreased capacity to inhibit C4b deposition via the classical and lectin pathways. The inhibitory effect of C1-INH on the contact system components factor XIIa, plasma kallikrein, and factor XIa was also strongly reduced by citrullination. In RA patient samples, autoantibody binding to PAD2- and PAD4-citrullinated C1-INH was detected. Significantly more binding was observed in anti-citrullinated protein antibody (ACPA)-positive than in ACPA-negative samples.

Conclusion

Citrullination of the C1-INH by recombinant human PAD2 and PAD4 enzymes impaired its ability to inhibit the complement and contact systems in vitro. Citrullination seems to render C1-INH more immunogenic, and citrullinated C1-INH might thus be an additional target of the autoantibody response observed in RA patients.

Clinical Potential of Hydrogen Sulfide in Peripheral Arterial Disease

Peripheral artery disease (PAD) affects more than 230 million people worldwide. PAD patients suffer from reduced quality of life and are at increased risk of vascular complications and all-cause mortality. Despite its prevalence, impact on quality of life and poor long-term clinical outcomes, PAD remains underdiagnosed and undertreated compared to myocardial infarction and stroke. PAD is due to a combination of macrovascular atherosclerosis and calcification, combined with microvascular rarefaction, leading to chronic peripheral ischemia. Novel therapies are needed to address the increasing incidence of PAD and its difficult long-term pharmacological and surgical management. The cysteine-derived gasotransmitter hydrogen sulfide (H₂S) has interesting vasorelaxant, cytoprotective, antioxidant and anti-inflammatory properties. In this review, we describe the current understanding of PAD pathophysiology and the remarkable benefits of H₂S against atherosclerosis, inflammation, vascular calcification, and other vasculo-protective effects.

The Concentration of Pro- and Antiangiogenic Factors in Saliva and Gingival Crevicular Fluid Compared to Plasma in Patients with Peripheral Artery Disease and Type 2 Diabetes

Several studies have investigated various biomarkers in relation to peripheral artery disease (PAD) for disease stratification and early-onset detection. In PAD, angiogenesis is required for tissue restoration and tissue perfusion. Considering changes in angiogenesis in patients with PAD, angiogenic factors could be explored as one of the new prognostic molecules. In recent studies, saliva and gingival crevicular fluid (GCF) have gained recognition as new, easily obtained diagnostic materials. This study aimed to compare the levels of selected circulating angiogenic factors (VEGF-A, PDGF-BB, and ANG-1) in unstimulated whole saliva (WS) and GCF versus plasma at three points in time to find possible correlations between their concentrations among patients with PAD and diabetes type 2 in 32 patients with Rutherford stages 5 and 6. A significant positive correlation has been demonstrated between circulating PDGF-BB levels in GCF and plasma. In most cases, comorbidities do not have an impact on the change in general correlation for the whole group. Our results clearly showed that GCF could be a good source for PDGF assessment. However, future studies with a larger number of subjects are warranted to confirm this finding and identify the most accurate angiogenic biomarkers in saliva or GCF that could be applied in clinical practice.

Peripheral arterial disease (PAD) - A challenging manifestation of atherosclerosis

The diagnosis of peripheral arterial disease (PAD) is not always evident as symptoms and signs may show great variation. As all grades of PAD are linked to both an increased risk for cardiovascular complications and adverse limb events, awareness of the condition and knowledge about diagnostic measures, prevention and treatment is crucial. This article presents in a condensed form information on PAD and its management.

Paper-based analytical device coupled with Bi-MOF: Electric field amplification and fluorescence sensing of glyphosate

Glyphosate, a potent herbicide wildly used in the world, involves potential hazards to human health by accumulating in the food chain. Due to its absence of chromophores and fluorophores, the rapid visual detection of glyphosate has always been difficult. Herein, a paper-based geometric field amplification device visualized by the amino-functionalized bismuth-based metal-organic framework (NH₂-Bi-MOF) was constructed for sensitive fluorescence determination of glyphosate. Fluorescence of the synthesized NH₂-Bi-MOF was immediately enhanced by interaction with glyphosate. The field amplification of glyphosate was implemented by coordinating the electric field and the electroosmotic flow, which was orchestrated by the geometric configuration of paper channel and the concentration of polyvinyl pyrrolidone, respectively. Under the optimal conditions, the developed method exhibited a linear range of 0.80-200 μmol L^-1 with about 12500-fold signal enhancement achieved by just 100 s electric field amplification. It was applied to soil and water with recoveries between 95.7% and 105.6%, holding great prospects in on-site analysis of hazardous anions for environment safety.

Increased Levels of Circulating Iron-Albumin Complexes in Peripheral Arterial Disease Patients

Under physiological conditions, extracellular iron circulates in the blood bound to transferrin. As a consequence of several pathologies, the circulating level of a Non-Transferrin Bound pool of Iron (NTBI) increases. The NTBI pool is biologically heterogeneous and represented by iron chelated either by small metabolites (citrate, amino acids, or cofactors) or by serum proteins. By promoting reactive oxygen species (ROS) and reactive nitrogen species (RNS) formation, NTBI causes oxidative stress and alteration of membrane lipids, seriously compromising the healthy state of organs and tissues. While NTBI involvement in several pathologies has been clarified, its contribution to vascular diseases remains to be investigated. Here we measure and analyze the pool of NTBI in the serum of a small group of peripheral arterial disease (PAD) patients. We show that: (i) the NTBI pool shifts from low molecular complexes to high-molecular ones in PAD patients compared to healthy controls; (ii) most of this NTBI is bound to the serum protein Albumin; (iii) this NTBI-Albumin complex can be isolated and quantitated following a simple immunoisolation procedure amenable to automation and suitable for clinical screening purposes.

AED delivery at night - Can drones do the Job? A feasibility study of unmanned aerial systems to transport automated external defibrillators during night-time

BACKGROUND

In their recent guidelines the European Resuscitation Council have recommended the use of Unmanned Aerial systems (UAS) to overcome the notorious shortage of AED. Exploiting the full potential of airborne AED delivery would mandate 24 h UAS operability. However, current systems have not been evaluated for nighttime use. The primary goal of our study was to evaluate the feasibility of night-time AED delivery by UAS. The secondary goal was to obtain and compare operational and safety data of night versus day missions.

METHODS

We scheduled two (one day, one night) flights each to ten different locations to assess the feasibility of AED delivery by UAS during night-time. We also compared operational data (mission timings) and safety data (incidence of critical events) of night versus day missions.

RESULTS

All missions were completed without safety incident. The flights were performed automatically without pilot interventions, apart from manually choosing the landing site and correcting the descent. Flight distances ranged from 910 m to 6.960 m, corresponding mission times from alert to AED release between 3:48 min and 11:20 min. Night missions (T¯_m:night = 7:26 ± 2:29 min) did not take longer than day missions (T¯_m:day = 7:59 ± 2:27 min). Despite slightly inferior visibility of the target site, night landings (T¯_land:night = 64 ± 15 sec) were on average marginally quicker than day landings (T¯_land:day = 69 ± 11sec).

CONCLUSIONS

Our results demonstrate the feasibility of UAS supported AED delivery during nighttime. Operational and safety data indicate no major differences between day- and night-time use. Future research should focus on integration of drone technology into the chain of survival.

Intravascular Lithotripsy and Drug-Coated Balloon Angioplasty for Severely Calcified Femoropopliteal Arterial Disease

INTRODUCTION

The combination of intravascular lithotripsy (IVL) and drug-coated balloon (DCB) angioplasty for calcified peripheral lesions is associated with promising short-term results. However, data regarding the 12 months performance of this treatment option is missing. This study reports on the outcomes of IVL and DCB angioplasty for calcified femoropopliteal disease.

METHODS

Patients treated with IVL and DCB for calcified femoropopliteal lesions between February 2017 and September 2020 were included into this study. The primary outcome measure of this analysis was primary patency. Secondary patency, freedom from target lesion revascularization (TLR) and overall mortality were additionally analyzed.

RESULTS

Fifty-five (n = 55) patients and 71 lesions were analyzed. Most patients presented with long-term limb-threatening ischemia (n = 31, 56%), 47% (n = 26) were diabetics, and 66% (n = 36) had long-term kidney disease. The median lesion length was 77 mm (interquartile range: 45-136), and 20% (n = 14) of the lesions were chronic total occlusions (CTOs). Eccentric calcification was found in 23% of the vessels (n = 16), and circumferential calcium (peripheral arterial calcium scoring system [PACSS] Class 3 and 4) was present in 78% (n = 55) of the treated lesions.The technical success after IVL amounted to 87% (n = 62) and the procedural success to 97% (n = 69). A flow-limiting dissection was observed in 2 cases (3%). Both the rates of target lesion perforation and distal embolization were 1% (n = 1). A bail-out scaffold was deployed in 5 lesions (7%). At 12 months the Kaplan-Meier estimate of primary patency was 81%, the freedom from TLR was 92% and the secondary patency 98%. The overall survival amounted to 89%, while the freedom from major amputation to 98%. The presence of eccentric disease, CTOs, or PACSS Class 4 did not increase the risk for loss of patency or TLR.

CONCLUSIONS

In this challenging cohort of patients, the use of IVL and DCB for calcified femoropopliteal lesions was associated with promising 12 months outcomes and an excellent safety profile.

Occurrence and ecotoxicological risk assessment of pharmacologically active dyes in the environmental water of Poland

The interest in the fate of pharmacologically active substances (PASs) in the aquatic environment continually increases. However, little is known about pharmacologically active dyes (PADs) as contaminants of water bodies. PADs are used in medicine, but due to their colouring properties are also applied in the textile, cosmetic and food industries. Their large-scale production and widespread applications have caused these dyes permeate to the aquatic environment. The pharmacological activity and toxicological properties of some of these dyes, caused their occurrence in water should be monitored. Up to now, PADs such as crystal violet, malachite green, methylene blue, rhodamine B, have been determined in the water of Greater China and Iran. However, there is no data on whether PADs pose an environmental problem for water bodies in Poland. Thus, different water samples were collected and analysed by the UPLC-MS/MS method allowing the determination of 20 PADs. The tests showed that dyes such as crystal violet, methyl violet 2 B and rhodamine B were found in 2 out of 36 water reservoirs (0.0122-0.0594 μgL^-1). The environmental risk assessment indicated that determined dyes for most model organisms did not pose a risk. Only the presence of methyl violet 2 B (0.0571 μgL^-1) was related to a low risk for rohu carp, and crystal violet (0.0122-0.0209 μgL^-1) showed a moderate risk for medaka fish. The occurrence of PADs was tested on a larger scale in the water samples collected from different water reservoirs in Poland. Based on obtained results, 96.3% of water samples collected from different water bodies (94.5%) were free from dyes. Thus, it could be stated that generally environmental water of Poland is contaminated with PADs at a low level. On the other hand, the presence of dyes in two samples indicates that PADs permeate the water environment, and their occurrence should be monitored.

The Characteristics of Dialysis Membranes: Benefits of the AN69 Membrane in Hemodialysis Patients

Patients undergoing hemodialysis (HD) experience serious cardiovascular complications, through malnutrition, inflammation, and atherosclerosis. Amputation for peripheral arterial disease (PAD) is more prevalent in patients undergoing HD than in the general population. In addition, revascularization procedures in dialysis patients are often associated with subsequent amputation and high mortality rates. To improve the prognosis of dialysis patients, malnutrition and inflammation must be properly treated, which necessitates a better understanding of the characteristics of dialysis membranes. Herein, the characteristics of several dialysis membranes were studied, with a special reference to the AN69 membrane, noting several similarities to low-density lipoprotein (LDL)-apheresis, which is also applicable for the treatment of PAD. Both systems (LDL-apheresis and AN69) have anti-inflammatory and anti-thrombogenic effects because they use a negatively charged surface for extracorporeal adsorptive filtration from the blood/plasma, and contact phase activation. The concomitant use of both these therapeutic systems may have additive therapeutic benefits in HD patients. Here, we reviewed the characteristics of dialysis membranes and benefits of the AN69 membrane in dialysis patients.

Negative Pressure Wound Therapy and Traditional Dressing: An Italian Health Technology Assessment Evaluation

This evaluation shows the main advantages related to the introduction of negative pressure wound therapy (NPWT) in Italian clinical practice for the management of incisions in vascular surgery in patients suffering from peripheral arterial disease (PAD) and at risk of postoperative complications, compared to treatment with traditional dressings. A health technology assessment (HTA) activity was conducted assuming the hospital perspective, within a 12-month time horizon. The nine EUnetHTA Core Model dimensions were deeply explored, using scientific evidence on the topic, real-life data, and healthcare professionals' perceptions. The evaluation shows that the use of NPWT has had a positive impact in terms of higher clinical effectiveness and safety profile. The process mapping highlights how NPWT allows a reduction of 2.5 hospitalization days compared with standard dressing, with the consequent benefits considering economic, organizational, and social aspects. A significant economic saving per patient emerged, with an overall optimization of the patient's clinical pathway, impacting positively on the hospital's capacity. The budget impact analysis shows that the higher number of patients treated with NPWT, the higher the economic advantages. Furthermore, assuming the patient's perspective, it would generate an overall reduction in social costs of 28%. In conclusion, the results of this study provide helpful evidence-based information to policymakers through examinations of the relative values of intervention, thus supporting the overall hospital and institutional decision-making process to define appropriate areas of investments, leading to the achievement of not only higher clinical outcomes, but also important social, economic, and organizational advantages.

Impact of neighborhood social disadvantage on the presentation and management of peripheral artery disease

OBJECTIVE

Studies examining the relationship between socioeconomic disparities and peripheral artery disease (PAD) often focus on individual social health determinants and fail to account for the complex interplay between factors that ultimately impact disease severity and outcomes. Area deprivation index (ADI), a validated measure of neighborhood adversity, provides a more comprehensive assessment of social disadvantage. Therefore, we examined the impact of ADI on PAD severity and its management.

METHODS

We identified all patients who underwent infrainguinal revascularization (open or endovascular) or amputation for symptomatic PAD in the Vascular Quality Initiative registry between 2003 and 2020. An ADI score of 1 to 100 was assigned to each patient based on their residential zip code, with higher ADI scores corresponding with increasing adversity. Patients were categorized by ADI quintiles (Q1-Q5). The outcomes of interest included indication for procedure (claudication, rest pain, or tissue loss) and rates of revascularization (vs primary amputation). Multinomial logistic regression was used to evaluate for an independent association between ADI quintile and these outcomes.

RESULTS

Among the 79,973 patients identified, 9604 (12%) were in the lowest ADI quintile (Q1), 14,961 (18.7%) in Q2, 19,800 (24.8%) in Q3, 21,735 (27.2%) in Q4, and 13,873 (17.4%) in Q5. There were significant trends toward lower rates of claudication (Q1: 39% vs Q5: 34%, P < .001), higher rates of rest pain (Q1: 12.4% vs Q5: 17.8%, P < .001) as the indication for intervention, and lower rates of revascularization (Q1: 80% vs Q5: 69%, P < .001) with increasing ADI quintiles. In adjusted analyses, there was a progressively higher likelihood of presenting with rest pain vs claudication, with patients in Q5 having the highest probability when compared with those in Q1 (relative risk: 2.0; 95% confidence interval: 1.8-2.2; P < .001). Patients in Q5, when compared with those in Q1, also had a higher likelihood of presenting with tissue loss vs claudication (relative risk: 1.4; 95% confidence interval: 1.3-1.6; P < .001). Compared with patients in Q1, patients in Q2-Q5 had a lower likelihood of undergoing any revascularization procedure.

CONCLUSIONS

Among patients who underwent infrainguinal revascularization or amputation in the Vascular Quality Initiative, those with higher neighborhood adversity had more advanced disease at presentation and lower rates of revascularization. Further work is needed to better understand neighborhood factors that are contributing to these disparities in order to identify community-level targets for improvement.

Salami-Tactics: when is it time for a major cut after multiple minor amputations?

INTRODUCTION

Repetitive minor amputations carry the concomitant risks of multiple surgical procedures, major amputations have physical and economical major drawbacks. The aim of this study was to evaluate whether there is a distinct number of minor amputations predicting a major amputation in the same leg and to determine risk factors for major amputation in multiple minor amputations.

MATERIALS AND METHODS

A retrospective chart review including 429 patients with 534 index minor amputations between 07/1984 and 06/2019 was conducted. Patient demographics and clinical data including number and level of re-amputations were extracted from medical records and statistically analyzed.

RESULTS

290 legs (54.3%) had one or multiple re-amputations after index minor amputation. 89 (16.7%) legs needed major amputation during follow up. Major amputation was performed at a mean of 32.5 (range 0 - 275.2) months after index minor amputation. No particular re-amputation demonstrated statistically significant elevated odds ratio (a.) to be a major amputation compared to the preceding amputation and (b.) to lead to a major amputation at any point during follow up. Stepwise multivariate Cox regression analysis revealed minor re-amputation within 90 days (HR 3.8, 95% CI 2.0-7.3, p <0.001) as the only risk factor for major amputation if at least one re-amputation had to be performed.

CONCLUSIONS

There is no distinct number of prior minor amputations in one leg that would justify a major amputation on its own. If a re-amputation has to be done, the timepoint needs to be considered as re-amputations within 90 days carry a fourfold risk for major amputation.

LEVEL OF EVIDENCE

Retrospective comparative study (Level III).

To Cross or Not to Cross: Using MRI-Histology to Characterize Dense Collagenous Plaque in Critical Limb Ischemia

Peripheral artery disease (PAD) is caused by atherosclerotic buildup in the lower extremities, leading to obstruction and inadequate perfusion to the peripheral vasculature. Impenetrable plaques initially treated with percutaneous vascular intervention (PVI) have led to worse secondary bypass outcomes and amputation in patients. In this case report, we discuss the importance of using magnetic resonance imaging (MRI) histology in PVI planning in a patient with critical limb ischemia. PVI attempts to recanalize the limb failed because of an impenetrable occlusion in the popliteal artery that was not identified on routine preoperative imaging. Subsequent bypass occluded multiple times eventually requiring an above-knee amputation. An MRI-histology protocol-using ultrashort echo time (UTE) and T2-weighted (T2W) sequences-that was performed prior to the index PVI identified the occlusion as a dense collagen plaque. Histology analysis of the amputated specimen confirmed the MRI finding. This imaging modality offers a novel approach to characterize plaque composition and morphology, thereby identifying lesions at greatest risk of PVI failure and potentially playing an important role in selecting the right candidates for an endovascular-first approach.

Prediction and Management of Surgical Site Infections in Hybrid Vascular Surgery for Peripheral Artery Disease

OBJECTIVES

Postoperative complications are an important problem that all surgeons face. Among all possible complications, local and systemic infections are one of the most prevalent postprocedural adverse events. It is difficult to assess whether or not a patient will develop a surgical site infection (SSI), but there are certain basic investigations that can suggest the probability of such an event. We also investigated some clinically assessable signs to help us better predict the occurrence of SSIs. Every bit of information brings us closer to an ideal where we can bring postoperative complications to a minimum. Close examination and attention to detail is crucial in the prediction and prevention of SSIs. Methods: A multicenter, retrospective and prospective observational study was carried out between 01.01.2019 â?" 01.09.2021. All adult patients with peripheral artery disease (PAD) who had disabling intermittent claudication or rest pain, were included in this study. We excluded minor or vascular surgery emergencies (ruptured aneurysms, acute ischemia or vascular trauma). We followed the postoperative complications as well as their management with an emphasis on surgical site infections (SSIs). Receiver Operating Characteristic (ROC) curves were used to determine key values of statistical relevance by calculating the Area Under the Curve (AUC). Multivariate analysis was used to assess the statistical relevance of our data. Results: The study evaluates 128 patients diagnosed with PAD, aged between 47 and 97, with a mean age of 71.26 Ã+- 10.8 years. There were significantly more male than female patients 71.09% vs. 28.91% (p 0.01). All patients were treated using hybrid vascular techniques. All complication rates were recorded but we focused on SSIs, which was the most prevalent complication (25%). C-Reactive Protein with values higher than 5 mg/dl, was confirmed as a positive predictive factor for postoperative surgical site infections (AUC = 0.80). Another positive predictive factor for SSIs is hyperglycemia. Glycemic values higher than 140mg/dl are more frequently associated with postoperative infections (p = 0.02), a predictability curve of statistical significance was also obtained (AUC = 0.71). Postoperative SSIs were more prevalent in patients with preoperative distal trophic lesions (p 0.01). The presence of other complications such as edema and lymphoceles were also linked to SSIs (p 0.01). Nevertheless, patients who underwent surgery over negative wound pressure therapy (NWPT) for infection management had significantly shorter hospital stays (p 0.01). Conclusions: There are multiple clinical or paraclinical predictors of SSIs. The coexistence of several such factors can carry an additional risk of developing a SSI and should be evaluated and controlled separately in the preoperative phase as much as possible. Admission to a diabetes center and regulation of glycemic values prior to elective vascular surgery, for patients who can be surgically postponed is an effective method of preventing infections. Surgical management remains the most reliable form of treatment of SSIs, being the most efficient therapy and offering immediate results, while simultaneously shortening hospital stays.

Income-Related Peripheral Artery Disease Treatment: A Nation-Wide Analysis from 2009-2018

Economic status has a measurable and significant effect on cardiovascular health. Socioeconomic- and income-related disparities worsen cardiovascular risk factors. Peripheral artery disease (PAD) remains a major risk factor for morbidity and mortality. Not all patients benefit equally from recent advances in outpatient healthcare. The implementation of guideline recommendations regarding treatment is inadequate. Income-related disparities for PAD treatment are unknown. We aimed to analyse income-stratified PAD prevalence, outpatient treatment and pharmacotherapy. Associations of statutory health insurance physicians at the regional level, income-stratified PAD prevalence and differences in outpatient care and pharmacotherapy were analysed in 70.1 million statutorily insured patients/year between 2009 and 2018. Analysis was based on claims data (§295 of the social code (SGB V)) and drug-prescription data (§300 SGB V). The diagnosis of PAD was defined by ICD I70.2-9. Regional income data were derived from the German Census Bureau. PAD prevalence was higher in low-income than in high-income areas. Low-income patients more often presented to angiology outpatient care and more frequently received guideline recommended pharmacotherapy. High-income patients more often presented to outpatient vascular surgery. This was true for statins, antiplatelets, intermittent claudication and critical limb ischemia alike. These data indicate that PAD and income are associated. Regional income is related to insufficiencies in guideline-recommended treatment and contact to vascular specialists. Our results aim to encourage medical professionals to implement PAD guideline recommendations, especially in high-income areas. Further studies on associations between spatial-level income and healthcare in PAD are needed.