Peripheral arterial disease: Epidemiology, natural history, diagnosis and treatment

Retrograde Tibio-Pedal Access for Endovascular Interventions for Treating Peripheral Arterial Disease

Retrograde tibio-pedal access represents a feasible method for endovascular revascularization when antegrade methods fail. The article offers an extensive review of retrograde tibio-pedal access, emphasizing the technique and documented outcomes.

Lower Limb Chronic Ischaemia Presenting Exclusively as Fungal Toenail Infection: Case Report and Brief Literature Review

BACKGROUND/AIM

Chronic lower limb ischaemia is a peripheral arterial disease (PAD) which is typically instigated by atherosclerotic plaques in the peripheral vasculature. This article reports on a unique case of chronic ischaemia in the lower limb, presenting in a distinctive manner as a fungal toenail infection.

CASE REPORT

An 82-year-old frail woman with multimorbidity presented with toenail symptoms in her right foot. While initial examination had shown onychomycosis, further investigation was unexpectedly consistent with chronic ischaemia in the lower limb. We explored the clinical presentation, diagnostic challenges encountered, and the subsequent management of this unique manifestation in the context of the patient's multimorbidity.

CONCLUSION

This case report highlights the need to consider chronic limb ischemia as a differential diagnosis in toenail infections when no alternative causes or predisposing factors are identified.

Comparison of Postoperative Complications in Patients Undergoing Limb Salvage Reconstructive Surgery Based on Estimated Prevalence of Preexisting Peripheral Arterial Disease

BACKGROUND

Limb salvage after lower extremity (LE) trauma requires optimal blood flow for successful microsurgical reconstruction. Peripheral arterial disease (PAD) decreases LE perfusion, affecting wound healing. Patients who present with LE trauma may have undiagnosed PAD, particularly those with atherosclerotic risk factors. This study assesses outcomes after LE salvage in patients at risk for PAD.

METHODS

This retrospective review evaluated patients who underwent LE reconstruction at a level 1 trauma center between 2007 and 2022. Patients with a nontraumatic mechanism of injury, missing postoperative records, and unspecified race were excluded. Demographics, flap characteristics, and postoperative complications were abstracted. The prevalence of LE PAD was calculated using a validated risk assessment tool.

RESULTS

At our institution, 285 LE flaps performed on 254 patients were included in the study. Patients were categorized by prevalence of PAD, including 12 (4.7%) with high risk, 45 (17.7%) with intermediate risk, and 197 (77.6%) patients with low risk. The high-risk cohort had higher rates of partial flap necrosis ( P = 0.037), flap loss ( P = 0.006), and amputation ( P < 0.001) compared with the low-risk group. Fewer high-risk patients achieved full ambulation compared with the low-risk ( P = 0.005) cohort. Overall flap survival and limb salvage rates were 94.5% and 96.5%, respectively. Among the intermediate- and high-risk cohorts, only 50.9% of patients received a preoperative vascular assessment, and 3.8% received a vascular surgery consultation.

CONCLUSIONS

Peripheral arterial disease represents a reconstructive challenge to microvascular surgeons. Patients with high-risk for PAD had higher rates of partial flap necrosis, flap loss, and amputation. In the setting of trauma, emphasis should be placed on preoperative vascular assessment for patients at risk of having undiagnosed PAD. Prospective studies collecting ankle-brachial index assessments and/or angiography will help validate this study's findings.

Ultrasonic AccV: a potential indicator of peripheral arteriosclerosis in patients with chronic obstructive pulmonary disease

OBJECTIVE

This study aimed to investigate the risk factors for peripheral arteriosclerosis (PAS) and peripheral artery disease (PAD) in chronic obstructive pulmonary disease (COPD) patients and potential ultrasound indicators that could be used to improve detection.

METHOD

Outpatients seeking care between January 1, 2017, and December 31, 2020, in The First Affiliated Hospital of China Medical University were prospectively recruited. Subjects were divided into COPD and non-COPD (control) groups, and the COPD group was further divided into PAD and non-PAD subgroup, at the same time, PAS and non-PAS subgroup. Indicators of PAD -ankle-brachial index (ABI), indicators of PAS- pulse wave velocity (PWV), and ultrasound indices -peak systolic blood flow velocity (PSV) and blood flow acceleration velocity (AccV) were compared.

RESULT

Sixty-nine (61.6%) of 112 enrolled subjects had COPD. COPD patients had higher age, and blood pressure (BP)lower than controls. Seventeen (24.6%) COPD patients had PAD, the prevalence of PAD increases with the decrease of lung function, and seven (16.3%) non-COPD patients had PAD, however, there was no significant statistical difference between COPD and non-COPD groups. Fifty (72.5%) COPD patients had PAS, and thirty-four (79.1%) non-COPD patients had PAS, however, there was also no significant difference. The PAS subgroup had higher age, body mass index(BMI), body fat percentage(BFP), lower FEV1 and FEV1/FVC, as well as higher levels of right brachial artery and left dorsalis pedis artery AccV. Factors that correlated with ABI were 6MWD, post-bronchodilator FEV1, FEV1/ FVC, and maximal middle expiratory flow between 75% and 25% of FVC. Age, BP, and 6MWD, but not pulmonary function, were associated with brachial-ankle PWV (baPWV). There was a positive correlation between baPWV and radial artery AccV bilaterally.

CONCLUSION

Radial artery AccV correlated well with baPWV, which suggests that ultrasound could be used to assess both morphological and functional changes in vessels, may serving as a better method to identify PAS in high-risk COPD patients.

Use of simple lymphatic drainage on truncal lymphoedema for a patient with diabetes and peripheral arterial disease

Lymphoedema is the gradual, abnormal build-up of lymph fluid in the tissues resulting from a failure of the lymphatic system. The swelling impedes movement and is painful. Compression garments are contraindicated and not tolerated by patients with extensive peripheral arterial disease. In this case study, simple lymphatic drainage was therefore considered a safer treatment option to reduce oedema and to encourage proactive self-management for a patient with bilateral amputations, diabetes and peripheral arterial disease.

Robotic Microsurgery in Extremity Reconstruction - Experience With a Novel Robotic System

Background: Robotic systems have successfully been introduced into other surgical fields in the past. First attempts with different setups are made in the field of microsurgery. The Symani® Surgical System, a flexible platform consisting of two robotic arms, features motion scaling with tremor filtration to address the demands and complexity of microsurgery. Symani's NanoWrist Instruments are the world's smallest, wristed surgical instruments, intended to improve a surgeon's range of motion beyond the capability of the human hand. This combination allows surgeons to scale their hand movements while seamlessly articulating the robotic micro instruments. Purpose: We report on our experience in extremity reconstruction with this novel system.Research Design: The Symani Surgical System® was used for 6 cases of extremity reconstruction. The surgeon controlled the manipulators along with the footswitch while either sitting away from the operating table relying on 3D visualization with an exoscope or sitting at the operating table using a standard microscope.Data Collection: Microsurgical anastomoses were performed in 4 patients (3 end-to-end arterial anastomoses and one end-to-side arterial anastomosis) and nerve grafting was performed in 2 patients.Results: Microvascular anastomoses were slower vs conventional microsurgery, but all anastomoses were patent. Epineural coaptation showed proper fascicle alignment and tissue manipulation could be kept to a minimum. The platform's motion scaling allows the surgeon to perform precise micro-movements with only minimal tissue manipulation and hard-to-reach anatomy becomes accessible more easily.Conclusions: Robotic microsurgery might gain importance in the nearer future but more data will need to be collected.

Sex-specific analysis of intravascular lithotripsy for peripheral artery disease from the Disrupt PAD III observational study

OBJECTIVE

Endovascular therapy of lower extremity peripheral artery disease (PAD) is associated with higher complication rates and worse outcomes in women vs men. Although intravascular lithotripsy (IVL) has shown similarly favorable outcomes in men and women in calcified coronary arteries, there is no published safety and effectiveness data of peripheral IVL differentiated by sex. This study aims to evaluate sex-specific acute procedural safety and effectiveness following IVL treatment of calcified PAD.

METHODS

We performed a secondary analysis of the multicenter Disrupt PAD III Observational Study, which assessed short-term procedural outcomes of patients undergoing treatment of symptomatic calcified lower extremity PAD with the Shockwave peripheral IVL system. Adjudicated acute safety and efficacy outcomes were compared by sex using univariate analysis performed with the χ2 test or Fisher exact test, as appropriate.

RESULTS

A total of 1262 patients (29.9% women) were included, with >85% having moderate to severe lesion calcification. Women were older (74 vs 71 years; P < .001), had lower ankle-brachial index (0.7 vs 0.8; P = .003), smaller reference vessel size (5.3 vs 5.6 mm; P = .009), and more severe stenosis at baseline vs men (82.3% vs 79.8%; P = .012). Rates of diabetes, renal insufficiency, chronic limb-threatening ischemia, lesion length, and atherectomy use were similar in both groups. Residual stenosis after IVL alone was significantly reduced in both groups. Final residual stenosis was 21.9% in women and 24.7% in men (P = .001). Serious angiographic complications were infrequent and similar in both groups (1.4% vs 0.6%; P = .21), with no abrupt vessel closure, distal embolization, or thrombotic events during any procedure.

CONCLUSIONS

The use of IVL to treat calcified PAD in this observational registry demonstrated favorable acute safety and effectiveness in both women and men.

Arterial and venous peripheral vascular assessment using wearable electro-resistive morphic sensors

Peripheral vascular diseases (PVDs) represent a significant burden on global human health and healthcare systems. With continued growth in obesity and diabetes, it is likely that the incidence of these conditions will increase. As many PVDs remain undiagnosed, low-cost and easy to use diagnostic methods are required. This work uses newly developed wearable electro-resistive morphic sensors to assess venous and arterial competence in the lower limbs of 36 healthy subjects. Comparison of this HeMo device was made to currently available benchtop light reflection rheography and photoplethymography devices. Results indicate that HeMo can detect the physiological signals of interest for both chronic venous insufficiency and peripheral arterial disease and all subjects were interpreted as healthy by each system. However, measurement repeatability of HeMo was highlighted as an issue that requires further system development. Furthermore, as HeMo captures changes in a section of limb circumference due to changes in underlying blood movement, rather than at a single point, the recorded signal is typically damped by comparison. This factor should be considered in any future developments.

Photoplethysmography for the Assessment of Arterial Stiffness

This review outlines the latest methods and innovations for assessing arterial stiffness, along with their respective advantages and disadvantages. Furthermore, we present compelling evidence indicating a recent growth in research focused on assessing arterial stiffness using photoplethysmography (PPG) and propose PPG as a potential tool for assessing vascular ageing in the future. Blood vessels deteriorate with age, losing elasticity and forming deposits. This raises the likelihood of developing cardiovascular disease (CVD), widely reported as the global leading cause of death. The ageing process induces structural modifications in the vascular system, such as increased arterial stiffness, which can cause various volumetric, mechanical, and haemodynamic alterations. Numerous techniques have been investigated to assess arterial stiffness, some of which are currently used in commercial medical devices and some, such as PPG, of which still remain in the research space.

Quantitative and large-format histochemistry to characterize peripheral artery compositional gradients

The femoropopliteal artery (FPA) is a long, flexible vessel that travels down the anteromedial compartment of the thigh as the femoral artery and then behind the kneecap as the popliteal artery. This artery undergoes various degrees of flexion, extension, and torsion during normal walking movements. The FPA is also the most susceptible peripheral artery to atherosclerosis and is where peripheral artery disease manifests in 80% of cases. The connection between peripheral artery location, its mechanical flexion, and its physiological or pathological biochemistry has been investigated for decades; however, histochemical methods remain poorly leveraged in their ability to spatially correlate normal or abnormal extracellular matrix and cells with regions of mechanical flexion. This study generates new histological image processing pipelines to quantitate tissue composition across high-resolution FPA regions-of-interest or low-resolution whole-section cross-sections in relation to their anatomical locations and flexions during normal movement. Comparing healthy ovine femoral, popliteal, and cranial-tibial artery sections as a pilot, substantial arterial contortion was observed in the distal popliteal and cranial tibial regions of the FPA which correlated with increased vascular smooth muscle cells and decreased elastin content. These methods aim to aid in the quantitative characterization of the spatial distribution of extracellular matrix and cells in large heterogeneous tissue sections such as the FPA. RESEARCH HIGHLIGHTS: Large-format histology preserves artery architecture. Elastin and smooth muscle content is correlated with distance from heart and contortion during flexion. Cell and protein analyses are sensitive to sectioning plane and image magnification.

Sex and Racial Disparities in Peripheral Artery Disease

Several studies have shown that women and racial and ethnic minority patients are at increased risk of developing lower extremity peripheral artery disease and suffering adverse outcomes from it, but a knowledge gap remains regarding the underlying causes of these increased risks. Both groups are more likely to be underdiagnosed, have poorly managed contributory comorbidities, and incur disparities in treatment and management postdiagnosis. Opportunities for improvement in the care of women and racial and ethnic minorities with peripheral artery disease include increased rates of screening, higher rates of clinical suspicion (particularly in the absence of typical symptoms of intermittent claudication), and more aggressive risk factor management before and after the diagnosis of peripheral artery disease.

Outcomes and use of healthcare resources after an intervention for chronic limb-threatening ischaemia

BACKGROUND

The fate of patients with chronic limb-threatening ischaemia undergoing revascularization or a primary amputation is unclear. The aim of this study was to assess the postoperative outcomes and post-procedural healthcare resource use/costs over 1 year after revascularization or a primary amputation for chronic limb-threatening ischaemia.

METHODS

The UK Kent Integrated Dataset, which links primary, community, and secondary care for 1.6 million people, was interrogated. All patients with a new diagnosis of chronic limb-threatening ischaemia undergoing revascularization or a major amputation between January 2016 and January 2019 (3 years) were identified. Postoperative events across all healthcare settings and post-procedure healthcare resource use were analysed over 1 year (until the end of 2019).

RESULTS

Overall, 4252 patients with a new diagnosis of chronic limb-threatening ischaemia were identified (65 per cent were male and the mean age was 73 years) between January 2016 and January 2019, of whom 579 (14 per cent) underwent an intervention (studied population); 296 (7 per cent) had an angioplasty, 75 (2 per cent) had bypass surgery, 141 (3 per cent) had a primary major lower limb amputation, 11 had a thrombo-embolectomy (0.3 per cent), and 56 had an endarterectomy (1.3 per cent). Readmissions (median of 2) were similar amongst different procedures within 1 year; bypass surgery was associated with more hospital appointments (median of 4 versus 2; P = 0.002). Patients undergoing a primary amputation had the highest number of cardiovascular events and 1-year mortality. In a linear regression model, index procedure type and Charlson co-morbidity index score were not predictors of appointments in primary/secondary care, community care visits, or readmissions after discharge. There were no statistically significant differences regarding post-procedural healthcare costs between procedures over 1 year.

CONCLUSION

Revascularization is not associated with more hospital, primary/community care appointments or increased post-procedural healthcare costs over 1 year when compared with primary amputation, in people with chronic limb-threatening ischaemia.

Indications for a "Surgery-First" Approach for the Treatment of Lower Extremity Arterial Disease

BACKGROUND

In recent years, there has been a tendency toward an "endovascular-first" approach for the treatment for femoropopliteal arterial disease. The purpose of this study is to determine if there are patients that are better served with an initial femoropopliteal bypass (FPB) rather than an endovascular attempt at revascularization.

METHODS

A retrospective analysis of all patients undergoing FPB between June 2006 - December 2014 was performed. Our primary endpoint was primary graft patency, defined as patent using ultrasound or angiography without secondary intervention. Patients with <1-year follow-up were excluded. Univariate analysis of factors significant for 5-year patency was performed using χ2 tests for binary variables. A binary logistic regression analysis incorporating all factors identified as significant by univariate analysis was used to identify independent risk factors for 5-year patency. Event-free graft survival was evaluated using Kaplan-Meier models.

RESULTS

We identified 241 patients undergoing FPB on 272 limbs. FPB indication was disabling claudication in 95 limbs, chronic limb-threatening ischemia (CLTI) in 148, and popliteal aneurysm in 29. In total, 134 FPB were saphenous vein grafts (SVG), 126 were prosthetic grafts, 8 were arm vein grafts, and 4 were cadaveric/xenografts. There were 97 bypasses with primary patency at 5 or more years of follow-up. Grafts patent at 5 years by Kaplan-Meier analysis were more likely to have been performed for claudication or popliteal aneurysm (63% 5-year patency) as compared with CLTI (38%, P < 0.001). Statistically significant predictors (using log rank test) of patency over time were use of SVG (P = 0.015), surgical indication of claudication or popliteal aneurysm (P < 0.001), Caucasian race (P = 0.019) and no history of COPD (P = 0.026). Multivariable regression analysis confirmed these 4 factors as significant independent predictors of 5-year patency. Of note, there was no statistical correlation between FPB configuration (above or below knee anastomosis, in-situ versus reversed saphenous vein) and 5-year patency. There were 40 FPBs in Caucasian patients without a history of COPD receiving SVG for claudication or popliteal aneurysm that had a 92% estimated 5-year patency by Kaplan-Meier survival analysis.

CONCLUSIONS

Long-term primary patency that was substantial enough to consider open surgery as a first intervention was demonstrated in Caucasian patients without COPD, having good quality saphenous vein, and who underwent FPB for claudication or popliteal artery aneurysm.

Lipoprotein(a) as a Risk Factor for Cardiovascular Diseases: Pathophysiology and Treatment Perspectives

Cardiovascular disease (CVD) is still a leading cause of morbidity and mortality, despite all the progress achieved as regards to both prevention and treatment. Having high levels of lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular disease that operates independently. It can increase the risk of developing cardiovascular disease even when LDL cholesterol (LDL-C) levels are within the recommended range, which is referred to as residual cardiovascular risk. Lp(a) is an LDL-like particle present in human plasma, in which a large plasminogen-like glycoprotein, apolipoprotein(a) [Apo(a)], is covalently bound to Apo B100 via one disulfide bridge. Apo(a) contains one plasminogen-like kringle V structure, a variable number of plasminogen-like kringle IV structures (types 1-10), and one inactive protease region. There is a large inter-individual variation of plasma concentrations of Lp(a), mainly ascribable to genetic variants in the Lp(a) gene: in the general po-pulation, Lp(a) levels can range from <1 mg/dL to >1000 mg/dL. Concentrations also vary between different ethnicities. Lp(a) has been established as one of the risk factors that play an important role in the development of atherosclerotic plaque. Indeed, high concentrations of Lp(a) have been related to a greater risk of ischemic CVD, aortic valve stenosis, and heart failure. The threshold value has been set at 50 mg/dL, but the risk may increase already at levels above 30 mg/dL. Although there is a well-established and strong link between high Lp(a) levels and coronary as well as cerebrovascular disease, the evidence regarding incident peripheral arterial disease and carotid atherosclerosis is not as conclusive. Because lifestyle changes and standard lipid-lowering treatments, such as statins, niacin, and cholesteryl ester transfer protein inhibitors, are not highly effective in reducing Lp(a) levels, there is increased interest in developing new drugs that can address this issue. PCSK9 inhibitors seem to be capable of reducing Lp(a) levels by 25-30%. Mipomersen decreases Lp(a) levels by 25-40%, but its use is burdened with important side effects. At the current time, the most effective and tolerated treatment for patients with a high Lp(a) plasma level is apheresis, while antisense oligonucleotides, small interfering RNAs, and microRNAs, which reduce Lp(a) levels by targeting RNA molecules and regulating gene expression as well as protein production levels, are the most widely explored and promising perspectives. The aim of this review is to provide an update on the current state of the art with regard to Lp(a) pathophysiological mechanisms, focusing on the most effective strategies for lowering Lp(a), including new emerging alternative therapies. The purpose of this manuscript is to improve the management of hyperlipoproteinemia(a) in order to achieve better control of the residual cardiovascular risk, which remains unacceptably high.

Endothelial Progenitor Cells and Macrophage Subsets Recruitment in Postischemic Mouse Hind Limbs

INTRODUCTION

Peripheral arterial disease (PAD) occurs from atherosclerotic obstruction of arteries in the lower extremities. Restoration of perfusion requires angiogenesis and arteriogenesis through migration and differentiation of endothelial progenitor cells (EPCs) and macrophages at the site of injury. The time of recruitment has not been fully investigated. In this study, we investigated the infiltration of these cells in murine hind limb ischemia (HLI) model of PAD.

METHODS

EPCs and M1-like and M2-like macrophages from ischemic skeletal muscles were quantified by flow cytometry at day-0, 1, 3, 7, and 14 post-HLI.

RESULTS

The abundance of EPCs increased from day 1 and was highest on day 7 until day 14. M1-like population similarly increased and was highest on day 14 during the experiment. M2-like population was significantly greater than M1-like at baseline but surpassed the highest value of M1-like by day 7 during the experiment. Muscle regeneration and capillary density also increased and were highest at days 3 and 7, respectively, during the experiment. All mice achieved near full perfusion recovery by day 14.

CONCLUSION

Thus, we observed a gradual increase in the percentage of EPC's and this was temporally paralleled with initial increase in M1-like followed by sustained increased in M2-like macrophages and perfusion recovered post-HLI.

Evaluation of post-natal angiogenesis in a mouse hind limb ischemia model

Hind limb ischemia is a useful model to assess metabolic and cellular responses. Here, we present a protocol for evaluating post-natal angiogenesis in a mouse hind limb ischemia model. We describe steps to induce a severe restriction of blood supply of the femoral artery and vein that mimics the real-life scenario observed in clinical settings. We then detail procedures for follow-up laser Doppler imaging to compare post-ischemic responses of four different mouse strains in their capacity to trigger compensatory arteriogenesis. For complete details on the use and execution of this protocol, please refer to Oberkersch et al. (2022).¹.

Factors that influence the feasibility and implementation of a complex intervention to improve the treatment of peripheral arterial disease in primary and secondary care: a qualitative exploration of patient and provider perspectives

OBJECTIVES

Our aim was to examine the feasibility and implementation of a complex intervention to improve the care of patients with peripheral arterial disease (the LEGS intervention) from the perspective of patients, general practitioners and secondary care clinicians.

DESIGN

A qualitative study involving semistructured individual interviews with patients and providers to gain an understanding of the feasibility of the LEGS intervention as well the barriers and facilitators to implementation in secondary and primary care.

SETTING

Primary and secondary care settings across two National Health Service Trusts.

PARTICIPANTS

Twenty-five semistructured telephone interviews were conducted with (1) patients who had received the intervention (n=11), (2) secondary care clinicians responsible for delivering the intervention (n=8) and (3) general practitioners (n=6).

ANALYSIS

Data were initially analysed using inductive descriptive thematic analysis. The consolidated framework for implementation research was then used as a matrix to explore patterns in the data and to map connections between the three participant groups. Lastly, interpretive analysis allowed for refining, and a final coding frame was developed.

RESULTS

Four overarching themes were identified: (1) the potential to make a difference, (2) a solution to address the gap in no man's land, (3), prioritising and making it happen and (4) personalised information and supportive conversations for taking on the advice. The impetus for prioritising and delivering the intervention was further driven by its flexibility and adaptability to be tailored to the individual and to the environment.

CONCLUSIONS

The LEGS intervention can be tailored for use at early and late stages of peripheral arterial disease, provides an opportunity to meet patient needs and can be used to promote shared working across the primary-secondary care interface.

Validating fatty acid binding protein 3 as a diagnostic and prognostic biomarker for peripheral arterial disease: A three-year prospective follow-up study

BACKGROUND

Patients with peripheral arterial disease (PAD) often remain undiagnosed and therefore suboptimally managed. Here, we investigated the diagnostic and prognostic potential of fatty acid binding protein 3 (FABP3) in patients with PAD.

METHODS

In the discovery phase, 374 PAD and 184 non-PAD patients were recruited from vascular surgery ambulatory clinics at St. Michael's Hospital (Toronto, Ontario, Canada) between October 4, 2017 to October 29, 2018. The diagnostic ability of baseline FABP3 level was investigated through receiver operator characteristic (ROC) curves to determine two cutoff points: 1) an exclusionary "rule out" cutoff point, and 2) a confirmatory "rule in" cutoff point. Next, these cutoff points were confirmed in the external validation phase using a separate cohort of 312 patients (180 PAD and 132 non-PAD) recruited from ambulatory vascular surgery clinics at St. Michael's Hospital (Canada) between November 6, 2018-July 30, 2019. Cox regression analyses were used to explore the independent association between FABP3 and major adverse limb events (MALE - defined as need for arterial revascularization or major amputation) and decrease in ankle-brachial index (ABI -defined as drop ≥0.15) during 3 years of follow-up.

FINDINGS

In the discovery phase, FABP3 levels were significantly elevated in patients with PAD compared to non-PAD patients. ROC analysis demonstrated that FABP3 had an AUC of 0.83 (95% CI: 0.81-0.86, p-value < 0.001). FABP3 exclusionary cutoff was <1.55 ng/ml (sensitivity = 96%; specificity = 40%), whereas FABP3 confirmatory cutoff was >3.55 ng/ml (sensitivity = 43%; specificity = 95%) - values that were confirmed in the external validation phase. Cox regression analysis demonstrated FABP3 to be an independent predictor of increase in MALE [HR = 1.14 (1.03-1.29); p-value = 0.010] and worsening PAD status (drop in ABI >0.15 [HR = 1.11 (1.02-1.19); p-value = 0.009]).

INTERPRETATION

Our findings suggested that FABP3 levels can be used as both a diagnostic and prognostic biomarker for PAD, and may facilitate risk stratification in select individuals for purposes of vascular evaluation or intensive medical management.

FUNDING

Funding for this study was provided by the Bill and Vicky Blair Foundation.

Weakness of lower limb muscle in symptomatic peripheral artery disease with media sclerosis detected by ultrasound shear wave elastography

Background: Symptomatic peripheral arterial disease (PAD) is difficult to non-invasively diagnose in the presence of calcified, media sclerotic arteries that are incompressible by blood pressure cuffs. Standard ankle-brachial index (ABI) measurements in these PAD patients are very often not helpful. Shear wave elastography (SWE) is a modern ultrasound technique to detect peripheral muscle stiffness changes i.e. muscle weakness during exercise. In a pilot study, we examined whether SWE could be a reproducible tool for diagnosing ischemic loss of muscle stiffness in patients with PAD and concomitant arterial media sclerosis. Patients and methods: N=13 consecutive patients with peripheral artery disease and media sclerosis were enrolled in the pilot study. All 13 patients were symptomatic in different stages of their PAD due to hemodynamically relevant arterial stenosis or occlusions of limb arteries as confirmed by oscillography, color-coded duplex sonography or angiography. Results: ABI measurements were invalid in all 13 patients. Mean SWE measurements of medial gastrocnemius muscles showed a significant transient muscle stiffness loss (weakness) at maximum exercise (active dorsal flexion of the foot, 103.4±25.9 kPa on the asymptomatic vs. 62.5±21.9 kPa on the symptomatic limb (p<0.001). Conclusions: SWE can reproducibly detect peripheral muscle weakness during exercise in the symptomatic leg of media sclerotic PAD patients. SWE of lower limb muscles may help to identify symptomatic PAD in patients presenting with invalid ABI measurements and unclear vascular status.

A Community and Hospital cAre Bundle to improve the medical treatment of severe cLaudIcation and critical limb iSchaemia (CHABLIS)

Background

Patients with peripheral artery disease (PAD) often do not receive optimal best medical therapy (BMT). Through interaction with patients and healthcare-professionals (HCPs) we developed the LEaflet Gp letter Structured checklist (LEGS) complex clinical intervention to support HCPs in providing guideline-compliant PAD BMT.

Methods

This was a prospective multicentre study assessing the feasibility and fidelity of delivering the LEGS intervention in primary and secondary care over six months. Intervention fidelity was scored based on the proportion of intervention components used correctly at discharge, 30 days, and six months.

Results

Overall, 129 individuals were screened and 120 took part (33% female, 74% with chronic limb threatening ischaemia; 93% recruitment rate). Of those, 118 (98% retention rate) completed follow-up. Mean intervention fidelity score at discharge (primary outcome measure) was 63% [95% Confidence Interval (CI): 39-68%, SD: 5%], exceeding the success criteria set at 60% by a panel of HCPs and patients. This, however, declined to 51% at six months. Eight patients (6.7%) died (all cardiovascular deaths), four (3.3%) had a major lower limb amputation, 12 (10%) had a cardiovascular event, and 13 (11%) were admitted due to limb ischaemia at six months. Incomplete lipid therapy prescriptions and LEGS intervention documents not received by primary care CHPs were the most common reasons for not complying with the LEGS intervention.

Conclusions

The LEGS intervention can be delivered in PAD care pathways across different hospitals, primary, and community healthcare settings with acceptable fidelity, to streamline and improve PAD BMT short- and medium-term.

Machine Learning-Based Peripheral Artery Disease Identification Using Laboratory-Based Gait Data

Peripheral artery disease (PAD) manifests from atherosclerosis, which limits blood flow to the legs and causes changes in muscle structure and function, and in gait performance. PAD is underdiagnosed, which delays treatment and worsens clinical outcomes. To overcome this challenge, the purpose of this study is to develop machine learning (ML) models that distinguish individuals with and without PAD. This is the first step to using ML to identify those with PAD risk early. We built ML models based on previously acquired overground walking biomechanics data from patients with PAD and healthy controls. Gait signatures were characterized using ankle, knee, and hip joint angles, torques, and powers, as well as ground reaction forces (GRF). ML was able to classify those with and without PAD using Neural Networks or Random Forest algorithms with 89% accuracy (0.64 Matthew's Correlation Coefficient) using all laboratory-based gait variables. Moreover, models using only GRF variables provided up to 87% accuracy (0.64 Matthew's Correlation Coefficient). These results indicate that ML models can classify those with and without PAD using gait signatures with acceptable performance. Results also show that an ML gait signature model that uses GRF features delivers the most informative data for PAD classification.

BAG3 Attenuates Ischemia-Induced Skeletal Muscle Necroptosis in Diabetic Experimental Peripheral Artery Disease

Peripheral artery disease (PAD) is characterized by impaired blood flow to the lower extremities, resulting in ischemic limb injuries. Individuals with diabetes and PAD typically have more severe ischemic limb injuries and limb amputations, but the mechanisms involved are poorly understood. Previously, we identified BAG3 as a gene within a mouse genetic locus termed limb salvage QTL1 on mouse chromosome 7 that determined the extent of limb necrosis following ischemic injury in C57Bl/6 mice. Whether BAG3 deficiency plays a role in the severe ischemic injury observed in diabetic PAD is not known. In vitro, we found simulated ischemia enhanced BAG3 expression in primary human skeletal muscle cells, whereas BAG3 knockdown increased necroptosis markers and decreased cell viability. In vivo, ischemic skeletal muscles from hind limbs of high-fat diet (HFD)-fed mice showed poor BAG3 expression compared to normal chow diet (NCD)-fed mice, and this was associated with increased limb amputations. BAG3 overexpression in ischemic skeletal muscles from hind limbs of HFD mice rescued limb amputation and improved autophagy, necroptosis, skeletal muscle function and regeneration. Therefore, BAG3 deficiency in ischemic skeletal muscles contributes to the severity of ischemic limb injury in diabetic PAD, likely through autophagy and necroptosis pathways.

Association between the risk of malnutrition and functional capacity in patients with peripheral arterial disease: A cross-sectional study

Introduction

The risk of malnutrition is an important predictor of functional capacity in the elderly population. However, whether malnutrition is associated with functional capacity in patients with peripheral artery disease (PAD) is poorly known.

Purpose

To analyse the association between the risk of malnutrition and functional capacity in patients with PAD.

Methods

This cross-sectional study included 135 patients with PAD of both genders, ≥50 years old, with symptomatic PAD (Rutherford stage I to III) in one or both limbs and with ankle-brachial index ≤0.90. The risk of malnutrition was assessed by the short form of the Mini Nutritional Assessment-Short Form and patients were classified as having normal nutritional status (n = 92) and at risk of malnutrition (n = 43). Functional capacity was objectively assessed using the six-minute walking test (6MWT, absolute maximal distance and relativized and expressed as a percentage of health subjects), short-physical performance battery (SPPB, balance, gait speed and the sit and stand test) and the handgrip test, and subjectively, using the Walking Impairment Questionnaire and Walking Estimated-Limitation Calculated by History. The association between the risk of malnutrition and functional capacity was analysed using bivariate and multivariate logistic regression adjustments for gender, age, ankle-brachial index, body mass index, use of statins, coronary arterial disease and stroke. For all statistical analyses, significance was accepted at p<0.05.

Results

Thirty-two per cent of our patients were classified with a risk of malnutrition. The risk of malnutrition was associated with the absolute 6MWT total distance (OR = 0.994, P = 0.031) relative 6MWT total distance (OR = 0.971, P = 0.038), lowest SPPB total score (OR = 0.682, P = 0.011), sit and stand (OR = 1.173, P = 0.003) and usual 4-meter walk test (OR = 1.757, P = 0.034).

Conclusion

In patients with PAD, the risk of malnutrition was associated with objective measurements of functional capacity.

microRNA-29a Regulates ADAM12 Through Direct Interaction With ADAM12 mRNA and Modulates Postischemic Perfusion Recovery

Background Peripheral artery disease is caused by atherosclerotic occlusion of vessels outside the heart and most commonly affects vessels of the lower extremities. Angiogenesis is a part of the postischemic adaptation involved in restoring blood flow in peripheral artery disease. Previously, in a murine hind limb ischemia model of peripheral artery disease, we identified ADAM12 (a disintegrin and metalloproteinase gene 12) as a key genetic modifier of postischemic perfusion recovery. However, less is known about ADAM12 regulation in ischemia. MicroRNAs are a class of small, noncoding, single-stranded RNAs that regulate gene expression primarily through transcriptional repression of messenger RNA (mRNA). We showed microRNA-29a (miR-29a) modulates ADAM12 expression in the setting of diabetes and ischemia. However, how miR-29a modulates ADAM12 is not known. Moreover, the physiological effects of miR-29a modulation in a nondiabetic setting is not known. Methods and Results We overexpressed or inhibited miR-29a in ischemic mouse gastrocnemius and tibialis anterior muscles, and quantified the effect on perfusion recovery, ADAM12 expression, angiogenesis, and skeletal muscle regeneration. In addition, using RNA immunoprecipitation-based anti-miR competitive assay, we investigated the interaction of miR-29a and ADAM12 mRNA in mouse microvascular endothelial cell, skeletal muscle, and human endothelial cell lysates. Ectopic expression of miR-29a in ischemic mouse hind limbs decreased ADAM12 mRNA expression, increased skeletal muscle injury, decreased skeletal muscle function, and decreased angiogenesis and perfusion recovery, with no effect on skeletal muscle regeneration and myofiber cross-sectional area following hind limb ischemia. RNA immunoprecipitation-based anti-miR competitive assay studies showed miR-29a antagomir displaced miR-29a and ADAM12 mRNA from the AGO-2 (Argonaut-2) complex in a dose dependent manner. Conclusions Taken together, the data show miR-29a suppresses ADAM12 expression by directly binding to its mRNA, resulting in impaired skeletal muscle function, angiogenesis, and poor perfusion. Hence, elevated levels of miR-29a, as seen in diabetes and aging, likely contribute to vascular pathology, and modulation of miR-29a could be a therapeutic target.

Comparative Analysis of Endovascular Intervention and Endarterectomy in Patients with Femoral Artery Disease: A Systematic Review and Meta-Analysis

Peripheral artery disease is a prevalent illness affecting more than 200 million people worldwide. A commonly used technique to manage the condition has been open endarterectomy. However, in recent times, a shift towards minimally invasive techniques has resulted in endovascular intervention as a popular alternative. This review aims to assess the safety and efficacy of endovascular intervention when compared with endarterectomy. A systematic review of the articles published in PubMed, Ovid, Embase, and Scopus within the last 10 years was conducted. The PRISMA guidelines were adhered to, and the Newcastle-Ottawa and NICE quality assessment scales were used. A meta-analysis of proportions was performed using the RStudio software (RStudio Team (2021). RStudio: Integrated Development Environment for R, PBC, Boston, MA, USA). Twenty-six studies were included, with a total of 7126 patients (endovascular, 2496; endarterectomy, 4630). Technical success was greater for endarterectomy than endovascular intervention with an odds ratio of 0.38; 95% CI [0.27–0.54]. In terms of safety as well endovascular intervention was better than endarterectomy with an odds ratio of 0.22; 95% CI [0.15 to 0.31] for wound infection. Endovascular intervention is a safe and effective procedure; however, it cannot be considered superior to endarterectomy.

Eligibility of Patients with Chronic Limb Threatening Ischemia for Deep Venous Arterialization

OBJECTIVES

Percutaneous deep venous arterialization (pDVA) has emerged as a new modality for limb salvage in patients with chronic limb threatening ischemia (CLTI) and no standard option for revascularization. The proportion of patients facing major amputation that are eligible for this technology remains unknown. This study aims to provide a real-life estimate of patient eligibility for pDVA to reduce major amputations.

METHODS

Electronic medical records of 100 consecutive patients with peripheral arterial disease (PAD) who underwent major amputation of 106 limbs were reviewed. Angiograms performed ≤6 months before amputation were assessed by two vascular surgeons. Disease severity was categorized using the Global Limb Anatomic Staging System and patients were classified as ideal, possible, or not candidates for pDVA. Ideal candidates had ≥1 patent tibial artery, no target in the foot, and no proximal disease. Possible candidates had ≥1 patent tibial artery with PAD, no target in the foot, and proximal disease amenable to endovascular therapy. Patients were not eligible if there was no patent tibial artery, extensive PAD, or an arterial target in the foot for bypass.

RESULTS

Of 106 limbs reviewed, 35 (33%) did not undergo angiography ≤6 months before amputation because of infection (n=14), advanced tissue loss (n=10), failed revascularizations (n=8), advanced limb ischemia (n=2), and refusing revascularization (n=1). Thus, 69 lower extremity angiograms (2 incomplete excluded) in 68 patients were analyzed. 15 patients with 16 limbs (23.2%) were identified as candidates for pDVA (ideal=7, possible=9). There were no differences in demographics between the two groups, but candidates for pDVA were less likely to have hyperlipidemia and congestive heart failure than those who were not candidates. pDVA candidates underwent significantly fewer interventions prior to major amputation compared to patients who were not candidates (1.50 ± 0.73 vs 2.61 ± 2.57, p=0.007). Angiographically, patients who were pDVA candidates had significantly higher Inframalleolar GLASS grades (1.81 ± 0.40 vs 0.86 ± 0.41, p<0.0001) but lower Femoropopliteal Glass grades (0.73 ± 1.10 vs 2.43 ± 1.71, p<0.0001) than patients who were not candidates. There was no significant difference in GLASS stage between these two groups (p=0.368). After mean follow-up of 48 months, there was no difference in mortality between both groups (40% vs 32.1%, p=0.567).

CONCLUSION

Among patients considered for revascularization, 23.2% had favorable angiography and 14.7% could have benefited for pDVA as a new therapeutic modality for limb salvage. 33% of major amputations were performed for clinically-deemed unsalvageable CLTI.

Covered vs. Bare Metal Stents in the Reconstruction of the Aortic Bifurcation: Early and Midterm Outcomes from the COBRA European Multicentre Registry

OBJECTIVE

To report outcomes following endovascular revascularisation for severe aorto-iliac occlusive disease (AIOD) using covered (CS) or bare metal (BMS) stent(s).

METHODS

This was a retrospective cohort study including patients who underwent treatment with CS or BMS for AIOD between November 2012 and March 2020 in 12 European centres. Outcome measures included death, freedom from target lesion revascularisation (TLR), major amputation, and major adverse cardiac and cerebrovascular events (MACCE).

RESULTS

Overall, 252 patients (53% males; mean age 65 ± 10 years) were included (102 with a bare metal and 150 with a covered aortic stent); 122 (48%) presented with chronic limb threatening ischaemia (CLTI). Severe arterial calcification was noted in > 65% of patients, 70% presented with Trans-Atlantic Societies Consensus (TASC) D lesions, 32% and 46% had aortic or iliac chronic total occlusion (CTO), respectively. Median follow up was 17 months (range 6 - 40; none lost to follow up). Median inpatient stay was two days (range two to four). During the first 30 days, two patients died (both with covered aortic stents, because of cardiovascular events), none required TLR, two (1%) patients had a major amputation (all presented with CLTI), and three (1%) had a MACCE. At 17 months, mortality (BMS 14% vs. CS 7%, hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.42 - 2.26, p = .94, log rank test) and TLR (11% vs. 10%, HR 1.98, 95% CI 0.89 - 4.43, p = .095) did not differ statistically significantly between the two groups; only three patients had a major limb amputation during late follow up (all with a covered stent). In a multivariable model, the use of an aortic CS did not influence TLR. In a conditional Cox regression, however, the concomitant use of aortic and iliac CSs was associated with improved freedom from TLR.

CONCLUSION

Endovascular reconstruction with aortic CSs or BMSs for severe AIOD showed comparable midterm performance. The use of both aortic and iliac CSs seems to be associated with reduced TLR.

Modulation of miR-29a and ADAM12 Reduces Post-Ischemic Skeletal Muscle Injury and Improves Perfusion Recovery and Skeletal Muscle Function in a Mouse Model of Type 2 Diabetes and Peripheral Artery Disease

Both Type 1 diabetes mellitus (DM1) and type 2 diabetes mellitus (DM2) are associated with an increased risk of limb amputation in peripheral arterial disease (PAD). How diabetes contributes to poor PAD outcomes is poorly understood but may occur through different mechanisms in DM1 and DM2. Previously, we identified a disintegrin and metalloproteinase gene 12 (ADAM12) as a key genetic modifier of post-ischemic perfusion recovery. In an experimental PAD, we showed that ADAM12 is regulated by miR-29a and this regulation is impaired in ischemic endothelial cells in DM1, contributing to poor perfusion recovery. Here we investigated whether miR-29a regulation of ADAM12 is altered in experimental PAD in the setting of DM2. We also explored whether modulation of miR-29a and ADAM12 expression can improve perfusion recovery and limb function in mice with DM2. Our result showed that in the ischemic limb of mice with DM2, miR-29a expression is poorly downregulated and ADAM12 upregulation is impaired. Inhibition of miR-29a and overexpression of ADAM12 improved perfusion recovery, reduced skeletal muscle injury, improved muscle function, and increased cleaved Tie 2 and AKT phosphorylation. Thus, inhibition of miR-29a and or augmentation of ADAM12 improves experimental PAD outcomes in DM2 likely through modulation of Tie 2 and AKT signalling.

Relationship between Retinal Nerve Fiber Layer Thickness and Aortic Distensibility in Peripheral Arterial Disease Patients

Aim and objective

To evaluate the relationship between aortic distensibility (AD) and aortic stiffness B index (ASBI) with retinal nerve fiber layer (RNFL) thickness measured with HD-OCT in peripheral arterial disease (PAD) patients.

Materials and methods

Twenty-six PAD patients and 22 age-matched healthy control were enrolled. Subjects with PAD were classified into two groups. Patients with diabetes (DM) or hypertension (HT) comprised group I (n = 18) and without DM or HT comprised group II (n = 8). Color Doppler imaging was performed on all patients and PAD was diagnosed by using the ankle-brachial index (ABI). Retinal nerve fiber layer thickness values between control and PAD patients and correlations between RNFL thickness and aortic stiffness parameters (AD and ASBI) were evaluated.

Results

The inferior-nasal and inferior-temporal quadrant were the thickest in healthy subjects and the PAD group. Retinal nerve fiber layer thickness significantly decreased in superior-nasal, temporal, inferior-nasal quadrants in group I than healthy subjects (p < 0.001, p = 0.005, p < 0.001). Temporal and inferior-nasal quadrant thicknesses were statistically significantly thinner in group II than controls (p = 0.02, p < 0.001). The nasal RNFL quadrant was significantly thinner in group I than group II (p = 0.014). The correlation between RNFL thickness and aortic elasticity parameters in each group was not found to be significant.

Conclusion and clinical significance

Isolated PAD without DM or HT may lead to localized RNFL loss in temporal and inferior-nasal quadrants. Aortic elasticity parameters did not seem to be correlated with RNFL thickness in PAD.

How to cite this article

Kumova D, Aktas Z, Eyiol A, et al. Relationship between Retinal Nerve Fiber Layer Thickness and Aortic Distensibility in Peripheral Arterial Disease Patients. J Curr Glaucoma Pract 2021;15(2):86–90.

Fatty acid binding protein 3 is associated with peripheral arterial disease

Background

Peripheral arterial disease (PAD) affects more than 150 million people worldwide and is associated with high rates of lower extremity amputation, myocardial infarction, stroke and death. Fatty acid binding protein 3 (FABP3) is released into circulation in patients with skeletal muscle injury. In this pilot study, we investigated a possible association between PAD and blood levels of FABP3.

Methods

Blood samples were collected from patients with clinical symptoms and diagnostic findings indicative of PAD (PAD group; ankle-brachial index [ABI] <0.9; n = 75) and in those without clinical or diagnostic features of PAD (non-PAD group; ABI >0.9; n = 75) presenting to vascular surgery ambulatory clinics at St. Michael's Hospital. Plasma samples were analyzed by protein multiplex to quantify FABP3 levels.

Results

PAD patients were found to have higher blood levels of FABP3 compared to patients without PAD (mean 3.90 ± 1.69 vs 2.03 ± 0.78; P < .001). A subgroup analysis demonstrated that the FABP3 levels were increased by almost two-fold in patients with PAD, independent of coronary artery disease (P < .001) or diabetes mellitus status (P < .001). Moreover, a significant negative correlation between FABP3 and the ABI was observed in PAD and patients without PAD matched groups (r = –0.51; P = .001). Last, immunohistochemistry demonstrated elevated expressions of FABP3 within skeletal muscle obtained from patients with the most severe form of PAD, chronic limb-threatening ischemia, when compared with patients without PAD.

Conclusions

Patients with PAD have elevated plasma levels of FABP3. An increasing severity of PAD is associated with higher FABP3 levels.

There is a pressing need for a simple, readily accessible, blood-based biomarker for PAD. In this study, we found elevated levels of FABP3 in patients with PAD. This increase in FABP3 was irrespective of history of coronary artery disease or diabetes. Furthermore, our data suggest that an increasing severity of PAD is associated with higher FABP3 levels. Subsequently, FABP3 may be a potential diagnostic biomarker for PAD. However, further studies are needed to confirm the capability of FABP3 to serve as a valid and reliable biomarker for PAD.

Are primary care physicians aware of peripheral artery disease risk reduction and management in the Saudi healthcare transformation era? A health cluster observational study

INTRODUCTION

Patients with peripheral artery disease (PAD) are often underdiagnosed and undertreated. This study aimed to assess the knowledge of the recommended target levels of blood pressure, low-density lipoprotein cholesterol, glycosylated hemoglobin A1C, and knowledge and attitude about PAD risk reduction therapies among physicians working in primary care settings in Saudi Arabia.

METHODS

This observational cross-sectional study included family medicine consultants, residents, and general practitioners working in a health cluster in the capital city of Saudi Arabia using a self-administered questionnaire.

RESULTS

Of the 129 physicians who completed the survey, 55% had completed PAD-related continuing medical education hours within the past 2 years. Despite this, the knowledge score of the recommended target levels was high in only 13.2% of the participants. Antiplatelet therapy was prescribed by 68.2% of the participants.

CONCLUSION

Here we identified the knowledge and action gaps among primary care providers in Saudi Arabia. Physicians had an excellent attitude about screening for and counseling about risk factors. However, they showed less interference in reducing these risk factors. We recommend addressing these knowledge gaps early in medical school and residency programs.

Efficacy and Safety of Rivaroxaban Compared with Other Therapies Used in Patients with Peripheral Artery Disease Undergoing Peripheral Revascularization: A Systematic Literature Review and Network Meta-Analysis

Background

The guidelines on antithrombotic treatment in patients with symptomatic peripheral artery disease (PAD) undergoing peripheral revascularization of the lower extremities were developed based on heterogeneous trials, assessing various dose regimens and recruiting patients who were subjected to different revascularization procedures.

Objective

To compare efficacy and safety of treatments used in patients with PAD undergoing peripheral revascularization accounting for between-trial heterogeneity and large dispersion of the quality of evidence.

Methods

A systematic literature review of randomised controlled trials (RCTs) recruiting adult patients with PAD receiving antithrombotics was conducted until January 2020. Hazard ratios (HR) were pooled using Bayesian network meta-analysis. The estimated between-treatment effects were presented as HR together with 95% credible intervals. The base case analysis included studies recruiting patients following recent peripheral revascularization, who received treatment regimens administered within the recommended therapeutic window, while a sensitivity scenario included all identified trials.

Results

Thirteen RCTs were identified (8 RCTs enrolled patients following peripheral revascularization and 5 RCTs regardless of the previous revascularization). Five trials, recruiting an overall of 8349 patients, were considered for the base case analysis. Of those, 6564 patients were recruited in the VOYAGER PAD trial comparing rivaroxaban plus aspirin (RIV plus ASA) versus ASA. RIV plus ASA was associated with a lower risk of repeated peripheral revascularization versus ASA monotherapy (HR = 0.88 [0.79, 0.99]), however having a trend towards an increased rate of major bleeding (HR = 1.43 [0.98, 2.11]). There was no evidence for differences between RIV plus ASA and dual antiplatelet therapy and vitamin K antagonists plus ASA. Similar results were observed in sensitivity analyses.

Conclusions

RIV plus ASA is associated with reduced risk of revascularization compared with ASA monotherapy, but the evidence for other comparators, in particular antiplatelet regimens, was insufficient to guide treatment decisions and highlights the challenge in establishing the magnitude of comparative efficacy using existing RCTs.

Nationwide analysis on the impact of peripheral vascular disease following primary total knee arthroplasty: A matched-control analysis

BACKGROUND

As the prevalence of peripheral vascular disease (PVD) continues to increase nationwide, studies demonstrating its effects following primary total knee arthroplasty (TKA) are limited. Therefore, the purpose of this study was to evaluate whether patients with PVD have higher rates of: 1) in-hospital lengths of stay (LOS); 2) readmissions; 3) medical complications; 4) implant-related complications; and 5) costs of care.

METHODS

Using a nationwide database, patients with PVD undergoing primary TKA were identified and matched to controls in a 1:5 ratio by age, sex, and medical comorbidities. The query yielded 1,547,092 between the cohorts. Outcomes analyzed included: in-hospital LOS, readmission rates, complications, and costs of care. A p-value less than 0.004 was considered statistically significant.

RESULTS

PVD patients had significantly longer in-hospital LOS (4-days vs. 3-days, p < 0.0001). Additionally, the study cohort had a higher incidence and odds (OR) of readmissions (20.5 vs. 15.2%; OR: 1.43, 95% CI: 1.42-1.45, p < 0.0001), medical complications (2.46 vs. 1.32%; OR: 1.88, CI: 1.83-1.94, p < 0.0001), and implant-related complications (3.82 vs. 2.18%; OR: 1.78, CI: 1.26-1.58, p < 0.0001). Additionally, the study found patients with PVD had higher day of surgery (p < 0.0001) and 90-day costs of care (p < 0.0001).

CONCLUSIONS

After adjusting for confounding variables the results of the study show patients with PVD undergoing primary TKA have longer in-hospital LOS; in addition to higher rates of complications, readmissions, and costs of care. The study can be utilized by orthopaedists to adequately counsel patients of the potential complications following their procedure.

Treatment of Aortoiliac Occlusive Disease With the Covered Endovascular Reconstruction of the Aortic Bifurcation (CERAB) Technique: Results of a UK Multicenter Study

OBJECTIVE

This UK multicenter study aims to report early- and medium-term results following covered endovascular reconstruction of aortic bifurcation (CERAB) for the treatment of aortoiliac occlusive disease (AIOD) in patients with chronic limb threatening ischemia (CLTI) or intermittent claudication (IC).

MATERIALS AND METHODS

Retrospective case analysis was performed of patients who underwent CERAB between November 1, 2012 and March 31, 2020 in 6 centers across the United Kingdom. Anatomical data, including degree of plaque calcification, were assessed using preoperative imaging. Outcome measures included mortality, perioperative complications, target lesion reintervention (TLR), and major limb amputation. Primary, assisted primary, and secondary patencies were calculated at set intervals.

RESULTS

A total of 116 patients underwent CERAB over the study period for the following reasons [48% presenting with CLTI (Rutherford 4-6) and 52% with IC (Rutherford 1-3)]; 82% presented had Trans-Atlantic Inter-Society Consensus (TASC) D AIOD disease. Median age was 65 years (range 42-90 years); 76% of the cohort were male. Severely calcified aortic and iliac lesions were noted in 90% and 80% of patients, respectively. Over a median follow-up of 18 months (range 1-91 months), 2 (1.7%) patients were lost to follow up. In total 5, (4.3%) patients died and 2 (1.7%) had a major amputation. Endovascular TLR was required in 14 (12.1%) patients at last follow up. Surgical TLR was performed in 4 (3.4%) patients at last follow-up. Seven (6%) patients developed an aortic/iliac stent occlusion at last follow-up. The Kaplan-Meier (KM) freedom from TLR at 1 year was 94% and KM 1-year primary patency, assisted primary patency, and secondary patency were 88%, 94%, and 98% respectively. Subanalysis found the following features were associated with need for TLR; TASC D disease (OR = 2.45, 95% CI 1.44 to 3.71), severe aortic calcification (OR = 2.01, 95% CI 1.03 to 2.20), and presence of tissue loss at baseline (OR = 1.43, 95% CI 1.01 to 4.63).

CONCLUSION

Perioperative (<30 days) and medium-term morbidity, mortality, and patency rates in this pragmatic cohort of patients with severe AIOD lesions show that CERAB is a valid revascularization option. A direct comparison with surgical treatments for AIOD in a randomized controlled trial is justified.

The Association Between Pleural Empyema and Peripheral Arterial Disease in Younger Patients: A Retrospective National Population-Based Cohort Study

Background: To investigate the relationship between pleural empyema (PE) and peripheral arterial disease (PAD).

Methods: We conducted a retrospective cohort study using data from the National Health Institute Research Database. Univariable and multivariable Cox's proportional hazard regressions were performed to investigate the association between PE and the risk of PAD. Kaplan–Meier method and the differences were assessed using a log-rank test.

Results: The overall incidence of PAD was higher in the PE cohort than in the non-PE cohort (2.76 vs. 1.72 per 1,000 person-years) with a crude hazard ratio (HR) of 1.61 [95% confidence interval (CI) = 1.41–1.83]. After adjustment for age, gender, and comorbidities, patients with PE were noted to be associated with an increased risk of PAD compared with those without PE [adjusted HR (aHR) = 1.18, 95% CI = 1.03–1.35]. Regarding the age-specific comparison between the PE and non-PE cohorts, PAD was noted to be significantly high in the ≤ 49 years age group (aHR = 5.34, 95% CI = 2.34–10.1). The incidence of PAD was higher in the first 2 years, with an aHR of 1.35 (95% CI = 1.09–1.68) for patients with PE compared with those without PE.

Conclusion: The risk of PAD was higher if patients with PE were younger than 49 years and within the 2-year diagnosis of PE.

Positive and negative well-being of older adults with symptomatic peripheral artery disease: A population-based investigation

Objective

We investigated positive and negative subjective well-being in relation to lower-extremity peripheral artery disease (PAD) in a sample of older adults.

Method

4760 participants in the English Longitudinal Study of Ageing (ELSA) provided baseline data on symptomatic PAD, sociodemographic characteristics, lifestyle risk factors, and co-morbid conditions. Baseline and two-year follow-up data were available for life satisfaction, quality of life, and depressive symptoms.

Results

Participants with PAD symptoms had lower baseline levels of life satisfaction (β = -0.03, p < .05) and quality of life (β = -0.04, p < .01), and more depressive symptoms (β = 0.03, p < .05). These associations remained statistically significant in multivariate analyses. Baseline PAD did not, however, influence well-being levels at two-year follow-up.

Discussion

Greater awareness of the potential for chronic vascular morbidity to disrupt the lives of older adults is needed to inform effective multidisciplinary support and interventions that help maintain the quality of life of those affected.

Platelet aggregation inhibitor prescription for newly diagnosed peripheral arterial disease in the Netherlands: a cohort study

OBJECTIVES

Pharmacological treatment of peripheral arterial disease (PAD) comprises of antiplatelet therapy (APT), blood pressure control and cholesterol optimisation. Guidelines provide class-I recommendations on the prescription, but there are little data on the actual prescription practices. Our study provides insight into the prescription of medication among patients with PAD in the Netherlands and reports a 'real-world' patient journey through primary and secondary care.

DESIGN

We conducted a cohort study among patients newly diagnosed with PAD between 2010 and 2014.

SETTING

Data were obtained from the PHARMO Database Network, a population-based network of electronic pharmacy, primary and secondary healthcare setting records in the Netherlands. The source population for this study comprised almost 1 million individuals.

PARTICIPANTS

'Newly diagnosed' was defined as a recorded International Classification of Primary Care code for PAD, a PAD-specific WCIA examination code or a diagnosis recorded as free text episode in the general practitioner records with no previous PAD diagnosis record and no prescription of P2Y12 inhibitors or aspirin the preceding year. The patient journey was defined by at least 1 year of database history and follow-up relative to the index date.

RESULTS

Between 2010 and 2014, we identified 3677 newly diagnosed patients with PAD. Most patients (91%) were diagnosed in primary care. Almost half of all patients (49%) had no APT dispensing record. Within this group, 33% received other anticoagulant therapy (vitamin K antagonist or direct oral anticoagulant). Mono-APT was dispensed as aspirin (40% of patients) or P2Y12 inhibitors (2.5% of patients). Dual APT combining aspirin with a P2Y12 inhibitor was dispensed to 8.5% of the study population.

CONCLUSION

Half of all patients with newly diagnosed PAD are not treated conforming to (international) guideline recommendations on thromboembolism prevention through APT. At least 33% of all patients with newly diagnosed PAD do not receive any antithrombotic therapy. Evaluation and improvement of APT prescription and thereby improved prevention of (secondary) cardiovascular events is warranted.

Ankle brachial index as a surrogate to vascular imaging in evaluation of peripheral artery disease in patients with type 2 diabetes

BACKGROUND

Peripheral artery disease (PAD) is common in persons with type 2 diabetes (T2DM) and contributes significantly to cardiovascular morbidity and mortality. Controversy exists regarding the utility of ankle brachial index (ABI) for clinical diagnosis of PAD in persons with diabetes. The aim of this study was to evaluate the reliability of ABI for diagnosis of PAD in patients with T2DM using duplex ultrasonography (DUS) as the gold standard.

RESULTS

A total of 319 legs from 163 patients comprising of 156 subjects with intact legs and 7 patients who had undergone unilateral lower limb amputations were studied. The mean age of the participants was 56.1 ± 17.3 years. One hundred and ninety-five legs (61.1%) had sonographically confirmed PAD which was mild, moderate and severe in 40%, 41.5% and 18.5% respectively. The accuracy of ABI in detecting PAD was 76.7% for mild stenosis, 91.7% for moderate stenosis and 93.1% for severe stenosis. The sensitivity of ABI improved with increasing severity of arterial stenosis, reaching 100% in severe cases. ABI demonstrated good agreement with DUS [kappa = 0.65 (95% CI 0.49-0.88), P < 0.001].

CONCLUSION

In comparison to DUS, the ABI demonstrated good reliability for diagnosis of PAD in high risk T2DM patients. The utility of this simple and non-invasive procedure should therefore be maximized in clinical practice.

Targeting Uremic Toxins to Prevent Peripheral Vascular Complications in Chronic Kidney Disease

Chronic kidney disease (CKD) exhibits progressive kidney dysfunction and leads to disturbed homeostasis, including accumulation of uremic toxins, activated renin-angiotensin system, and increased oxidative stress and proinflammatory cytokines. Patients with CKD are prone to developing the peripheral vascular disease (PVD), leading to poorer outcomes than those without CKD. Cumulative evidence has showed that the synergy of uremic milieu and PVD could exaggerate vascular complications such as limb ischemia, amputation, stenosis, or thrombosis of a dialysis vascular access, and increase mortality risk. The role of uremic toxins in the pathogenesis of vascular dysfunction in CKD has been investigated. Moreover, growing evidence has shown the promising role of uremic toxins as a therapeutic target for PVD in CKD. This review focused on uremic toxins in the pathophysiology, in vitro and animal models, and current novel clinical approaches in reducing the uremic toxin to prevent peripheral vascular complications in CKD patients.

Impact of prior endovascular interventions on outcomes of lower limb bypass surgery: A systematic review and meta-analysis

The aim of this meta-analysis was to evaluate the mortality, amputation and complication rates in patients with peripheral lower limb arterial disease undergoing bypass surgery with or without a prior history of endovascular operation. A systematic literature screen was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines on four academic databases, Medline, Scopus, Embase and Cochrane Central Register of Controlled Trials. Out of 1,072 records, six articles involving 11,420 patients (mean age, 68.1±2.0 years) met the inclusion criteria. The findings presented a 2b level of evidence (i.e. overall evidence represents data from individual cohort study or low quality randomized controlled trials) and suggested lower mortality, amputation and complication rates for patients undergoing bypass surgery without any history of endovascular operation, compared with those with a history of prior endovascular operation. Moreover, a random-effect meta-analysis suggested a small, positive reduction in mortality (Hedge's g=0.08), amputation (Hedge's g=0.18) and complication rates (Hedge's g=0.05) for patients undergoing bypass surgery without any history of endovascular operation. Nevertheless, owing to the scarcity of high-quality data, further studies and randomized clinical trials are needed to confirm these effects.

Combined (endo-)vascular intervention and microsurgical lower extremity free flap reconstruction-A propensity score matching analysis in 5386 ACS-NSQIP patients

BACKGROUND

Compromised lower limb perfusion due to vascular changes such as peripheral artery disease impedes wound healing and may lead to large-scale tissue defects and lower limb amputation. In such patients with defects and compromised or lacking recipient vessels, combined vascular reconstruction with free flap transfer is an option for lower extremity salvage.

METHODS

By using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database (2005-2018), we analyzed two patient cohorts undergoing (A) free flap lower limb reconstruction (LXTR) only and (B) combined (endo-)vascular reconstruction (vascLXTR). The preoperative variables assessed included demographic data and comorbidities, including smoking, diabetes mellitus, preoperative steroid use, and American Society of Anesthesiology (ASA) Physical Status Classification. Using a neighbor matching algorithm, we performed a 1:1 propensity score matching of 615 LXTR patients and 615 vascLXTR patients. Bivariate analysis for postoperative surgical and medical complications was performed for outcomes in the propensity-matched cohort.

RESULTS

We identified 5386 patients who underwent microsurgical free flap reconstruction of the lower extremity. A total of 632 patients underwent a combined (endo-)vascular intervention and lower extremity free flap reconstruction. Diabetes and smoking were more prevalent in this group, with 206 patients having diabetes (32.6%) and 311 being smokers (49.2%). More patients returned to the operating room in the cohort that underwent a combined vascular intervention (24.4% versus 9.9%; p<0.0001). The 30-day mortality for patients undergoing a combined vascular procedure was 3.5%, compared with 1.3% with free tissue transfer only (p<0.0001).

CONCLUSION

Despite the risks associated, the combined intervention decreases the very high mortality associated with limb amputation in severely sick patient populations. Careful preoperative assessment of modifiable risk factors may reduce complication rates while allowing limb salvage.

Skin disorders indicating peripheral arterial occlusive disease and chronic venous insufficiency in organ transplant recipients

BACKGROUND

Peripheral arterial occlusive disease (PAOD) and chronic venous insufficiency (CVI) in organ transplant recipients (OTR) can lead to harmful outcomes. We made an inventory of cutaneous manifestations of PAOD and CVI in OTR in relation with diabetes and other potential risk factors.

METHODS

A prospective study in a single center was performed. OTR (n = 112) were included at the outpatient clinic to investigate clinical signs of PAOD and CVI. The most commonly associated risk factors were determined.

RESULTS

PAOD had been diagnosed in 15.6% and CVI in 30.0% of the patients. Diabetes was the cause of organ failure in 9.8% of the patients. Type 1 diabetes had been diagnosed in 8.9% and type 2 diabetes in 21.4% (59.1% new-onset diabetes after transplantation). Type 1 diabetes showed an increased risk for PAOD and limb amputation with hazard ratios of 11.0 (95%CI 3.0-40.2) and 9.1 (95%CI 1.4-58.6). Type 2 diabetes showed no increased risk.

CONCLUSIONS

Patients with a history of type 1 diabetes were at high risk for PAOD even years after a simultaneous pancreas kidney transplantation and they should remain under close observation for PAOD even though they are supposedly "cured" from their diabetes to prevent a harmful outcome.

Concomitant chronic venous insufficiency in patients with peripheral artery disease: insights from MR angiography

OBJECTIVES

The clinical presentation of peripheral artery disease (PAD) and chronic venous insufficiency (CVI) can overlap and the conditions may co-exist. The purpose of our study was to investigate the prevalence and clinical significance of concomitant CVI in patients with PAD examined with run-off MR angiography (MRA).

METHODS

We analysed 180 patients (median age 69 years, range 27 to 91) with known or suspected PAD who underwent MRA at our institution between 2012 and 2018. MRA datasets were re-evaluated for manifestations of CVI. Electronic charts were reviewed to analyse whether diagnosis of CVI was documented and to determine Fontaine stage of PAD.

RESULTS

Evidence of possible CVI on MRA was found in 38 (21%) patients. Only seven (18%) of these patients had a documented diagnosis of CVI. Patients with co-existing PAD and CVI were more likely obese (median BMI 29.7 vs. 26.3 kg/m2, p = 0.001) and diabetic (55 vs. 35%, p = 0.039) than patients without CVI. The frequency of concomitant CVI manifestations decreased from distal to proximal with the lower leg affected in all 38 patients and the thigh in 17 patients (45%). Patients with co-existing PAD and CVI were more likely to have a clinical diagnosis of stage IV PAD than patients without co-existing CVI (57% vs. 34%, relative risk 1.68, p = 0.018).

CONCLUSIONS

Signs of possible concomitant CVI can be seen in approximately one-fifth of patients with known or suspected PAD examined with run-off MRA. If present, these findings should be reported since CVI may mimic or contribute to symptoms attributed to PAD.

KEY POINTS

• In total, 21% of patients with PAD patients examined with MR angiography show signs of possible co-existing CVI. • Patients with co-existing CVI were 1.7-fold more likely to have a clinical diagnosis of stage IV PAD. • Our data also showed that co-existing chronic venous insufficiency is under-diagnosed in patients with PAD.

Altered coagulation profile in peripheral artery disease patients

OBJECTIVE

Peripheral artery disease patients have been shown to be more susceptible to thrombotic events compared to non-peripheral artery disease patients. Therefore, the aim of this study was to investigate the coagulation profile in peripheral artery disease patients with chronic limb threatening ischemia, moderate peripheral artery disease patients with claudication, and non-peripheral artery disease controls.

METHODS

Chronic limb threatening ischemia patients were matched to peripheral artery disease patients with claudication and non-peripheral artery disease controls in a 1:1:1 ratio. Each patient had their cytokines, markers of thrombin generation, coagulation factors, natural anti-coagulants, fibrinolysis, and endothelial injury markers assessed.

RESULTS

Markers of thrombin activation, thrombin Fragments F1 + 2 (Frag 1 + 2), and thrombin-anti-thrombin complex were found to be significantly elevated in all peripheral artery disease and chronic limb threatening ischemia patients relative to non-peripheral artery disease controls. Similarly, relative to non-peripheral artery disease controls, inflammatory markers including C-reactive protein, soluble platelet factor 4, and neutrophil gelatinase-associated lipocalin were also found to be significantly upregulated in chronic limb threatening ischemia patients, but not in peripheral artery disease patients with claudication. Furthermore, our data demonstrated significant increases in markers of endothelial injury in chronic limb threatening ischemia patients relative to non-peripheral artery disease controls. Finally, decreases in natural anti-coagulants (protein C and protein S) and coagulation factors FIX, FXI, and FXII were also observed in chronic limb threatening ischemia patients when compared with non-peripheral artery disease controls.

CONCLUSIONS

Our data suggest that in relation to non-peripheral artery disease controls, chronic limb threatening ischemia patients are more hypercoagulable. However, peripheral artery disease patients with claudication appear to have similar levels of circulating procoagulant markers as non-peripheral artery disease patients. This may explain the increased risk of thrombotic events observed in chronic limb threatening ischemia patients.

Monitored Anesthesia Care Is Associated With a Decrease in Morbidity After Endovascular Angioplasty in Aortoiliac Disease

OBJECTIVES

Few studies have evaluated the association between anesthesia type and outcomes after endovascular angioplasty/stents for aortoiliac occlusive disease. The aim of the present study was to evaluate the association between primary anesthesia type and postprocedural complications for endovascular angioplasty of aortoiliac occlusion.

DESIGN

Retrospective cohort study.

SETTING

Multi-institutional.

PARTICIPANTS

The study comprised 3,110 patients undergoing endovascular angioplasty of aortoiliac occlusive disease, with 1,974 and 1,136 patients who underwent monitored anesthesia care (MAC) and general anesthesia (GA), respectively. The American College of Surgeons National Surgical Quality Improvement Program database for the years 2012 to 2016 was used for the present study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The final analysis included 3,110 patients, 63% of whom received MAC and 37% of whom received GA. The mean age was 64 years among the GA group, of whom 57.2% were male. The mean age among that MAC group was 65 years, 55.8% of whom were male. After adjusting for demographic factors and preoperative comorbidities, there was a statistically significant lower odds of postoperative complications (ie, pulmonary complications, infection, intraoperative/postoperative transfusion, reoperation, and amputation) and shorter length of stay in the MAC group compared with the GA group (p < 0.05).

CONCLUSIONS

Although larger observational studies and randomized controlled trials are needed to further evaluate the potential effect of MAC versus GA, MAC anesthesia should be considered for patients undergoing endovascular angioplasty for aortoiliac occlusion.