Evidence-Based Medical Management of Peripheral Artery Disease

The Use of Clot Strength as a Predictor of Thrombosis in Peripheral Artery Disease

OBJECTIVES

Graft/stent thrombosis is the leading cause of amputation in patients over 60, and while dual antiplatelet therapy is the standard of care, there is a significant variability in platelet response and limited guidance on measuring effectiveness. Thromboelastography with platelet mapping (TEG-PM) can objectively detail an individual's coagulation profile, namely the strength of the clot and its response to antiplatelet medication. Although TEG-PM has been used for predicting postoperative bleeding and assessing platelet dysfunction in TBI, its application in thrombosis diseases such as peripheral artery disease (PAD) remains unexplored. The aim of this observational study was to determine if objective measures of clot strength could predict a high clinical risk of thrombosis.

METHODS

Patients > 60 years with peripheral artery disease (PAD) undergoing revascularization were prospectively evaluated from 2021-2023. They were clinically followed for one year to detect any thrombotic events. TEG-PM was used to objectively evaluate coagulation profiles in patients at 1, 3, 6, and 9 months. These follow-up periods were chosen based on studies showing that 1-3 month intervals in the first year after lower extremity revascularization (LER) optimize therapy and risk control. The TEG-PM data preceding a thrombotic/stenotic event in patients with thrombosis was compared to the last known well TEG-PM event in those without a thrombotic/stenotic event. We stratified the groups based on the occurrence of thrombosis/stenotic events. Descriptive statistics were applied to characterize each group and a chi-square test was conducted to assess the variance between both groups. An unpaired t-test was ran to identify differences in platelet function. ROC analysis was performed to determine the optimal TEG-PM cutoff for predicting a higher risk of thrombosis.

RESULTS

One hundred and fifty-eight patients were analyzed, from whom 28 (17.7%) experienced a thrombotic event. The thrombosis cohort exhibited significantly greater MAADP, MAFibrin, and MAThrombin [50.2 vs. 40.0, p<0.05], [18.19 vs. 14.64, p<0.05] and [63.8 vs. 58.5, p<0.05] respectively indicative of greater clot strength. By ROC analysis, the optimal predictor cutoff for MAADP, indicating a higher risk of thrombosis, was >42mm [p<0.05] with 82% sensitivity and 50% specificity.

CONCLUSIONS

An increase in clot strength was found to be predictive of thrombosis/stenosis within 30 days. Using a MAADP cutoff greater than 42mm might serve as an alternative approach to tailor the use of antiplatelet medication, potentially reducing the risk of thrombosis.

The association between completion of supervised exercise therapy and long-term outcomes in patients with intermittent claudication, concomitant sarcopenia and cardiometabolic multimorbidity

INTRODUCTION

The combination of intermittent claudication (IC), cardiometabolic multimorbidity (CMM) and sarcopenia is associated with worse outcomes than IC alone. This study aimed to identify whether the completion of Supervised exercise therapy(SET) attenuates these adverse outcomes in patients with combined IC, sarcopenia and CMM.

METHODS

This registry review included consecutive IC patients with concomitant CMM and sarcopenia, who were referred for SET from 2014 to 2017. CMM was defined as two or more comorbidities (diabetes, heart disease, stroke, or chronic kidney disease). Sarcopenia was assessed using the L3-skeletal muscle index (L3SMI) from CT scans in the preceding 18 months. Outcomes of interest were progression to chronic limb-threatening ischemia (CLTI), major adverse cardiovascular events (MACE), and major adverse limb events (MALE). Survival and Cox regression analyses were performed.

RESULTS

Eighty-two patients with a combination of IC, CMM and sarcopenia were included. Of these, 56 declined or prematurely discontinued SET and 26 completed SET. Baseline characteristics and L3SMI did not significantly differ between groups. Completion of SET was associated with slower progression to CLTI (HR: 0.23; 95% CI: 0.07-0.69; p = 0.02) and a reduced risk of MALE (HR: 0.21; 95%CI: 0.057-0.775;p=0.02). However, there was no reduction in the risk of MACE (HR: 0.88; 95%CI: 0.423-1.629; p=0.73). Models demonstrated good predictive accuracy (Harrell's C-index>0.6).

CONCLUSION

Completion of SET was associated with significant improvements in adverse limb outcomes in patients with IC, concomitant sarcopenia and CMM.

Standardization and clinical applications of retinal imaging biomarkers for cardiovascular disease: a Roadmap from an NHLBI workshop

The accessibility of the retina with the use of non-invasive and relatively low-cost ophthalmic imaging techniques and analytics provides a unique opportunity to improve the detection, diagnosis and monitoring of systemic diseases. The National Heart, Lung, and Blood Institute conducted a workshop in October 2022 to examine this concept. On the basis of the discussions at that workshop, this Roadmap describes current knowledge gaps and new research opportunities to evaluate the relationships between the eye (in particular, retinal biomarkers) and the risk of cardiovascular diseases, including coronary artery disease, heart failure, stroke, hypertension and vascular dementia. Identified gaps include the need to simplify and standardize the capture of high-quality images of the eye by non-ophthalmic health workers and to conduct longitudinal studies using multidisciplinary networks of diverse at-risk populations with improved implementation and methods to protect participant and dataset privacy. Other gaps include improving the measurement of structural and functional retinal biomarkers, determining the relationship between microvascular and macrovascular risk factors, improving multimodal imaging 'pipelines', and integrating advanced imaging with 'omics', lifestyle factors, primary care data and radiological reports, by using artificial intelligence technology to improve the identification of individual-level risk. Future research on retinal microvascular disease and retinal biomarkers might additionally provide insights into the temporal development of microvascular disease across other systemic vascular beds.

Bioactive Metal-Organic Frameworks as a Distinctive Platform to Diagnosis and Treat Vascular Diseases

Vascular diseases (VDs) pose the leading threat worldwide due to high morbidity and mortality. The detection of VDs is commonly dependent on individual signs, which limits the accuracy and timeliness of therapies, especially for asymptomatic patients in clinical management. Therefore, more effective early diagnosis and lesion-targeted treatments remain a pressing clinical need. Metal-organic frameworks (MOFs) are porous crystalline materials formed by the coordination of inorganic metal ions and organic ligands. Due to their unique high specific surface area, structural flexibility, and functional versatility, MOFs are recognized as highly promising candidates for diagnostic and therapeutic applications in the field of VDs. In this review, the potential of MOFs to act as biosensors, contrast agents, artificial nanozymes, and multifunctional therapeutic agents in the diagnosis and treatment of VDs from the clinical perspective, highlighting the integration between clinical methods with MOFs is generalized. At the same time, multidisciplinary cooperation from chemistry, physics, biology, and medicine to promote the substantial commercial transformation of MOFs in tackling VDs is called for.

Associations between lipoprotein(a), oxidized phospholipids, and extracoronary vascular disease

The roles of lipoprotein(a) [Lp(a)] and related oxidized phospholipids (OxPLs) in the development and progression of coronary disease is known, but their influence on extracoronary vascular disease is not well-established. We sought to evaluate associations between Lp(a), OxPL apolipoprotein B (OxPL-apoB), and apolipoprotein(a) (OxPL-apo(a)) with angiographic extracoronary vascular disease and incident major adverse limb events (MALEs). Four hundred forty-six participants who underwent coronary and/or peripheral angiography were followed up for a median of 3.7 years. Lp(a) and OxPLs were measured before angiography. Elevated Lp(a) was defined as ≥150 nmol/L. Elevated OxPL-apoB and OxPL-apo(a) were defined as greater than or equal to the 75th percentile (OxPL-apoB ≥8.2 nmol/L and OxPL-apo(a) ≥35.8 nmol/L, respectively). Elevated Lp(a) had a stronger association with the presence of extracoronary vascular disease compared to OxPLs and was minimally improved with the addition of OxPLs in multivariable models. Compared to participants with normal Lp(a) and OxPL concentrations, participants with elevated Lp(a) levels were twice as likely to experience a MALE (odds ratio: 2.14, 95% confidence interval: 1.03, 4.44), and the strength of the association as well as the C statistic of 0.82 was largely unchanged with the addition of OxPL-apoB and OxPL-apo(a). Elevated Lp(a) and OxPLs are risk factors for progression and complications of extracoronary vascular disease. However, the addition of OxPLs to Lp(a) does not provide additional information about risk of extracoronary vascular disease. Therefore, Lp(a) alone captures the risk profile of Lp(a), OxPL-apoB, and OxPL-apo(a) in the development and progression of atherosclerotic plaque in peripheral arteries.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes of Alprostadil As an Adjuvant Therapy with Indirect Angiosomal Revascularization in Patients with Critical Limb Ischemia after Failure of Direct Revascularization

BACKGROUND

This study was carried out to assess the effectiveness of alprostadil (prostaglandin E1) when used as an adjuvant therapy with indirect revascularization in patients with critical limb ischemia (CLI) after the failure of direct revascularization (DR).

METHODS

At our centers, 120 patients suffering from infrainguinal peripheral arterial disease with CLI underwent a failed trial of DR procedure, all revascularization procedures were endovascular. Median follow-up was 2 years and 2.5 years for patients with and without diabetes mellitus (DM). In the alprostadil group, the mean age was 63.41 ± 12.52; 36 (60%) for males and 24 (40%) for females. Post-endovascular intervention alprostadil was administrated immediately postoperatively by intravenous infusion of 40 μg alprostadil diluted in 100 ml of normal saline, over 2 hr every 12 hr for 6 days.

RESULTS

In the alprostadil group, the mean ± standard deviation (SD) of the baseline ankle-brachial index (ABI) was 0.45 ± 0.175, while the mean ± SD of ABI at the end of our study was 0.65 ± 0.216 with a difference from the baseline of 0.2 ± 0.041 (P value = 0.08, <0.05 meaning that it is significant). Our 1-month primary patency rate was 93.3%, while our 3- and 6-month patency rate was 92.9%. In the control group, the mean ± SD of the baseline ABI was 0.68 ± 0.22, while the mean ± SD of ABI at the end of our study was 0.69 ± 0.23 with a difference from the baseline of 0.01 ± 0.01 (P value >0.05 meaning that it is nonsignificant) 1-month patency rate was 89%, while 3- and 6-month patency rate was 75%. When we compared the patient's leg vessels before and after our intervention, we found that the percentage of the no-runoff-vessels group decreased from 10 (16.7%) to 4 (6.67%). One-runoff-vessel group percentage dropped from 40 (66.7%) to 36 (60%), whereas, in the two-runoff-vessel group, the percentage increased from 10 (16.7%) to 20 (33.3%). We evaluate leg arteries; we do no pedal arch intervention in the alpostradil group. Out of the total of 60 patients, limb salvage occurred in 58 (96.7%) patients, and 2 (3.3%) patients underwent below-the-knee amputation before the study ended.

CONCLUSIONS

Our results show the efficacy and safety of alprostadil as an adjuvant therapy with indirect angiosomal revascularization in patients with tissue loss due to CLI.

Effectiveness of a Glyceryl Trinitrate (GTN) Patch in Preventing Amputation, Improving Pain Control and Reducing the Size of Tissue Loss for a Patient With Critical Limb-Threatening Ischaemia (CLTI)

Background  Foot ulcer is a common complication of poorly controlled diabetes and peripheral vascular disease (PVD). The current standard of treatment for diabetic foot ulcers includes the management of underlying risk factors, wound debridement, use of antibiotics for infection, off-loading with cast, and revascularisation surgery. The glyceryl trinitrate (GTN) patch is currently off-licence in treating PVD or diabetic foot ulcers. This study aims to evaluate the effectiveness of the GTN patch in preventing amputation, improving pain control, and reducing the size of tissue loss (ulcer/gangrene) or localised ischaemic area. Method This is a pilot study of 30 patients who were started on the GTN patch from February 2020 to October 2021. Inclusion criteria were patients who have critical limb-threatening ischaemia (CLTI) and with no viable options or are at high risk for revascularisation, both endovascular and open surgery. Patients who were on a GTN patch for less than six weeks at the time of data collection or had unclear outcomes were excluded. The outcomes were retrospectively collected on prevention of amputation, improvement in pain control, and reduction in tissue loss (the size of ulcer/gangrene) or localised ischaemic area with the use of a GTN patch. The binomial test was used to compare the observed outcome of the GTN patch and the expected outcome, which was assumed to be 50% in this study. Results  Ninety-three per cent (93%) of the patients who had GTN patches successfully avoided amputation (p<0.0001). Eighty-four per cent (84%) of patients reported better pain control (p=0.0022) and improvement in the size of ulcer/gangrene/localised ischaemic areas (p=0.0005). Conclusion The GTN patch is effective in preventing amputation, improving pain control, and reducing the size of ulcer/gangrene/localised ischaemic areas in patients who have end-stage CLTI and no viable options or who are at high risk for revascularisation surgery.

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

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

Importance of Using Angiography for the Early Detection of Chronic Limb Ischemia in Diabetic Foot Wounds

Peripheral artery disease (PAD) affects millions of people worldwide, presenting with varying symptom severity, including chronic total occlusion of arteries, and occasionally, limb amputation. There are various interventions, such as atherectomy and the use of drug-coated balloons and stents, which have been developed to revascularize affected ischemic regions. However, each interventional approach must be individualized due to a patient's unique underlying conditions. Comorbid conditions, especially diabetes, play a significant role in PAD, as poorly controlled diabetes can accelerate PAD progression. For this reason, an early and accurate diagnosis of PAD is crucial, especially when symptoms may present dissimilar to classic PAD symptoms, often leading to misdiagnosis. The presented cases highlight the tailored interventions to revascularize arteries in patients with diabetic foot wounds utilizing catheters, stents, guidewires, and balloons, made possible after early angiogram. These interventions have been promising in treating PAD patients, and highlight the need for early diagnosis and timely and customized interventions to prevent limb amputation and mitigate potential complications.

Adherence and Persistence to Antiplatelet Therapy in Lower Extremity Peripheral Arterial Disease: A Danish Population Based Cohort Study

OBJECTIVE

Adherence to antiplatelet therapy is recommended but unexplored in patients with symptomatic lower extremity peripheral arterial disease (PAD). Therefore, this study aimed to determine adherence and persistence to antiplatelet therapy in patients with PAD, defined as intermittent claudication and chronic limb threatening ischaemia.

DESIGN

Population based nationwide cohort study.

METHODS

This study included all Danish citizens aged ≥ 40 years with a first inpatient or outpatient diagnosis of symptomatic PAD between 2010 - 2017, and who had at least one prescription claim for aspirin and/or clopidogrel within 90 days after diagnosis. Adherence was determined by the proportion of days covered (PDC) during the first year after diagnosis. Persistence was defined as no treatment gap ≥ 30 days between prescription renewals over three year follow up.

RESULTS

A total of 39 687 patients were eligible for inclusion, of whom 23 279 (58.7%) claimed a prescription for aspirin and/or clopidogrel within 90 days of diagnosis. Among these, 12 898 (55.4%) were prevalent users, while the remainder comprised new users who initiated the therapy after the index PAD diagnosis. The mean PDC was 74.5% (SD 35.0%) for prevalent users and 60.5% (SD 30.5%) for new users. Adherence increased with age and number of concomitant drugs. The overall one year cumulative incidence treatment discontinuation was 13.0% (95% CI 12.5 - 13.4%) overall, 17.2% (CI 16.6 - 17.9%) for prevalent users, and 7.9% (CI 7.4 - 8.4%) for new users. At three year follow up, the cumulative incidence of discontinuation was 31.5% (CI 30.9 - 32.2%) overall, 44.6% (CI 43.7 - 45.4%) for prevalent users, and 14.6% (CI 13.9 - 15.3) for new users.

CONCLUSION

Less than 60% of patients with newly diagnosed symptomatic PAD claimed a prescription for antiplatelet therapy within 90 days of diagnosis, and both adherence and persistence were moderate during the first year after diagnosis. These findings underscore the importance of efforts to improve the initiation and continuation of antiplatelet therapy in patients with PAD.

Predicting Outcomes Following Lower Extremity Endovascular Revascularization Using Machine Learning

BACKGROUND

Lower extremity endovascular revascularization for peripheral artery disease carries nonnegligible perioperative risks; however, outcome prediction tools remain limited. Using machine learning, we developed automated algorithms that predict 30-day outcomes following lower extremity endovascular revascularization.

METHODS AND RESULTS

The National Surgical Quality Improvement Program targeted vascular database was used to identify patients who underwent lower extremity endovascular revascularization (angioplasty, stent, or atherectomy) for peripheral artery disease between 2011 and 2021. Input features included 38 preoperative demographic/clinical variables. The primary outcome was 30-day postprocedural major adverse limb event (composite of major reintervention, untreated loss of patency, or major amputation) or death. Data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, 6 machine learning models were trained using preoperative features. The primary model evaluation metric was area under the receiver operating characteristic curve. Overall, 21 886 patients were included, and 30-day major adverse limb event/death occurred in 1964 (9.0%) individuals. The best performing model for predicting 30-day major adverse limb event/death was extreme gradient boosting, achieving an area under the receiver operating characteristic curve of 0.93 (95% CI, 0.92-0.94). In comparison, logistic regression had an area under the receiver operating characteristic curve of 0.72 (95% CI, 0.70-0.74). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.09. The top 3 predictive features in our algorithm were (1) chronic limb-threatening ischemia, (2) tibial intervention, and (3) congestive heart failure.

CONCLUSIONS

Our machine learning models accurately predict 30-day outcomes following lower extremity endovascular revascularization using preoperative data with good discrimination and calibration. Prospective validation is warranted to assess for generalizability and external validity.

A systematic review of the neutrophil to lymphocyte and platelet to lymphocyte ratios in patients with lower extremity arterial disease

Lower extremity arterial disease (LEAD) is caused by atherosclerotic plaque in the arterial supply to the lower limbs. The neutrophil to lymphocyte and platelet to lymphocyte ratios (NLR, PLR) are established markers of systemic inflammation which are related to inferior outcomes in multiple clinical conditions, though remain poorly described in patients with LEAD. This review was carried out in accordance with PRISMA guidelines. The MEDLINE database was interrogated for relevant studies. Primary outcome was the prognostic effect of NLR and PLR on clinical outcomes following treatment, and secondary outcomes were the prognostic effect of NLR and PLR on disease severity and technical success following revascularisation. There were 34 studies included in the final review reporting outcomes on a total of 19870 patients. NLR was investigated in 21 studies, PLR was investigated in two studies, and both NLR & PLR were investigated in 11 studies. Relating to increased levels of systemic inflammation, 20 studies (100%) reported inferior clinical outcomes, 13 (92.9%) studies reported increased disease severity, and seven (87.5%) studies reported inferior technical results from revascularisation. The studies included in this review support the role of elevated NLR and PLR as key components influencing the clinical outcomes, severity, and success of treatment in patients with LEAD. The use of these easily accessible, cost effective and routinely available markers is supported by the present review.

Using Machine Learning (XGBoost) to Predict Outcomes After Infrainguinal Bypass for Peripheral Artery Disease

OBJECTIVE

To develop machine learning (ML) algorithms that predict outcomes after infrainguinal bypass.

BACKGROUND

Infrainguinal bypass for peripheral artery disease carries significant surgical risks; however, outcome prediction tools remain limited.

METHODS

The Vascular Quality Initiative database was used to identify patients who underwent infrainguinal bypass for peripheral artery disease between 2003 and 2023. We identified 97 potential predictor variables from the index hospitalization [68 preoperative (demographic/clinical), 13 intraoperative (procedural), and 16 postoperative (in-hospital course/complications)]. The primary outcome was 1-year major adverse limb event (composite of surgical revision, thrombectomy/thrombolysis, or major amputation) or death. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained 6 ML models using preoperative features. The primary model evaluation metric was the area under the receiver operating characteristic curve (AUROC). The top-performing algorithm was further trained using intraoperative and postoperative features. Model robustness was evaluated using calibration plots and Brier scores.

RESULTS

Overall, 59,784 patients underwent infrainguinal bypass, and 15,942 (26.7%) developed 1-year major adverse limb event/death. The best preoperative prediction model was XGBoost, achieving an AUROC (95% CI) of 0.94 (0.93-0.95). In comparison, logistic regression had an AUROC (95% CI) of 0.61 (0.59-0.63). Our XGBoost model maintained excellent performance at the intraoperative and postoperative stages, with AUROCs (95% CI's) of 0.94 (0.93-0.95) and 0.96 (0.95-0.97), respectively. Calibration plots showed good agreement between predicted and observed event probabilities with Brier scores of 0.08 (preoperative), 0.07 (intraoperative), and 0.05 (postoperative).

CONCLUSIONS

ML models can accurately predict outcomes after infrainguinal bypass, outperforming logistic regression.

An Unusual Case of Proteus mirabilis-Induced Severe Contiguous Bacterial Osteomyelitis in an Elderly Nursing Home Resident: A Case Report

Contiguous bacterial osteomyelitis results from the spread of a variety of pyogenic bacteria from nearby skin, soft tissue, or joint infections into the underlying bone. This report describes a case of severe contiguous bacterial osteomyelitis in an 82-year-old female nursing home resident with newly diagnosed and comorbid peripheral arterial disease, along with a history of decubitus ulcers as a result of presumed neglect at her residence. The patient initially presented with multiple ulcerative lesions overlying the left foot and ankle with associated severe pain and chronic vascular insufficiency. The patient was empirically started on broad-spectrum antibiotics, with a subsequent wound culture demonstrating heavy growth of Proteus mirabilis. Multiple imaging modalities irrefutably demonstrated destructive bony changes characteristic of osteomyelitis. Left below-the-knee amputation was thereafter agreed upon as the most beneficial treatment method, with concomitant prolonged antibiotic therapy. This case emphasizes the importance of providing adequate medical and preventative care for elderly nursing home residents in an effort to reduce the incidence of contiguous bacterial osteomyelitis, a topic rarely discussed in current literature.

A Non-Coronary, Peripheral Arterial Atherosclerotic Disease (Carotid, Renal, Lower Limb) in Elderly Patients-A Review PART II-Pharmacological Approach for Management of Elderly Patients with Peripheral Atherosclerotic Lesions outside Coronary Territory

BACKGROUND

Aging is a key risk factor for atherosclerosis progression that is associated with increased incidence of ischemic events in supplied organs, including stroke, coronary events, limb ischemia, or renal failure. Cardiovascular disease is the leading cause of death and major disability in adults ≥ 75 years of age. Atherosclerotic occlusive disease affects everyday activity, quality of life, and it is associated with reduced life expectancy. As most multicenter randomized trials exclude elderly and very elderly patients, particularly those with severe comorbidities, physical or cognitive dysfunctions, frailty, or residence in a nursing home, there is insufficient data on the management of older patients presenting with atherosclerotic lesions outside coronary territory. This results in serious critical gaps in knowledge and a lack of guidance on the appropriate medical treatment. In addition, due to a variety of severe comorbidities in the elderly, the average daily number of pills taken by octogenarians exceeds nine. Polypharmacy frequently results in drug therapy problems related to interactions, drug toxicity, falls with injury, delirium, and non-adherence. Therefore, we have attempted to gather data on the medical treatment in patients with extra-cardiac atherosclerotic lesions indicating where there is some evidence of the management in elderly patients and where there are gaps in evidence-based medicine. Public PubMed databases were searched to review existing evidence on the effectiveness of lipid-lowering, antithrombotic, and new glucose-lowering medications in patients with extra-cardiac atherosclerotic occlusive disease.

Machine Learning to Predict Outcomes of Endovascular Intervention for Patients With PAD

Importance

Endovascular intervention for peripheral artery disease (PAD) carries nonnegligible perioperative risks; however, outcome prediction tools are limited.

Objective

To develop machine learning (ML) algorithms that can predict outcomes following endovascular intervention for PAD.

Design, Setting, and Participants

This prognostic study included patients who underwent endovascular intervention for PAD between January 1, 2004, and July 5, 2023, with 1 year of follow-up. Data were obtained from the Vascular Quality Initiative (VQI), a multicenter registry containing data from vascular surgeons and interventionalists at more than 1000 academic and community hospitals. From an initial cohort of 262 242 patients, 26 565 were excluded due to treatment for acute limb ischemia (n = 14 642) or aneurysmal disease (n = 3456), unreported symptom status (n = 4401) or procedure type (n = 2319), or concurrent bypass (n = 1747). Data were split into training (70%) and test (30%) sets.

Exposures

A total of 112 predictive features (75 preoperative [demographic and clinical], 24 intraoperative [procedural], and 13 postoperative [in-hospital course and complications]) from the index hospitalization were identified.

Main Outcomes and Measures

Using 10-fold cross-validation, 6 ML models were trained using preoperative features to predict 1-year major adverse limb event (MALE; composite of thrombectomy or thrombolysis, surgical reintervention, or major amputation) or death. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). After selecting the best performing algorithm, additional models were built using intraoperative and postoperative data.

Results

Overall, 235 677 patients who underwent endovascular intervention for PAD were included (mean [SD] age, 68.4 [11.1] years; 94 979 [40.3%] female) and 71 683 (30.4%) developed 1-year MALE or death. The best preoperative prediction model was extreme gradient boosting (XGBoost), achieving the following performance metrics: AUROC, 0.94 (95% CI, 0.93-0.95); accuracy, 0.86 (95% CI, 0.85-0.87); sensitivity, 0.87; specificity, 0.85; positive predictive value, 0.85; and negative predictive value, 0.87. In comparison, logistic regression had an AUROC of 0.67 (95% CI, 0.65-0.69). The XGBoost model maintained excellent performance at the intraoperative and postoperative stages, with AUROCs of 0.94 (95% CI, 0.93-0.95) and 0.98 (95% CI, 0.97-0.99), respectively.

Conclusions and Relevance

In this prognostic study, ML models were developed that accurately predicted outcomes following endovascular intervention for PAD, which performed better than logistic regression. These algorithms have potential for important utility in guiding perioperative risk-mitigation strategies to prevent adverse outcomes following endovascular intervention for PAD.

A Non-Coronary, Peripheral Arterial Atherosclerotic Disease (Carotid, Renal, Lower Limb) in Elderly Patients-A Review: Part I-Epidemiology, Risk Factors, and Atherosclerosis-Related Diversities in Elderly Patients

Atherosclerosis is a generalized and progressive disease. Ageing is a key risk factor for atherosclerosis progression that is associated with the increased incidence of ischemic events in supplied organs, including stroke, coronary events, limb ischemia, or renal failure. Cardiovascular disease is the leading cause of death and major disability in adults ≥ 75 years of age. Atherosclerotic occlusive disease affects everyday activity and quality of life, and it is associated with reduced life expectancy. Although there is evidence on coronary artery disease management in the elderly, there is insufficient data on the management in older patients presented with atherosclerotic lesions outside the coronary territory. Despite this, trials and observational studies systematically exclude older patients, particularly those with severe comorbidities, physical or cognitive dysfunctions, frailty, or residence in a nursing home. This results in serious critical gaps in knowledge and a lack of guidance on the appropriate medical treatment and referral for endovascular or surgical interventions. Therefore, we attempted to gather data on the prevalence, risk factors, and management strategies in patients with extra-coronary atherosclerotic lesions.

Using machine learning to predict outcomes following suprainguinal bypass

OBJECTIVE

Suprainguinal bypass for peripheral artery disease (PAD) carries important surgical risks; however, outcome prediction tools remain limited. We developed machine learning (ML) algorithms that predict outcomes following suprainguinal bypass.

METHODS

The Vascular Quality Initiative database was used to identify patients who underwent suprainguinal bypass for PAD between 2003 and 2023. We identified 100 potential predictor variables from the index hospitalization (68 preoperative [demographic/clinical], 13 intraoperative [procedural], and 19 postoperative [in-hospital course/complications]). The primary outcomes were major adverse limb events (MALE; composite of untreated loss of patency, thrombectomy/thrombolysis, surgical revision, or major amputation) or death at 1 year following suprainguinal bypass. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained six ML models using preoperative features (Extreme Gradient Boosting [XGBoost], random forest, Naïve Bayes classifier, support vector machine, artificial neural network, and logistic regression). The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). The best performing algorithm was further trained using intra- and postoperative data. Model robustness was evaluated using calibration plots and Brier scores. Performance was assessed on subgroups based on age, sex, race, ethnicity, rurality, median Area Deprivation Index, symptom status, procedure type, prior intervention for PAD, concurrent interventions, and urgency.

RESULTS

Overall, 16,832 patients underwent suprainguinal bypass, and 3136 (18.6%) developed 1-year MALE or death. Patients with 1-year MALE or death were older (mean age, 64.9 vs 63.5 years; P < .001) with more comorbidities, had poorer functional status (65.7% vs 80.9% independent at baseline; P < .001), and were more likely to have chronic limb-threatening ischemia (67.4% vs 47.6%; P < .001) than those without an outcome. Despite being at higher cardiovascular risk, they were less likely to receive acetylsalicylic acid or statins preoperatively and at discharge. Our best performing prediction model at the preoperative stage was XGBoost, achieving an AUROC of 0.92 (95% confidence interval [CI], 0.91-0.93). In comparison, logistic regression had an AUROC of 0.67 (95% CI, 0.65-0.69). Our XGBoost model maintained excellent performance at the intra- and postoperative stages, with AUROCs of 0.93 (95% CI, 0.92-0.94) and 0.98 (95% CI, 0.97-0.99), respectively. Calibration plots showed good agreement between predicted and observed event probabilities with Brier scores of 0.12 (preoperative), 0.11 (intraoperative), and 0.10 (postoperative). Of the top 10 predictors, nine were preoperative features including chronic limb-threatening ischemia, previous procedures, comorbidities, and functional status. Model performance remained robust on all subgroup analyses.

CONCLUSIONS

We developed ML models that accurately predict outcomes following suprainguinal bypass, performing better than logistic regression. Our algorithms have potential for important utility in guiding perioperative risk mitigation strategies to prevent adverse outcomes following suprainguinal bypass.

Supervised Exercise Therapy for Intermittent Claudication: A Propensity Score Matched Analysis of Retrospective Data on Long Term Cardiovascular Outcomes

OBJECTIVE

This study aimed to explore the long term outcomes of patients with intermittent claudication (IC) who completed supervised exercise therapy (SET) vs. those who declined or prematurely discontinued SET, focusing on the incidence of chronic limb threatening ischaemia (CLTI), revascularisation, major adverse limb events (MALE), and major adverse cardiovascular events (MACE).

METHODS

A retrospective registry analysis of consecutive patients with IC who were referred for SET between March 2015 and August 2016 and followed up for a minimum of five years. Serial univariable analysis and logistic regression were performed to identify the statistically significant clinical variables that were independent predictors of each outcome measure. The resulting statistically significant variables were used to guide 1:1 propensity score matching (PSM) using the nearest neighbour method with a calliper of 0.2. Cox proportional hazards regression was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the association between SET and the outcomes of interest.

RESULTS

Two hundred and sixty-six patients were referred to SET between March 2015 and August 2016. Of these, 64 patients completed SET and 202 patients did not. After PSM, 49 patients were analysed in each cohort. The Cox proportional hazards analysis revealed a significant association between completion of SET and revascularisation requirement (HR 0.46 95% CI 0.25 - 0.84; p = .011), completion of SET and progression to CLTI (HR 0.091, 95% CI 0.04 - 0.24; p < .001), completion of SET and MACE (HR 0.52; 95% CI 0.28 - 0.99; p = .05) and completion of SET and MALE (HR 0.28, 95% CI 0.13 - 0.65; p = .003). The Harrell's C index for all of these models was greater than 0.75, indicating good predictive accuracy.

CONCLUSION

Completion of SET is associated with better outcomes in patients who completed SET compared with patients who declined or discontinued SET with respect to clinically important cardiovascular outcomes over seven years.

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.

Metabolic clues to aging: exploring the role of circulating metabolites in frailty, sarcopenia and vascular aging related traits and diseases

Background: Physical weakness and cardiovascular risk increase significantly with age, but the underlying biological mechanisms remain largely unknown. This study aims to reveal the causal effect of circulating metabolites on frailty, sarcopenia and vascular aging related traits and diseases through a two-sample Mendelian Randomization (MR) analysis. Methods: Exposures were 486 metabolites analyzed in a genome-wide association study (GWAS), while outcomes included frailty, sarcopenia, arterial stiffness, atherosclerosis, peripheral vascular disease (PAD) and aortic aneurysm. Primary causal estimates were calculated using the inverse-variance weighted (IVW) method. Methods including MR Egger, weighted median, Q-test, and leave-one-out analysis were used for the sensitive analysis. Results: A total of 125 suggestive causative associations between metabolites and outcomes were identified. Seven strong causal links were ultimately identified between six metabolites (kynurenine, pentadecanoate (15:0), 1-arachidonoylglycerophosphocholine, androsterone sulfate, glycine and mannose) and three diseases (sarcopenia, PAD and atherosclerosis). Besides, metabolic pathway analysis identified 13 significant metabolic pathways in 6 age-related diseases. Furthermore, the metabolite-gene interaction networks were constructed. Conclusion: Our research suggested new evidence of the relationship between identified metabolites and 6 age-related diseases, which may hold promise as valuable biomarkers.

Feasibility study of Syngo iFlow in predicting hemodynamic improvement post-endovascular procedure in peripheral artery disease

OBJECTIVE

This study endeavors to examine the feasibility of predicting the clinical outcomes of patients suffering from peripheral artery disease (PAD) who undergo endovascular intervention, by employing the Syngo iFlow technology.

METHODS

Retrospectively enrolling 76 patients from December 2021 to May 2023, yielding a total of 77 affected limbs, this study employs clinical outcomes (improvement or otherwise) as the gold standard. Two physicians conducted visual assessments on both DSA and iFlow images to gauge patient improvement and assessed inter-observer consistency for each image modality. The Time to Peak (TTP) of regions of interest (ROI) at the femoral head, knee joint, and ankle joint was measured. Differences in pre- and post-procedure TTP were juxtaposed, and statistically significant parameter cutoff values were identified via ROC analysis. Employing these cutoffs for TTP classification, multivariate logistic regression and the C-statistic were utilized to assess the predictive value of distinct parameters for clinical success.

RESULTS

Endovascular procedure exhibited technical and clinical success rates of 82.58 and 75.32%, respectively. Diagnostic performance of iFlow image visual assessment surpassed that of DSA images. Inter-observer agreement for iFlow and DSA image evaluations was equivalent (κ = 0.48 vs 0.50). Post-classification using cutoff values, multivariate logistic regression demonstrated the statistical significance of ankle joint TTP in post-procedure iFlow images of the endovascular procedure for clinical success evaluation (OR 7.21; 95% CI 1.68, 35.21; P = 0.010), with a C-statistic of 0.612.

CONCLUSION

Syngo iFlow color-encoded imagery holds practical value in assessing the technical success of post-endovascular procedures, offering comprehensive lower limb arterial perfusion visualization. Its quantifiable parameters exhibit promising potential for prognosticating clinical success.

Predicting outcomes following lower extremity open revascularization using machine learning

Lower extremity open revascularization is a treatment option for peripheral artery disease that carries significant peri-operative risks; however, outcome prediction tools remain limited. Using machine learning (ML), we developed automated algorithms that predict 30-day outcomes following lower extremity open revascularization. The National Surgical Quality Improvement Program targeted vascular database was used to identify patients who underwent lower extremity open revascularization for chronic atherosclerotic disease between 2011 and 2021. Input features included 37 pre-operative demographic/clinical variables. The primary outcome was 30-day major adverse limb event (MALE; composite of untreated loss of patency, major reintervention, or major amputation) or death. Our data were split into training (70%) and test (30%) sets. Using tenfold cross-validation, we trained 6 ML models. Overall, 24,309 patients were included. The primary outcome of 30-day MALE or death occurred in 2349 (9.3%) patients. Our best performing prediction model was XGBoost, achieving an area under the receiver operating characteristic curve (95% CI) of 0.93 (0.92-0.94). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.08. Our ML algorithm has potential for important utility in guiding risk mitigation strategies for patients being considered for lower extremity open revascularization to improve outcomes.

Assessment of clinical and economic impact of rivaroxaban plus aspirin vs. aspirin alone as a secondary prophylaxis in patients with chronic and symptomatic peripheral arterial disease in the United States

AIM

The objective in this study was to assess the clinical and economic implications of the inclusion of rivaroxaban as a secondary prophylaxis in patients with chronic or symptomatic peripheral artery disease (PAD) in the United States (US).

METHODS

A cost-consequence model was adapted to evaluate the economic impact of rivaroxaban plus aspirin in a hypothetical 1-million-member health plan. The model inputs were taken from multiple sources: efficacy and safety of rivaroxaban + aspirin vs. aspirin alone were abstracted from COMPASS and VOYAGER randomized clinical trials; the prevalence of chronic and symptomatic PAD and incidence rates of clinical events (major adverse cardiac events [MACE], major adverse limb events [MALE], and major bleeding), were abstracted from the analysis of claims data; healthcare costs of clinical events and wholesale acquisition costs for rivaroxaban were abstracted from the literature and Red Book, respectively (2022 USD). One-way sensitivity analyses and subgroup analyses were also conducted.

RESULTS

Over one year, with a 5% uptake of rivaroxaban, the model estimated rivaroxaban + aspirin to reduce 21 MACE/MALE events in the PAD patient population. The reduction in these clinical events offsets the increased risk of major bleeding (16 additional events), demonstrating a positive health benefit of the rivaroxaban addition. These benefits led to a $0.27 incremental cost per member per month (PMPM) to a US plan. The major driver of the incremental cost was the cost of rivaroxaban. In a subgroup of patients with the presence of any high-risk factor (heart failure, diabetes, renal insufficiency, or history of vascular disease affecting two or more vascular beds), the incremental PMPM cost was $0.13.

CONCLUSIONS

Rivaroxaban + aspirin was found to provide positive net clinical benefit on the annual number of MACE/MALE avoided, with a modest increase in the PMPM cost.

Hypertension Management in Peripheral Artery Disease: A Mini Review

Lower extremity peripheral artery disease (PAD) affects over 230 million adults globally, with hypertension being one of the major risk factors for the development of PAD. Despite the high prevalence, patients with hypertension who have concomitant PAD are less likely to receive adequate therapy. Through this review, we present the current evidence underlying hypertension management in PAD, guideline-directed therapies, and areas pending further investigation. Multiple studies have shown that both high and relatively lower blood pressure levels are associated with worse health outcomes, including increased morbidity and mortality. Hence, guideline-directed recommendation involves cautious management of hypertensive patients with PAD while ensuring hypotension does not occur. Although any antihypertensive medication can be used to treat these patients, the 2017 American Heart Association/American College of Cardiology (AHA/ACC), 2017 European Society of Cardiology (ESC), and 2022 Canadian guidelines favor the use of angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) as the initial choice. Importantly, data on blood pressure targets and treatment of hypertension in PAD are limited and largely stem from sub-group studies and post-hoc analysis. Large randomized trials in patients with PAD are required in the future to delineate hypertension management in this complex patient population.

Predicting outcomes following open revascularization for aortoiliac occlusive disease using machine learning

OBJECTIVE

Open surgical treatment options for aortoiliac occlusive disease carry significant perioperative risks; however, outcome prediction tools remain limited. Using machine learning (ML), we developed automated algorithms that predict 30-day outcomes following open aortoiliac revascularization.

METHODS

The National Surgical Quality Improvement Program (NSQIP) targeted vascular database was used to identify patients who underwent open aortoiliac revascularization for atherosclerotic disease between 2011 and 2021. Input features included 38 preoperative demographic/clinical variables. The primary outcome was 30-day major adverse limb event (MALE; composite of untreated loss of patency, major reintervention, or major amputation) or death. The 30-day secondary outcomes were individual components of the primary outcome, major adverse cardiovascular event (MACE; composite of myocardial infarction, stroke, or death), individual components of MACE, wound complication, bleeding, other morbidity, non-home discharge, and unplanned readmission. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained six ML models using preoperative features. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). Model robustness was evaluated with calibration plot and Brier score. Variable importance scores were calculated to determine the top 10 predictive features. Performance was assessed on subgroups based on age, sex, race, ethnicity, symptom status, procedure type, and urgency.

RESULTS

Overall, 9649 patients were included. The primary outcome of 30-day MALE or death occurred in 1021 patients (10.6%). Our best performing prediction model for 30-day MALE or death was XGBoost, achieving an AUROC of 0.95 (95% confidence interval [CI], 0.94-0.96). In comparison, logistic regression had an AUROC of 0.79 (95% CI, 0.77-0.81). For 30-day secondary outcomes, XGBoost achieved AUROCs between 0.87 and 0.97 (untreated loss of patency [0.95], major reintervention [0.88], major amputation [0.96], death [0.97], MACE [0.95], myocardial infarction [0.88], stroke [0.93], wound complication [0.94], bleeding [0.87], other morbidity [0.96], non-home discharge [0.90], and unplanned readmission [0.91]). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.05. The strongest predictive feature in our algorithm was chronic limb-threatening ischemia. Model performance remained robust on all subgroup analyses of specific demographic/clinical populations.

CONCLUSIONS

Our ML models accurately predict 30-day outcomes following open aortoiliac revascularization using preoperative data, performing better than logistic regression. They have potential for important utility in guiding risk-mitigation strategies for patients being considered for open aortoiliac revascularization to improve outcomes.

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

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

Global disease burden and its attributable risk factors of peripheral arterial disease

Peripheral arterial disease (PAD) is a prevalent subtype of atherosclerotic cardiovascular diseases. It is crucial to assess the PAD-related burden and its attributable risk factors. We use the Global Burden of Disease study 2019 database to calculate the incidence, prevalence, mortality, disability-adjusted life years (DALY), attributable risk factors and estimated annual percentage change. The disease burden of PAD grows significantly with age accompanied by prominent heterogeneity between male and female. Despite the increase in the absolute numbers of disease burden from 1990 to 2019, the global PAD-related age-standardized death rate (ASDR) and age-standardized disability-adjusted life years rate (ASDALYR) have a mild downward trend from 1990 to 2019, which negatively correlated with sociodemographic index (SDI). Smoking and high systolic blood pressure (SBP) were the primary attributable risk factors for males (ASDR: 33.4%; ASDALYR: 43.4%) and females (ASDR: 25.3%; ASDALYR: 27.6%), respectively. High fasting plasma glucose (FPG) had become the second risk factor for ASDR (males: 28.5%; females: 25.2%) and ASDALYR (males: 29.3%; females: 26.3%) with an upward tendency. Low-middle SDI regions were predicted to have the most remarkable upward trend of PAD-related burden caused by high FPG. Smoking caused more disease burden in males before 85-90 years old and females before 65-70 years old, while high FPG and high SBP caused more burden after that. The patterns of PAD-related burden and its attributable risk factors are heterogeneous across ages, genders, and SDI regions. To reduce disease burden, tailored strategies should be implemented.

Rehabilitation contributes to lower readmission rates for individuals with peripheral arterial disease: A retrospective observational study

BACKGROUND

Non-pharmacological interventions, such as rehabilitation, are crucial for the treatment of people with peripheral arterial disease (PAD). Although several studies have shown rehabilitation is effective in improving the functional prognosis of PAD, there is currently insufficient evidence regarding its effect on readmission rates.

OBJECTIVES

To examine the impact of rehabilitation on readmission rates for people with PAD.

METHODS

A retrospective analysis of the JMDC hospital database was performed on data from two groups of people aged ≥20 years who were hospitalized between 2014 and 2020 with PAD, as based on a previous diagnosis. Participants were divided according to whether they did, or did not, receive any form of rehabilitation as part of their treatment in hospital. The primary outcome was readmission rates at 30, 60, 90, and 180 days after initial admission. A one-to-one propensity score matching was used to compare readmission rates between rehabilitation and non-rehabilitation groups.

RESULTS

We included 13,453 people with PAD, of whom 2701 pairs (5402 subjects) were selected after being matched in the rehabilitation and non-rehabilitation groups. The rehabilitation group participants had significantly lower mortality and readmission rates at 30, 60, 90, and 180 days. The odds ratios (95% confidence interval) for both groups were 0.79 (0.69-0.91; 30 days), 0.81 (0.71-0.91; 60 days), 0.78 (0.69-0.88; 90 days), and 0.79 (0.71-0.88; 180 days).

CONCLUSIONS

This large, nationwide study found that rehabilitation treatment during hospitalization was associated with lower readmission rates and mortality for people following hospitalization with PAD and supports its inclusion as a standard PAD treatment.

Granulocyte Colony-Stimulating Factor Improves Endothelial Progenitor Cell-Mediated Neovascularization in Mice with Chronic Kidney Disease

Patients with chronic kidney disease (CKD) have a higher prevalence of peripheral arterial disease (PAD), and endothelial progenitor cells (EPCs) play a pivotal role. We examined the impact of granulocyte colony-stimulating factor (G-CSF) on EPC function in response to tissue ischemia. Eight-week-old male C57BL/6J male mice were divided into sham operation and subtotal nephrectomy (SNx) groups, received hindlimb ischemic operation after seven weeks, then randomly received G-CSF or PBS intervention for four weeks with weekly follow-ups. SNx mice had significantly reduced limb reperfusion, decreased plasma EPC mobilization, and impaired angiogenesis in ischemic hindlimbs compared to the control group. However, G-CSF increased IL-10 and reversed these adverse changes. Additionally, ischemia-associated protein expressions, including IL-10, phospho-STAT3, VEGF, and phospho-eNOS, were significantly downregulated in the ischemic hindlimbs of SNx mice versus control, but these trends were reversed by G-CSF. Furthermore, in cultured EPCs, G-CSF significantly attenuated the decrease in EPC function initiated by indoxyl sulfate through IL-10. Overall, we discovered that G-CSF can improve EPC angiogenic function through a hypoxia/IL-10 signaling cascade and impede neovascular growth in response to ischemia of SNx mice. Our results highlight G-CSF's potential to restore angiogenesis in CKD patients with PAD via EPC-based methods.

Baseline modern medical management in the BEST-CLI trial

OBJECTIVES

The use of optimal medical therapy (OMT) in patients with chronic limb-threatening ischemia (CLTI) has not been well-studied. The Best Endovascular vs Best Surgical Therapy in Patients with CLTI study (BEST-CLI) is a multicenter, randomized, controlled trial sponsored by the National Institutes of Health comparing revascularization strategies in patients with CLTI. We evaluated the use of guideline-based OMT among patients with CLTI at the time of their enrollment into the trial.

METHODS

A multidisciplinary committee defined OMT criteria related to blood pressure and diabetic management, lipid-lowering and antiplatelet medication use, and smoking status for patients enrolled in BEST-CLI. Status reports indicating adherence to OMT were provided to participating sites at regular intervals. Baseline demographic characteristics, comorbid medical conditions, and use of OMT at trial entry were evaluated for all randomized patients. A linear regression model was used to identify the relationship of predictors to the use of OMT.

RESULTS

At the time of randomization (n = 1830 total enrolled), 87% of patients in BEST-CLI had hypertension, 69% had diabetes, 73% had hyperlipidemia, and 35% were currently smoking. Adherence to four OMT components (controlled blood pressure, not currently smoking, use of one lipid-lowering medication, and use of an antiplatelet agent) was modest. Only 25% of patients met all four OMT criteria; 38% met three, 24% met two, 11% met only one, and 2% met none. Age ≥80 years, coronary artery disease, diabetes, and Hispanic ethnicity were positively associated, whereas Black race was negatively associated, with the use of OMT.

CONCLUSIONS

A significant proportion of patients in BEST-CLI did not meet OMT guideline-based recommendations at time of entry. These data suggest a persistent major gap in the medical management of patients with advanced peripheral atherosclerosis and CLTI. Changes in OMT adherence over the course of the trial and their impact on clinical outcomes and quality of life will be assessed in future analyses.

Updates and Advances in Cardiovascular Nursing: Peripheral Arterial Disease

This article focuses on peripheral arterial disease (PAD) of the lower extremities. There is a higher incidence of myocardial infarction, stroke, and cardiovascular death, resulting in higher rates of all-cause mortality compared with patients without PAD. Thus, the presence of PAD is a marker for systemic atherosclerotic disease and can lead to the early detection and treatment of coronary artery disease or cerebrovascular disease. This article reviews the latest information about the prevalence, symptoms, classification, diagnosis, and treatment of PAD. Monitoring and detection of PAD are also discussed, including implications for nursing care.

Association between dietary magnesium intake and peripheral arterial disease: Results from NHANES 1999-2004

BACKGROUND

Magnesium has been found to have a strong association with peripheral arterial disease (PAD), and dietary magnesium intake shows promise as a predictor of the condition. However, the relationship between low dietary magnesium intake and an increased risk of PAD remains uncertain, and further research is needed to clarify this relationship.

METHODS

This study analyzed data from 5969 participants in the National Health and Nutrition Examination Survey (NHANES) of the United States from 1999 to 2004. Multifactorial logistic regression models were used to investigate the association between dietary magnesium intake and PAD.

RESULTS

Participants with PAD had lower dietary magnesium intake compared to those without PAD. After adjusting for all covariates, dietary magnesium intake remained negatively associated with PAD (OR: 0.999, 95% CI: 0.998, 1.000). When dietary magnesium intake was divided into quartiles, compared with the fourth quantile, the first quartile is associated with a higher incidence rate of PAD (OR: 1.560, 95%CI: 1.019, 2.386). Subgroup analysis revealed that the link between dietary magnesium intake and PAD remained significant among specific subgroups, including non-white, never or former smokers, and non-hypertensive, non-diabetic individuals (P < 0.05).

CONCLUSION

Our study provides evidence that dietary magnesium intake is negatively associated with the incidence of PAD. Therefore, people with inadequate dietary magnesium intake, particularly those with excessively low intake, should increase their magnesium intake to reduce the risk of PAD.

Factors associated with non-adherence to angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in older patients with peripheral arterial disease

Introduction: As in other chronic conditions, medication adherence is important in the treatment of peripheral arterial disease (PAD). Our study aimed at a) analysing non-adherence to angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) in groups of older ACEI and ARB users with PAD, and b) identifying characteristics associated with non-adherence. Methods: We focused on the implementation phase of adherence (i.e., after treatment initiation and before possible discontinuation of treatment). The study cohort included ACEI/ARB users aged ≥65 years in whom PAD was newly diagnosed during 2012. Non-adherence was defined as Proportion of Days Covered (PDC) < 80%. Results: Among 7,080 ACEI/ARB users (6,578 ACEI and 502 ARB users), there was no significant difference in the overall proportion of non-adherent patients between ACEI and ARB users (13.9% and 15.3%, respectively). There were differences in factors associated with non-adherence between the groups of persistent and non-persistent (i.e., discontinued treatment at some point during follow-up) ACEI and ARB users. Increasing age, dementia and bronchial asthma were associated with non-adherence in persistent ACEI users. General practitioner as index prescriber was associated with adherence in the groups of non-persistent ACEI users and persistent ARB users. Conclusion: Identified factors associated with non-adherence may help in determining the groups of patients who require increased attention.

Comparison of angiography and ultrasound for femoropopliteal angioplasty: decision-making and 12-month outcomes

BACKGROUND

This study aimed to investigate whether intravascular ultrasound (IVUS) combined with angiography during percutaneous transluminal angioplasty impacts treatment strategies and the 12-month patency of the femoropopliteal artery, compared to angiography alone.

METHODS

This retrospective, single-center study enrolled 137 patients who underwent a femoropopliteal endovascular intervention between February 2020 and May 2021. Among these interventions, 43 were guided by IVUS combined with angiography and the remaining 94 were guided by angiography only. Treatment strategies and 12-month patency were analyzed in both groups. Multivariable analysis was performed to clarify the predictors of restenosis within 12 months.

RESULTS

Primary patency at 12 months was significantly higher in the IVUS group than in the angiography group (56.4% vs. 76.7%, P=0.047). The reference diameter on IVUS images was greater than that on angiography images. Therefore, the IVUS group presented a higher balloon-to-vessel ratio [1.0 (0.97, 1.01) vs. 1.06 (1.0.1.25)]. More adjunctive stents were required in the angiography group. However, more dissections were performed in the IVUS group, with no difference in flow-limiting dissections between groups. Target disease length (odds ratio 1.02, P=0.021) and balloon-to-vessel ratio (odds ratio 0.01, P=0.021) were independent predictors of restenosis.

CONCLUSIONS

Compared with angiography guidance alone, IVUS guidance for femoropopliteal artery-related treatment can significantly increase primary patency. This finding may be explained by the selection of larger balloons in IVUS and the resulting sufficient plaque compression and elastic membrane stretch. Moreover, IVUS was shown to detect more non-flow-limiting dissections than angiography.

Comprehensive Care of Lower-Extremity Wounds

There are 5 common types of chronic nonhealing lower-extremity wounds: arterial, venous, diabetic foot ulcer, pressure, and mixed or atypical. Each chronic wound type has distinct features, and understanding the underlying cause will dictate the wound treatment plan. Here, the authors review the distinguishing wound properties for these 5 common chronic nonhealing lower-extremity wounds and outline a comprehensive treatment plan that addresses wound perfusion, debridement, infection control, moisture balance, and use of complementary advanced wound care products.

MCP-1-Loaded Poly(l-lactide-co-caprolactone) Fibrous Films Modulate Macrophage Polarization toward an Anti-inflammatory Phenotype and Improve Angiogenesis

Tissue engineering approaches such as the electrospinning technique can fabricate nanofibrous scaffolds which are widely used for small-diameter vascular grafting. However, foreign body reaction (FBR) and lack of endothelial coverage are still the main cause of graft failure after the implantation of nanofibrous scaffolds. Macrophage-targeting therapeutic strategies have the potential to address these issues. Here, we fabricate a monocyte chemotactic protein-1 (MCP-1)-loaded coaxial fibrous film with poly(l-lactide-co-ε-caprolactone) (PLCL/MCP-1). The PLCL/MCP-1 fibrous film can polarize macrophages toward anti-inflammatory M2 macrophages through the sustained release of MCP-1. Meanwhile, these specific functional polarization macrophages can mitigate FBR and promote angiogenesis during the remodeling of implanted fibrous films. These studies indicate that MCP-1-loaded PLCL fibers have a higher potential to modulate macrophage polarity, which provides a new strategy for small-diameter vascular graft designing.

Target and Cell Therapy for Atherosclerosis and CVD

Cardiovascular diseases (CVD) and, in particular, atherosclerosis, remain the main cause of death in the world today. Unfortunately, in most cases, CVD therapy begins after the onset of clinical symptoms and is aimed at eliminating them. In this regard, early pathogenetic therapy for CVD remains an urgent problem in modern science and healthcare. Cell therapy, aimed at eliminating tissue damage underlying the pathogenesis of some pathologies, including CVD, by replacing it with various cells, is of the greatest interest. Currently, cell therapy is the most actively developed and potentially the most effective treatment strategy for CVD associated with atherosclerosis. However, this type of therapy has some limitations. In this review, we have tried to summarize the main targets of cell therapy for CVD and atherosclerosis in particular based on the analysis using the PubMed and Scopus databases up to May 2023.

Simulation and Experimental Investigation of Balloon Folding and Inserting Performance for Angioplasty: A Comparison of Two Materials, Polyamide-12 and Pebax

BACKGROUND

A balloon dilatation catheter is a vital tool in percutaneous transluminal angioplasty. Various factors, including the material used, influence the ability of different types of balloons to navigate through lesions during delivery.

OBJECTIVE

Thus far, numerical simulation studies comparing the impacts of different materials on the trackability of balloon catheters has been limited. This project seeks to unveil the underlying patterns more effectively by utilizing a highly realistic balloon-folding simulation method to compare the trackability of balloons made from different materials.

METHODS

Two materials, nylon-12 and Pebax, were examined for their insertion forces via a bench test and a numerical simulation. The simulation built a model identical to the bench test's groove and simulated the balloon's folding process prior to insertion to better replicate the experimental conditions.

RESULTS

In the bench test, nylon-12 demonstrated the highest insertion force, peaking at 0.866 N, significantly outstripping the 0.156 N force exhibited by the Pebax balloon. In the simulation, nylon-12 experienced a higher level of stress after folding, while Pebax had demonstrated a higher effective strain and surface energy density. In terms of insertion force, nylon-12 was higher than Pebax in specific areas.

CONCLUSION

nylon-12 exerts greater pressure on the vessel wall in curved pathways when compared to Pebax. The simulated insertion forces of nylon-12 align with the experimental results. However, when using the same friction coefficient, the difference in insertion forces between the two materials is minimal. The numerical simulation method used in this study can be used for relevant research. This method can assess the performance of balloons made from diverse materials navigating curved paths and can yield more precise and detailed data feedback compared to benchtop experiments.

Demographic and regional trends of peripheral artery disease-related mortality in the United States, 2000 to 2019

INTRODUCTION

Peripheral artery disease (PAD) is a common progressive atherosclerotic disease associated with significant morbidity and mortality in the US; however, data regarding PAD-related mortality trends are limited. This study aims to characterize contemporary trends in mortality across sociodemographic and regional groups.

METHODS

The Centers for Disease Control and Prevention Wide-Ranging OnLine Data for Epidemiologic Research (CDC WONDER) was queried for data regarding PAD-related deaths from 2000 to 2019 in the overall sample and different demographic (age, sex, race/ethnicity) and regional (state, urban-rural) subgroups. Crude and age-adjusted mortality rates (CMR and AAMR, respectively) per 100,000 people were calculated. Associated annual percentage changes (APC) were computed using Joinpoint Regression Program Version 4.9.0.0 trend analysis software.

RESULTS

Between 2000 and 2019, a total of 1,959,050 PAD-related deaths occurred in the study population. Overall, AAMR decreased from 72.8 per 100,000 in 2000 to 32.35 per 100,000 in 2019 with initially decreasing APCs followed by no significant decline from 2016 to 2019. Most demographic and regional subgroups showed initial declines in AAMRs during the study period, with many groups exhibiting no change in mortality in recent years. However, men, non-Hispanic (NH) Black or African American individuals, people aged ⩾ 85 years, and rural counties were associated with the highest AAMRs of their respective subgroups. Notably, there was an increase in crude mortality rate among individuals 25-39 years of age from 2009 to 2019.

CONCLUSION

Despite initial improvement, PAD-related mortality has remained stagnant in recent years. Disparities have persisted across several demographic and regional groups, requiring further investigation.

Exploring telehealth interventions to monitor rehabilitation in patients with peripheral artery disease

Peripheral artery disease is a manifestation of systemic atherosclerosis, and these patients often have claudication pain in the legs during activity. This leads to generally adopting an inactive lifestyle; hence, even small changes in physical activity could reduce the risk of an adverse cardiovascular event. For patients with peripheral artery disease compliance with non-invasive interventions like assistive devices and long-term exercise therapy is important for improved health outcomes. Benefits to patients can only be measured if patients with peripheral artery disease adhere to the intervention and barriers are identified with improved solutions. The effect of mobile health including pedometers and smartphone technological applications in motivating the patient to continue adhering to the intervention and persist in physical activity is a new venture to be explored.

Peripheral arterial disease: A small and large vessel problem

Peripheral arterial disease (PAD) is one clinical manifestation of systemic atherosclerosis and is very common. Despite its prevalence, PAD remains underdiagnosed, undertreated, and understudied. The most common symptom in patients with PAD is intermittent claudication (IC), or pain in the lower extremities with walking or exertion, which is relieved after a short period of rest. Many patients with confirmed PAD are asymptomatic or have symptoms other than IC. Regardless of symptoms, patients with PAD have poor cardiovascular outcomes. PAD has largely been viewed a disease of large vessel atherosclerosis but what is becoming clear is that arterial plaques and occlusions are only one piece of the puzzle. Recent work has shown that abnormalities in the microvasculature contribute to the outcome of patients with PAD. From the perspective of the leg, limitation in blood flow is not the only problem as patients have a myriad of other problems, including muscle fibrosis, neuropathic changes, changes in the cellular respiration machinery and dysfunction of the small vessels that perfuse skeletal muscle and the supporting structures. Supervised exercise training remains one of the most effective tool to treat patients with PAD, however, the mechanisms behind its effectiveness are still being elucidated and use of structured exercise programs is not widespread. Medical therapy to treat systemic atherosclerosis is underutilized in patients with PAD. Invasive therapies are used only when patients with PAD have reached an advanced stage. While invasive strategies are effective in some patients with PAD, these strategies are costly, carry risk, and many patients are not amenable to invasive therapy. Appreciating the complex pathophysiology of PAD will hopefully spur new research and development of effective therapies for PAD.

Early identification and treatment for peripheral arterial disease in patients with ischemic cerebrovascular disease

Ischemic cerebrovascular disease (ICVD) is a major cause of mortality and disability worldwide and is often caused by atherosclerosis. As a systemic disease, atherosclerosis usually affects multiple vascular beds, mainly including cerebral, coronary, and peripheral arteries. Therefore, ICVD is easily complicated by lower-extremity peripheral arterial disease (PAD). ICVD patients with PAD have more serious symptoms and a worse prognosis, however, neurologists might neglect the evaluation and management of the coexistent PAD, and there is still a lack of consensuses about the diagnosis and treatment for such patients. By summarizing relevant research progresses, this review showed that duplex ultrasound had more advantages in the early screening and evaluation of PAD in ICVD patients among multiple methods to diagnose PAD. Furthermore, the current evidence seems to support that single-drug antiplatelet can be used as the basic treatment, and new antithrombotic strategies, such as ticagrelor only or aspirin combined with low-dose rivaroxaban are expected to further reduce the incidence of stroke for ICVD patients with PAD. More effective treatments would be explored by large-scale trials to guide the clinical management to prevent secondary stroke for such patients.

Long-term use of an ankle-foot orthosis intervention in patients with peripheral artery disease using the integrated promoting action on research implementation in health services (i-PARIHS) framework

BACKGROUND

Peripheral artery disease (PAD) is a cardiovascular disease that limits patients' walking ability. Persistent ankle-foot orthosis (AFO) use may increase the distance patients can walk as well as physical activity.

PURPOSE

The purpose of the study was to determine the implementation and patients' perspectives related to the use or disuse of the AFO intervention six months post-intervention. This study was guided by a semi-structured interview and survey based on the integrated Promoting Action on Research Implementation in Health Services (i-PARIHS) constructs.

DESIGN

A convergent mixed methods design was used to evaluate participants' perceptions six months following a three-month AFO intervention. A survey and semi-structured questionnaire based on the i-PARIHS constructs were administered and analyzed.

SETTING

Vascular surgery clinic and biomechanics research laboratory.

PARTICIPANTS

Patients (N = 7; male, 100%; age, 71.9 ± 0.6.7y; body mass index, 29.0 ± 0.5.5; ankle brachial index 0.50 ± 0.17) with claudication completed the study.

INTERVENTIONS

A certified orthotist fit participants with an AFO that was worn for 3 months.

MAIN OUTCOME MEASURES

Qualitative analysis of semi-structured interviews and quantitative analysis of the survey.

RESULTS

The highest positive ratings were seen in the dimensions of usability and cost-effectiveness. The patients found the AFO device and instructions to wear, easy when starting the intervention and there were no out-of-pocket costs. The lower scores and challenges faced with observability and relative advantage domains indicated issues related to motivation for sustained use of the AFO.

CONCLUSIONS

Barriers associated with AFO function that prevent common activities and poor health seem to be the biggest issue for not wanting to wear the AFO after the 3-month intervention. Addressing patients' perceptions and challenges to wearing the AFO is essential to increasing compliance and physical activity. Future research should concentrate on understanding the compatibility of orthotic device interventions with the subject's lifestyle.

CLINICAL TRIAL REGISTRATION NO

NCT02902211.

Reinitiation and Subsequent Discontinuation of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers among New and Prevalent Users Aged 65 Years or More with Peripheral Arterial Disease

Angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin-receptor blockers (ARBs) are recommended in the treatment of arterial hypertension in patients with peripheral arterial disease (PAD). The aims of our study were: (a) to analyse the extent of reinitiation and subsequent discontinuation in older hypertensive PAD patients non-persistent with ACEIs/ARBs; (b) to determine patient and medication factors associated with reinitiation and subsequent discontinuation; and (c) to compare these factors between prevalent and new users. The analysis of reinitiation was performed on a sample of 1642 non-persistent patients aged ≥65 years with PAD newly diagnosed in 2012. Patients reinitiating ACEIs/ARBs were used for the analysis of subsequent discontinuation identified according to the treatment gap period of at least 6 months without any prescription of ACEI/ARB. In the group of non-persistent patients, 875 (53.3%) patients reinitiated ACEIs/ARBs during a follow-up (24.8 months on average). Within this group, subsequent discontinuation was identified in 414 (47.3%) patients. Being a new user was associated with subsequent discontinuation, but not with reinitiation. Myocardial infarction during non-persistence and after reinitiation was associated with reinitiation and lower likelihood of subsequent discontinuation, respectively. Being a prevalent or a new user is associated with the use of medication also after initial discontinuation.

The Impact of Diabetes in Intermittent Claudication: A Prospective Cohort Study

The aim of this study was to determine the lower-limb outcome in patients with intermittent claudication (IC) and to identify predictors for deterioration. This study employed a prospective observational cohort single-centre design. One hundred fifty patients with IC attending a vascular surgery unit for the first time were recruited. Lower limb perfusion was assessed utilising ankle brachial index (ABI) measures, toe-brachial index (TBI) measures, Doppler waveform analysis and the walking impairment questionnaire. Follow-up was conducted after 1 year and 2 years following recruitment to assess haemodynamic parameters, symptom severity and outcome. Recruited participants had a mean age of 69.7 (±9.3) years, BMI 27.8(±4.2) and 79.3% were men. Significant haemodynamic decline (decline in ABPI by ≥0.15 and/or decline in TBPI by ≥0.1) occurred in 50.6% of the cohort within 2 years of whom 23.3% developed chronic limb threatening ischaemia (CLTI) with rest pain and/or tissue loss. Baseline ABPI, ABPI ≤ 0.5, TBPI ≤ 0.39, infrapopliteal artery (IPA) disease and high Haemoglobin A1c were identified as significant predictors for deterioration to CLI. (P < .05, binomial logistic regression). Patients with IC are at a high risk of developing CLTI within 2 years. Risk of lower limb adverse events is tripled in patients with IPA disease, low ankle and toe pressures and poorly controlled diabetes. Early identification of those at high risk for early deterioration may justify a paradigm shift in the management of this subgroup.

The Potential Role of Antioxidants in the Treatment of Peripheral Arterial Disease: A Systematic Review

Peripheral arterial disease (PAD) has a worldwide prevalence and is a significant cause of cardiovascular morbidity and mortality. Due to its high prevalence and higher rates of ischemic cardiovascular and lower-extremity events, its treatment is essential. Increased levels of oxidative stress cause disease. This review aimed to evaluate different studies of antioxidant treatments for PAD patients. A systematic search for relevant studies was performed on the PubMed, SCOPUS, and ScienceDirect databases, and 18 studies fulfilled the inclusion criteria. In total, 16.6% of the studies used natural antioxidants, and 83.3% used synthetic antioxidants. The reviewed studies show that natural antioxidants were completely effective in treating PAD, and synthetic antioxidants showed effective results in only 53% of the studies. A less-than-optimal pro-oxidant-antioxidant balance does not improve the symptoms of PAD. In conclusion, antioxidants in their natural forms are more effective for PAD patients, and ensuring the optimal pro-oxidant-antioxidant balance is an effective method for managing treatment with antioxidants.

Intervention time decides the status of autophagy, NLRP3 activity and apoptosis in macrophages induced by ox-LDL

Background

It has been determined through extensive studies that autophagy, the Nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome and apoptotic responses in macrophages jointly contribute to atherogenesis and its development in the presence of lipid abnormalities. Few studies have investigated in full-scale if the intervention time for lipids abnormality or NLRP3 activation have a significant effect on autophagy, NLRP3 or the apoptotic status in macrophages.

Methods

Human THP-1 monocyte-derived macrophages were established by challenging THP-1 monocytes with 80 µg/ml oxidized low-density lipoprotein (ox-LDL) for specific durations. Foam cell formation was observed by Oil Red O (ORO) staining. Western blots were employed to determine protein expression. Transmission electron microscope (TEM) and immunofluorescence microscopy were applied to observe the autophagic status of cells. Cell apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL).

Results

The cells were treated with ox-LDL for 12 h and 36 h, which were considered to represent early and advanced stages of atherogenesis for this study. The results showed that inhibition of ox-LDL phagocytosis by cytochalasin D in the early stage improved autophagic status, reduced NLRP3 activation and the apoptotic response significantly. In contrast, cytochalasin D had little effect on blocking the detrimental effect of ox-LDL at the advanced stage. Moreover, the changes in autophagy, apoptosis and NLRP3 expression after treatment with small interfering (si) RNA targeting NLRP3 in the early and advanced stages of atherogenesis were consistent with the above data.

Conclusions

Interventions against lipid disorders or inflammatory reactions in the early or advanced stages of atherogenesis may have different results depending on when they are applied during the process of atherosclerotic pathogenesis. These results may help improve therapeutic strategies for atherosclerosis prevention. Furthermore, a healthy lifestyle should still be recommended as the most important and inexpensive measure to prevent atherogenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01714-x.