Health Disparities in Peripheral Artery Disease: A Scientific Statement From the American Heart Association

The Effect of Social Determinants of Health in Treating Chronic Limb-Threatening Ischemia

Social determinants of health (SDOHs) are broadly defined as nonmedical factors that impact the outcomes of one's health. SDOHs have been increasingly recognized in the literature as profound and modifiable factors on the outcomes of vascular care in peripheral artery disease (PAD) and chronic limb-threatening ischemia (CLTI) despite surgical and technological advancements. In this paper, we briefly review the SDOH and its impact on the management and outcome of patients with CLTI. We highlight the importance of understanding how SDOH impacts our patient population so the vascular community may provide more effective, inclusive, and equitable care.

Nrf2-Keap1 in Cardiovascular Disease: Which Is the Cart and Which the Horse?

High levels of oxidant stress in the form of reactive oxidant species are prevalent in the circulation and tissues in various types of cardiovascular disease including heart failure, hypertension, peripheral arterial disease, and stroke. Here we review the role of nuclear factor erythroid 2-related factor 2 (Nrf2), an important and widespread antioxidant and anti-inflammatory transcription factor that may contribute to the pathogenesis and maintenance of cardiovascular diseases. We review studies showing that downregulation of Nrf2 exacerbates heart failure, hypertension, and autonomic function. Finally, we discuss the potential for using Nrf2 modulation as a therapeutic strategy for cardiovascular diseases and autonomic dysfunction.

Competing risk analysis to estimate amputation incidence and risk in lower-extremity peripheral artery disease

Background: Patients with peripheral artery disease face high amputation and mortality risk. When assessing vascular outcomes, consideration of mortality as a competing risk is not routine. We hypothesize standard time-to-event methods will overestimate major amputation risk in chronic limb-threatening ischemia (CLTI) and non-CLTI. Methods: Patients undergoing peripheral vascular intervention from 2017 to 2018 were abstracted from the Vascular Quality Initiative registry and stratified by mean age (⩾ 75 vs < 75 years). Mortality and amputation data were obtained from Medicare claims. The 2-year cumulative incidence function (CIF) and risk of major amputation from standard time-to-event analysis (1 - Kaplan-Meier and Cox regression) were compared with competing risk analysis (Aalen-Johansen and Fine-Gray model) in CLTI and non-CLTI. Results: A total of 7273 patients with CLTI and 5095 with non-CLTI were included. At 2-year follow up, 13.1% of patients underwent major amputation and 33.4% died without major amputation in the CLTI cohort; 1.3% and 10.7%, respectively, in the non-CLTI cohort. In CLTI, standard time-to-event analysis overestimated the 2-year CIF of major amputation by 20.5% and 13.7%, respectively, in patients ⩾ 75 and < 75 years old compared with competing risk analysis. The standard Cox regression overestimated adjusted 2-year major amputation risk in patients ⩾ 75 versus < 75 years old by 7.0%. In non-CLTI, the CIF was overestimated by 7.1% in patients ⩾ 75 years, and the adjusted risk was overestimated by 5.1% compared with competing risk analysis. Conclusions: Standard time-to-event analysis overestimates the incidence and risk of major amputation, especially in CLTI. Competing risk analyses are alternative approaches to estimate accurately amputation risk in vascular outcomes research.

Twelve-Month Health Status Response Following Peripheral Vascular Intervention for Femoropopliteal Lesions Using Zilver PTX Databases Focusing on the Role of Preprocedural Health Status, Comorbid Risks, and Global Setting

OBJECTIVE

Tailoring resources of peripheral vascular interventions (PVIs) to those who stand to gain the most, would allow for more equitable and value-based care. One way of evaluating the benefit of PVIs in patients with symptomatic peripheral artery disease (PAD) is evaluating their health status and identifying predictors of health status response 12 months following the intervention.

METHODS

Patients undergoing femoropopliteal PVI between March 2005 and August 2008 from the Zilver PTX randomized trial and single-arm study were combined into a single cohort for secondary data analysis. The pre-procedural and 12-month health status was assessed by the EuroQol-5D-3L (EQ-5D). First, we evaluated the 12-month EQ-5D index (per 1-unit increase), adjusted for treatment condition and patient characteristics using a linear regression. Second, using the minimally clinically important difference (MCID) threshold for the EQ-5D index, we identified 12-month non-responders (worsened or no change) vs. responders (improved) and conducted an adjusted logistic regression model.

RESULTS

A total of 513 patients were included (mean age 67.8 ± 9.2 years; 25.1% female), with 17.8% USA and 82.2% non-USA global enrollment sites. The MCID for the EQ-5D was 0.058. For 12-month post PVI health status, a total of 57.9% improved, 31.4% experienced no change, and 10.7% worsened, relative to their preprocedural health status. Patients who were more likely to be non-responders were more likely to have a history of carotid artery disease or were situated at a USA enrolling center.

CONCLUSION

The majority of patients reported improved or stable health status after femoral-popliteal PVI. About 4 in 10 were non-responders, with the highest risk for non-response including individuals with existing carotid disease or those undergoing PVIs in the USA vs. non-USA settings.

Discrepancy in Opioid Prescription Patterns for Black or African American Patients Following Lower Extremity Bypass Surgery for Chronic Limb-Threatening Ischemia

INTRODUCTION

Disparity in the allocation of medical services and resources based on race is present within the health care industry today including the prescription of postoperative analgesics. The purpose of this study was to evaluate the presence of race-based disparity in the prescription of post discharge opioids following lower extremity bypass (LEB) surgery for chronic limb-threatening ischemia (CLTI).

METHODS

Retrospective analysis was conducted on adult CLTI patients who underwent LEB from 2000 to 2023 in the TrinetX database. Patients were stratified into two groups based on race: White (Group I) and black or African American (Group II). Primary outcomes were defined as oral opioid prescriptions at 7 days and 30 days post discharge, and mortality at 1 year postoperatively. Secondary outcomes included length of stay (LOS) and 30-day postoperative outcomes including myocardial infarction (MI), pulmonary embolism (PE), cerebral vascular accident (CVA), deep vein thrombosis (DVT), acute kidney injury (AKI), major amputation, minor amputation, Major Adverse Cardiac Events (MACE), and Major Adverse Limb Events (MALE). Stratified analysis was conducted based on disease stage (rest pain vs lower extremity ulcer vs gangrene). Univariate analysis was performed via two-sample t-test and Chi-squared test. Logistic regression was performed to estimate the association of Black or AA (vs. White) race while controlling for pertinent preoperative potential confounders.

RESULTS

3,345 patients met inclusion criteria. Group I included 2,661 White patients and Group II included 684 Black or African American patients. Group II patients were more likely to be younger, female, present with gangrene, and have a history of hypertension, diabetes, chronic kidney disease, or diabetic neuropathy. At both seven- and thirty-days post discharge, the Black or AA cohort had significantly lower rates of opioid prescriptions (33.2% vs 42.5% and 35.8% vs 47.2%, respectively) (all p<0.05). Stratification by indication showed that opioid prescription disparity persisted despite black or AA patients presenting at worse stages of disease both at seven and thirty days post discharge (7-days: Rest pain 43.4% vs. 33.7%, p=0.013, Ulcer 41.4% vs 31.7%, p=0.027, Gangrene, 42.7% vs 33.6%, p=0.006 & 30-days: Rest pain 47.8% vs. 37.1%, p=0.007, Ulcer 45.4% vs 33.5%, p=0.007, Gangrene, 48.2% vs 36.1%, p<0.001). Adjusted analysis confirmed that Black or African American race was associated with lower rates of seven (AOR 0.607, p=0.001) and thirty-day (AOR 0.56, p=0.001) post discharge opioid prescriptions.

CONCLUSION

Black or African American patients were less likely to receive post discharge opioid prescriptions compared with their white counterparts at seven- and 30-days following LEB for CLTI.

The association of chronic obstructive pulmonary disease and 30-day outcomes of infrainguinal bypass surgery: A propensity-score matching study

BACKGROUND

Infrainguinal bypass surgery is an effective treatment for peripheral artery disease (PAD). While chronic obstructive pulmonary disease (COPD) has been linked to heightened risks of mortality and morbidity in major surgery, a thorough investigation into COPD's impact on infrainguinal bypass outcomes remained underexplored. Thus, this study aimed to assess the 30-day outcomes for COPD patients undergoing infrainguinal bypass surgery.

METHODS

COPD and non-COPD patients who underwent infrainguinal bypass were identified in American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2011 to 2022. Patients of age<18 were excluded. A 1:1 propensity-score matching was used to match demographics, baseline characteristics, symptomatology, procedure, conduit, and anesthesia. Thirty postoperative outcomes were compared.

RESULTS

There were 3,183 (12.64%) and 22,004 (87.36%) patients with and without COPD, respectively, who underwent infrainguinal bypass. COPD patients had a higher comorbid burden. After propensity-score matching, COPD patients had higher sepsis (3.55% vs 2.42%, p = 0.01), wound complications (18.94% vs 16.40%, p = 0.01), and 30-day readmission (18.00% vs 14.92%, p < 0.01). However, COPD and non-COPD patients had comparable 30-day mortality (2.54% vs 2.67%, p = 0.81), and organ system complications including cardiac (3.58% vs 3.99%, p = 0.43), pulmonary (3.96% vs 3.20%, p = 0.12), and renal complications (1.70% vs 1.82%, p = 0.78). Limb-specific outcomes including major amputation (2.95% vs 2.50%, p = 0.30), untreated loss of patency (1.85% vs 1.38%, p = 0.16), and patent graft (98.24% vs 98.65%, p = 0.27) were also comparable between the cohorts.

CONCLUSION

While COPD might be associated with the development of PAD due to potentially shared pathophysiology, it may not be an independent risk factor for the major 30-day outcomes in infrainguinal bypass surgery.

Using Vascular Deserts as a Guide for Limb Preservation Outreach Programs Successfully Targets Underserved Populations

BACKGROUND

Vascular deserts, regions without vascular providers, previously described targets for limb salvage efforts. The Comprehensive Heart and Multidisciplinary Limb Preservation Outreach Networks (CHAMPIONS) programs targeted regions for outreach and evaluated the population using desert maps.

METHODS

At 2 events targeting underserved regions between 2022 and 2023, providers screened and educated participants on peripheral arterial and cardiovascular disease (PACD). Demographics and cardiovascular risk factors were collected. Using Arc geographic information system, vascular surgeons, and Vascular Quality Initiative (VQI) participating facilities were mapped with a 30-mile buffer. Participants were mapped with census data, and the healthy places index (HPI) was overlayed for population and social determinants of health data analysis in medical service study areas (MSSA), a geographical analysis unit. (Figure 1) Results were compared to prior statewide deserts.

RESULTS

Outreach program participants' mean age was 56 (range 6-88); 39% were male, and the majority were Hispanic (86%). 27% had no primary care provider (PCP). 30% had diabetes, 10% undiagnosed before the event, 38% had hypertension, 40% undiagnosed prior to the event, and 21% described intermittent claudication. 81% made <$30,000 annually, and 28% reported no health insurance. Similarities were observed when comparing program participant demographics to the population-level data from the targeted regions. Patients were more frequently Hispanic than other desert regions (68% vs. 36%, P < 0.001). Compared to other vascular desert regions, the target population was more disadvantaged in all HPI domains, including economic (18 vs. 38%, P < 0.001), education (21 vs. 39%, P < 0.001), and transportation (30 vs. 40%, P < 0.001). Worse education, financial, and transportation resources correspond to decreased care access due to poor literacy and travel burdens.

CONCLUSIONS

CHAMPIONS programs successfully targeted populations needing care based on vascular care desert maps, demonstrating that at-risk populations can be successfully identified and screened for cardiovascular disease.

Peripheral artery disease is an independent risk factor for higher in-hospital mortality in Stanford type A aortic dissection repair

BACKGROUND

Type A aortic dissection (TAAD) is an emergent condition that warrants immediate intervention. Peripheral artery disease (PAD) is a prevalent disease associated with worse outcomes in various cardiovascular procedures. However, it remains unclear whether PAD influences outcomes of TAAD repair. This study aimed to undertake a population-based analysis to assess impact of PAD on in-hospital outcomes following TAAD repair.

METHODS

Patients underwent TAAD repair were identified in National Inpatient Sample from Q4 2015 to 2020. Multivariable logistic regressions were used to compare in-hospital outcomes between patients with and without PAD, adjusted for demographics, socioeconomic status, primary payer status, hospital characteristics, comorbidities, and transfer/admission status.

RESULTS

1525 patients with PAD and 2757 non-PAD patients underwent TAAD. PAD patients had higher mortality (18.62% vs 13.17%, aOR = 1.287, p = .01), AKI (51.41% vs 47.48%, aOR = 1.222, p < .01), infection (10.69% vs 8.02%, aOR = 1.269, p = .03), and vascular complication (7.28% vs 3.77%, aOR = 1.846, p < .01) but lower risks of pericardial complications (15.21% vs 19.95%, aOR = 0.696, p < .01). In addition, patients with PAD had longer time from admission to operation (1.29 ± 3.95 vs 0.70 ± 2.09 days, p < .01), longer LOS (14.92 ± 13.98 vs 13.41 ± 11.66 days, p = .01), and higher hospital charge (499,064 ± 519,405 vs 409,754 ± 405,663 US dollars, p < .01).

CONCLUSION

PAD was independently associated with worse outcome after TAAD repair. The elevated mortality rate could be attributed to the delay in surgery, which may be related to preoperative peripheral malperfusion syndrome that is common in PAD patients. A balance between preoperative management and immediate TAAD repair might be essential to prevent the increased mortality risk from treatment delays among PAD patients.

Racial and ethnic representation in peripheral artery disease randomized clinical trials

Clinical trial enrollment provides various benefits to study participants including early access to novel therapies that may potentially alter the trajectory of disease states. Trial sponsors benefit from enrolling demographically diverse trial participants enabling the trial outcomes to be generalizable to a larger proportion of the community at large. Despite these and other well-documented benefits, clinical trial enrollment for Black and Hispanic Americans as well as women continues to be low. Specific disease states such as peripheral artery disease (PAD) have a higher prevalence and clinical outcomes are relatively worse in Black Americans compared with non-Hispanic white Americans. The recruitment process for PAD clinical trials can be costly and challenging and usually comes at the expense of representation. Participant willingness and trust, engagement, and socioeconomic status play essential roles in the representation of under-represented minority (URM) groups. Despite the contrary belief, URM groups such as Blacks and Hispanics are just as willing to participate in a clinical trial as non-Hispanic Whites. However, financial burdens, cultural barriers, and inadequate health literacy and education may impede URMs' access to clinical trials and medical care. Clinical trials' enrollment sites often pose transportation barriers and challenges that negatively impact creating a diverse study population. Lack of diversity among a trial population can stem from the stakeholder level, where corporate sponsors of academic readers do not consider diversity in clinical trials a priority due to false cost-benefit assumptions. The funding source may also impact the racial reporting or the results of a given trial. Industry-based trials have always been criticized for over-representing non-Hispanic White populations, driven by the desire to reach high completion rates with minimum financial burdens. Real efforts are warranted to ensure adequate minorities' representation in the PAD clinical trials and to the process toward the ultimate goal of developing more durable and effective PAD treatments that fit the needs of real-world populations.

Effects of short-term dietary nitrate supplementation on exercise and coronary blood flow responses in patients with peripheral artery disease

Background

Peripheral arterial disease (PAD) is a prevalent vascular disorder characterized by atherosclerotic occlusion of peripheral arteries, resulting in reduced blood flow to the lower extremities and poor walking ability. Older patients with PAD are also at a markedly increased risk of cardiovascular events, including myocardial infarction. Recent evidence indicates that inorganic nitrate supplementation, which is abundant in certain vegetables, augments nitric oxide (NO) bioavailability and may have beneficial effects on walking, blood pressure, and vascular function in patients with PAD.

Objective

We sought to determine if short-term nitrate supplementation (via beetroot juice) improves peak treadmill time and coronary hyperemic responses to plantar flexion exercise relative to placebo (nitrate-depleted juice) in older patients with PAD. The primary endpoints were peak treadmill time and the peak coronary hyperemic response to plantar flexion exercise.

Methods

Eleven PAD patients (52-80 yr.; 9 men/2 women; Fontaine stage II) were randomized (double-blind) to either nitrate-rich (Beet-IT, 0.3 g inorganic nitrate twice/day; BRnitrate) or nitrate-depleted (Beet-IT, 0.04 g inorganic nitrate twice/day, BRplacebo) beetroot juice for 4 to 6 days, followed by a washout of 7 to 14 days before crossing over to the other treatment. Patients completed graded plantar flexion exercise with their most symptomatic leg to fatigue, followed by isometric handgrip until volitional fatigue at 40% of maximum on day 4 of supplementation, and a treadmill test to peak exertion 1-2 days later while continuing supplementation. Hemodynamics and exercise tolerance, and coronary blood flow velocity (CBV) responses were measured.

Results

Although peak walking time and claudication onset time during treadmill exercise did not differ significantly between BRplacebo and BRnitrate, the diastolic blood pressure response at the peak treadmill walking stage was significantly lower in the BRnitrate condition. Increases in CBV from baseline to peak plantar flexion exercise after BRplacebo and BRnitrate showed a trend for a greater increase in CBV at the peak workload of plantar flexion with BRnitrate (p = 0.06; Cohen's d = 0.56).

Conclusion

Overall, these preliminary findings suggest that inorganic nitrate supplementation in PAD patients is safe, well-tolerated, and may improve the coronary hyperemic and blood pressure responses when their calf muscles are most predisposed to ischemia.Clinical trial registration:https://clinicaltrials.gov/, identifier NCT02553733.

The lack of ethnic and racial diversity among patients undergoing coronary artery calcium scanning

BACKGROUND

While coronary artery calcium (CAC) CAC scanning has become increasingly used as a tool for primary cardiovascular disease prevention, there has been little study regarding its comparative utilization among ethnic and racial minorities.

METHODS

We contrasted the temporal trends in the ethnoracial composition for 73,856 out-patients undergoing stress/rest radionuclide myocardial perfusion imaging (MPI) between 1991 and 2020 and 32,906 undergoing CAC scanning between 1998 and 2020. Both groups were divided into those below and above 65 years. Initial medical insurance claims were used to identify which patients self-paid for SPECT-MPI and CAC studies.

RESULTS

Among stress-MPI patients <65 years, the prevalence of White patients declined from 85.5% to 54.0% over the temporal span of our study while the prevalence of Blacks increased from 7.2% to 15.1% and that of Hispanics from 2.3 to 21.6%. Increasing ethnoracial diversification was also noted for SPECT-MPI patients ≥65 years. By contrast, over four-fifths of CAC studies were performed in White patients in each temporal period among both younger and older patients. Among CAC patients <65 years, over 95% of studies were self-paid by patients. For CAC patients ≥65 years, nearly two-third of studies were first submitted to Medicare, but there was no difference in the ethnoracial composition in this group versus initial self-paying patients.

CONCLUSIONS

While the ethnoracial diversity of patients undergoing SPECT-MPI markedly increased at our Institution over recent decades, CAC scanning has been disproportionately and consistently utilized by self-paying White patients. These findings highlight the need to make CAC scanning more available among ethnoracial minorities.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

Evaluating the impact of an interdisciplinary integrated limb preservation service operating concurrently with a single-specialty service

BACKGROUND

This study examined the efficacy of an interdisciplinary limb preservation service (LPS) in improving surgical outcomes for diabetic foot ulcer (DFU) patients compared to traditional care.

METHODS

Data from January 1, 2017 to September 30, 2020 were retrospectively reviewed. An interdisciplinary LPS clinic began on August 1, 2018, coexisting with a preexisting single specialty service. Primary outcomes were major/minor amputation rates and ratios and hospital length of stay. Surgical endpoints pre- and post-LPS launch were compared.

RESULTS

Among 976 procedures for 731 unique DFU patients, most were male (80.4%) and Hispanic (89.3%). Patient demographics were consistent before and after LPS initiation. Major amputation rates decreased by 45.5% (15.4%-8.4%, p = 0.001), with outpatient procedures increasing over 5-fold (3.3% pre-LPS to 18.7% post-LPS, p < 0.001). Hospital stay reduced from 10.1 to 8.5 days post-LPS (p < 0.001). The major to minor amputation ratio declined from 22.4% to 12.7%.

CONCLUSIONS

The interdisciplinary LPS improved patient outcomes, marked by fewer major amputations and reduced hospital stays, suggesting the model's potential for broader application.

Overview and comparison of contemporary Society for Vascular Surgery, American Heart Association/American College of Cardiology, and European Society for Vascular Surgery guidelines for the management of patients with intermittent claudication

Intermittent claudication (IC) is a phenotype of peripheral artery disease that is characterized by pain in the lower extremity muscles during activity that is relieved by rest. Medical management, risk factor control, smoking cessation, and exercise therapy have historically been the mainstays of treatment for IC, but advances in endovascular technology have led to increasing use of peripheral vascular interventions in this patient population. There are meaningful differences in published society guidelines and appropriate use criteria relevant to the management of IC, especially regarding indications for peripheral vascular interventions. The current review aims to highlight similarities and differences between major society recommendations for the management of IC, and to discuss practice trends, disparities, and evidence gaps in the use of peripheral vascular interventions for IC in the context of existing guidelines.

Impact of regional differences and neighborhood socioeconomic deprivation on the outcomes of patients with lower extremity wounds evaluated by a limb-preservation service

OBJECTIVE

Management of lower extremity (LE) wounds has evolved with the establishment of specialized limb preservation services. Although clinical factors contribute to limb outcomes, socioeconomic status and community factors also influence the risk for limb loss. The Distressed Community Index (DCI) score is a validated index of social deprivation created to provide an objective measure of economic well-being in United States communities. Few studies have examined the influence of geographic deprivation on outcomes in patients with LE wounds. We examined relationships between socioeconomic deprivation and outcomes of inpatients evaluated by a dedicated limb preservation service (Functional Limb Extremity Service [FLEX]).

METHODS

Inpatients referred to FLEX over a 5-year period were included. Wound, Ischemia, foot Infection (WIfI) staging was collected. DCI scores were determined using seven indices based on ZIP Code. Outcomes included any minor or major amputations, any endovascular or open LE revascularization, or wound care procedures. Disease etiology, demographic, and anthropometric data were collected. Associations between neighborhood deprivation and limb-specific outcomes were evaluated in models for the DCI and each of its components separately.

RESULTS

A total of 677 patients were included. Thirty-eight percent were female, with a mean age of 64 years. Sixty percent had WIfI stage 3 or 4 risk of amputation, and 43% had WIfI stage 3 or 4 risk of revascularization. Mean ankle-brachial index and toe pressure were 0.96 (standard deviation [SD], 0.43) and 80 (SD, 57) mmHg. Thirty-five percent were non-White. Amputation was performed in 31% of patients, whereas 17% underwent revascularization. The mean distress score was 64 (SD, 24). Mean DCI scores did not differ across WIfI scores. Likewise, overall DCI distress score was not related to any of the outcomes in univariable or multivariable linear regression models. In univariable linear regression models for amputation, higher poverty rate (odds ratio for SD increase 1.20; 95% confidence interval, 1.02-1.42; P = .025) was significantly associated with the outcome. In multivariable models, neither DCI distress score nor any of its components remained significantly associated with the outcome.

CONCLUSIONS

Despite known racial disparities in limb-specific outcomes, an aggregate measure of community level distress was not found to be related to outcomes. Although the poverty rate demonstrated a significant relationship with amputation in univariable analysis, this association was not found in multivariable models. Notably, non-White race emerged as a predictor of amputation, underscoring the importance of addressing racial disparities in LE outcomes. Further investigation of potential determinants of LE outcomes is needed, particularly the interaction of such factors with race.

Towards a Remote Patient Monitoring Platform for Comprehensive Risk Evaluations for People with Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) significantly affect the lives of patients and increase the risk of hospital stays and amputation. We suggest a remote monitoring platform for better DFU care. This system uses digital health metrics (scaled from 0 to 10, where higher scores indicate a greater risk of slow healing) to provide a comprehensive overview through a visual interface. The platform features smart offloading devices that capture behavioral metrics such as offloading adherence, daily steps, and cadence. Coupled with remotely measurable frailty and phenotypic metrics, it offers an in-depth patient profile. Additional demographic data, characteristics of the wound, and clinical parameters, such as cognitive function, were integrated, contributing to a comprehensive risk factor profile. We evaluated the feasibility of this platform with 124 DFU patients over 12 weeks; 39% experienced unfavorable outcomes such as dropout, adverse events, or non-healing. Digital biomarkers were benchmarked (0-10); categorized as low, medium, and high risk for unfavorable outcomes; and visually represented using color-coded radar plots. The initial results of the case reports illustrate the value of this holistic visualization to pinpoint the underlying risk factors for unfavorable outcomes, including a high number of steps, poor adherence, and cognitive impairment. Although future studies are needed to validate the effectiveness of this visualization in personalizing care and improving wound outcomes, early results in identifying risk factors for unfavorable outcomes are promising.

Assessment of causal associations between obesity and peripheral artery disease: a bidirectional Mendelian randomization study

Background

Several observational studies have documented a potential link between obesity and peripheral artery disease (PAD), although conflicting findings exist. The causal relationship between obesity and PAD continues to be a subject of ongoing debate in the medical community.

Objectives

In this study, we employed a bidirectional Mendelian randomization (MR) analysis to explore the potential causal relationship between obesity and the risk of PAD.

Methods

To investigate these causal relationships, we conducted bidirectional MR analysis using publicly available genome-wide association study (GWAS) data. Effect estimates were calculated using the random-effects inverse variance-weighted (IVW) method.

Results

We identified eight independent single nucleotide polymorphisms (SNPs) associated with obesity in 218,735 samples involving 16,380,465 SNPs, all of which met the genome-wide significance threshold (p < 5 × 10-⁸). The IVW analysis indicates a significant positive association between genetic obesity and multiple datasets with PAD as the outcome: Queue-1 (GWAS ID: finn-b-I9_PAD) (OR = 1.138, 95% CI: 1.027-1.261, p = 0.013), Queue-2 (GWAS ID: bbj-a-144) (OR = 1.190, 95% CI: 1.019-1.390, p = 0.028), Queue-3 (GWAS ID: ebi-a-GCST90018670) (OR = 1.174, 95% CI: 1.014-1.360, p = 0.032), and Queue-4 (GWAS ID: ebi-a-GCST90018890) (OR = 1.194, 95% CI: 1.099-1.296, p < 0.001). However, we did not observe a significant genetic-level association between obesity and PAD for Queue-5 (GWAS ID: ukb-d-I9_PAD) (OR = 1.001, 95% CI: 1.000-1.002, p = 0.071). Furthermore, we conducted a reverse causal MR analysis to explore the potential reverse causal relationship between obesity and PAD. This comprehensive analysis did not provide evidence of a reverse causal association between these two factors.

Conclusions

In summary, our study offers genetic evidence suggesting a possible causal link between obesity and PAD. While we did not find evidence supporting the "obesity paradox", prudent weight management remains crucial, as lower weight does not necessarily guarantee better outcomes. As with any study, caution is required in interpreting the findings. Further research is essential to assess the clinical relevance of weight in preventing PAD, which could inform the development of more precise intervention strategies.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Development of 3D printed electrospun vascular graft loaded with tetramethylpyrazine for reducing thrombosis and restraining aneurysmal dilatation

Background

Small-diameter vascular grafts have become the focus of attention in tissue engineering. Thrombosis and aneurysmal dilatation are the two major complications of the loss of vascular access after surgery. Therefore, we focused on fabricating 3D printed electrospun vascular grafts loaded with tetramethylpyrazine (TMP) to overcome these limitations.

Methods

Based on electrospinning and 3D printing, 3D-printed electrospun vascular grafts loaded with TMP were fabricated. The inner layer of the graft was composed of electrospun poly(L-lactic-co-caprolactone) (PLCL) nanofibers and the outer layer consisted of 3D printed polycaprolactone (PCL) microfibers. The characterization and mechanical properties were tested. The blood compatibility and in vitro cytocompatibility of the grafts were also evaluated. Additionally, rat abdominal aortas were replaced with these 3D-printed electrospun grafts to evaluate their biosafety.

Results

Mechanical tests demonstrated that the addition of PCL microfibers could improve the mechanical properties. In vitro experimental data proved that the introduction of TMP effectively inhibited platelet adhesion. Afterwards, rat abdominal aorta was replaced with 3D-printed electrospun grafts. The 3D-printed electrospun graft loaded with TMP showed good biocompatibility and mechanical strength within 6 months and maintained substantial patency without the occurrence of acute thrombosis. Moreover, no obvious aneurysmal dilatation was observed.

Conclusions

The study demonstrated that 3D-printed electrospun vascular grafts loaded with TMP may have the potential for injured vascular healing.

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.

Factors Associated With Myocardial Infarction in a Rural Population With Peripheral Arterial Diseases

Peripheral arterial disease (PAD) studies in rural populations are limited. The incidence of myocardial infarction (MI) is higher in patients with PAD. This study examined the association between sociodemographic and clinical risk factors and MI in patients with PAD in Central Appalachia, comprising of 230 counties across six states in the United States. Data from electronic medical records of 13,455 patients with PAD were extracted from a large health system in Central Appalachia. Bivariate and logistic regression analyses were conducted. The final sample consisted of 5574 patients with PAD, of whom 24.85% were also diagnosed with MI. The mean age was 71 ± 11.23 years, and the majority were male (56.40%). After adjusting for confounders, patients with hypertension had three times higher odds of MI (adjusted Odds Ratio [aOR] = 3.21; 95% CI: 2.50-4.14) compared with those without hypertension. The likelihood of MI increased by 51% among patients with diabetes (aOR = 1.51; 95% CI: 1.33-1.71), 34% among ever-smokers (aOR = 1.34; 95% CI: 1.18-1.52), and 45% in males (aOR = 1.45; 95% CI: 1.27-1.65). Hypertension, diabetes, smoking, and male sex were identified as significant risk factors for MI. Screening and effective management of these risk factors in rural areas could potentially prevent MI incidence among patients with PAD.

Microbiome of limb-threatening diabetic foot ulcers indicates the association of fastidious Stenotrophomonas and major amputation

BACKGROUND

Proper identification of the polymicrobial microorganisms in patients with limb-threatening diabetic foot ulcers (LTDFUs) using conventional culture is insufficient. This prospective study evaluates the potential value of adjuvant molecular testing assisting in identify fastidious micro-organisms in LTDFUs compared to standard treatment alone.

METHODS

Ninety patients with LTDFUs received interdisciplinary and standard antibiotic treatment in a referral diabetic foot center. A simultaneous 16S amplicon sequencing (16S AS) specimen along with conventional culture collected at admission was used to retrospectively evaluate the microbiological findings and its association with amputation outcomes.

RESULTS

The microorganism count revealed by 16S AS overwhelmed that of conventional culturing (17 vs. 3 bacteria/ulcer respectively). The Stenotrophomonas spp. revealed in 29 patients were highly correlated with major (above ankle) amputation (OR: 4.76, 95% CI 1.01-22.56), while only one had been concomitantly identified by conventional culturing. Thus, there were 27 cases without proper antibiotics coverage during treatment.

CONCLUSIONS

Adjuvant molecular testing assisted identification of fastidious pathogens such as Stenotrophomonas infection and might be associated with major amputation in patients with LTDFUs.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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.