Reducing Nontraumatic Lower-Extremity Amputations by 20% by 2030: Time to Get to Our Feet: A Policy Statement From the American Heart Association

Trends in lower extremity peripheral arterial disease incidence since 1990 and forecasting future statistics using Global Burden of Disease 2021: a time-series analysis

Background

Lower extremity peripheral arterial disease (LEPAD) significantly affects quality of life and is associated with severe cardiovascular risks. Studies on its long-term incidence trends are limited.

Objective

This study aims to analyze global trends in LEPAD incidence from 1990 to 2021 using the Global Burden of Disease (GBD) 2021 database and to forecast future trends between 2022 and 2030, providing insights for healthcare planning and resource allocation.

Methods

Data were extracted from the GBD 2021 database by genders, age groups, continents, and sociodemographic index (SDI) levels. Using Joinpoint regression analysis, annual percentage changes (APC) and average annual percentage changes (AAPC) were calculated to assess age-standardized incidence rates (ASIR) historical trends. Autoregressive integrated moving average (ARIMA) model was applied to predict ASIR between 2022 and 2030.

Results

The global ASIR of LEPAD showed a slight decrease from 1990 to 2021, though regional differences were notable. In 2021, the highest ASIR was in the Americas, while Africa had the lowest. Gender and age disparities were significant, and females and older populations were at higher risk. ARIMA predictions indicate a stable ASIR trend from 2025 onward.

Conclusion

This study provides a comprehensive analysis of LEPAD incidence trends and a forecast through 2030. While global incidence may stabilize, the rising burden in lower-income countries calls for prioritizing early intervention and health education in high-risk regions. These findings emphasize the importance of targeted resource allocation and strategic prevention efforts.

New horizons in nuclear cardiology: Imaging of peripheral arterial disease

Lower extremity peripheral artery disease (PAD) is characterized by impairment of blood flow associated with arterial stenosis and frequently coexisting microvascular disease and is associated with high rates of morbidity and mortality. Current diagnostic modalities have limited accuracy in early diagnosis, risk stratification, preprocedural assessment, and evaluation of therapy and are focused on the detection of obstructive atherosclerotic disease. Early diagnosis and assessment of both large vessels and microcirculation may improve risk stratification and guide therapeutic interventions. Single-photon emission computed tomography and positron emission tomography imaging have been shown to be accurate to detect changes in perfusion in preclinical models and clinical disease, and have the potential to overcome limitations of existing diagnostic modalities, while offering novel information about perfusion, metabolic, and molecular processes. This review provides a comprehensive reassessment of radiotracer-based imaging of PAD in preclinical and clinical studies, emphasizing the challenges that arise due to the complex physiology in the peripheral vasculature. We will also highlight the latest advancements, underscoring emerging artificial intelligence and big data analysis, as well as clinically relevant areas where the field could advance in the next decade.

Ankle Peak Systolic Velocity Correlates with Toe Pressure in Patients with Peripheral Artery Disease

BACKGROUND

Conventional screening of Peripheral Artery Disease (PAD) with Ankle Brachial Index may be limited in diabetic patients due to arterial calcification. Alternatively, ankle peak systolic velocity (APSV) may be a more accurate measure of limb perfusion in those patients. This study aims to assess the correlation between APSV and toe pressure (TP) in patients evaluated for PAD.

METHODS

This is a single-center retrospective study examining the correlation between APSV and TP in patients evaluated for PAD at a tertiary medical center between January 2019 and August 2020. Spearman Correlation and multivariate linear regression were used to assess the association between APSV and TP. The optimal cutoffs for APSV corresponding to TP of 30 mm Hg and 50 mm Hg were generated using the Youden index.

RESULTS

A total of 224 patients with median age of 72 years were included in this study. 61% of patients were females and 54% were diabetic. The mean APSV of the overall population was 62 cm/s. APSV was significantly correlated with TP (R = 0.6, P < 0.001) in both diabetic and nondiabetic patients. On multivariate analysis, TP was significantly associated with APSV (estimate B 0.41, 95% confidence interval 0.29-0.53, P < 0.001). The optimal cutoffs of APSV to detect a TP ≤ 30 mm Hg and TP ≥ 50 mm Hg were 35 cm/s and 44 cm/s, respectively.

CONCLUSION

APSV is a reliable measure for evaluating perfusion in PAD patients. Its adoption in the clinical setting can significantly improve the accuracy of PAD diagnosis, allowing earlier detection and treatment.

Applying mobility prediction models to real-world patients with major amputations

BACKGROUND

Outcome prediction models (PMs) have become commonplace and are promoted to aid in counseling patients. The aim of this study is to evaluate the performance of existing mobility PMs for post-major amputation (MA) patients in a real-world, socioeconomically disadvantaged population.

METHODS

A retrospective review of patients with MA secondary to peripheral arterial disease from 2016 to 2022 was performed. Patients who were nonambulatory before MA or with contralateral MA were excluded. Three published PMs were investigated: (1) AmpPredict (predicts 1-year mobility), (2) Amputee Single Item Mobility Measure, (predicts degree of mobility with prosthesis at 1 year), both derived from Veteran's Affairs data, and (3) a Vascular Quality Initiative (VQI) data-derived model (predicts 1-year mobility). Predicted mobility rates vs actual mobility rates were compared.

RESULTS

The study cohort consisted of 126 patients, 71% male, 60% non-White race, with a mean state Area Deprivation Index of 9 of 10. Baseline characteristics were significantly different between the study and derivation cohorts. Actual mobility at 1 year was 43%. Of the 38 patients with an AmpPredict 1-year mobility of ≥70%, 45% actually achieved mobility. Of 101 patients with a high predicted probability from the VQI score (≥71%), 48% achieved mobility. The mean difference between AmpPredict and VQI for a given patient was 36% (range, 1%-81%). The Amputee Single Item Mobility Measure predicted 87% of patients would be community (vs home) ambulators at 1 year and 32% of patients actually achieved community ambulation (sensitivity of 91%, specificity of 14%, positive predictive value of 33%, and negative predictive value of 79%).

CONCLUSIONS

Published models dramatically overestimated the likelihood of mobility in our patient cohort. This result may be related to the demographics and comorbidities of our cohort being significantly different from the derivation cohorts. We recommend caution when applying PMs to a population with significantly different characteristics from the population used to derive the model.

Cost-Effectiveness Analysis for Managing Diabetic Foot Ulcer (DFU) in USA: Platelet-Rich Plasma (PRP) vs Standard of Care (SoC)

Purpose

Chronic skin ulcers in diabetic foot patients are a significant health concern. Diabetic foot ulcers (DFUs) significantly threaten the health and longevity of individuals with diabetes, leading to severe complications like infection and amputation and contributing to high morbidity and mortality rates. Given the severe implications, practical strategies to prevent and manage DFUs are crucial to reducing amputation rates. Platelet-rich plasma (PRP) has emerged as a popular treatment option due to its properties that mimic the body's natural healing process. The objective of the study was to evaluate the cost-effectiveness of PRPR vs standard of care in US context.

Methods

Decision analytical model was used to synthesize clinical and economic parameters. In detail a CEA analysis was employed using a Markov decision-making model to evaluate patients with chronic DFUs lasting over three weeks and at high risk for orthopedic complications. The study assessed the effectiveness of different treatments, measured in quality-adjusted life years (QALYs), and reported costs in 2023 dollars using a micro-costing approach alongside a clinical trial.

Results

The study concluded that PRP gel is a cost-effective treatment for non-healing DFUs, resulting in lower care costs over one year compared to other treatments and cost savings over five years.

Conclusion

Thus, PRP treatment is a promising and practical option, improving patient outcomes and reducing healthcare costs. It is an attractive choice for healthcare providers and insurers in managing non-healing diabetic foot ulcers.

A scoping review of limb preservation interventions with primary care providers caring for US Indigenous patients with diabetes and peripheral artery disease

Amputation disparities due to diabetes and peripheral artery disease occur among vulnerable and historically mistreated populations. In Oklahoma, some of the highest amputation rates occur in Indigenous residents. Knowing that primary care providers are often the first to tackle prevention and assess at-risk limbs, we sought to understand the historical efforts made by primary care providers in this high-risk population. This scoping review evaluates the literature to summarize prior amputation prevention interventions and their characteristics, including the outcome metrics used among Indigenous populations in the United States. We searched MEDLINE using a combination of Medical Subject Headings and keywords related to amputation, limb preservation, limb salvage, and American Indian and Indigenous health inequities or disparities and ethnicity. We conducted our final search on October 4, 2024, including articles in English and those that focused on primary care practice-based interventions. We excluded case reports, trauma- or oncologic-related amputations, or articles describing interventions not conducted in the United States. We identified 404 articles and 3 fit the review criteria. All interventions were analyses of programs to improve diabetes care. All interventions occurred between 1986 and 2001 and were multilevel in structure. Intervention strategies used included expanded infrastructure, provider and patient education, implementation of clinical workflow and provider metrics, community awareness projects, foot-care expertise and footwear, and field visits. No interventions specifically targeted peripheral artery disease. This scoping review identifies a significant contemporary gap in amputation reduction interventions among Indigenous populations in the United States and highlights multiple areas where interventions may be needed to combat ongoing amputation disparities for a high-risk population.

Institutional toe & flow programs: How and why the teams work

Diabetic foot ulcers with or without concomitant chronic limb-threatening ischemia put patients at exceedingly high risk of limb loss and death. The toe & flow model is a multidisciplinary team-based model captained by a podiatrist or orthopedic foot and ankle specialist and a vascular specialist, which streamlines treatment for patients with diabetic foot ulcer and chronic limb-threatening ischemia. This model creates a functional ecosystem around it by integrating other medical professionals and community partners. It provides a high standard of care first via community education and engagement. It eliminates barriers to access between it and the community by establishing clear referral pathways. This model uses the best available evidence to create treatment pathways governing the patient trajectory through different stage of disease. Once acute treatment is provided, it aims to consolidate success and disease remission through aggressive surveillance and collaboration with the community. An important aspect of this model is that it collects and reports its outcomes and serves as an educational hub within its region. It ultimately aims to develop national policies and allocate resources to continue to improve. This review sheds light on successes associated with institutional toe & flow programs.

Association between guideline-directed medical therapy and reintervention risk following peripheral vascular interventions in patients with peripheral artery disease

INTRODUCTION

Reintervention following peripheral vascular intervention (PVI) for peripheral artery disease (PAD) is common. Guideline-directed medical therapy (GDMT) is recommended post-PVI, yet its association with reintervention outcomes remains unclear.

METHODS

We analyzed Vascular Quality Initiative registry data linked with Medicare outcome for patients undergoing PVI for PAD (2017-2018). GDMT was defined as the receipt of statin, antiplatelet, and angiotensin-converting enzyme or angiotensin receptor blocker (ACE/ARB) therapy if hypertensive at discharge. Competing risk analyses and conditional risk models assessed the reintervention outcome, and the recurrent reintervention outcomes within 2 years, by GDMT receipt, compliance with each GDMT element, the number of elements received, and GDMT rate across sites and operators in a 1:1 propensity score-matched cohort.

RESULTS

We included 13,244 patients (mean age 72.0 ± 9.9, women 41.0%). The reintervention outcome did not differ by GDMT receipt (cumulative incidence: 43.0% [95% CI 41.0-44.9%] in no GDMT vs 41.2% [95% CI 39.4- 43.0%] in GDMT; subhazard ratio (sHR): 1.03 [95% CI 0.97-1.10]), compliance with GDMT elements, the number of elements received, or site and operator GDMT rates (sHR per 10% increase: 1.00 [95% CI 0.98-1.03] and 1.00 [95% CI 0.98-1.02]) (all p > 0.05). However, a higher operator GDMT rate reduced the recurrent reintervention risk (HR: 0.98 [95% CI 0.97-1.00], p = 0.026).

CONCLUSION

Around 40% of patients undergoing a PVI experience reintervention within 2 years, but the outcome was not reduced with GDMT receipt, and higher GDMT rates by site and operators were not associated with reintervention risk. Future studies should focus on medication adherence, refills, and more granular GDMT data for PAD care surveillance postrevascularization.

Variations in Revascularization Strategies for Chronic Limb-Threatening Ischemia: A Nationwide Analysis of Medicare Beneficiaries

BACKGROUND

Recent data support both surgical-first and endovascular-first revascularization approaches for chronic limb-threatening ischemia (CLTI), but hospital-based practices are poorly described.

OBJECTIVES

This aim of this study was to characterize contemporary variations and outcomes associated with each strategy among U.S. hospitals providing both approaches.

METHODS

Medicare beneficiaries ≥66 years of age with CLTI treated at institutions offering both strategies between October 1, 2015 to December 31, 2021 were analyzed. A marginal Cox regression approach was used, and models were adjusted for patient-level covariates.

RESULTS

Among 196,070 patients at 1,832 institutions, 82.5% underwent endovascular treatment. Patients undergoing endovascular revascularization were older and had a higher comorbidity burden. The adjusted median OR for receiving an endovascular procedure was 2.32 among hospitals (Q1-Q3: 2.24-2.40; P < 0.01), demonstrating high variability in intervention use. Patients undergoing endovascular revascularization at the highest quintile hospitals had a lower rate of major amputation (adjusted HR [aHR]: 0.82; 95% CI: 0.77-0.88; P < 0.01) and a higher rate of repeat procedures (aHR: 1.37; 95% CI: 1.32-1.43; P < 0.01). Patients undergoing surgical bypass at the highest quintile hospitals had a higher rate of major amputation (aHR: 1.21; 95% CI: 1.13-1.29; P < 0.01) and a lower rate of repeat procedures (aHR: 0.73; 95% CI: 0.70-0.76; P < 0.01).

CONCLUSIONS

This study showed large interhospital variability in revascularization strategies, as well as improved outcomes for patients receiving endovascular treatment at higher volume sites. Further work is needed to standardize treatments with the goal of improving limb salvage rates.

Allogenic Vertebral Body Adherent Mesenchymal Stromal Cells Promote Muscle Recovery in Diabetic Mouse Model of Limb Ischemia

BACKGROUND

Chronic limb-threatening ischemia (CLTI) carries a significant risk for amputation, especially in diabetic patients with poor options for revascularization. Phase I trials have demonstrated efficacy of allogeneic mesenchymal stromal cells (MSC) in treating diabetic CLTI. Vertebral bone-adherent mesenchymal stromal cells (vBA-MSC) are derived from vertebral bodies of deceased organ donors, which offer the distinct advantage of providing a 1,000x greater yield compared to that of living donor bone aspiration. This study describes the effects of intramuscular injection of allogenic vBA-MSC in promoting limb perfusion and muscle recovery in a diabetic CLTI mouse model.

METHODS

A CLTI mouse model was created through unilateral ligation of the femoral artery in male polygenic diabetic TALLYHO mice. The treated mice were injected with vBA-MSC into the gracilis muscle of the ischemic limb 7 days post ligation. Gastrocnemius or tibialis muscle was assessed postmortem for fibrosis by collagen staining, capillary density via immunohistochemistry, and mRNA by quantitative real-time polymerase chain reaction (PCR). Laser Doppler perfusion imaging and plantar flexion muscle testing (MT) were performed to quantify changes in limb perfusion and muscle function.

RESULTS

Compared to vehicle (Veh) control, treated mice demonstrated indicators of muscle recovery, including decreased fibrosis, increased perfusion, muscle torque, and angiogenesis. PCR analysis of muscle obtained 7 and 30 days post vBA-MSC injection showed an upregulation in the expression of MyoD1 (P = 0.03) and MyH3 (P = 0.008) mRNA, representing muscle regeneration, vascular endothelial growth factor A (VEGF-A) (P = 0.002; P = 0.004) signifying angiogenesis as well as interleukin (IL-10) (P < 0.001), T regulatory cell marker Foxp3 (P = 0.04), and M2-biased macrophage marker Mrc1 (CD206) (P = 0.02).

CONCLUSIONS

These findings indicate human allogeneic vBA-MSC ameliorate ischemic muscle damage and rescue muscle function. These results in a murine model will enable further studies to develop potential therapies for diabetic CLTI patients.

Quantification of the Survival Disadvantage Associated with Major Amputation in Patients with Peripheral Arterial Disease

Objective: Despite advancements in vascular surgery, the mortality among peripheral arterial disease (PAD) patients undergoing major amputations remains high. While a large body of evidence has previously covered survival rates after major amputation, there is less evidence regarding the associated survival penalty from an epidemiological perspective. The present analysis aimed at quantifying the survival disadvantage after major lower limb amputation while investigating which factors are associated with mortality in this patient cohort. Methods: Data from 246 PAD patients undergoing major amputations were retrospectively collected and matched with mortality records from the Austrian National Death Registry. Life expectancy was estimated using population-based life tables, and differences between observed and expected survival were analyzed across subgroups. Results: The median follow-up was 492 days (Q1-Q3: 73-1438), and 82.5% (n = 203) of patients died, with cardiovascular events being the leading cause (41%). A profound discrepancy between estimated (4697 days, Q1-Q3: 2962-6236) and observed survival (457 days, Q1-Q3: 73-1438, p < 0.001) was seen. In men, an associated median survival penalty of 11.2 years was observed, equivalent to a proportionate reduction in life expectancy of over 90%, while the difference in women was 8.7 years, equaling a reduction of 84.6%. In a multiple regression model, 1 year in life expectancy was associated with a survival penalty of -0.96 years, thereby affecting younger patients with the highest life expectancies the most. Conclusions: Major amputation in PAD patients is associated with a significant reduction in survival compared to standardized mortality rates in the general population. The survival disadvantage exceeds 70% of estimated survival times in over 70% of patients. Elevated mortality rates after major amputation in PAD patients should not be interpreted as a causal relationship but as a surrogate for impaired systemic cardiovascular health.

Descriptive Analysis of Types and Diagnoses Associated with Lower Extremity Amputation: Analysis of the US Veterans Health Administration Database 2019-2023

INTRODUCTION

Veterans in the US have higher rates of lower extremity amputation (LEA) compared to the general population and these rates have increased between 2008 and 2018. There is limited data which directly evaluate the potential underlying comorbidities associated with LEA in the veterans' population especially with the most recent data. Such information is critical to help inform clinical management strategies to reduce the risk of amputations among our veterans.

METHODS

This was a retrospective observational study of adults in the Veterans Health Administration database who underwent LEA from January 1, 2019 to December 31, 2023. The date of the first LEA procedure was defined as the index date. Index LEA type, patient demographic at baseline, and clinical characteristics (including diagnoses for conditions associated with LEA and other comorbidities) 1 year before and 30 days after the index LEA procedure (except for bacterial infections which the identification period was 30 days before and 30 days after the index LEA procedure) were described.

RESULTS

Of the 27,134 Veterans with LEA, 67.3% were ≥ 65 years of age, 97.0% were male, and 65.3% were non-Hispanic white. The most common type of LEA was transmetatarsal (52.9%), followed by toe (21.9%), above-knee (15.4%), and below-knee (9.8%). The most prevalent diagnoses associated with LEA were diabetes (81.6%), bacterial infections (79.1%), and peripheral artery disease (PAD; 63.3%). Only 15 Veterans (< 0.1%) had a diagnosis for combat-related injuries to lower extremities.

CONCLUSION

Diabetes and PAD are highly prevalent and among the main conditions associated with LEA among US Veterans. Earlier and more effective preventative and clinical management of these conditions offer an opportunity to significantly reduce the rates of LEA in this population.

Declining Incidence of Major Lower-Extremity Amputations in the Northern Danish Region Between 2016 and 2021: The Impact of Diabetes and Preventive Vascular Procedures

BACKGROUND

Preventing lower-extremity amputations (LEAs) is pivotal. In the present study, we aimed to examine the recent trends in nontraumatic LEAs seen in the Northern Danish Region.

METHODS

Using data from the regional Business Intelligence unit, we identified all nontraumatic LEAs (n = 689) performed in people above 50 years of age in the Northern Danish Region between January 2016 and December 2021 (approximately 600,000 inhabitants). Persons with diabetes (n = 26,025) were identified based on International Classification of Diseases-10 codes and data from the National Health Insurance Service Registry, while preventive vascular procedures (n = 1,097) were identified using surgical codes. Major LEA was defined as any amputation above the ankle. Incidence rates were expressed as events per 1,000 person-years. Trends were described as differences between the periods 2016-2018 and 2019-2021.

RESULTS

A total of 249 (36%) major LEAs were performed in people with diabetes. People with diabetes were younger (71 vs 77 years, P < 0.001) and more frequently male (70% versus 54%, P < 0.001). Between 2016-2018 and 2019-2021, the incidence of major LEA declined from 1.76 (95% CI: 1.75-1.76) to 1.39 (1.39-1.39) in people with diabetes and from 0.47 (0.47-0.47) to 0.20 (0.20-0.20) in people without diabetes (all P < 0.001). Simultaneously, the incidence of preventive vascular surgery increased from 2.26 (2.26-2.26) to 3.48 (3.48-3.48) in people with diabetes and declined slightly in people without 0.49 (0.49-0.49) to 0.47 (0.47-0.47) (all P < 0.001).

CONCLUSIONS

Despite significant declines in major LEA in both people with and without diabetes, most of the decline was driven by a large reduction in major LEAs in people without diabetes.

Racial and Socioeconomic Health Disparities in Peripheral Artery Disease

Peripheral artery disease (PAD) is a progressive atherosclerotic disease that causes lower extremity arterial stenosis or occlusion. Patients with PAD are at increased risk of myocardial infarction, stroke, limitations in ambulation, and amputation. Despite the advances in medicine and technology, the outcomes from PAD, including critical limb-threatening ischemia, acute limb ischemia amputation, and mortality, remain increased among specific racial and ethnic groups that have been historically marginalized in America, including Black, Hispanic, and American Indian individuals in the United States when compared with White persons. The purpose of this review is to summarize PAD literature that incorporates racial and ethnic disparities in PAD. There are a rising number of studies focused on the interface of racial and ethnic disparities and PAD. The majority of these studies are specifically focused on Black race, whereas there are limited studies focused on other minoritized racial and ethnic groups in the United States. The application of race and ethnicity has also been shown to play a synergistic role with socioeconomic status on PAD outcomes. Effective strategies focused on implementing policies that support quality measures and focus on social determinants of health have been shown to promote health equity and reduce disparities. Current evidence suggests that biological differences are less likely to be the leading cause of disparities in PAD between racial and ethnic groups compared with White Americans and supports a renewed focus on social determinants of health to achieve health equity.

Practice patterns of peripheral vascular interventions for peripheral artery disease in the office-based laboratory setting versus outpatient hospital

OBJECTIVE

Controversy exists regarding the value and limitations of different sites of service for peripheral artery disease treatment. We aimed to examine practice patterns associated with peripheral vascular interventions (PVIs) performed in the office-based laboratory (OBL) vs outpatient hospital site of service using a nationally representative database.

METHODS

Using 100% Medicare fee-for-service claims data, we identified all patients undergoing PVI for claudication or chronic limb-threatening ischemia (CLTI) between January 2017 and December 2022. We evaluated the associations of patient and procedure characteristics with site of service using multivariable hierarchical logistic regression. We used multinomial regression models to estimate the relative risk ratios (RRRs) of site of service and intervention type (angioplasty, stent, or atherectomy) and intervention anatomic level (iliac, femoropopliteal, or tibial) after adjusting for baseline patient characteristics and clustering by physician.

RESULTS

Of 848,526 PVI, 485,942 (57.3%) were performed in an OBL. OBL use increased significantly over time from 48.3% in 2017 to 65.5% in 2022 (P < .001). Patients treated in OBLs were more likely to be Black (adjusted odds ratio [aOR], 1.14; 95% confidence interval [CI], 1.11-1.18) or other non-White race (aOR, 1.13; 95% CI, 1.08-1.18), have fewer comorbidities, and undergo treatment for claudication vs CLTI (aOR, 1.30; 95% CI, 1.26-1.33) compared with patients treated in outpatient hospital settings. Physicians with majority practice (>50% procedures) in an OBL were more likely to practice in urban settings (aOR, 21.58; 95% CI, 9.31-50.02), specialize in radiology (aOR, 18.15; 95% CI, 8.92- 36.92), and have high-volume PVI practices (aOR, 2.15; 95% CI, 2.10-2.29). The median time from diagnosis to treatment was shorter in OBLs, particularly for patients with CLTI (29 vs 39 days; P < .001). The OBL setting was the strongest predictor of patients receiving an atherectomy alone (adjusted RRR [aRRR] 6.67; 95% CI, 6.59-6.76) or atherectomy + stent (aRRR, 10.84; 95% CI, 10.64-11.05), and these findings were consistent in subgroup analyses stratified by PVI indication. The OBL setting was also associated with higher risk of tibial interventions for both claudication (aRRR, 3.18; 95% CI, 3.11-3.25) and CLTI (aRRR, 1.89; 95% CI, 1.86-1.92). The average reimbursement (including professional and facility fees) was slightly higher for OBLs compared with the hospital ($8742/case vs $8459/case; P < .001). However, in a simulated cohort resetting the OBL's intervention type distribution to that of the hospital, OBLs were associated with a hypothetical cost savings of $221,219,803 overall and $2602 per case.

CONCLUSIONS

The OBL site of service was associated with greater access to care for non-White patients and a shorter time from diagnosis to treatment, but more frequently performed high-cost interventions compared with the outpatient hospital setting. The benefit to patients from improved access to peripheral artery disease care in OBL settings must be balanced with the potential limitations of receiving differential care.

Successful revascularization of the occluded anterior tibial artery using ultrasound-guided puncture of the occluded dorsal pedal artery: A case report with literature review

A bidirectional approach is necessary for treating critical limb ischemia with complex, multiple lesions. We report an ultrasound-guided bidirectional puncture through an occluded vessel to treat an obstruction extending from the anterior tibial artery to the dorsal foot artery in a patient with toe gangrene and rest pain. This technique effectively restored arterial patency and is a promising approach for managing challenging critical limb ischemia occlusions.

Automated transtibial prosthesis alignment: A systematic review

This comprehensive systematic review critically analyzes the current progress and challenges in automating transtibial prosthesis alignment. The manual identification of alignment changes in prostheses has been found to lack reliability, necessitating the development of automated processes. Through a rigorous systematic search across major electronic databases, this review includes the highly relevant studies out of an initial pool of 2111 records. The findings highlight the urgent need for automated alignment systems in individuals with transtibial amputation. The selected studies represent cutting-edge research, employing diverse approaches such as advanced machine learning algorithms and innovative alignment tools, to automate the detection and adjustment of prosthesis alignment. Collectively, this review emphasizes the immense potential of automated transtibial prosthesis alignment systems to enhance alignment accuracy and significantly reduce human error. Furthermore, it identifies important limitations in the reviewed studies, serving as a catalyst for future research to address these gaps and explore alternative machine learning algorithms. The insights derived from this systematic review provide valuable guidance for researchers, clinicians, and developers aiming to propel the field of automated transtibial prosthesis alignment forward.

Using Multidisciplinary Teams to Improve Outcomes for Treating Chronic-Limb Threatening Ischemia

Multidisciplinary teams are necessary to treat complex patients with chronic limb-threatening ischemia (CLTI). The need for adequate wound care and control of comorbid conditions cannot be accomplished by the vascular specialist alone. Numerous specialties have a role in this group to include surgical podiatrists, orthopedic surgery, plastic and reconstructive surgery endocrinology, and wound care. However, the vascular specialist must drive this team as the patients are usually referred to them and numerous studies have shown a direct correlation between major amputations and the lack of vascular involvement. Creating these teams is unique in each community and must consider practice patterns that are relevant in the local region. CLTI is a challenging disease to manage, and multidisciplinary teams have demonstrated an ability to improve outcomes and deliver superior care to this patient population.

Clinical Comparison of Drug-Coated Balloon and Drug-Eluting Stent for Femoropopliteal Lesions in Chronic Limb-Threatening Ischemia With Wounds

BACKGROUND

Endovascular therapy (EVT) with devices such as drug-coated balloons (DCBs) and drug-eluting stents (DESs) for atherosclerotic disease in the femoropopliteal (FP) artery has been established. However, EVT using drug-based devices for chronic limb-threatening ischemia (CLTI) remains challenging. The optimal device for FP lesions in patients with CLTI remains unknown. This study compared the clinical efficacy of DCB and DES in patients with CLTI and FP lesions.

METHODS AND RESULTS

This retrospective single-center study included 539 consecutive patients (562 lesions) treated with EVT between January 2018 and December 2022; 166 patients with CLTI and Rutherford Class 5 or 6 wounds underwent EVT with DCB or DES. Clinical outcomes were compared between 53 pairs after propensity score matching. There were no significant differences between the DCB and DES groups in the incidence of complete wound healing without death or major amputation (84.8% vs. 80.2%, respectively; P=0.99), primary patency (69.4% vs. 75.6%, respectively; P=0.65), and freedom from target lesion revascularization at 1 year (78.6% vs. 78.0%, respectively; P=0.92). Multivariate analysis showed that complete wound healing at 1 year is negatively associated with hemodialysis and Wound, Ischemia, and foot Infection Stage 4, but positively associated with Global Limb Anatomic Staging System FP Grade 3 or 4.

CONCLUSIONS

No significant differences in clinical outcomes were found between DCB and DES for patients with CLTI and FP lesions.

Creation of a Limb Loss and Preservation Registry for Improving the Quality of Patient Care in the United States

Objective

To describe the development of a national Limb Loss and Preservation Registry (LLPR) designed to collect, standardize, and report patient outcomes data on limb loss and limb difference in the United States.

Design

Clinical Data Registry.

Setting

The LLPR was developed through consensus of key stakeholders from academia, industry, patient advocacy, and payers as well as the available scientific evidence. Data are collected from multiple sources, including hospitals, providers, and patients.

Participants

Data are collected from all 50 states.

Interventions

Not applicable.

Main Outcome Measures

More than 1100 trigger codes are used to identify patients who have limb difference or have received a limb preservation or amputation procedure. Once a patient is identified, all subsequent episodes of care are collected for the life of the patient. An integrated model is used for collecting, validating, cleaning, transforming, aggregating, and storing the data received from all sources. The information contained is then provided in a thorough and easily comprehensible manner.

Results

To date, the LLPR has captured data from >435,000 patients and >11.5 million episodes of care.

Conclusions

The LLPR creates opportunities to apply large-data analytical methodologies to provides caregivers, researchers, manufacturers, payers, and policy makers the tools needed to improve the quality of clinical care, quantify patient-centric outcomes, develop clinical practice guidelines, assess patient quality of life, identify appropriate technology, and guide creation of national policies to allocate scarce sources appropriately.

Prosthetic fitting and mortality after major lower extremity amputation

BACKGROUND

Studies suggest that ambulation after major lower extremity amputation (LEA) is low and mortality after LEA is high. Successful prosthetic fitting after LEA has a significant quality of life benefit; however, it is unclear if there are benefits in post-LEA mortality. Our objective was to examine a contemporary cohort of patients who underwent LEA and determine if there is an association between fitting for a prosthetic and mortality.

METHODS

We reviewed all patients who underwent LEA between 2015 and 2022 at two academic health care systems in a large metropolitan city. The exposure of interest was prosthetic fitting after LEA. The primary outcomes were mortality within 1 and 3 years of follow-up. Ambulation after LEA was defined as being ambulatory with or without an assistive device. Patients with prior LEA were excluded. Extended Cox models with time-dependent exposure were used to evaluate the association between prosthetic fitting and mortality at 1 and 3 years of follow-up.

RESULTS

Among 702 patients who underwent LEA, the mean (SD) age was 64.3 (12.6) years and 329 (46.6%) were fitted for prosthetic. The study population was mostly male (n = 488, 69.5%), predominantly non-Hispanic Black (n = 410, 58.4%), and nearly one-fifth were non-ambulatory before LEA (n = 139 [19.8%]). Of note, 14.3% of all subjects who were nonambulatory at some point after LEA, and 28.5% of patients not ambulatory preoperatively were eventually ambulatory after LEA. The rate of death among those fitted for a prosthetic was 12.0/100 person-years at 1 year and 5.8/100 person-years at 3 years of follow-up; among those not fitted for a prosthetic, the rate of death was 55.7/100 person-years and 50.7/100 person-years at 1 and 3 years of follow-up, respectively. After adjusting for several sociodemographic data points, comorbidities, pre- or post- coronavirus disease 2019 pandemic timeframe, and procedural factors, prosthetic fitting is associated with decreased likelihood of mortality within 1 year of follow-up (adjusted hazard ratio, 0.24; 95% confidence interval, 0.14-0.40) as well as within 3 years (adjusted hazard ratio, 0.40; 95% confidence interval, 0.29-0.55).

CONCLUSIONS

Prosthetic fitting is associated with improved survival, and preoperative functional status does not always predict postoperative functional status. Characterizing patient, surgical, and rehabilitation factors associated with receipt of prosthetic after LEA may improve long-term survival in these patients. Process measures employed by the Department of Veterans Affairs, such as prosthetic department evaluation of all amputees, may represent a best practice.

Factors Associated with Urgent Amputation Status and Its Impact on Mortality

BACKGROUND

Thirty-day mortality is higher after urgent major lower extremity amputations compared to elective lower extremity amputations. This study aims to identify factors associated with urgent amputations and to examine their impact on perioperative outcomes and long-term mortality.

METHODS

Patients undergoing major lower limb amputation from 2013 to 2020 in the Vascular Quality Initiative were included. Urgent amputation was defined as occurring within 72 hr of admission. Associations with sociodemographic characteristics, comorbidities, and outcomes including postoperative complication, inpatient death, and long-term survival were compared using univariable tests and multivariable logistic regression. Long-term survival between groups was compared using Kaplan-Meier analysis.

RESULTS

Of the 12,874 patients included, 4,850 (37.7%) had urgent and 8,024 (62.3%) had elective amputations. Non-White patients required urgent amputation more often than White patients (39.8% vs. 37.9%, P = 0.03). A higher proportion of Medicaid and self-pay patients presented urgently (Medicaid: 13.0% vs. 11.0%; self-pay: 3.4% vs. 2.5%, P < 0.001). Patients requiring urgent amputation were less often taking aspirin (55.6% vs. 60.1%, P < 0.001) or statin (62.2% vs. 67.2%, P < 0.001), had fewer prior revascularization procedures (41.0% vs. 48.8%, P < 0.001), and were of higher American Society of Anesthesiologists (ASA) class 4-5 (50.9% vs. 40.1%, P < 0.001). Urgent amputations were more commonly for uncontrolled infection (48.1% vs. 29.4%, P < 0.001) or acute limb ischemia (14.3% vs. 6.2%, P < 0.001). Postoperative complications were higher after urgent amputations (34.7% vs. 16.6%, P < 0.001), including need for return to operating room (23.8% vs. 8.4%, P < 0.001) and need for higher revision (15.2% vs. 4.5%, P < 0.001). Inpatient mortality was higher after urgent amputation (8.9% vs. 5.4%, P < 0.001). Multivariable analysis revealed non-White race, self-pay, homelessness, current smoking, ASA class 4-5, and amputations for uncontrolled infection or acute limb ischemia were associated with urgent status, whereas living in a nursing home or prior revascularization were protective. Furthermore, urgent amputation was associated with an increased odds of postoperative complication or death (odds ratio 1.86 [1.69-2.04], P < 0.001) as well as long-term mortality (odds ratio: 1.24 [1.13-1.35], P < 0.001). Kaplan-Meier analysis corroborated that elective status was associated with improvement of long-term survival.

CONCLUSIONS

Patients requiring urgent amputations are more often non-White, uninsured, and less frequently had prior revascularization procedures, revealing disparities in access to care. Urgency was associated with a higher postoperative complication rate, as well as increased long-term mortality. Efforts should be directed toward reducing these disparities to improve outcomes following amputation.

Analysis of Oklahoma amputation trends and identification of risk factors to target areas for limb preservation interventions

OBJECTIVE

Annual trends of lower extremity amputation due to end-stage chronic disease are on the rise in the United States. These amputations are leading to massive expenses for patients and the medical system. In Oklahoma, we have a high-risk population because access to care is low, the number of uninsured is high, cardiovascular health is poor, and our overall health care performance is ranked 50th in the country. But we know little about Oklahomans and their risk of limb loss. It is, therefore, imperative to look closely at this population to discover contemporary rates, trends, and state-specific risk factors for amputation due to diabetes and/or peripheral arterial disease (PAD). We hypothesize that state-specific groups will be identified as having the highest risk for limb loss and that contemporary trends in amputations are rising. To create implementable solutions to limb preservation, a baseline must be set.

METHODS

We conducted a 12-consecutive-year observational study using Oklahoma's hospital discharge data. Discharges among patients 20 years or older with a primary or secondary diagnosis of diabetes and/or PAD were included. Diagnoses and amputation procedures were identified using International Classification of Disease-9 and -10 codes. Amputation rates were calculated per 1000 discharges. Trends in amputation rates were measured by annual percentage changes (APC). Prevalence ratios evaluated the differences in amputation rates across demographic groups.

RESULTS

Over 5,000,000 discharges were identified from 2008 to 2019. Twenty-four percent had a diagnosis of diabetes and/or PAD. The overall amputation rate was 12 per 1000 discharges for those with diabetes and/or PAD. Diabetes and/or PAD-related amputation rates increased from 8.1 to 16.2 (APC, 6.0; 95% confidence interval [CI], 4.7-7.3). Most amputations were minor (59.5%), and although minor, increased at a faster rate compared with major amputations (minor amputation APC, 8.1; 95% CI, 6.7-9.6 vs major amputation APC, 3.1; 95% CI, 1.5-4.7); major amputations were notable in that they were significantly increasing. Amputation rates were the highest among males (16.7), American Indians (19.2), uninsured (21.2), non-married patients (12.7), and patients between 45 and 49 years of age (18.8), and calculated prevalence ratios for each were significant (P = .001) when compared within their respective category.

CONCLUSIONS

Amputation rates in Oklahoma have nearly doubled in 12 years, with both major and minor amputations significantly increasing. This study describes a worsening trend, underscoring that amputations due to chronic disease is an urgent statewide health care problem. We also present imperative examples of amputation health care disparities. By defining these state-specific areas and populations at risk, we have identified areas to pursue and improve care. These distinctive risk factors will help to frame a statewide limb preservation intervention.

Association of remoteness and ethnicity with major amputation following minor amputation to treat diabetes-related foot disease

INTRODUCTION

Minor amputation is commonly needed to treat diabetes-related foot disease (DFD). Remoteness of residence is known to limit access to healthcare and has previously been associated with poor outcomes. The primary aim of this study was to examine the associations between ethnicity and remoteness of residency with the risk of major amputation and death following initial treatment of DFD by minor amputation. A secondary aim was to identify risk factors for major amputation and death following minor amputation to treat DFD.

RESEARCH DESIGN AND METHODS

This was a retrospective analysis of data from patients who required a minor amputation to treat DFD between 2000 and 2019 at a regional tertiary hospital in Queensland, Australia. Baseline characteristics were collected together with remoteness of residence and ethnicity. Remoteness was classified according to the 2019 Modified Monash Model (MMM) system. Ethnicity was based on self-identification as an Aboriginal and Torres Strait Islander or non-Indigenous person. The outcomes of major amputation, repeat minor amputation and death were examined using Cox-proportional hazard analyses.

RESULTS

A total of 534 participants were included, with 306 (57.3%) residing in metropolitan or regional centres, 228 (42.7%) in rural and remote communities and 144 (27.0%) were Aboriginal or Torres Strait Islander people. During a median (inter quartile range) follow-up of 4.0 (2.1-7.6) years, 103 participants (19.3%) had major amputation, 230 (43.1%) had repeat minor amputation and 250 (46.8%) died. The risks (hazard ratio [95% CI]) of major amputation and death were not significantly higher in participants residing in rural and remote areas (0.97, 0.67-1.47; and 0.98, 0.76-1.26) or in Aboriginal or Torres Strait Islander people (HR 1.44, 95% CI 0.96, 2.16 and HR 0.89, 95% CI 0.67, 1.18). Ischemic heart disease (IHD), peripheral artery disease (PAD), osteomyelitis and foot ulceration (p<0.001 in all instances) were independent risk factors for major amputation.

CONCLUSION

Major amputation and death are common following minor amputation to treat DFD and people with IHD, PAD and osteomyelitis have an increased risk of major amputation. Aboriginal and Torres Strait Islander People and residents of remote areas were not at excess risk of major amputation.

Trends in peripheral artery disease and critical limb ischemia hospitalizations among cocaine and methamphetamine users in the United States: a nationwide study

Background

Peripheral artery disease (PAD) is on the rise worldwide, ranking as the third leading cause of atherosclerosis-related morbidity; much less is known about its trends in hospitalizations among methamphetamine and cocaine users.

Objectives

We aim to evaluate the overall trend in the prevalence of hospital admission for PAD with or without the use of stimulant abuse (methamphetamine and cocaine) across the United States. Additionally, we evaluated the PAD-related hospitalizations trend stratified by age, race, sex, and geographic location.

Methods

We used the National Inpatient Sample (NIS) database from 2008 to 2020. The Cochran Armitage trend test was used to compare the trend between groups. Multivariate logistic regression was used to examine adjusted odds for PAD and CLI hospitalizations among methamphetamine and cocaine users.

Results

Between 2008 and 2020, PAD-related hospitalizations showed an increasing trend in Hispanics, African Americans, and western states, while a decreasing trend in southern and Midwestern states (p-trend <0.05). Among methamphetamine users, an overall increasing trend was observed in men, women, western, southern, and midwestern states (p-trend <0.05). However, among cocaine users, PAD-related hospitalization increased significantly for White, African American, age group >64 years, southern and western states (p-trend <0.05). Overall, CLI-related hospitalizations showed an encouraging decreasing trend in men and women, age group >64 years, and CLI-related amputations declined for women, White patient population, age group >40, and all regions (p-trend <0.05). However, among methamphetamine users, a significantly increasing trend in CLI-related hospitalization was seen in men, women, White & Hispanic population, age group 26-45, western, southern, and midwestern regions.

Conclusions

There was an increasing trend in PAD-related hospitalizations among methamphetamine and cocaine users for both males and females. Although an overall decreasing trend in CLI-related hospitalization was observed for both genders, an up-trend in CLI was seen among methamphetamine users. The upward trends were more prominent for White, Hispanic & African Americans, and southern and western states, highlighting racial and geographic variations over the study period.

Editor's Choice - Analysis of Lower Limb Amputations in Brazil's Public Health System over 13 Years

OBJECTIVE

Understanding the causes of amputation is crucial for defining health policies that seek to avoid such an outcome, but only a few studies have investigated the epidemiology of patients submitted to amputations in developing countries. The objective of this study was to analyse all lower limb amputations performed in the public health system in Brazil over a 13 year period, evaluating trends in the number of cases, patient demographics, associated aetiologies, hospital length of stay, and in hospital mortality rate.

METHODS

This was a retrospective, population based analysis of all lower limb amputations performed in the Brazilian public health system between 1 January 2008 and 31 December 2020. Using a public database, all types of amputations were selected, defining the number of procedures, their main aetiologies, anatomical level of limb loss, demographic data, regional distribution, and other variables of interest.

RESULTS

A total of 633 455 amputations were performed between 2008 and 2020, mostly (55.6%) minor amputations, predominantly in males (67%). There was an upward trend in the number of amputations, determined mainly by the increase in major amputations (50.4% increase in the period). Elderly individuals have the highest rates of amputation. Diabetes mellitus (DM) is becoming the main primary diagnosis associated with amputations over the years. The highest in hospital mortality rate occurred after major amputations and was associated with peripheral arterial disease (PAD).

CONCLUSION

Amputation rates in Brazil show an upward trend. DM is becoming the most frequent associated primary diagnosis, although PAD is the diagnosis most associated with major amputations and in hospital death.

Factors Affecting 30-Day Outcomes in Patients Undergoing Nontraumatic Upper Extremity Amputation: A Retrospective Descriptive Longitudinal Study

BACKGROUND

Current literature concerning upper extremity amputations (UEAs) is very sparse. In this study, we conducted the first multicenter retrospective analysis aiming to identify risk factors associated with unfavorable outcomes in patients undergoing nontraumatic UEAs.

METHODS

A retrospective cohort study was conducted using the National Surgical Quality Improvement Program database. Adult patients who underwent nontraumatic UEAs between 2005 and 2021 were divided into two cohorts based on whether they experienced 30-day major morbidity (MM). Thereafter, multivariable binary logistic regression analysis was used to identify risk factors of MM.

RESULTS

From a total of 2984 cases, MM was observed in 8.7% of patients. Factors associated with MM included American Society of Anesthesiologists classes 3 (odds ratio [OR], 2.974 [1.862 to 4.748]) and 4 (OR, 4.736 [2.857 to 7.848]), being underweight (OR, 2.370 [1.251 to 4.491]), and suffering from insulin-dependent diabetes (OR, 1.390 [1.018 to 1.898]). In addition, an infectious surgical indication was associated with an increased risk of MM compared with having a benign (OR, 0.648 [0.488 to 0.682]) or malignant (OR, 0.205 [0.091 to 0.462]) indication. Moreover, patients undergoing shoulder amputations were at an increased risk of MM compared with those undergoing amputations of the forearm/wrist (OR, 0.243 [0.072 to 0.819]) and hands/fingers (OR, 0.286 [0.095 to 0.861]).

CONCLUSION

The risk factors identified for MM after nontraumatic UEAs should guide surgeons toward appropriately identifying high-risk patients and adequately counseling them preoperatively.

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.

Leveraging the Cardiovascular Team in Peripheral Artery Disease Diagnosis: A Call to Action

Lower extremity peripheral artery disease (PAD) is a common atherosclerotic cardiovascular disease (ASCVD) involving the aortoiliac, femoropopliteal, and infrapopliteal arterial segments. PAD remains a largely underdiagnosed and undertreated condition. The ankle-brachial index (ABI) is a simple and widely available test that is key detection tool in the diagnosis of PAD and is prognostic for mortality and morbidity. The cardiovascular (CV) team is a diverse array of health care clinicians (eg, nurses, nurse practitioners, physician assistants/associates, pharmacists, podiatrists) who have the qualifications and skills to be able to recognize when patients are at risk for PAD and perform an ABI. It is critical that the healthcare community recognize the critical role the CV team could play in improving outcomes and reducing disparities for patients with PAD.

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.

Multi-modality imaging for assessment of the microcirculation in peripheral artery disease: Bench to clinical practice

Peripheral artery disease (PAD) is a highly prevalent disorder with a high risk of mortality and amputation despite the introduction of novel medical and procedural treatments. Microvascular disease (MVD) is common among patients with PAD, and despite the established role as a predictor of amputations and mortality, MVD is not routinely assessed as part of current standard practice. Recent pre-clinical and clinical perfusion and molecular imaging studies have confirmed the important role of MVD in the pathogenesis and outcomes of PAD. The recent advancements in the imaging of the peripheral microcirculation could lead to a better understanding of the pathophysiology of PAD, and result in improved risk stratification, and our evaluation of response to therapies. In this review, we will discuss the current understanding of the anatomy and physiology of peripheral microcirculation, and the role of imaging for assessment of perfusion in PAD, and the latest advancements in molecular imaging. By highlighting the latest advancements in multi-modality imaging of the peripheral microcirculation, we aim to underscore the most promising imaging approaches and highlight potential research opportunities, with the goal of translating these approaches for improved and personalized management of PAD in the future.

Injectable thermosensitive selenium-containing hydrogel as mesenchymal stem cell carrier to improve treatment efficiency in limb ischemia

Limb ischemia is a refractory disease characterized by persistent inflammation, insufficient angiogenesis, and tissue necrosis. Although mesenchymal stem cells (MSCs) have shown potential for treating limb ischemia, their therapeutic effects are limited by low engraftment rates. Therefore, developing an optimal MSC delivery system that enhances cell viability is imperative. Selenium, known for its cytoprotective properties in various cell types, offers a potential strategy to enhance therapeutic effect of MSCs. In this study, we evaluated the cytoprotective effects of selenium on MSCs, and developed an injectable thermosensitive selenium-containing hydrogel based on PLGA-PEG-PLGA triblock copolymer, as a cell carrier to improve MSC viability after engraftment. The biocompatibility, biodegradability, and cytoprotective capabilities of selenium-containing hydrogels were assessed. Furthermore, the therapeutic potential of MSCs encapsulated within a thermosensitive selenium-containing hydrogel in limb ischemia was evaluated using cellular and animal experiments. Selenium protects MSCs from oxidative damage by upregulating GPX4 through a transcriptional mechanism. The injectable thermosensitive selenium-containing hydrogel exhibited favorable biocompatibility, biodegradability, and antioxidant properties. It can be easily injected into the target area in liquid form at room temperature and undergoes gelation at body temperature, thereby preventing the diffusion of selenium and promoting the cytoprotection of MSCs. Furthermore, MSCs encapsulated within the selenium-containing hydrogel effectively inhibited macrophage M1 polarization while promoting macrophage M2 polarization, thus accelerating angiogenesis and restoring blood perfusion in ischemic limbs. This study demonstrated the potential of an injectable thermosensitive selenium-containing hydrogel as a promising method for MSC delivery. By addressing the challenge of low retention rate, which is a major obstacle in MSC application, this strategy effectively improves limb ischemia.

Quantification of Skeletal Muscle Perfusion in Peripheral Artery Disease Using 18F-Sodium Fluoride Positron Emission Tomography Imaging

BACKGROUND

Perfusion deficits contribute to symptom severity, morbidity, and death in peripheral artery disease (PAD); however, no standard method for quantifying absolute measures of skeletal muscle perfusion exists. This study sought to preclinically test and clinically translate a positron emission tomography (PET) imaging approach using an atherosclerosis-targeted radionuclide, fluorine-18-sodium fluoride (18F-NaF), to quantify absolute perfusion in PAD.

METHODS AND RESULTS

Eight Yorkshire pigs underwent unilateral femoral artery ligation and dynamic 18F-NaF PET/computed tomography imaging on the day of and 2 weeks after occlusion. Following 2-week imaging, calf muscles were harvested to quantify microvascular density. PET methodology was validated with microspheres in 4 additional pig studies and translated to patients with PAD (n=39) to quantify differences in calf perfusion across clinical symptoms/stages and perfusion responses in a case of revascularization. Associations between PET perfusion, ankle-brachial index, toe-brachial index, and toe pressure were assessed in relation to symptoms. 18F-NaF PET/computed tomography quantified significant deficits in calf perfusion in pigs following arterial occlusion and perfusion recovery 2 weeks after occlusion that coincided with increased muscle microvascular density. Additional studies confirmed that PET-derived perfusion measures agreed with microsphere-derived perfusion measures. Translation of imaging methods demonstrated significant decreases in calf perfusion with increasing severity of PAD and quantified perfusion responses to revascularization. Perfusion measures were also significantly associated with symptom severity, whereas traditional hemodynamic measures were not.

CONCLUSIONS

18F-NaF PET imaging quantifies perfusion deficits that correspond to clinical stages of PAD and represents a novel perfusion imaging strategy that could be partnered with atherosclerosis-targeted 18F-NaF PET imaging using a single radioisotope injection.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03622359.

Vascular surgeons are positioned to fight healthcare disparities

Comprehensively managing vascular disease in the United States can seem overwhelming. Vascular surgery providers encounter daily stress-inducing challenges, including caring for sick patients who often, because of healthcare barriers, struggle with access to care, socioeconomic challenges, and a complex medical system. These individuals can present with advanced disease and comorbidities, and many have limited treatment options. Subsequently, it could seem as if the vascular surgeon's efforts have little opportunity to make a difference. This review describes a method to counter this sentiment through directed action, hope, and community building. Vascular surgeons are passionate about what they do and are built to fight healthcare disparities. This review also outlines the reasoning for attempting to create change and one approach to begin making a difference.

Impact of Intensity of Vascular Care Preceding Major Amputation Among Patients With Chronic Limb-Threatening Ischemia

BACKGROUND

Lower-limb amputation rates in patients with chronic limb-threatening ischemia vary across the United States, with marked disparities in amputation rates by gender, race, and income status. We evaluated the association of patient, hospital, and geographic characteristics with the intensity of vascular care received the year before a major lower-limb amputation and how intensity of care associates with outcomes after amputation.

METHODS

Using Medicare claims data (2016-2019), beneficiaries diagnosed with chronic limb-threatening ischemia who underwent a major lower-limb amputation were identified. We examined patient, hospital, and geographic characteristics associated with the intensity of vascular care received the year before amputation. Secondary objectives evaluated all-cause mortality and adverse events following amputation.

RESULTS

Of 33 036 total Medicare beneficiaries undergoing major amputation, 7885 (23.9%) were due to chronic limb-threatening ischemia; of these, 4988 (63.3%) received low-intensity and 2897 (36.7%) received high-intensity vascular care. Mean age, 76.6 years; women, 38.9%; Black adults, 24.5%; and of low income, 35.2%. After multivariable adjustment, those of low income (odds ratio, 0.65 [95% CI, 0.58-0.72]; P<0.001), and to a lesser extent, men (odds ratio, 0.89 [95% CI, 0.81-0.98]; P=0.019), and those who received care at a safety-net hospital (odds ratio, 0.87 [95% CI, 0.78-0.97]; P=0.012) were most likely to receive low intensity of care before amputation. High-intensity care was associated with a lower risk of all-cause mortality 2 years following amputation (hazard ratio, 0.79 [95% CI, 0.74-0.85]; P<0.001).

CONCLUSIONS

Patients who were of low-income status, and to a lesser extent, men, or those cared for at safety-net hospitals were most likely to receive low-intensity vascular care. Low-intensity care was associated with worse long-term event-free survival. These data emphasize the continued disparities that exist in contemporary vascular practice.

Next Steps: Studying Diabetic Foot Infections with Next-Generation Molecular Assays

Purpose of Review

In 2019, the International Working Group on the Diabetic Foot voiced six concerns regarding the use of molecular microbiology techniques for routine diagnosis of infection complicating diabetic foot ulcers. The purpose of this review is to evaluate contemporary evidence addressing each of these concerns and describe promising avenues for continued development of molecular microbiology assays.

Recent Findings

Since 2019, the feasibility of conducting metagenomic and metatranscriptomic studies on diabetic foot ulcer samples has been shown. However, these preliminary studies used small samples with concerns for selection bias. We await larger-scale, longitudinal studies, potentially using the recently formed Diabetic Foot Consortium, to identify microbiome profiles associated with infection and patient outcomes. How these results would translate into a clinical diagnostic requires further clarification.

Summary

High-throughput molecular microbiology techniques are not yet ready for clinical adoption as first-line diagnostics. However, moving from amplicon sequencing to metagenomic and metatranscriptomic studies has the potential to significantly accelerate development of assays that might meaningfully impact patient care.

Direct and Indirect Effects of Race and Socioeconomic Deprivation on Outcomes After Lower Extremity Bypass

OBJECTIVE

To evaluate the potential pathway, through which race and socioeconomic status, as measured by the social deprivation index (SDI), affect outcomes after lower extremity bypass chronic limb-threatening ischemia (CLTI), a marker for delayed presentation.

BACKGROUND

Racial and socioeconomic disparities persist in outcomes after lower extremity bypass; however, limited studies have evaluated the role of disease severity as a mediator to potentially explain these outcomes using clinical registry data.

METHODS

We captured patients who underwent lower extremity bypass using a statewide quality registry from 2015 to 2021. We used mediation analysis to assess the direct effects of race and high values of SDI (fifth quintile) on our outcome measures: 30-day major adverse cardiac event defined by new myocardial infarction, transient ischemic attack/stroke, or death, and 30-day and 1-year surgical site infection (SSI), amputation and bypass graft occlusion.

RESULTS

A total of 7077 patients underwent a lower extremity bypass procedure. Black patients had a higher prevalence of CLTI (80.63% vs 66.37%, P < 0.001). In mediation analysis, there were significant indirect effects where Black patients were more likely to present with CLTI, and thus had increased odds of 30-day amputation [odds ratio (OR): 1.11, 95% CI: 1.068-1.153], 1-year amputation (OR: 1.083, 95% CI: 1.045-1.123) and SSI (OR: 1.052, 95% CI: 1.016-1.089). There were significant indirect effects where patients in the fifth quintile for SDI were more likely to present with CLTI and thus had increased odds of 30-day amputation (OR: 1.065, 95% CI: 1.034-1.098) and SSI (OR: 1.026, 95% CI: 1.006-1.046), and 1-year amputation (OR: 1.068, 95% CI: 1.036-1.101) and SSI (OR: 1.026, 95% CI: 1.006-1.046).

CONCLUSIONS

Black patients and socioeconomically disadvantaged patients tended to present with a more advanced disease, CLTI, which in mediation analysis was associated with increased odds of amputation and other complications after lower extremity bypass compared with White patients and those that were not socioeconomically disadvantaged.

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.

A Novel Strategy to Manage Below-Knee-Amputation (BKA) Stump Complications for Early Wound Healing and BKA Salvage

INTRODUCTION

The optimal management of major stump complications (operative infection or dehiscence) following below-knee-amputation (BKA) is unknown. We evaluated a novel operative strategy to aggressively treat major stump complications hypothesizing it would improve our rate of BKA salvage.

METHODS

Retrospective review of patients requiring operative intervention for BKA stump complications between 2015 and 2021. A novel strategy employing staged operative debridement for source control, negative pressure wound therapy, and reformalization was compared to standard care (less structured operative source control or above knee amputation).

RESULTS

32 patients were studied, 29 of which were male (90.6%) with an average age of 56.1 ± 9.6 y. 30 (93.8%) had diabetes and 11 (34.4%) peripheral arterial disease (PAD). The novel strategy was used in 13 patients and 19 had standard care. Novel strategy patients had higher BKA salvage rates, 100% vs 73.7% (P = .064), and postoperative ambulatory status, 84.6% vs 57.9% (P = .141). Importantly, none of the patients undergoing the novel therapy had PAD, while all progressing to above-knee amputation (AKA) did. To better assess the efficacy of the novel technique, patients progressing to AKA were excluded. Patients undergoing novel therapy who had their BKA level salvaged (n = 13) were compared to usual care (n = 14). The novel therapy's time to prosthetic referral was 72.8 ± 53.7 days vs 247 ± 121.6 days (P < .001), but they did undergo more operations (4.3 ± 2.0 vs 1.9 ± 1.1, P < .001).

CONCLUSION

Utilization of a novel operative strategy for BKA stump complications is effective in salvaging BKAs, particularly for patients without PAD.

Randomized clinical Trial Comparing drug Eluting Stent Zilver PTX® Versus Bare Metal Stent Zilver Flex® for Treatment of Lesions in Femoral and Popliteal Arteries in Chronic Limb Threatening Ischemia

OBJECTIVE

Drug eluting stents (DES) might improve the results of stenting in the femoropopliteal (FP) segment, but randomized data between DES and BMS in the treatment of patients with chronic limb threatening ischemia (CLTI) is lacking. The aim of this study was to perform a randomized comparison, between DES and bare metal stent (BMS) implantation in a subgroup of CLTI patients with lesions in the superficial femoral artery (SFA) and the P1-P2 portion of the popliteal artery.

METHODS

Patients presenting with CLTI scheduled for endovascular treatment of FP lesions were randomly assigned by blinded envelopes 1:1 in a single blinded, parallel group design to DES or BMS after lesion crossing. Primary endpoints were target lesion revascularization (TLR) at 12 and 24 months and primary patency at 12 and 24 months. Secondary endpoints were technical success (TS), clinical success, secondary patency at 12 and 24 months, limb salvage, serious adverse events (SAE) at 24 month and survival at five years.

RESULTS

A total of 48 CLTI patients and 49 limbs, were enrolled, 22 in the BMS group and 27 in the DES group. Demographics, comorbidities, and Rutherford class were similar in both treatment arms. The overall rate of total occlusions was 96% and the corresponding overall median lesion length was 240 mm. No patients were lost to follow up. No significant differences were detected between groups regarding TLR and primary patency. The overall primary patency at 12 and 24 months was 42.9% and 36.7% respectively and the overall freedom from TLR was 67.3% and 61.2% respectively. The results in the two groups were also similar regarding secondary outcomes.

CONCLUSIONS

This single centre, randomized study could not demonstrate superiority of DES compared to BMS when treating long FP lesions in patients with CLTI but was limited by insufficient patient inclusion.

Limb and cardiovascular event risk in type 1 and 2 diabetic patients with peripheral artery disease

Background: Peripheral artery disease (PAD) is a risk factor for adverse limb events (LE) and cardiovascular events (CVE) that coexists with type 1 (T1) and 2 (T2) diabetes mellitus (DM). Little is known about comparative risk of LE and CVE in T1/T2 DM patients with PAD. Patients and methods: We queried our database of 40,144 patients ≥18 years old who underwent ankle brachial index (ABI) measurement from 01/1996-02/2020. We isolated T1/T2 DM patients with PAD diagnosed by ankle brachial index (ABI; low [<1.0] or elevated [>1.4]) and retrieved demographics including glycated hemoglobin (HbA1c). Primary outcomes were LE (critical limb ischemia/vascular amputation) and CVE (myocardial infarction/ischemic stroke). All-cause mortality was a secondary outcome. Multivariable Cox proportional regression yielded hazard ratios (HR) with 95% confidence intervals (CI) after adjusting for pertinent risk factors including age, hypertension, hyperlipidemia, smoking, and HbA1c. Results: Our study found 10,156 patients with PAD and DM (34% T1DM, 66% T2DM) with median follow-up time 34 mo (IQR 85 mo). T1DM patients were younger than T2DM (mean age 67 vs. 70 years), with higher median HbA1c (7.7 [IQR 1.9] vs. 6.7% [IQR 1.6]), and more prevalent hypertension, hyperlipidemia, CAD, and CKD. Antiplatelet and statin use was equivocal. Elevated ABI was more common in T1DM (47 vs. 28%). LE occurred in 23% and CVE in 12% patients. LE risk was higher in T1 than T2 DM patients (HR 1.58 [95% CI 1.44, 1.73], p<0.0001), but CVE and all-cause mortality were equivocal. These observations were preserved across ABI and HbA1c subgroup analyses. Conclusions: PAD patients with T1DM had a higher LE risk than those with T2DM, even after adjustment for glycemic control and pertinent risk factors, but CVE risk and all-cause mortality were equivocal. These data suggest a potential role for more intensive LE risk modification in PAD patients with T1DM, but further investigation is needed.

A Nurse-Led Telehealth Program for Diabetes Foot Care: Feasibility and Usability Study

BACKGROUND

Diabetes mellitus can lead to severe and debilitating foot complications, such as infections, ulcerations, and amputations. Despite substantial progress in diabetes care, foot disease remains a major challenge in managing this chronic condition that causes serious health complications worldwide.

OBJECTIVE

The primary aim of this study was to examine the feasibility and usability of a telehealth program focused on preventive diabetes foot care. A secondary aim was to descriptively measure self-reported changes in diabetes knowledge, self-care, and foot care behaviors before and after participating in the program.

METHODS

The study used a single-arm, pre-post design in 2 large family medical practice clinics in Texas. Participants met individually with the nurse practitioner once a month for 3 months using synchronous telehealth videoconferencing. Each participant received diabetes foot education guided by the Integrated Theory of Health Behavior Change. Feasibility was measured with rates of enrollment and program and assessment completion. Usability was measured with the Telehealth Usability Questionnaire. Diabetes knowledge, self-care, and foot care behaviors were measured with validated survey instruments at baseline, 1.5 months, and 3 months.

RESULTS

Of 50 eligible individuals, 39 (78%) enrolled; 34 of 39 (87%) completed the first videoconference and 29 of 39 (74%) completed the second and third videoconferences. Of the 39 who consented, 37 (95%) completed the baseline assessment; 50% (17/34) of those who attended the first videoconference completed the assessment at 1.5 months, and 100% (29/29) of those who attended the subsequent videoconferences completed the final assessment. Overall, participants reported a positive attitude toward the use of telehealth, with a mean Telehealth Usability Questionnaire score of 6.24 (SD 0.98) on a 7-point scale. Diabetes knowledge increased by a mean of 15.82 (SD 16.69) points of 100 (P<.001) from baseline to 3 months. The values for the Summary of Diabetes Self-Care Activities measure demonstrated better self-care, with participants performing foot care on average 1.74 (SD 2.04) more days per week (P<.001), adhering to healthy eating habits on average 1.57 (SD 2.12) more days per week (P<.001), and being physically active on average 1.24 (SD 2.21) more days per week (P=.005). Participants also reported an improvement in the frequency of foot self-examinations and general foot care behaviors. The mean scores for foot care increased by a mean of 7.65 (SD 7.04) points (scale of 7 to 35) from baseline to 3 months postintervention (P<.001).

CONCLUSIONS

This study demonstrates that a nurse-led telehealth educational program centered on diabetes foot care is feasible, acceptable, and has the potential to improve diabetes knowledge and self-care, which are precursors to preventing debilitating foot complications.

The importance of socio-economic determinants of health in the care of patients with peripheral artery disease: A narrative review from VAS

Socio-economic determinants of health (SDoH) include various nonmedical factors in the socio-economic sphere with a potentially significant impact on health outcomes. Their effects manifest through several mediators/moderators (behavioral characteristics, physical environment, psychosocial circumstances, access to care, and biological factors). Various critical covariates (age, gender/sex, race/ethnicity, culture/acculturation, and disability status) also interact. Analyzing the effects of these factors is challenging due to their enormous complexity. Although the significance of SDoH for cardiovascular diseases is well documented, research regarding their impact on peripheral artery disease (PAD) occurrence and care is less well documented. This narrative review explores to what extent SDoH are multifaceted in PAD and how they are associated with its occurrence and care. Additionally, methodological issues that may hamper this effort are addressed. Finally, the most important question, whether this association may contribute to reasonable interventions aimed at SDoH, is analyzed. This endeavor requires attention to the social context, a whole systems approach, multilevel-thinking, and a broader alliance that reaches out to more stakeholders outside the medical sphere. More research is needed to justify the power in this concept to improve PAD-related outcomes like lower extremity amputations. At the present time, some evidence, reasonable consideration, and intuitive reasoning support the implementation of various interventions in SDoH in this field.

Racial Differences in Vascular Assessment Prior to Amputation in the Veterans Health Administration

Purpose

It is unclear whether disparities in the care provided before lower extremity amputation (LEA) is driven by differences in receipt of diagnostic work-up versus revascularization attempts.

Methods

We performed a national cohort study of Veterans who underwent LEA between March 2010 and February 2020 to assess receipt of vascular assessment with arterial imaging and/or revascularization in the year prior to LEA.

Results

Among 19,396 veterans (mean age 66.8 years; 26.6% Black), Black veterans had diagnostic procedures more often than White veterans (47.5% vs. 44.5%) and revascularization as often (25.8% vs. 24.5%).

Conclusion

We must identify patient and facility-level factors associated with LEA as disparities do not appear related to differences in attempted revascularization.