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

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.

Analysis Of Oklahoma Amputation Trends and Identification of Risk Factors to Target Areas For Limb Preservation Interventions

BACKGROUND

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 healthcare 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.

STUDY DESIGN

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 ICD-9 and ICD-10 codes. Amputation rates were calculated per 1,000 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 2008-2019. Twenty-four percent had a diagnosis of diabetes and/or PAD. The overall amputation rate was 12 per thousand 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% CI:4.7-7.3). Most amputations were minor (59.5%), and though minor increased at a faster rate compared to major (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=0.001) when compared within their respective category.

CONCLUSION

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 healthcare problem. We also present imperative examples of amputation healthcare 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.

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.

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.

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.

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.

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.

Racial, ethnic, and socioeconomic inequities in amputation risk for patients with peripheral artery disease and diabetes

Peripheral artery disease and diabetes are highly prevalent diseases and the leading cause of limb loss. Despite advances in medical and surgical techniques, there are stark differences in delivery and outcomes of lower extremity amputation among populations when stratified by race, ethnicity, and socioeconomic status. We reviewed studies from the last 2 decades (1999-2022) to provide a comprehensive assessment of the current impact of disparities on the risk for, and management of, lower extremity amputation and offer action items that can optimize health outcomes.

Injury Precipitating Tissue Loss and Time to Referral to a Vascular Center in Patients with Chronic Limb-Threatening Ischemia

AIM

This study aimed to report injury precipitating tissue loss and to provide updated information on the time from tissue loss occurrence to referral to a vascular center for patients who developed chronic limb-threatening ischemia (CLTI) in Japan.

METHODS

We examined 450 patients who developed CLTI with tissue loss and were registered in a multicenter prospective study between October 2017 and June 2020. They were referred to the participating vascular centers for revascularization. Information on the injury precipitating tissue loss and time to referral was collected at registration. The severity of tissue loss was evaluated using the Wound, Ischemia, and foot Infection classification.

RESULTS

Injury precipitating tissue loss was absent in 52.0% (95% confidence interval, 47.3%-56.6%) of the patients. The absence was associated with lower albumin levels and preserved pressure sensation. Although the time to referral was significantly shorter in cases without a history of prereferral revascularization, 16.8% (12.8%-20.7%) of the patients were referred to the vascular centers more than 3 months after tissue loss occurrence. Time to referral, but not the lack of a clear precipitant for tissue loss, was significantly associated with the severity of tissue loss.

CONCLUSION

A clear precipitant for tissue loss was often lacking, particularly in patients with low albumin levels and preserved pressure sensation. Delayed referral to a vascular center is still common.

Racial and ethnic disparities in major adverse limb events persist for chronic limb threatening ischemia despite presenting limb threat severity after peripheral vascular intervention

OBJECTIVE

Racial and ethnic disparities have been well-documented in the outcomes for chronic limb threatening ischemia (CLTI). One purported explanation has been the disease severity at presentation. We hypothesized that the disparities in major adverse limb events (MALE) after peripheral vascular intervention (PVI) for CLTI would persist despite controlling for disease severity at presentation using the WIfI (Wound, Ischemia, foot Infection) stage.

METHODS

The Vascular Quality Initiative PVI dataset (2016-2021) was queried for CLTI. Patients were excluded if they were missing the WIfI stage. The primary end point was the incidence of 1-year MALE, defined as major amputation (through the tibia or fibula or more proximally) or reintervention (endovascular or surgical) of the initial treatment limb. A multivariate hierarchical Fine-Gray analysis was performed, controlling for hospital variation, competing risk of death, and presenting WIfI stage, to assess the independent association of Black/African American race and Latinx/Hispanic ethnicity with MALE. A Cox proportional hazard regression model was used for the 1-year survival analysis.

RESULTS

Overall, 47,830 patients (60%) had had WIfI scores reported (73% White, 20% Black, and 7% Latinx). The 1-year unadjusted cumulative incidence of MALE was 13.1% (95% confidence interval [CI], 12.6%-13.5%) for White, 14.3% (95% CI, 13.5%-15.3%) for Black, and 17.0% (95% CI, 15.3%-18.9%) for Latinx patients. On bivariate analysis, the occurrence of MALE was significantly associated with younger age, Black race, Latinx ethnicity, coronary artery disease, cerebrovascular disease, congestive heart failure, hypertension, diabetes, dialysis, intervention level, any prior minor or major amputation, and WIfI stage (P < .001). The cumulative incidence of 1-year MALE increased by increasing WIfI stage: stage 1, 11.7% (95% CI, 10.9%-12.4%); stage 2, 12.4% (95% CI, 11.8%-13.0%); stage 3, 14.8% (95% CI, 13.8%-15.8%); and stage 4, 15.4% (95% CI, 14.3%-16.6%). The cumulative incidence also increased by intervention level: inflow, 10.7% (95% CI, 9.8%-11.7%), femoropopliteal, 12.3% (95% CI, 11.7%-12.9%); and infrapopliteal, 14.1% (95% CI, 13.5%-14.8%). After adjustment for WIfI stage only, Black race (subdistribution hazard ratio [SHR], 1.30; 95% CI, 1.17-1.44; P < .001) and Latinx ethnicity (SHR, 1.58; 95% CI, 1.37-1.81; P < .001) were associated with an increased 1-year hazard of MALE compared with White race. On adjusted multivariable analysis, MALE disparities persisted for Black/African American race (SHR, 1.12; 95% CI, 1.01-1.25; P = .028) and Latinx/Hispanic ethnicity (SHR, 1.34; 95% CI, 1.16-1.54; P < .001) compared with White race.

CONCLUSIONS

Black/African American and Latinx/Hispanic patients had a higher associated hazard of MALE after PVI for CLTI compared with White patients despite an adjustment for WIfI stage at presentation. These results suggest that disease severity at presentation does not account for disparities in outcomes. Further work should focus on better understanding the underlying mechanisms for disparities in historically marginalized racial and ethnic groups presenting with CLTI.

Numerical Analysis of a Transtibial Prosthesis Socket Using 3D-Printed Bio-Based PLA

Lower-limb prosthesis design and manufacturing still rely mostly on the workshop process of trial-and-error using expensive unrecyclable composite materials, resulting in time-consuming, material-wasting, and, ultimately, expensive prostheses. Therefore, we investigated the possibility of utilizing Fused Deposition Modeling 3D-printing technology with inexpensive bio-based and bio-degradable Polylactic Acid (PLA) material for prosthesis socket development and manufacturing. The safety and stability of the proposed 3D-printed PLA socket were analyzed using a recently developed generic transtibial numeric model, with boundary conditions of donning and newly developed realistic gait cycle phases of a heel strike and forefoot loading according to ISO 10328. The material properties of the 3D-printed PLA were determined using uniaxial tensile and compression tests on transverse and longitudinal samples. Numerical simulations with all boundary conditions were performed for the 3D-printed PLA and traditional polystyrene check and definitive composite socket. The results showed that the 3D-printed PLA socket withstands the occurring von-Mises stresses of 5.4 MPa and 10.8 MPa under heel strike and push-off gait conditions, respectively. Furthermore, the maximum deformations observed in the 3D-printed PLA socket of 0.74 mm and 2.66 mm were similar to the check socket deformations of 0.67 mm and 2.52 mm during heel strike and push-off, respectively, hence providing the same stability for the amputees. We have shown that an inexpensive, bio-based, and bio-degradable PLA material can be considered for manufacturing the lower-limb prosthesis, resulting in an environmentally friendly and inexpensive solution.

Surgery or Endovascular Therapy for Chronic Limb-Threatening Ischemia

BACKGROUND

Patients with chronic limb-threatening ischemia (CLTI) require revascularization to improve limb perfusion and thereby limit the risk of amputation. It is uncertain whether an initial strategy of endovascular therapy or surgical revascularization for CLTI is superior for improving limb outcomes.

METHODS

In this international, randomized trial, we enrolled 1830 patients with CLTI and infrainguinal peripheral artery disease in two parallel-cohort trials. Patients who had a single segment of great saphenous vein that could be used for surgery were assigned to cohort 1. Patients who needed an alternative bypass conduit were assigned to cohort 2. The primary outcome was a composite of a major adverse limb event - which was defined as amputation above the ankle or a major limb reintervention (a new bypass graft or graft revision, thrombectomy, or thrombolysis) - or death from any cause.

RESULTS

In cohort 1, after a median follow-up of 2.7 years, a primary-outcome event occurred in 302 of 709 patients (42.6%) in the surgical group and in 408 of 711 patients (57.4%) in the endovascular group (hazard ratio, 0.68; 95% confidence interval [CI], 0.59 to 0.79; P<0.001). In cohort 2, a primary-outcome event occurred in 83 of 194 patients (42.8%) in the surgical group and in 95 of 199 patients (47.7%) in the endovascular group (hazard ratio, 0.79; 95% CI, 0.58 to 1.06; P = 0.12) after a median follow-up of 1.6 years. The incidence of adverse events was similar in the two groups in the two cohorts.

CONCLUSIONS

Among patients with CLTI who had an adequate great saphenous vein for surgical revascularization (cohort 1), the incidence of a major adverse limb event or death was significantly lower in the surgical group than in the endovascular group. Among the patients who lacked an adequate saphenous vein conduit (cohort 2), the outcomes in the two groups were similar. (Funded by the National Heart, Lung, and Blood Institute; BEST-CLI ClinicalTrials.gov number, NCT02060630.).

Temporal Trends, Practice Variation, and Associated Outcomes With IVUS Use During Peripheral Arterial Intervention

BACKGROUND

Intravascular ultrasound (IVUS) has been shown in limited prospective studies to improve procedural outcomes for patients undergoing lower extremity peripheral arterial intervention (PVI).

OBJECTIVES

The authors aimed to study temporal trends, practice variation, and associated outcomes with the use of IVUS during PVI among Medicare beneficiaries.

METHODS

All PVIs performed from 2016 to 2019 among Medicare beneficiaries aged >65 years were included. Temporal trends in IVUS use were stratified by procedural location (inpatient, outpatient, or ambulatory surgery center [ASC]/office-based laboratory [OBL]) and physician specialty. The primary outcome was major adverse limb events (MALE). Inverse probability weighting was used to account for differences in baseline characteristics. Cox regression with competing risks was used to estimate weighted hazard ratios.

RESULTS

During the study period, 543,488 PVIs were included, of which 63,372 (11.7%) used IVUS. A substantial growth in IVUS use was observed, which was driven by procedures performed in ASCs/OBLs (23.6% increase from quarter 1 of 2016 through quarter 4 of 2019). Among operators who used IVUS, there was also notable variation in use (median operator use 5.4% of cases; IQR: 2.2%-15.0%; range, <1%-100%). In weighted analysis, IVUS use during PVI was associated with a lower risk of MALE through a median of 514 days (adjusted hazard ratio: 0.73; 95% CI: 0.70-0.75; P < 0.0001).

CONCLUSIONS

In contemporary nationwide data, IVUS use during PVI has increased since 2016, driven by growth in the ASC/OBL setting. However, there remains substantial variation in operator practice. When used during PVI, IVUS was associated with a lower risk of short- and long-term MALE.

Knowledge, attitude and perception towards lower limb amputation amongst persons living with diabetes in rural South Africa: A qualitative study

Background

South Africa has a high prevalence of diabetes mellitus (DM), a leading risk factor for lower limb amputation (LLA). Lower limb amputation is associated with significant morbidity and mortality. Lower limb amputation incidence can be mitigated through prompt identification and treatment of individuals at risk and engagement in self-management practices. Also, when LLA is inevitable, outcomes or prognosis can be improved with timely surgery.

Aim

This study explored the knowledge, attitude and perception of persons living with diabetes towards LLA and its prevention.

Setting

Nqamakwe, a rural community in the Eastern Cape province of South Africa.

Method

This was a descriptive, qualitative study involving persons living with DM, with and without LLA, and community leaders. Fifteen participants were recruited purposively and conveniently from a rural community in the Eastern Cape, South Africa. Data collection took place through semistructured interviews, in English and a local language, Xhosa. Interviews were transcribed and translated, and an inductive approach was used for thematic analysis.

Results

A total of 15 individual interviews were conducted. Of those, 13 were persons with DM, five with LLA, including one with bilateral LLA. There was a gap in knowledge on foot self-examination as a measure of preventing LLA amongst persons with DM. The attitude of persons without LLA was mostly fearful and their fears centred around perioperative death, risk for contralateral amputation, loss of limb and independence. Consent to LLA procedure was a last resort and only when pain levels were unbearable. Family support and information on rehabilitation services and assistive devices also fostered consent to LLA surgery.

Conclusion

There is a need for awareness creation and adequate health education for persons living with DM on LLA and its prevention measures, especially foot care practices. Also, health education programmes for persons living with DM in rural areas should address the various misperceptions of LLA to reduce delays.

Contribution

The article revealed gaps in knowledge on LLA and its prevention among individuals living with diabetes as well as areas of concerns that may potentially delay acceptance when LLA is inevitable. Findings from our study may assist primary health care providers to determine important issues to be addressed during routine and pre-operative patient education.

Peripheral artery disease and the risk of venous thromboembolism

Summary: Background: Peripheral artery disease (PAD) impacts 3–12% of patients worldwide and is characterized by endothelial dysfunction and inflammatory pathways which are also common to venous thromboembolism (VTE), but there is a paucity of evidence regarding VTE risk in PAD patients. We investigated whether PAD is an independent risk factor for VTE. Patients and methods: We reviewed medical records of patients undergoing ABI studies at Mayo Clinic from 01/1996-02/2020. We classified patients by ABI (low [<1.0], normal [1.0–1.4], or elevated [>1.4]), as well as by specific low ABI subgroup: severely reduced (ABI: 0.00–0.39), moderately reduced (0.40–0.69), mildly reduced (0.70–0.90), and borderline reduced (0.91–0.99). The primary outcome was incident VTE event (acute lower extremity deep vein thrombosis or pulmonary embolism) after ABI measurement. Multivariable Cox proportional regression was used to calculate hazard ratios (HR) with 95% confidence intervals (CI) after adjusting for age, sex, active smoking, cancer, previous VTE, thrombophilia, anticoagulation, and revascularization. Results: 39,834 unique patients (mean age 66.3±14.3 years, median follow-up 34 months) were identified. 2,305 VTE events occurred in patients without PAD (13.0%), 2,218 in low ABI patients (13.0%), and 751 in elevated ABI patients (14.8%). After risk factor adjustment, VTE risk was modestly increased for PAD overall (HR: 1.12, 95% CI [1.06, 1.18]), including low ABI (HR: 1.11, 95% CI [1.04, 1.18]) and elevated ABI groups (HR: 1.15, 95% CI [1.04, 1.26]), compared to patients without PAD. The greatest VTE risk was in severely low ABI patients (HR: 1.46, 95% CI [1.31, 1.64]). Conclusions: In a large longitudinal cohort, we present strong clinical evidence of PAD, with low and elevated ABI, as an independent VTE risk factor, with the highest risk seen in patients with severely low ABI. Continued research is required to further investigate this relationship and its intersection with functional performance status to optimize VTE risk reduction or anticoagulation strategies in the PAD population.

Differences in Comorbidities Explain Black-White Disparities in Outcomes After Femoropopliteal Endovascular Intervention

BACKGROUND

Black adults have a higher incidence of peripheral artery disease and limb amputations than White adults in the United States. Given that peripheral endovascular intervention (PVI) is now the primary revascularization strategy for peripheral artery disease, it is important to understand whether racial differences exist in PVI incidence and outcomes.

METHODS

Data from fee-for-service Medicare beneficiaries ≥66 years of age from 2016 to 2018 were evaluated to determine age- and sex-standardized population-level incidences of femoropopliteal PVI among Black and White adults over the 3-year study period. Patients' first inpatient or outpatient PVIs were identified through claims codes. Age- and sex-standardized risks of the composite outcome of death and major amputation within 1 year of PVI were examined by race.

RESULTS

Black adults underwent 928 PVIs per 100 000 Black beneficiaries compared with 530 PVIs per 100 000 White beneficiaries (risk ratio, 1.75 [95% CI, 1.73-1.77]; P<0.01). Black adults who underwent PVI were younger (mean age, 74.5 years versus 76.4 years; P<0.01), were more likely to be female (52.8% versus 42.7%; P<0.01), and had a higher burden of diabetes (70.6% versus 56.0%; P<0.01), chronic kidney disease (67.5% versus 56.6%; P<0.01), and heart failure (47.4% versus 41.7%; P<0.01) than White adults. When analyzed by indication for revascularization, Black adults were more likely to undergo PVI for chronic limb-threatening ischemia than White adults (13 023 per 21 352 [61.0%] versus 59 956 per 120 049 [49.9%]; P<0.01). There was a strong association between Black race and the composite outcome at 1 year (odds ratio, 1.21 [95% CI, 1.16-1.25]). This association persisted after adjustment for socioeconomic status (odds ratio, 1.08 [95% CI, 1.03-1.13]) but was eliminated after adjustment for comorbidities (odds ratio, 0.96 [95% CI, 0.92-1.01]).

CONCLUSIONS

Among fee-for-service Medicare beneficiaries, Black adults had substantially higher population-level PVI incidence and were significantly more likely to experience adverse events after PVI than White adults. The association between Black race and adverse outcomes appears to be driven by a higher burden of comorbidities. This analysis emphasizes the critical need for early identification and aggressive management of peripheral artery disease risk factors and comorbidities to reduce Black-White disparities in the development and progression of peripheral artery disease and the risk of adverse events after PVI.

Lower Extremity Amputations Among Veterans: Have Ambulatory Outcomes and Survival Improved?

OBJECTIVE

We hypothesize among patients undergoing lower extremity amputation, access to pre, and post operative rehabilitation services; as well as improved medical care, have led to higher rates of postoperative ambulation, and improved survival.

METHODS

Retrospective single center review of all major lower extremity amputations performed at the Greater Los Angeles Veterans Affairs Healthcare System from 2000 - 2020 stratified into multiyear cohorts. We abstracted demographics, operative indication, comorbidities, preoperative medical management, perioperative complications, discharge location, and pre- and postoperative ambulatory status. Odds of ambulation after amputation were analyzed using multivariate logistic regression. Survival was analyzed using multivariate logistic regression and Kaplan-Meier survival analysis. Multivariate logistic predictors were selected based on prior literature and clinical experience.

RESULTS

We identified 654 operations in our study, noting less amputations performed in the latest three cohort years as compared to the initial cohort (2000 - 2004). Patients undergoing below-knee amputations (BKA) had 2.7 times (p < 0.05) greater odds of postoperative ambulation and 86% (p < 0.05) increased odds of survival compared to above-knee amputations (AKA). The odds of ambulation increased by 8.8% (p < 0.05) for each consecutive study year. Ambulation post-amputation conferred 13.2 times (p < 0.05) greater odds of survival. The odds of survival in "emergent" operations decreased by 48% (p < 0.05) compared to an "elective" operation. For each additional comorbidity, the odds of survival decreased by 18% (p < 0.05). Patients with any perioperative complication had a 48% (p < 0.05) lower odds of survival. Kaplan Meier survival estimates demonstrated significant survival difference between patients by amputation level and postoperative ambulatory status (p < 0.05).

CONCLUSIONS

Ambulatory status following distal amputation has improved over time and is significantly associated with increased survival post-amputation. Patients undergoing a BKA or discharged home were most likely to ambulate postoperatively. Amputation level, preoperative comorbidities, and perioperative complications remain strong predictors of survival.

Disparities In Diabetes-Related Lower Extremity Amputations In The United States: A Systematic Review

Disparities in rates of peripheral diabetic neuropathy and lower extremity amputation exist in the United States. To investigate the factors linked to this disparity, we performed a systematic review of the literature on the subject published during the period 2000-20. Nineteen observational studies were included. Disparities in rates of lower extremity amputation were reported according to patient race, ethnicity, sex, and age; across hospital referral regions, residential area characteristics, and income estimates; and on the basis of payer type and hospital characteristics. Several of these factors were interrelated. There was a reduction in major lower extremity amputation rates among Black, Hispanic, and White patients with diabetes over time, suggesting narrowing disparities in the odds of this procedure among Black and White patients. There is a need for a national strategy that integrates public awareness, screening, early initiated multidisciplinary care, and quality measures for peripheral artery disease management, as well as neighborhood-level public health interventions, to reduce the disproportionate burden of lower extremity amputation in underserved communities.

PBMNCs Treatment in Critical Limb Ischemia and Candidate Biomarkers of Efficacy

When in critical limb ischemia (CLI) the healing process aborts or does not follow an orderly and timely sequence, a chronic vascular wound develops. The latter is major problem today, as their epidemiology is continuously increasing due to the aging population and a growth in the incidence of the underlying diseases. In the US, the mean annualized prevalence of necrotic wounds due to the fact of CLI is 1.33% (95% CI, 1.32–1.34%), and the cost of dressings alone has been estimated at USD 5 billion per year from healthcare budgets. A promising cell treatment in wound healing is the local injection of peripheral blood mononuclear cells (PBMNCs). The treatment is aimed to induce angiogenesis as well to switch inflammatory macrophages, called the M1 phenotype, into anti-inflammatory macrophages, called M2, a phenotype devoted to tissue repair. This mechanism is called polarization and is a critical step for the healing of all human tissues. Regarding the clinical efficacy of PBMNCs, the level of evidence is still low, and a considerable effort is necessary for completing the translational process toward the patient bed site. From this point of view, it is crucial to identify some candidate biomarkers to detect the switching process from M1 to M2 in response to the cell treatment.

Spatial analysis of factors impacting lower limb major amputation rates in Hungary

Summary: Background: Lower limb major amputations represent a substantial public health burden in Hungary, where previous research revealed markedly high rates with significant spatial variations. Therefore, we aimed to assess to what extent healthcare and socio-economic factors in the local environment explain the regional disparity. Patients and methods: In a retrospective cohort analysis, based on the healthcare administrative data of the Hungarian population, lower limb major amputations were identified from 1st of January 2017 to 31st of December 2019. The permanent residence of the amputees on the local administrative level (197 geographic units) was used to identify potential healthcare (outpatient care, revascularisation activity) and socio-economic (educational attainment, local infrastructure and services, income and employment) determinants of amputations. Spatial effects were modelled using the spatial Durbin error regression model. Results: 10,209 patients underwent 11,649 lower limb major amputations in the observational period. In our spatial analysis, outpatient care was not associated with local amputation rates. However, revascularisation activity in a geographic unit entailed an increased rate of amputations, while revascularisations in the neighbouring areas were associated with a lower rate of amputations, resulting in an overall neutral effect (β=−0.002, 95% CI: −0.05 – 0.04, p=0.96). The local socio-economic environment had a significant direct inverse association with amputations (β=−7.45, 95% CI: −10.50 – −4.42, p<0.0001) . Our spatial model showed better performance than the traditional statistical modelling (ordinary least squares regression), explaining 37% of the variation in amputations rates. Conclusions: Regional environmental factors explain a substantial portion of spatial disparities in amputation practice. While the socio-economic environment shows a significant inverse relationship with the regional amputation rates, the impact of the local healthcare-related factors (outpatient care, revascularisation activity) is not straightforward. Unravelling the impact of the location on amputation practice requires complex spatial modelling, which may guide efficient healthcare policy decisions.

Comparative mortality according to peripheral artery disease and coronary heart disease/stroke in the United States

BACKGROUND AND AIMS

A recent trial reported that patients with peripheral artery disease (PAD) without coronary heart disease or stroke (CHD/stroke) had worse prognosis than those with CHD/stroke without PAD. However, community-based data are lacking. The purpose of this study was to compare mortality according to the status of PAD and CHD/stroke in the general population.

METHODS

In 6780 participants (aged ≥40 years) from the National Health and Nutrition Examination Surveys 1999-2004, we compared mortality risk according to PAD (ankle-brachial index ≤0.9) and CHD/stroke (self-report) at baseline using the Kaplan-Meier method and multivariable Cox models accounting for sampling weights.

RESULTS

The prevalence of having both PAD and CHD/stroke was 1.6%. The prevalence of PAD without CHD/stroke and CHD/stroke without PAD was 4.1% and 8.5%, respectively (85.8% without PAD or CHD/stroke). Over a median follow-up of 12.8 years, 21.2% died. Individuals with both PAD and CHD/stroke had the worst survival (25.5% at 12 years). Those with PAD without CHD/stroke had the second worst prognosis (47.7%), followed by those with CHD/stroke without PAD (53.2%) and those without CHD/stroke or PAD (87.2%). Adjusted hazard ratio of mortality was 2.70 (95% CI, 2.07-3.53) for PAD with CHD/stroke, 1.81 (1.54-2.12) in CHD/stroke without PAD, and 1.68 (1.35-2.08) in PAD without CHD/stroke vs. no CHD/stroke or PAD.

CONCLUSIONS

In the US adults, PAD contributed to increased mortality in persons with and without CHD/stroke. The prognosis of PAD without CHD/stroke was no better than that of CHD/stroke without PAD. These results suggest the importance of recognizing the presence of PAD in the community.

Lower limb amputations among individuals living with diabetes mellitus in low- and middle-income countries: A systematic review protocol

Background

The burden of diabetes mellitus (DM) and its associated complications continue to burgeon, particularly in low- and middle-income countries (LMICs). Lower limb amputation (LLA) is one of the most life-altering complications of DM, associated with significant morbidity, mortality and socio-economic impacts. High-income countries have reported a decreasing incidence of DM-associated LLA, but the situation in many LMICs is unknown. We aim to conduct a systematic review to determine the incidence and prevalence of DM-associated LLA in LMICs to better inform appropriate interventions and health system response.

Methods and analysis

A systematic search of the literature will be conducted on five databases: MEDLINE, Embase, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Scopus and African Journal Online (AJOL). Only observational, quantitative studies reporting the incidence and/or prevalence of DM-related LLA will be considered. A validated study design-specific critical appraisal tool will be used to assess the risk of bias in individual studies. We will determine the incidence of LLA by examining the number of new cases of LLA among individuals with confirmed DM diagnosis during the specified period, while the prevalence will be based on the total number of all new and existing LLAs in a population. LLA will be considered as the resection of the lower limb from just above the knee to any point down to the toe. If heterogeneity is low to moderate, a random-effects meta-analysis will be conducted on extracted crude prevalence/incidence rates, with the median and interquartile range also reported. The systematic review will be performed in accordance with the JBI guideline for prevalence and incidence review. Study reporting will follow the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guideline.

Prospero registration number

CRD42021238656.

Smoking cessation: health system challenges and opportunities

The systematic integration of evidence-based tobacco treatment has yet to be broadly viewed as a standard-of-care. The Framework Convention on Tobacco Control recommends the provision of support for tobacco cessation. We argue that the provision of smoking cessation services in clinical settings is a fundamental clinical responsibility and permits the opportunity to more effectively assist with cessation. The role of clinicians in prioritising smoking cessation is essential in all settings. Clinical benefits of implementing cessation services in hospital settings have been recognised for three decades-but have not been consistently provided. The Ottawa Model for Smoking Cessation has used an 'organisational change' approach to its introduction and has served as the basis for the introduction of cessation programmes in hospital and primary care settings in Canada and elsewhere. The significance of smoking cessation dwarfs that of many preventive interventions in primary care. Compelling evidence attests to the importance of providing cessation services as part of cancer treatment, but implementation of such programmes has been slow. We recognise that the provision of such services must reflect the realities and resources of a particular health system. In low-income and middle-income countries, access to treatment facilities pose unique challenges. The integration of cessation programmes with tuberculosis control services may offer opportunities; and standardisation of peri-operative care to include smoking cessation may not require additional resources. Mobile phones afford unique opportunities for interactive cessation programming. Health system change is fundamental to improving the provision of cessation services; clinicians can be powerful advocates for such change.

Lower Limb Amputation Rates in Germany

Background and Objectives: The current epidemiology of lower limb amputations is unknown. Therefore, the purpose of this study was to determine (1) lower extremity amputation rates as a function of age, gender, and amputation level between 2015 and 2019, (2) main diagnoses indicating amputation, (3) revision rates after lower extremity amputation. Materials and Methods: Lower extremity amputation rates were quantified based on annual Operation and Procedure Classification System (OPS) and International Classifications of Disease (ICD)-10 codes from all German medical institutions between 2015 through 2019, provided by the Federal Statistical Office of Germany (Destatis). Results: In 2019, 62,016 performed amputations were registered in Germany. Out of these 16,452 procedures (26.5%) were major amputations and 45,564 patients (73.5%) underwent minor amputations. Compared to 2015, the incidence of major amputations decreased by 7.3% to 24.2/100,000 inhabitants, whereas the incidence of minor amputation increased by 11.8% to 67.1/100,000 inhabitants. Highest incidence was found for male patients aged 80-89 years. Patients were mainly diagnosed with peripheral arterial disease (50.7% for major and 35.7% for minor amputations) and diabetes mellitus (18.5% for major and 44.2% for minor amputations). Conclusions: Lower limb amputations remain a serious problem. Further efforts in terms of multidisciplinary team approaches and patient optimization strategies are required to reduce lower limb amputation rates.

The association between socioeconomic distress communities index and amputation among patients with peripheral artery disease

Background

Socioeconomic factors have been shown to be associated with amputation in peripheral artery disease (PAD); however, analyses have normally focused on insurance status, race, or median income. We sought to determine whether community-level socioeconomic distress was associated with major amputation and if that association differed by race.

Materials and methods

Community-level socioeconomic distress was measured using the distressed communities index (DCI). The DCI is a zip code level compositive socioeconomic score (0-100) that accounts for unemployment, education level, poverty rate, median income, business growth, and housing vacancies. A distressed community was defined as a zip code with DCI of 40 or greater. We calculated one-year risk of major amputation by DCI score for individuals with peripheral artery disease in South Carolina, 2012-2017. Treating death as competing event, we reported Fine and Gray subdistribution hazards ratios (sdHR), adjusted for patient demographic and clinical comorbidities associated with amputation. Further analyses were completed to identify potential differences in outcomes within strata of race and DCI.

Results

Among 82,848 individuals with peripheral artery disease, the one-year incidence of amputation was 3.5% (95% CI: 3.3%, 3.6%) and was significantly greater in distressed communities than non-distressed communities (3.9%; 95% CI: 3.8%, 4.1% vs. 2.4%; 95% CI: 2.2%, 2.6%). After controlling for death and adjusting for covariates, we found an increased hazard of amputation among individuals in a distressed community (sdHR: 1.25; 95% CI: 1.14, 1.37), which persisted across racial strata. However, regardless of DCI score, Black individuals had the highest incidence of amputation.

Conclusion

Socioeconomic status is independently predictive of limb amputation after controlling for demographic characteristics and clinical comorbidities. Race continues to be an important risk factor, with Black individuals having higher incidence of amputation, even in non-distressed communities, than White individuals had in distressed communities.

Treatment of Peripheral Arterial Occlusive Disease around the Globe: Malta

INTRODUCTION

Malta is a small island in the middle of the Mediterranean with a population of 514,564 inhabitants and is served by one public tertiary hospital, Mater Dei Hospital. The Vascular unit was set up in 2007. The aim of this review is to analyse the work related to peripheral arterial occlusive disease (PAOD) in Malta with an in-depth focus on amputations and revascularisation procedures since the introduction of the Vascular unit.

METHOD

Various sources of data have been interrogated to address this subject. Population and prevalence data on obesity and type II diabetes mellitus from 2003 to 2019 was obtained from the National Statistics Office, the World Health Organization, and the International Diabetes Federation, respectively. The Maltese Vascular Register (MaltaVasc), and in-hospital reports from 2003 to 2019 was used to obtain data on revascularisation procedures, major amputations and minor amputation rates in Malta.

RESULTS

Malta has one of the highest rates of obesity in Europe. In 2015, the prevalence rate was 30.6%. Similarly, data from the International Diabetes Federation Atlas showed that the prevalence rate of T2DM among adults was 14% in 2017. There was a mean of 33 open/hybrid procedures per 100,000 population (28-38, 95% confidence interval) between 2005 and 2009 and a mean of 57 endovascular procedures per 100,000 population (46-68, 95% confidence interval) during the same time-period. From 2009 to 2019, there was a mean of 16 major amputations and 78 minor amputations per 100,000 population.

CONCLUSION

A significant reduction in major amputation rates with an increase in minor amputation rates and revascularisation rates has been noted since the establishment of the vascular unit in Malta. During this period, there has been an increase in prevalence in obesity and T2DM together with an aging population.

Up and down waves of glycemic control and lower-extremity amputation in diabetes

Lower extremity amputations (LEA) are associated with a high mortality and medical expenditure. Diabetes accounts for 45% to 70% of LEA and is one of the most potent risk factors for peripheral artery diseases (PAD). The existence of a link between the recent relaxation of glycemic targets and the resurgence of LEA is suggested from the analysis of adult participants in the National Health and Nutrition Examination Survey (NHANES) between 2010 and 2015, when diabetes-related LEA increased by more than 25% associated with a decline in glycemic control. Indeed, in “the perfect wave” of NHANES, including the years 2007–2010, there was the highest number of diabetic people with hemoglobin A1c (HbA1c), non-high-density lipoprotein (HDL) cholesterol and blood pressure levels at their respective targets, associated with the lowest number of LEA. Until now, the ACCORD study, testing the role of aggressive vs conventional glucose control, and the LEADER trial, evaluating the effects of liraglutide versus placebo, have shown a reduced incidence of LEA in people with type 2 diabetes. The results of ongoing clinical trials involving glucagon-like peptide-1 receptor agonists (GLP-1RA, liraglutide or semaglutide) hopefully will tell us whether the wider use of these drugs may provide additional vascular benefits for diabetic people affected by PAD to decrease their risk of LEA.

Contemporary Medical Management of Peripheral Artery Disease

Peripheral artery disease (PAD) is a manifestation of systemic atherosclerosis. Modifiable risk factors including cigarette smoking, dyslipidemia, diabetes, poor diet quality, obesity, and physical inactivity, along with underlying genetic factors contribute to lower extremity atherosclerosis. Patients with PAD often have coexistent coronary or cerebrovascular disease, and increased likelihood of major adverse cardiovascular events, including myocardial infarction, stroke and cardiovascular death. Patients with PAD often have reduced walking capacity and are at risk of acute and chronic critical limb ischemia leading to major adverse limb events, such as peripheral revascularization or amputation. The presence of polyvascular disease identifies the highest risk patient group for major adverse cardiovascular events, and patients with prior critical limb ischemia, prior lower extremity revascularization, or amputation have a heightened risk of major adverse limb events. Medical therapies have demonstrated efficacy in reducing the risk of major adverse cardiovascular events and major adverse limb events, and improving function in patients with PAD by modulating key disease determining pathways including inflammation, vascular dysfunction, and metabolic disturbances. Treatment with guideline-recommended therapies, including smoking cessation, lipid lowering drugs, optimal glucose control, and antithrombotic medications lowers the incidence of major adverse cardiovascular events and major adverse limb events. Exercise training and cilostazol improve walking capacity. The heterogeneity of risk profile in patients with PAD supports a personalized approach, with consideration of treatment intensification in those at high risk of adverse events. This review highlights the medical therapies currently available to improve outcomes in patients with PAD.

Advances in Revascularization for Peripheral Artery Disease: Revascularization in PAD

Effective revascularization of the patient with peripheral artery disease is about more than the procedure. The approach to the patient with symptom-limiting intermittent claudication or limb-threatening ischemia begins with understanding the population at risk and variation in clinical presentation. The urgency of revascularization varies significantly by presentation; from patients with intermittent claudication who should undergo structured exercise rehabilitation before revascularization (if needed) to those with acute limb ischemia, a medical emergency, who require revascularization within hours. Recent years have seen the rapid development of new tools including wires, catheters, drug-eluting technology, specialized balloons, and biomimetic stents. Open surgical bypass remains an important option for those with advanced disease. The strategy and techniques employed vary by clinical presentation, lesion location, and lesion severity. There is limited level 1 evidence to guide practice, but factors that determine technical success and anatomic durability are largely understood and incorporated into decision-making. Following revascularization, medical therapy to reduce adverse limb outcomes and a surveillance plan should be put in place. There are many hurdles to overcome to improve the efficacy of lower extremity revascularization, such as restenosis, calcification, microvascular disease, silent embolization, and tools for perfusion assessment. This review highlights the current state of revascularization in peripheral artery disease with an eye toward technologies at the cusp, which may significantly impact current practice.

Racial and Ethnic Disparities in Peripheral Artery Disease

Peripheral artery disease is an obstructive, atherosclerotic disease of the lower extremities causing significant morbidity and mortality. Black Americans are disproportionately affected by this disease while they are also less likely to be diagnosed and promptly treated. The consequences of this disparity can be grim as Black Americans bear the burden of lower extremity amputation resulting from severe peripheral artery disease. The risk factors of peripheral artery disease and how they differentially affect certain groups are discussed in addition to a review of pharmacological and nonpharmacological treatment modalities. The purpose of this review is to highlight health care inequities and provide a review and resource of available recommendations for clinical management of all patients with peripheral artery disease.