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

Delayed or forgone medical care associated with increased resource utilization and health care expenditures among patients with peripheral artery disease in the United States

OBJECTIVE

Peripheral artery disease (PAD) affects >12 million Americans and poses significant financial burdens on patients, but the relationship between delayed/forgone (D/F) care and resource use in this population is unknown. We sought to assess the relationship between D/F care, resource use, and health care expenditures among patients with PAD.

METHODS

Adults with PAD in the United States were identified in the Medical Expenditure Panel Survey for years 2007 to 2017. Unweighted counts of reasons for D/F care were tabulated. Proportions of patients with ≥1 emergency department (ED), ≥1 inpatient, ≥1 outpatient, and >5 office-based encounters were compared using Rao-Scott adjusted χ2 tests. Annual per capita total, out-of-pocket, ED, inpatient, outpatient, office-based visits, and prescription medication expenditures were compared using two-part econometric models.

RESULTS

The study cohort included 2,926,654 patients with PAD. Among the 264,172 patients with PAD (9%) reporting D/F care, 41.2% of patients cited financial barriers as the primary reason for D/F care. There were greater proportions of patients with ≥1 ED visits (52% vs 31%; P < .001), ≥1 outpatient hospital visits (56% vs 43%; P = .004), and >5 office-based visits (81% vs 71%; P = .04) among those reporting D/F care vs those who did not. Patients with D/F care had $7742 (95% confidence interval, $3170-$12,314; P = .001) greater per capita total and $5156 (95% confidence interval, $692-$9,619; P = .02) greater per capita inpatient expenditures per year than patients without D/F care.

CONCLUSIONS

D/F care is associated with increased resource use and health care expenditures among patients with PAD. Further work is needed to elucidate the underlying causes of D/F care and mitigate financial burdens on patients with PAD.

Advances in Cell-based therapies for peripheral arterial disease

PURPOSE

To examine recent advances in cell-based therapies for peripheral arterial disease (PAD), focusing on mechanisms of action, clinical applications, and regulatory considerations. The review aimed to evaluate the therapeutic potential of various cell types and assess their efficacy in addressing the unmet needs of PAD patients,particularly those with critical limb ischemia (CLI).

METHODS

The review analysed current literature on cell-based therapies for PAD, including preclinical studies using animal models, clinical trials from phase I to III, and regulatory frameworks. Multiple cell types were evaluated, including mesenchymal stem cells (MSCs), endothelial progenitor cells (EPCs), bone marrow mononuclear cells (BMMNCs),and adipose-derived stem cells (ADSCs).

RESULTS

Preclinical studies demonstrated significant improvements in limb perfusion and neovascularization across various cell types. Clinical trials, particularly those utilizing MSCs and BM-MNCs, showed encouraging outcomes in wound healing and reduced amputation rates. The therapeutic effects were mediated through multiple mechanisms, including direct vessel formation, paracrine signalling, immunomodulation, and tissue repair. The FDA's implementation of a tiered, risk-based system for human cells, tissues, and cellular and tissue-based products (HCT/Ps) has provided a regulatory framework balancing innovation with safety.

CONCLUSION

Cell-based therapies show promising potential for PAD treatment, particularly for patients with limited conventional treatment options. While clinical trials demonstrate encouraging results, challenges remain in standardizing cell characterization methods and establishing appropriate potency assays. Future research should focus on optimizing cell delivery methods, identifying the most effective cell types, and conducting larger clinical trials to establish definitive efficacy.

Single-cell transcriptome integrated with genome-wide association study reveals heterogeneity of carotid and femoral plaques and its association with plaque stability

Carotid and femoral plaques exhibit varying degrees of stability; however, the relationships of different genes/cell types with plaque embolism are poorly understood. We evaluated differential gene/cell expression and investigated the cells/genes associated with carotid and femoral artery plaque embolism. sc-RNA-seq and bulk RNA data were obtained to identify differentially expressed genes (DEGs). Seven machine learning models were trained, and the top 10 DEGs across all models were selected. The most disturbed cells in carotid and femoral artery plaques were identified using Augur, while the genes and cells in the carotid plaque associated with embolism were analyzed through scPagwas. The differences in most disturbed cells and embolism-related cells were further analyzed. Compared with femoral plaques, carotid plaques had 80 downregulated and 90 upregulated genes. Machine learning identified the key DEGs between carotid and femoral plaques were predominantly from the HOX gene family. Natural Killer (NK) cells were the most significantly disturbed cells between carotid and femoral plaques, and they may be most strongly associated with plaque embolism. Among the differential genes in NK cells, CD2 was most associated with embolism. Our research may offer new insights into atherosclerosis at different locations.

Impact of Peripheral Arterial Disease on Clinical Outcomes of Patients Undergoing Complex vs Noncomplex Percutaneous Coronary Intervention

Peripheral arterial disease (PAD) often predicts poor outcomes in patients undergoing percutaneous coronary intervention (PCI). Here we examine the impact of PAD in patients receiving complex PCI (CPCI) and noncomplex PCI. Patients undergoing PCI at the Mount Sinai Hospital between 2012 and 2022 were stratified by the presence of CPCI and PAD. The primary outcome was major adverse cardiovascular events (MACE), a composite of death, myocardial infarction, target vessel revascularization, or stroke within 1 year; secondary endpoints included bleeding events. An adjusted Cox proportional hazard method was used to evaluate risks of each outcome within each subgroup. Among 20,376 patients, 8,200 (40.2%) had CPCI and 1,959 (9.6%) had PAD. PAD patients were older and more likely to be female and have risk factors such as diabetes and smoking and were more commonly discharged with anticoagulants. 1-year risk of MACE was significantly higher for patients with PAD in both CPCI (19.6% vs 14.4%, adj. hazard ratio [HR] 1.31, 95% confidence interval [CI] 1.08 to 1.58, p = 0.006) and no-CPCI strata (13.9% vs 9.2%, adj. HR 1.35, 95% CI 1.12 to 1.64, p = 0.002; p-interaction = 0.349). Bleeding events were also more frequent in PAD patients for CPCI (8.5% vs 5.5%, adj. HR 1.40, 95% CI 1.07 to 1.84, p = 0.014) and no-CPCI (7.1% vs 4.3%, adj. HR 1.52, 95% CI 1.18 to 1.96, p = 0.001; p-interaction = 0.608). In conclusion, presence of PAD is associated with a significantly increased risk of MACE and bleeding after PCI, regardless of procedural complexity.

Comparison of Local and General Anesthesia on 30-Day Outcomes of Emergency Infrainguinal Endovascular Revascularization for Patients with Chronic Limb-Threatening Ischemia

BackgroundInfrainguinal endovascular interventions can be the first-choice treatment for suitable patients with peripheral artery disease (PAD). However, the choice of anesthesia for infrainguinal endovascular procedures, particularly in emergency situations, remains underexplored. This study aimed to conduct a retrospective analysis based on a multi-institutional nationwide registry to compare the 30-day outcomes of patients with chronic limb-threatening ischemia (CLTI) who received either local anesthesia (LA) or general anesthesia (GA) during emergency infrainguinal endovascular interventions.MethodsPatients who underwent emergency infrainguinal endovascular revascularization for CLTI (tissue loss or rest pain) were selected from the ACS-NSQIP database from 2012-2022. Multivariable logistic regression was used to compare 30-day outcomes between patients under GA and LA, where demographics, baseline characteristics, and symptomatology were adjusted.ResultsAmong 703 patients, 292 (41.54%) were under LA, and 411 (58.46%) were under GA. Patients under LA had lower bleeding requiring transfusion (aOR = 0.428, 95 CI = 0.281-0.653, P < 0.01), lower postoperative wound complications (aOR = 0.289, 95 CI = 0.137-0.612, P < 0.01), and shorter operative time (102.00 ± 72.38 vs 150.70 ± 105.40 minutes, P < 0.01). All other 30-day outcomes, including mortality, organ system complications, and limb-specific outcomes, were comparable between patients under LA and GA.ConclusionLA and GA can be considered equivalent options for eligible CLTI patients undergoing emergency infrainguinal endovascular revascularization, with close monitoring of wound and bleeding complications recommended for GA patients. Further studies are necessary to evaluate long-term outcomes in these patients.

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.

Thirty-day outcomes from the Disrupt PAD BTK II study of the Shockwave Intravascular Lithotripsy System for treatment of calcified below-the-knee peripheral arterial disease

BACKGROUND

Below-the-knee (BTK) lesions may be particularly challenging to treat owing to length, diffuse disease, and extent of calcification. Landmark interventional clinical studies have not reached consensus on the optimal standard of care for BTK lesions, and many published trials excluded patients with moderate or severe lesion calcification. Calcium modification with intravascular lithotripsy (IVL) was shown to be superior to percutaneous transluminal angioplasty in the femoropopliteal artery and successful in treating BTK lesions in pilot studies. The Disrupt BTK II study is a core laboratory-adjudicated, prospective, multicenter, single-arm study of patients with moderate to severely calcified BTK lesions treated with the Shockwave Medical Peripheral IVL System.

METHODS

Disrupt BTK II enrolled 250 subjects with calcified infrapopliteal lesions and Rutherford category 3-5 presentation from 38 sites in the United States and Europe. The primary safety endpoint was major adverse limb events or postoperative death at 30 days, a composite of all-cause death, above-ankle amputation of the index limb, and/or major reintervention of the index limb involving an infrapopliteal artery. The primary effectiveness endpoint was procedural success, defined as ≤50% residual stenosis for all treated target lesions without serious core laboratory-adjudicated serious angiographic complications. The study used independent angiographic and duplex ultrasound core laboratories, and follow-up is planned through 2 years.

RESULTS

A total of 305 lesions in 250 patients were treated with a procedural success of 97.9%. The mean target lesion length was 76 ± 65 mm, diameter stenosis was 78% ± 18%, and 84.8% had moderate or severe calcification as assessed by an independent angiographic core laboratory. After IVL, residual stenosis was reduced to 29%, and after optional postdilatation and/or stent implantation, to 26%. At 30 days, there were no deaths, major adverse limb event rate was 0.8%, and mean improvement in Vascular Quality of Life scores was 4.0 ± 5.0 (P < .0001). Of the patients with baseline wounds, 15.8% healed and 53.4% were improved at 30 days.

CONCLUSIONS

The Disrupt PAD BTK II study demonstrated that treatment with the Shockwave Medical Peripheral IVL System in patients with moderate-severe calcified lesions resulted in high procedural success, significant reduction in residual stenosis, improvements in patient quality of life, and wound healing, with minimal adverse events at 30-day follow-up.

The Impact of Follow-Up on Mortality in Chronic Limb-Threatening Ischemia

BACKGROUND

Chronic limb-threatening ischemia (CLTI) is associated with high morbidity and mortality. As such, close follow-up is recommended to ensure patency of revascularization, limb viability, and optimization of cardiovascular risk factors. This study aimed to test the association between follow-up adherence and mortality, and to identify risk factors for nonadherence with recommended vascular follow-up.

METHODS

All patients hospitalized from 2019 to 2023 with infrainguinal CLTI and at least 30 days of posthospitalization survival were included. Patients were stratified based on adherence with any outpatient vascular follow-up within 1 year defined as any outpatient visit conducted after the index hospitalization in which CLTI of the index limb was addressed. The primary endpoint was 1-year mortality and risk factors for follow-up nonadherence were assessed to identify targets for improvement. Multivariable models adjusted for other relevant contributors to mortality including age, clinical comorbidities, medical therapies, and anatomic/clinical limb severity among others. Additional sensitivity analyses were conducted using various definitions of follow-up adherence to enhance reliability of the findings.

RESULTS

A total of 131 patients with a median age of 73 years were included. A majority had tissue loss (97, 74.1%), 118 (90.1%) underwent index revascularization and 13 (9.9%) received no intervention due to nonsalvageable disease or patient preference. The overall 1-year mortality rate was 19.8% and follow-up adherence was 83.2%. Nonadherence with vascular follow-up was associated with greater 1-year mortality (40.9% vs. 15.6%, odds ratio (OR) 6.67, P = 0.005), a finding which persisted when all definitions of follow-up were tested. Risk factors for follow-up nonadherence include transfer from another institution (30.2% vs. 10.2%, OR 3.704, P = 0.014) and lack of a primary care provider (66.7% vs. 11.8%, OR 14.603, P < 0.001).

CONCLUSIONS

Nonadherence with vascular follow-up is associated with higher 1-year mortality among patients with CLTI. Improved referral of CLTI patients to a vascular surgeon in the outpatient setting before the need for urgent interhospital transfer as well as care coordination through a primary care provider may help improve adherence with vascular follow-up.

Racial Variability in Platelet Response Among Patients With Peripheral Artery Disease

INTRODUCTION

Peripheral artery disease (PAD) is prevalent among the elderly population, with Black Americans facing a higher incidence and complications than White Americans. Antiplatelet therapy is crucial for PAD. This observational study aims to discern racial variability in platelet function using viscoelastic assays in patients' postrevascularization for PAD.

METHODS

Patients with PAD who underwent revascularization between December 2020 and October 2023 were prospectively enrolled. The cohort was divided by race and antiplatelet therapy regimen. Serial perioperative Thromboelastography with Platelet Mapping assays were performed, and the platelet function was evaluated.

RESULTS

A total of 42 patients met the study criteria, and 99 samples were analyzed. In the Thromboelastography with Platelet Mapping assay, the White-Americans cohort showed a significantly lower maximum amplitude (clot strength), lower percentage of platelet aggregation (platelet reactivity), and a significantly higher percentage of platelet inhibition than Black, Asian, and Hispanic Americans on the same antiplatelet regimen.

CONCLUSIONS

These findings suggest potential racial disparities in platelet response to standard medications, highlighting the critical need for personalized pharmacological approaches that account for genetic and physiological variations across different ethnic populations. Further research is essential to elucidate the underlying mechanisms of these differential platelet responses, which could have significant implications for precision medicine and targeted therapeutic strategies.

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.

Optimizing Patients With Chronic Obstructive Pulmonary Disease Preoperatively May Reduce Complications and Improve Outcomes in Infrainguinal Endovascular Revascularization

BACKGROUND

Peripheral artery disease (PAD) and chronic obstructive pulmonary disease (COPD) are both systemic inflammatory diseases that may share similar pathophysiological pathways. Given their potential overlap, the impact of COPD on perioperative outcomes following infrainguinal endovascular revascularization warrants further examination. Therefore, this study aimed to analyze the 30-day postoperative outcomes for COPD patients after infrainguinal endovascular revascularization.

METHODS

Chronic obstructive pulmonary disease and non-COPD patients who underwent infrainguinal endovascular revascularization were identified in the ACS-NSQIP database from 2012 to 2022. Exclusion criteria included aged less than 18 years and emergency cases. A 1:1 propensity-score matching was used to match demographics, baseline characteristics, symptomatology, and anesthesia. Thirty-day postoperative outcomes were compared.

RESULTS

Of 24 223 patients who underwent infrainguinal endovascular revascularization, 2472 (10.21%) had COPD. All COPD patients were 1:1 propensity-score-matched to the non-COPD patients. Chronic obstructive pulmonary disease patients had higher risks of mortality (3.24% vs 2.18%, p=0.03), major adverse cardiovascular events (MACE) (3.48% vs 2.47%, p=0.04), pulmonary complications (3.24% vs 2.02%, p=0.01), and 30-day readmission (15.41% vs 13.23%, p=0.03). All other 30-day outcomes were comparable between the groups.

CONCLUSION

Chronic obstructive pulmonary disease independently increases the risk of 30-day mortality and cardiopulmonary complications after infrainguinal endovascular revascularization. Identification and optimization of COPD patients before considering invasive treatment can be important for preventing complications. Patients may undergo mini-spirometry to screen for COPD. If identified, COPD patients may begin intensive inhalation therapy and medical treatment prior to the surgery.

CLINICAL IMPACT

Both PAD and COPD are systemic inflammatory diseases that may share similar pathophysiological pathways. This study analyzed the 30-day postoperative outcomes for COPD patients after infrainguinal endovascular revascularization. It was found that COPD independently increases the risk of mortality, cardiopulmonary complications, and 30-day readmissions. Identification and optimization of COPD patients before considering invasive treatment can be important for preventing complications in infrainguinal endovascular revascularization. Patients may undergo mini-spirometry to screen for COPD. If identified, COPD patients may begin intensive inhalation therapy and medical treatment prior to the surgery.

An assessment of the BEST-CLI Trial demonstrates that infrainguinal bypass offers a potential advantage in smokers with chronic limb-threatening ischemia

OBJECTIVE

Smoking is an established risk factor in many pathologies of the cardiovascular system. The Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) trial affords an in-depth evaluation into the effect of smoking on patients with chronic limb-threatening ischemia (CLTI). BEST-CLI's prospective, randomized design evaluated outcomes in patients suitable for both open or endovascular intervention and randomized patients between endovascular intervention (ENDO) vs open surgical bypass (OPEN). The outcomes are reported stratified by smoking status.

METHODS

In the BEST-CLI trial, patients were stratified by current smokers (CS) and nonsmokers (NS), which included both previous smokers or never smokers. Endpoints at 4 years include the primary trial outcomes (major adverse limb events [MALE] or all-cause death), as well as above-ankle amputation, all-cause death, major or minor reintervention, major adverse cardiac events (MACE), MALE, and MALE or perioperative death. Multivariable Cox regression models were created with NS serving as the reference group.

RESULTS

Patients received bypass using single-segment saphenous vein (n = 621), bypass using alternative conduits (n = 236), or endovascular procedures (n = 923). There were 641 CSs and 1137 NSs. In the combined cohort of patients receiving ENDO or OPEN, CS status was associated with a higher rate of MALE (hazard ratio [HR], 1.27; 95% confidence interval [CI], 1.05-1.55; P = .02) but a lower rate of all-cause death (HR, 0.80; 95% CI, 0.66-0.97; P = .02) when compared with NS status. In the OPEN group, CSs had a lower rate of all-cause death (HR, 0.74; 95% CI, 0.56-0.98; P = .04) than NSs and no significant difference in MALE (HR, 1.18; 95% CI, 0.85-1.63; P = .34). In the ENDO group, CSs had a higher rate of above-ankle amputation (HR, 1.51; 95% CI, 1.04-2.19; P = .03) and MALE (HR, 1.33; 95% CI, 1.04-1.69; P = .02). Additionally, on subset analysis of the entire cohort, it was found that, when comparing prior smokers to never-smokers, there was a 24% increase in reintervention (P = .05), and when comparing CSs to never smokers, there was a 27% increase in reintervention (P = .04).

CONCLUSIONS

CSs had worse limb outcomes in the BEST-CLI trial. CSs undergoing endovascular revascularization had higher rates of MALE and above-ankle amputations following adjustment. Current smoking did not impact MALE in patients with CLTI undergoing open surgical bypass.

Pilot study protocol for a novel perioperative mind-body intervention for peripheral vascular interventions

Background

A novel mind-body intervention (MBI) targeting vascular surgery patients undergoing peripheral vascular interventions (PVIs) under procedural sedation and analgesia (PSA) was recently developed, but has yet to be clinically tested. An exploratory randomized controlled trial is planned to test the novel intervention in patients undergoing PVIs under PSA.

Methods

Patients undergoing PVIs under PSA by vascular surgeons across four hospitals in Massachusetts and New Hampshire will be screened for enrollment. Exclusion criteria include urgent or emergent procedures, prior ipsilateral lower extremity amputations (including digit amputations) and non-English speakers. 30 patients will be enrolled and randomized 1:1 to either a perioperative MBI on the day of surgery (n = 15), or a standard of care control (n = 15). There would be no restriction on anesthesia practice, and collected data will include perioperative pain and sedation requirements and qualitative feedback from both the patients and perioperative staff.

Conclusions

This protocol delineates a pilot randomized controlled trial to test the feasibility and acceptability of a novel perioperative MBI for patients undergoing PVIs under PSA.

Understanding the Prevalence of Medial Arterial Calcification Among Complex Reconstructive Patients: Insights from a Decade of Experience at a Tertiary Limb Salvage Center

Background: Medial arterial calcification (MAC), a distinct form of vascular pathology frequently coexisting with peripheral arterial disease (PAD), poses unique challenges in limb salvage among patients with diabetes, chronic kidney disease, and end-stage renal disease. This study examines the incidence of MAC and its impact on limb salvage outcomes over a decade of experience at a tertiary limb salvage center. Methods: A retrospective review of all complex lower extremity (LE) reconstructions using local flap (LF) or free tissue transfer (FTT), performed from July 2011 to September 2022, was conducted. Patients were classified into MAC and No MAC groups based on pedal radiography evaluations using the Ferraresi MAC scoring system. The primary outcomes were major lower extremity amputation (MLEA), the need for postoperative vascular intervention, major adverse limb events (MALE; defined as the composite of any unplanned reoperation, MLEA, or postoperative revascularization attempt), and mortality. Results: During the study period, a total of 430 LE reconstructions were performed with LF or FTT. A total of 323 cases (75.1%) demonstrated no MAC while the remaining 107 (24.9%) demonstrated MAC. The MAC group exhibited significantly higher rates of diabetes, PAD, and renal disease. With a follow-up duration of 17.0 (IQR: 33.9) months, the MAC group demonstrated a significantly higher rate of MLEA (24.3% vs. 13.0%, p = 0.006), postoperative vascular intervention (23.4% vs. 8.7%, p < 0.001), MALE (57.0% vs. 25.7%, p < 0.001), and mortality (28.0% vs. 9.9%, p < 0.001). Multivariate analysis identified MAC as independently predictive of MALE (OR: 1.8, CI: 1.1-3.0, p = 0.033). Conclusion: MAC is prevalent among surgical candidates for limb salvage. Patients with MAC represent a significant medical and reconstructive challenge. Radiographic screening for MAC should be considered in all limb salvage candidates with LE wounds, especially in those with diabetes and kidney disease. Assessing MAC is important for better evaluating risk factors and surgical options so as to optimize outcomes in this challenging population.

Discrepancy in opioid prescription patterns for Black or African American patients following lower extremity bypass surgery for chronic limb-threatening ischemia

BACKGROUND

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

METHODS

Retrospective analysis was conducted on adult CLTI patients who underwent LEB from 2000 to 2023 in the TrinetX database. Patients were stratified into two groups based on race: White (group I) and black or African American (AA) (group II). Primary outcomes were defined as oral opioid prescriptions at 7 days and 30 days after discharge, and mortality at 1 year postoperatively. Secondary outcomes included length of stay and 30-day postoperative outcomes, including myocardial infarction, pulmonary embolism, cerebral vascular accident, deep vein thrombosis, acute kidney injury, major amputation, minor amputation, major adverse cardiac events, and major adverse limb events. Stratified analysis was conducted based on disease stage (rest pain vs lower extremity ulcer vs gangrene). Univariate analysis was performed via two-sample t test and χ2 test. Logistic regression was performed to estimate the association of Black or AA (vs White) race while controlling for pertinent preoperative potential confounders.

RESULTS

There were 3345 patients who met the inclusion criteria. Group I included 2661 White patients and group II included 684 Black or AA patients. Group II patients were more likely to be younger, female, present with gangrene, and have a history of hypertension, diabetes, chronic kidney disease, or diabetic neuropathy. At both 7 and 30 days after discharge, the Black or AA cohort had significantly lower rates of opioid prescriptions (33.2% vs 42.5% and 35.8% vs 47.2%, respectively) (all P < .05). Stratification by indication showed that opioid prescription disparity persisted despite black or AA patients presenting at worse stages of disease both at 7 and 30 days after discharge (7 days: rest pain 43.4% vs 33.7% [P = .013], ulcer 41.4% vs 31.7% [P = .027], gangrene, 42.7% vs 33.6% [P = .006] and 30 days: rest pain 47.8% vs 37.1% [P = .007], ulcer 45.4% vs 33.5% [P = .007], gangrene, 48.2% vs 36.1% [P < .001]). Adjusted analysis confirmed that Black or AA race was associated with lower rates of 7- (adjusted odds ratio, 0.607; P = .001) and 30-day (adjusted odds ratio, 0.56; P = .001) postdischarge opioid prescriptions.

CONCLUSIONS

Black or AA patients were less likely to receive postdischarge opioid prescriptions compared with their White counterparts at 7 and 30 days after LEB for CLTI.

Twelve-month health status response after peripheral vascular intervention for femoropopliteal lesions using Zilver PTX databases focusing on the role of preprocedural health status, comorbid risks, and global setting

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

The majority of patients reported improved or stable health status after femoral-popliteal PVI. Approximately 4 in 10 patients were nonresponders, with the highest risk for nonresponse including individuals with existing carotid disease or those undergoing PVIs in the U.S. vs non-U.S.

SETTINGS

Smoking Status Impacts Mitochondrial Function and Synthetic Function in Mesenchymal Stem Cells Derived from Diabetics with Arterial Insufficiency

Objective: Diabetes and smoking are frequently co-morbid conditions leading to arterial insufficiency, significantly increasing the risk of non-healing wounds and subsequent major amputation. Autologous patient-specific mesenchymal stem cells (MSCs) present a novel tool for regenerative therapy to treat advanced stages of arterial insufficiency. The regenerative performance of cells from diabetics with impaired arterial perfusion is known to be reduced, but the impact of additional patient factors such as smoking remains poorly understood. Approach: MSCs were harvested from amputees under IRB approval. Mitochondria were evaluated for mitophagy and bioenergetic function. MSC growth, reactive oxygen species (ROS), and synthetic function were measured. Exogenous nicotine was used to mimic smoking byproducts. Data were analyzed by one-way analysis of variance with p < 0.05 considered statistically significant. Results: Four MSC patient lines were from smokers and four were from non-smokers. All were male, diabetic, and matched for age. Mitochondrial turnover, ROS production, proliferation, and doubling time were comparable between groups. Smoking status significantly decreased glycolytic capacity, maximal mitochondrial respiration, and the synthetic function of MSCs compared with non-smokers (p < 0.05). Acute nicotine exposure in non-smoker MSCs significantly increased mitochondrial function, an effect that incompletely resolved with nicotine withdrawal (p < 0.001). Innovation: This study implicates mitochondrial dysfunction in smoking-mediated impairment of MSC synthetic function. Conclusion: Smoking alters mitochondrial bioenergetics and synthetic function of MSCs from diabetic patients with arterial insufficiency. Restoring mitochondrial function may improve synthetic function and therapeutic capabilities of smoker MSCs. Targeted rejuvenation strategies may be required based on smoking status for autologous MSC therapies for patients with arterial insufficiency.

Can simultaneous coronary and peripheral angiography alter the treatment planning in Fontaine stage IV peripheral arterial disease?

OBJECTIVES

Peripheral arterial disease (PAD) and coronary artery disease (CAD) are major contributors to global morbidity and mortality. Many PAD patients remain asymptomatic for CAD, which often leads to undetected coronary artery involvement. This hidden coronary disease poses significant risks, particularly following peripheral revascularization, as increased cardiac demand can precipitate complications.

METHODS

This cross-sectional descriptive study assessed the prevalence of coronary artery stenosis in patients with Fontaine Stage IV peripheral arterial disease. Simultaneous angiography of both the coronary and lower extremity arteries was performed, and the severity of arterial stenosis was rigorously evaluated. The correlation between the extent of peripheral and coronary artery disease was analyzed.

RESULTS

A total of 60 patients (63.3% male, 36.7% female; mean age 65.23 ± 9.86 years) were included. Comorbidities were common, with 90% having diabetes, 50% hypertension, 23.3% hyperlipidemia, and 30% smoking history. Severe peripheral artery stenosis was frequently observed, particularly in the posterior tibial artery (total occlusion in 26.6% and 20% of the right and left arteries, respectively). Significant coronary involvement was also prevalent, with 51.7% exhibiting three-vessel disease. Coronary revascularization was required in the majority of cases (CABG: 40%, PCI: 35%), with a higher proportion among women (77.2%) and men (73.7%).

CONCLUSION

This study highlights the necessity of comprehensive coronary evaluation in patients with advanced lower limb ischemia. A substantial proportion of these patients have silent but critical coronary disease, which, if left unaddressed, could result in serious post-revascularization complications.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Association of erectile dysfunction and peripheral arterial disease in NHANES 2001-2004: a cross-sectional study

Objective

To evaluate the association between Erectile dysfunction (ED) and peripheral arterial disease (PAD) in adult American males using a large database.

Methods

The relationship between ED and PAD prevalence among participants in the 2001-2004 National Health and Nutrition Examination Survey (NHANES) database was assessed using a series of statistical analyses. ED was evaluated based on a single-item measure of self-reported erection problems from the Massachusetts Male Aging Study. PAD was defined as ankle-brachial index (ABI) < 0.9 in at least one leg. Multifactorial logistic regression models were used to investigate the association between ED and PAD.

Results

A total of 2394 participants were enrolled, of whom 905 individuals (37.8%) were diagnosed with ED. After adjusting for confounding variables, the association between ED and PAD remained positive, with an odds ratio of 2.05 (95% confidence interval 1.24-3.39). Subgroup analysis revealed that the relationship between ED and PAD was significant in patients aged >50 years old, without hypertension, without diabetes, without cardiovascular disease, without high cholesterol, former smokers, low physical activity levels, and a body mass index of 25-30 (P < 0.05). In addition, all subgroups analyzed were evaluated for any potential interaction, and no statistically significant association was discovered.

Conclusions

In a sample of US adults aged ≥40, this cross-sectional study found that ED is related to a higher occurrence of PAD. ED may be an independent predictor of PAD, and thus it should be considered in the treatment of patients with ED.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Racial and ethnic representation in peripheral artery disease randomized clinical trials

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

Interaction and combined effect of triglyceride-glucose index and hypertension on type 2 diabetes individuals' peripheral arterial disease risk

BACKGROUND

The interaction and combined effect of the triglyceride-glucose (TyG) index, an alternative parameter of insulin resistance, along with hypertension (HT), on the risk of peripheral arterial disease (PAD), a specific type of atherosclerotic cardiovascular disease, in individuals with type 2 diabetes (T2D) seems straightforward. However, specific research on this topic remains scarce.

METHODS

In this cross-sectional study, 2027 adult participants with T2D were devided into four groups based on the mean values of TyG index and various blood pressure parameters along with its category. Binary logistic regression, interaction analysis, combined effect size, and goodness-of-fit of the constructed models were performed.

RESULTS

The TyG index's individual effect and it's combined effect with HT, or higher systolic blood pressure (SBP) or higher mean arterial pressure in patients with T2D correlated with a higher PAD risk respectively (odds ratio [OR], 0.50, [95% confidence interval {CI} 0.28-0.89]; OR, 0.32, [95% CI 0.12-0.90]; OR, 0.35, [95% CI 0.13-0.94]; OR, 0.35, [95% CI 0.12-0.98], respectively). Only an interaction effect exists between the TyG index and SBP (multiplicative interaction{INTM}: 1.02 [1.002, 1.038]). Combining them can significantly improve the accuracy of predicting PAD (area under the receiver operating characteristic curve {AUC}MAX = 0.7, AUCModel3 + TyG index + SBP-AUCModel3 = 0.027). All P values were < 0.05.

CONCLUSION

This study suggested that TyG index and hypertension, as well as their combined and interaction effect were significantly correlated with the risk of PAD in T2D individuals.

Ruanjian Qingmai Granules for the Treatment of Early Symptomatic Peripheral Arterial Disease: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Clinical Trial Protocol

Purpose

Peripheral arterial disease (PAD) is a chronic ischemic disease caused by atherosclerosis of the lower extremities, with early clinical symptoms manifesting mainly as intermittent claudication. Current treatment of PAD is based on the control of cardiovascular risk factors. However, even vasoactive drugs are not ideal for improving ischemic symptoms in the lower limbs of PAD patients. Ruanjian Qingmai granules, derived from the classic formula of the late Professor Jiuyi Xi, a famous traditional Chinese medicine doctor in Shanghai, have good clinical efficacy in the treatment of the pattern of blood vessel stasis and obstruction of PAD and have been used by more than 600,000 PAD patients over the past three decades. This study aims to evaluate the efficacy and safety of Ruanjian Qingmai granules in patients with symptomatic PAD.

Patients and methods

A prospective, center-randomized, double-blind, placebo-controlled clinical trial will be conducted at 9 grade A tertiary hospitals in Shanghai. It is anticipated that 250 patients with early symptomatic PAD will be recruited and randomized to the control and intervention groups (1:1 ratio of central randomization). Subjects will be treated with Ruanjian Qingmai granules or placebo at 6 g twice daily for 16 weeks. The primary efficacy indicators are the pain-free walking distance and maximum walking distance. The secondary efficacy indicators are the ankle-brachial index, walking impairment questionnaire, quality of life score, and Chinese medicine syndrome score.

Conclusion

Positive results from this study will demonstrate the efficacy and safety of Ruanjian Qingmai granules in improving ischemic symptoms in patients with symptomatic PAD.

Clinical Registration

This study has been registered with the Chinese Clinical Trials Registry (ChiCTR2200056109, Date: 02/01/2022, https://www.chictr.org.cn/showproj.html?proj=150982).

Metabolic and behavioural risk factors for cardiovascular diseases in Southern Latin America: analysis of the Global Burden of Disease 1990-2019

OBJECTIVES

Cardiovascular diseases (CVDs) are the leading causes of global mortality. Modifiable behavioural and metabolic risk factors significantly contribute to the burden of CVD. Given the vast socio-demographic and health outcome heterogeneity in Latin America, similar southern Latin American countries (Argentina, Chile, and Uruguay) were analysed as a distinct group to describe the CVD death rates related to metabolic and behavioural risk factors.

STUDY DESIGN

An ecological study was performed using data from the Global Burden of Disease Study 2019.

METHODS

Metabolic and behavioural risk factors-related CVD death were examined by analysing age-standardised rates per 100,000 individuals in the three countries between 1990 and 2019.

RESULTS

While exposure to behavioural risk is decreasing, an upwards trend was observed in metabolic risks. Among the assessed risk factors, metabolic factors emerged as the primary contributors to deaths. High fasting plasma glucose exhibited a remarkable increase in relative importance across most studied contexts. Dietary risks stood out among behavioural factors due to their complexity and substantial changes observed. Although mortality rates have declined for overall CVD, peripheral artery disease mortality is rising.

CONCLUSION

Modifiable behavioural and metabolic risk factors significantly influence CVD mortality in Southern Latin America. Despite the increasing exposure to metabolic risks, advancements in prevention and treatment are evidenced in the decline of mortality rates for most CVD. These findings emphasise the need for targeted interventions and comprehensive strategies to address their impact on cardiovascular health, advocating for healthy lifestyle behaviours to mitigate the progression and CVD development.

Long-Term Adverse Limb Events After Femoral Artery Endovascular Revascularization: The Boston FAROUT Study

Background

: Patient, lesion, and procedural characteristics may impact the long-term risks of adverse limb outcomes differently after successful endovascular revascularization for lower extremity peripheral artery disease. The study objective was to assess the relationships of patient, lesion, and procedural characteristics to the subsequent risk of major and minor adverse limb events over the decade after successful endovascular revascularization of the superficial femoral artery for chronic limb-threatening ischemia (CLTI) or lifestyle-limiting claudication.

Methods

A retrospective cohort of patients who underwent endovascular revascularization between 2003-2011 were followed for a median of 9.3 (IQR, 6.8-11.1) years. Hazard ratios (HR) and 95% CI from Cox proportional hazards models assessed the risk of major adverse limb events (MALE) (major amputation, bypass, or thrombolysis) or minor revascularization, MALE alone, and minor revascularization alone.

Results

There were 232 index limb revascularizations in 185 patients. Longer lesion length was associated with a higher risk of MALE or minor revascularization (HR, 2.09; 95% CI, 1.22-3.60) and minor revascularization alone (HR, 2.53; 95% CI, 1.39-4.61). Current smoking was linked with minor revascularization (HR, 3.83; 95% CI, 1.54-9.56). CLTI was associated with MALE or minor revascularization (HR, 1.89; 95% CI, 1.09-3.29), and MALE alone (HR, 7.43; 95% CI, 3.11-17.79). Black race/ethnicity (HR, 4.74; 95% CI, 1.51-14.9) and low-density lipoprotein >100 mg/dL (HR, 2.76; 95% CI, 1.20-6.35) were linked to MALE alone.

Conclusions

Factors related to MALE differed from those related to minor revascularization. Lesion length and smoking were linked to minor revascularization, whereas CLTI, Black race/ethnicity, and elevated low-density lipoprotein were linked to MALE.

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

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

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

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

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

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

The Impact of Sex on Antiplatelet and Anticoagulant Thromboprophylaxis in Patients With Peripheral Artery Disease Post-revascularization

OBJECTIVE

The aim of this prospective study was to (1) objectively quantify the impact of sex on platelet function in patients with peripheral artery disease (PAD) taking antiplatelet and anticoagulant medications and (2) to develop and test a personalized, iterative algorithm that personalizes thromboprophylaxis that incorporates platelet function testing.

BACKGROUND

Women with PAD have worse outcomes as compared with their male counterparts despite having lower risk factors. This health disparity may be mitigated by personalizing thromboprophylaxis regimens.

METHODS

Patients undergoing revascularization were enrolled. Serial thromboelastography (TEG) and TEG with platelet mapping (TEG-PM) were performed up to 6 months postoperatively to determine objective coagulation profiles. In a subset of patients, the Antiplatelet Coagulation Exactness (ACE) algorithm was implemented, where patients were iteratively evaluated with TEG and given antiplatelet medications to maintain platelet inhibition at >29%. Statistical analysis was performed using unpaired t test, analysis of variance, and Fisher exact test.

RESULTS

One hundred eighty-one patients met the study criteria. Fifty-eight (32%) patients were females and 123 (68%) were males. In the Aspirin cohort, females showed significantly greater clot strength as maximum amplitude - arachidonic acid (MA AA ) and significantly lower platelet inhibition than males: (37.26 vs 32.38, P <0.01) and (52.95% vs 61.65%, P <0.05), respectively. In the Clopidogrel cohort, females showed higher Maximum Amplitude - Adenosine Diphosphate (MA ADP ) (42.58 vs 40.35, P = not significant [NS]) compared with males. Females on dual antiplatelet therapy had higher MA ADP (39.74 vs 35.07, P =NS) and lower platelet inhibition (45.25% vs 54.99%, P= NS) than males. The incidence of thrombosis of the revascularized segment, defined as thrombotic event, was objectively identified on an arterial duplex. Women showed significantly higher thrombotic events than men (22.95% vs 10.57%, P< 0.05) on the same medication. In our pilot study, implementation of the ACE algorithm led to a significant decrease in the thrombosis rate (3%), including nonthrombotic events for females, versus the historic thrombotic rate (22%) from our institution.

CONCLUSIONS

Women with PAD exhibited higher platelet reactivity, clot strength, and reduced platelet inhibition in response to antiplatelet therapy. The use of the ACE algorithm to tailor antiplatelet medication in patients with PAD post-revascularization, resulted in a significant decrease in thrombotic event rates. This may serve as an opportune way to mitigate outcome sex-specific disparities caused by inadequate thromboprophylaxis in women.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Background

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

Objective

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

Methods

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

Results

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

Conclusion

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

AIM

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

METHODS

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

STRUCTURE

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

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

AIM

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

METHODS

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

STRUCTURE

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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

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

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

Background

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

Objectives

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

Methods

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

Results

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

Conclusions

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

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

Background

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

Methods

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

Results

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

Conclusions

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

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

Importance

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

Objective

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

Design, Setting, and Participants

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

Exposures

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

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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