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

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Advancing Health Equity in the Cardiovascular Device Life Cycle

Despite advancements in diagnostics and therapeutics for cardiovascular disease, significant health disparities persist among patients from historically marginalized racial and ethnic groups, women, individuals who are socioeconomically under-resourced or underinsured, and those living in rural communities. While transcatheter interventions have revolutionized the treatment landscape in cardiology, populations bearing the greatest burden of disease continue to face inequitable access and poorer outcomes. A notable gap in the literature concerns the role of modern approaches to cardiovascular device innovation in shaping and perpetuating health disparities. Health equity has been declared one of the top strategic initiatives for 2022 to 2025 by the Food and Drug Administration Center for Devices and Radiological Health, underscoring the need for greater attention, dialogue, and targeted interventions in this space. This narrative review uses the cardiovascular device life cycle as a conceptual framework to enhance understanding and guide future efforts to mitigate disparities in the field of interventional cardiology. Drawing on illustrative examples from interventional cardiology, we examine current practices in cardiovascular device regulation and approval, clinical trial evaluation, adoption patterns, and postprocedural outcomes with the aim of uncovering potential mechanisms of disparities and identifying opportunities for targeted interventions.

"All in one" lipid-polymer nanodelivery system for gene therapy of ischemic diseases

Gene therapy offers a promising avenue for treating ischemic diseases, yet its clinical efficacy is hindered by the limitations of single gene therapy and the high oxidative stress microenvironment characteristic of such conditions. Lipid-polymer hybrid vectors represent a novel approach to enhance the effectiveness of gene therapy by harnessing the combined advantages of lipids and polymers. In this study, we engineered lipid-polymer hybrid nanocarriers with tailored structural modifications to create a versatile membrane fusion lipid-nuclear targeted polymer nanodelivery system (FLNPs) optimized for gene delivery. Our results demonstrate that FLNPs facilitate efficient cellular uptake and gene transfection via membrane fusion, lysosome avoidance, and nuclear targeting mechanisms. Upon encapsulating Hepatocyte Growth Factor plasmid (pHGF) and Catalase plasmid (pCAT), HGF/CAT-FLNPs were prepared, which significantly enhanced the resistance of C2C12 cells to H2O2-induced injury in vitro. In vivo studies further revealed that HGF/CAT-FLNPs effectively alleviated hindlimb ischemia-induced gangrene, restored motor function, and promoted blood perfusion recovery in mice. Metabolomics analysis indicated that FLNPs didn't induce metabolic disturbances during gene transfection. In conclusion, FLNPs represent a versatile platform for multi-dimensional assisted gene delivery, significantly improving the efficiency of gene delivery and holding promise for effective synergistic treatment of lower limb ischemia using pHGF and pCAT.

Appropriate care in chronic limb threatening ischemia: A review of current evidence and outcomes

Chronic limb threatening ischemia (CLTI) poses a significant treatment challenge for vascular surgeons, interventionalists, podiatrists, and associated medical specialists. The evidence for what constitutes appropriate care is rapidly evolving and new treatment options are in constant development. This review examines the current guidelines for CLTI care, as well as reported outcomes for multiple care strategies in this patient population, including revascularization and medical optimization. We performed a literature review of the PubMed database, reviewing articles that reported outcomes for CLTI care between 2000 and 2023, and described these outcomes as they relate to the current state of CLTI treatment. Significant data are still forthcoming regarding CLTI care, but widespread adoption of appropriate CLTI care is essential for the treatment of this vulnerable population.

The impact of the Affordable Care Act Medicaid Expansion in Medicare beneficiaries with peripheral artery disease

Background: In 2014, the Affordable Care Act Medicaid Expansion (ME) increased Medicaid eligibility for adults with an income level up to 138% of the federal poverty level. In this study, we examined the impact of ME on mortality and amputation in patients with peripheral artery disease (PAD). Methods: The 100% MedPAR and Part-B Carrier files from 2011 to 2018 were queried to identify all fee-for-service Medicare beneficiaries with PAD using International Classification of Diseases codes. Our primary exposure was whether a state had adopted the ME on January 1, 2014. Our primary outcomes were the change in all-cause 1-year mortality and leg amputation. We used a state-level difference-in-differences (DID) analysis to compare the rates of the primary outcomes among patients who were in states (including the District of Columbia) who adopted ME (n = 25) versus those who were in states that did not (n = 26). We performed a subanalysis stratifying by sex, race, region, and dual-eligibility status. Results: Over the 8-year period, we studied 37,743,929 patients. The average unadjusted 1-year mortality decreased from 2011 to 2018 in both non-ME (9.5% to 8.7%, p < 0.001) and ME (9.1% to 8.3%, p < 0.001) states. The average unadjusted 1-year amputation rate did not improve in either the non-ME (0.86% to 0.87%, p = 0.17) or ME (0.69% to 0.69%, p = 0.65) states. Across the entire cohort, the DID model revealed that ME did not lead to a significant change in mortality (p = 0.15) or amputation (p = 0.34). Conclusion: Medicaid Expansion was not associated with reduced mortality or leg amputation in Medicare beneficiaries with PAD.

Establishing a Critical Limb Ischemia Outpatient Center: Separating Facts from Myth

Critical Limb Ischemia or chronic limb-threatening ischemia represents the end stage of peripheral artery disease where arterial flow is compromised to the lower extremities and risk of limb loss may become imminent. Revascularization of lower extremities is one of the cornerstones of limb salvage and amputation prevention. Establishing centers of high quality CLI therapy requires creating different foundational pillars in order to be successful. This article discusses critical limb ischemia center creation from the perspective of critical limb ischemia therapists working in an outpatient setting.