Stem Cell Therapy for Wound Healing in Ischemic Limbs: Is It Effective?

Critical limb ischemia is an important clinical entity due to its association with increased morbidity and mortality. The mortality and amputation-free survival remains poor especially in those where revascularization is not an option. Recently, the role of cellular therapy has emerged as a promising therapeutic measure that may aid in wound healing and revascularization and improve functional outcomes.

Intentional coronary revascularization versus conservative therapy in patients after peripheral artery revascularization due to critical limb ischemia: the INCORPORATE trial.

OBJECTIVES: INCORPORATE trial was designed to evaluate whether default coronary-angiography (CA) and ischemia-targeted revascularization is superior compared to a conservative approach for patients with treated critical limb ischemia (CLI). Registered at clinicaltrials.gov (NCT03712644) on October 19, 2018. BACKGROUND: Severe peripheral artery disease is associated with increased cardiovascular risk and poor outcomes. METHODS: INCORPORATE was an open-label, prospective 1:1 randomized multicentric trial that recruited patients who had undergone successful CLI treatment. Patients were randomized to either a conservative or invasive approach regarding potential coronary artery disease (CAD). The conservative group received optimal medical therapy alone, while the invasive group had routine CA and fractional flow reserve-guided revascularization. The primary endpoint was myocardial infarction (MI) and 12-month mortality. RESULTS: Due to COVID-19 pandemic burdens, recruitment was halted prematurely. One hundred eighty-five patients were enrolled. Baseline cardiac symptoms were scarce with 92% being asymptomatic. Eighty-nine patients were randomized to the invasive approach of whom 73 underwent CA. Thirty-four percent had functional single-vessel disease, 26% had functional multi-vessel disease, and 90% achieved complete revascularization. Conservative and invasive groups had similar incidences of death and MI at 1 year (11% vs 10%; hazard ratio 1.21 [0.49-2.98]). Major adverse cardiac and cerebrovascular events (MACCE) trended for hazard in the Conservative group (20 vs 10%; hazard ratio 1.94 [0.90-4.19]). In the per-protocol analysis, the primary endpoint remained insignificantly different (11% vs 7%; hazard ratio 2.01 [0.72-5.57]), but the conservative approach had a higher MACCE risk (20% vs 7%; hazard ratio 2.88 [1.24-6.68]). CONCLUSION: This trial found no significant difference in the primary endpoint but observed a trend of higher MACCE in the conservative arm.

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

Background: Peripheral artery disease (PAD) is on the rise worldwide, ranking as the third leading cause of atherosclerosis-related morbidity; much less is known about its trends in hospitalizations among methamphetamine and cocaine users. Objectives: We aim to evaluate the overall trend in the prevalence of hospital admission for PAD with or without the use of stimulant abuse (methamphetamine and cocaine) across the United States. Additionally, we evaluated the PAD-related hospitalizations trend stratified by age, race, sex, and geographic location. Methods: We used the National Inpatient Sample (NIS) database from 2008 to 2020. The Cochran Armitage trend test was used to compare the trend between groups. Multivariate logistic regression was used to examine adjusted odds for PAD and CLI hospitalizations among methamphetamine and cocaine users. Results: Between 2008 and 2020, PAD-related hospitalizations showed an increasing trend in Hispanics, African Americans, and western states, while a decreasing trend in southern and Midwestern states (p-trend <0.05). Among methamphetamine users, an overall increasing trend was observed in men, women, western, southern, and midwestern states (p-trend <0.05). However, among cocaine users, PAD-related hospitalization increased significantly for White, African American, age group >64 years, southern and western states (p-trend <0.05). Overall, CLI-related hospitalizations showed an encouraging decreasing trend in men and women, age group >64 years, and CLI-related amputations declined for women, White patient population, age group >40, and all regions (p-trend <0.05). However, among methamphetamine users, a significantly increasing trend in CLI-related hospitalization was seen in men, women, White & Hispanic population, age group 26-45, western, southern, and midwestern regions. Conclusions: There was an increasing trend in PAD-related hospitalizations among methamphetamine and cocaine users for both males and females. Although an overall decreasing trend in CLI-related hospitalization was observed for both genders, an up-trend in CLI was seen among methamphetamine users. The upward trends were more prominent for White, Hispanic & African Americans, and southern and western states, highlighting racial and geographic variations over the study period.

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.

LncRNA H19/miR-107 regulates endothelial progenitor cell pyroptosis and promotes flow recovery of lower extremity ischemia through targeting FADD.

BACKGROUND: Peripheral artery disease (PAD) is an ischemic disease with a rising incidence worldwide. The lncRNA H19 (H19) is enriched in endothelial progenitor cells (EPCs), and transplantation of pyroptosis-resistant H19-overexpressed EPCs (oe-H19-EPCs) may promote vasculogenesis and blood flow recovery in PAD, especially with critical limb ischemia (CLI). METHODS: EPCs isolated from human peripheral blood was characterized using immunofluorescence and flow cytometry. Cell proliferation was determined with CCK8 and EdU assays. Cell migration was assessed by Transwell and wound healing assays. The angiogenic potential was evaluated using tube formation assay. The pyroptosis pathway-related protein in EPCs was detected by western blot. The binding sites of H19 and FADD on miR-107 were analyzed using Luciferase assays. In vivo, oe-H19-EPCs were transplanted into a mouse ischemic limb model, and blood flow was detected by laser Doppler imaging. The transcriptional landscape behind the therapeutic effects of oe-H19-EPCs on ischemic limbs were examined with whole transcriptome sequencing. RESULTS: Overexpression of H19 in EPCs led to an increase in proliferation, migration, and tube formation abilities. These effects were mediated through pyroptosis pathway, which is regulated by the H19/miR-107/FADD axis. Transplantation of oe-H19-EPCs in a mouse ischemic limb model promoted vasculogenesis and blood flow recovery. Whole transcriptome sequencing indicated significant activation of vasculogenesis pathway in the ischemic limbs following treatment with oe-H19-EPCs. CONCLUSIONS: Overexpression of H19 increases FADD level by competitively binding to miR-107, leading to enhanced proliferation, migration, vasculogenesis, and inhibition of pyroptosis in EPCs. These effects ultimately promote the recovery of blood flow in CLI.

Association between tissue loss type and amputation risk among Medicare patients with concomitant diabetes and peripheral arterial disease.

OBJECTIVE: Prior studies have described risk factors associated with amputation in patients with concomitant diabetes and peripheral arterial disease (DM/PAD). However, the association between the severity and extent of tissue loss type and amputation risk remains less well-described. We aimed to quantify the role of different tissue loss types in amputation risk among patients with DM/PAD, in the context of demographic, preventive, and socioeconomic factors. METHODS: Applying International Classification of Diseases (ICD)-9 and ICD-10 codes to Medicare claims data (2007-2019), we identified all patients with continuous fee-for-service Medicare coverage diagnosed with DM/PAD. Eight tissue loss categories were established using ICD-9 and ICD-10 diagnosis codes, ranging from lymphadenitis (least severe) to gangrene (most severe). We created a Cox proportional hazards model to quantify associations between tissue loss type and 1- and 5-year amputation risk, adjusting for age, race/ethnicity, sex, rurality, income, comorbidities, and preventive factors. Regional variation in DM/PAD rates and risk-adjusted amputation rates was examined at the hospital referral region level. RESULTS: We identified 12,257,174 patients with DM/PAD (48% male, 76% White, 10% prior myocardial infarction, 30% chronic kidney disease). Although 2.2 million patients (18%) had some form of tissue loss, 10.0 million patients (82%) did not. The 1-year crude amputation rate (major and minor) was 6.4% in patients with tissue loss, and 0.4% in patients without tissue loss. Among patients with tissue loss, the 1-year any amputation rate varied from 0.89% for patients with lymphadenitis to 26% for patients with gangrene. The 1-year amputation risk varied from two-fold for patients with lymphadenitis (adjusted hazard ratio, 1.96; 95% confidence interval, 1.43-2.69) to 29-fold for patients with gangrene (adjusted hazard ratio, 28.7; 95% confidence interval, 28.1-29.3), compared with patients without tissue loss. No other demographic variable including age, sex, race, or region incurred a hazard ratio for 1- or 5-year amputation risk higher than the least severe tissue loss category. Results were similar across minor and major amputation, and 1- and 5-year amputation outcomes. At a regional level, higher DM/PAD rates were inversely correlated with risk-adjusted 5-year amputation rates (R2 = 0.43). CONCLUSIONS: Among 12 million patients with DM/PAD, the most significant predictor of amputation was the presence and extent of tissue loss, with an association greater in effect size than any other factor studied. Tissue loss could be used in awareness campaigns as a simple marker of high-risk patients. Patients with any type of tissue loss require expedited wound care, revascularization as appropriate, and infection management to avoid amputation. Establishing systems of care to provide these interventions in regions with high amputation rates may prove beneficial for these populations.

Comparison of outcomes of percutaneous deep venous arterialization in multiple practice settings.

OBJECTIVE: We compared the efficacy of percutaneous deep venous arterialization (pDVA) in patients with no-option chronic limb-threatening ischemia in the hospital vs in office-based laboratory (OBL) settings. METHODS: A retrospective chart review was performed of all patients who underwent pDVA using off-the-shelf devices from January 2018 to March 2023 in a hospital and an OBL. We identified 73 eligible patients, 41 from a hospital setting (59% male; median age, 72 years; interquartile range, 18 years) and 32 from an OBL setting (59% males; 67 years; interquartile range, 16 years). All eligible patients were deemed to have no-option critical limb ischemia, had at least one patent proximal tibial artery available for the creation of an arteriovenous anastomosis, and were classified as having Rutherford classification IV or higher peripheral arterial disease. Patients were ineligible if classified as Rutherford classification III or lower, had active infection, did not have at least one appropriate venous target, and/or had rapidly progressing wounds requiring immediate major amputation. The primary outcome was major amputation-free survival (AFS). Secondary outcomes included technical success, limb salvage, survival, primary patency, reintervention rate, adverse events, and partial and complete wound healing. Outcomes were evaluated using Kaplan-Meier method, log-rank, and two-stage procedure tests. RESULTS: Technical success was achieved in 70 patients (96%) with 1 hospital (2.4%) and 2 OBL (6.3%) patients lost to follow-up. Major AFS estimates at 6 months, 1 year, and 2 years were 51.4%, 40.4%, and 30.2% in the hospital group and 69.4%, 54.0%, and 49.5% in the OBL group, respectively. Partial wound healing estimates at 6 months, 1 year, and 2 years were 27.5%, 71.7%, and 81.2% in the hospital group and 62.7% at all time points in the OBL group. Complete wound healing estimates at 6 months, 1 year, and 2 years were 6.7%, 33.3%, and 33.3% in the hospital group and 5.3%, 37.7%, and 41.6% in the OBL group, respectively. There was no significant difference in major AFS (P = .13), limb salvage (P = .07), survival (P = .69), primary patency (P = .53), partial (P = .08), or complete wound healing (P = .79) between groups. Reintervention was performed in 8 hospital (20.5%) and 14 OBL (45.2%) patients. CONCLUSIONS: pDVA is a feasible and safe procedure for no-option critical limb ischemia in the hospital and OBL setting without significant differences in outcomes at ≤2 years.

Single-Center In-Hospital and Outpatient Opioid Use for Lower Extremity Arterial Disease.

INTRODUCTION: The pain associated with lower extremity arterial disease is difficult to treat, even with lower extremity revascularization. We sought to evaluate in-hospital and post-operative opioid usage in patients with different disease severities and treatments for lower extremity vascular disease. METHODS: A retrospective review was performed for all hospital encounters for patients with an International Classification of Diseases (ICD) code consistent with lower extremity arterial disease admitted to a single center between January 2018 and March 2023. Cases included patients admitted to the hospital with a primary diagnosis of lower extremity arterial disease. These patients were subdivided based on disease severity, treatment type, and comorbid diagnosis of diabetes mellitus. The analysis focused on in-hospital opioid use frequency and dosage among these patients. The control group (CON) included encounters for patients admitted with a secondary diagnosis of lower extremity atherosclerotic disease. A total of 438 patients represented by all the analyzed encounters were then reviewed for the number and type of vascular procedures performed as well as opioid use in the outpatient setting for one year. RESULTS: Critical limb ischemia (CLI) encounters were more likely to use opioids as compared to the CON and peripheral arterial disease (PAD) without rest pain, ulcer or gangrene groups (CLI 67.9% (95% CI: 63.6%-71.6%) versus CON 52.1% (95% CI: 48.5%-55.7%), p < 0.001 and CLI 67.9% (95% CI: 63.6%-71.6%) versus PAD 50.2% (95% CI: 42.6%-57.4%), p < 0.001). Opioid use was also more common in encounters for gangrene and groups treated with revascularization (REVASC) and amputation (AMP) as compared to CON (gangrene 74.5% (95% CI: 68.5%-82.1%) versus CON 52.1% (95% CI: 48.5%-55.7%), p < 0.01; REVASC 58.3% (95% CI: 57.3%-66.4%) versus CON 52.1% (95% CI: 48.5%-55.7%), p =0.01; and AMP 72.3% (95% CI: 62.1%-74.0%) versus CON 52.1% (95% CI: 48.5%-55.7%), p < 0.01). Significantly increased oral opioid doses per day (MME/day) were not noted for any of the investigated groups as compared to the CON. In the outpatient setting, 186 (42.5% (95% CI: 37.2%-46.4%)) patients were using opioids one month after the most recent vascular intervention. By one year, 31 (7.1% (95% CI: 1.30%-7.70%)) patients were still using opioids. No differences in opioid usage were noted for patients undergoing single versus multiple vascular interventions at one year. Patients undergoing certain vascular surgery procedures were more likely to be using opioids at one year. CONCLUSION: Patients with CLI and gangrene as well as those undergoing vascular treatment have a greater frequency of opioid use during hospital encounters as compared to those patients with less severe disease and undergoing conservative management, respectively. However, these findings do not equate to higher doses of opioids used during hospitalization. Patients undergoing multiple vascular procedures are not more likely to be using opioids long-term (at one year) as compared to those patients treated with single vascular procedures.

Histological Changes in the Popliteal Artery Wall in Patients with Critical Limb Ischemia.

INTRODUCTION: This prospective study aims to illustrate the histopathological arterial changes in the popliteal artery in peripheral arterial disease of the lower limbs. MATERIAL AND METHOD: A total of 60 popliteal artery segments taken from patients who had undergone lower limb amputation were examined between April and June 2023. The degree of arterial stenosis, medial calcinosis, and the vasa vasorum changes in the arterial adventitia were quantified. The presence of risk factors for atherosclerosis was also observed. RESULTS: Atherosclerotic plaque was found in all of the examined segments. Medial calcinosis was observed in 40 (66.6%) of the arterial segments. A positive association between the degree of arterial stenosis and the vasa vasorum changes in the arterial adventitia was also found (p = 0.025). The level of blood sugar and cholesterol were predictive factors for the severity of atherosclerosis. CONCLUSIONS: Atherosclerosis and medial calcinosis are significant in patients who underwent lower limb amputation. Medial calcinosis causes damage to the arterial wall and leads to a reduction in responsiveness to dilator stimuli.

Clinical Outcomes and Resource Utilization in Patients With Peripheral Arterial Disease Hospitalized for Acute Coronary Syndrome.

Previous studies have shown an association between acute limb ischemia and higher mortality in patients with acute myocardial infarction. Although peripheral artery disease (PAD) is a well-known risk factor for development of macrovascular pathology, the effect of its severity is not well investigated in patients hospitalized for acute coronary syndrome (ACS). Using a national cohort of patients with various degrees of PAD, we investigated in-hospital outcomes in patients who were admitted for ACS. Using the 2016 to 2020 Nationwide Readmissions Database, we queried all patients who were hospitalized for ACS (unstable angina, non-ST-elevation myocardial infarction, and ST-elevation myocardial infarction). Patients were further divided into 3 groups, either no PAD (non-PAD), PAD, or critical limb ischemia (CLI). Multivariable models were designed to adjust for patient and hospital factors and examine the association between ACS and PAD severity. Of approximately 3,834,181 hospitalizations for ACS, 6.4% had PAD, 0.2% had CLI, and all others were non-PAD. After risk adjustment, in-hospital mortality was higher by 24% in PAD (adjusted odds ratio 1.24, 95% confidence interval [CI] 1.21 to 1.28) and 86% in CLI (adjusted odds ratio 1.86, 95% CI 1.62 to 2.09) compared with non-PAD. Furthermore, PAD and CLI were linked to 1.23-fold (95% CI 1.20 to 1.26) and 1.67-fold (95% CI 1.45 to 1.86) greater odds of cardiogenic shock compared with non-PAD. Additionally, PAD and CLI were linked with higher odds of mechanical circulatory support usage, cardiac arrest and acute kidney injury compared with non-PAD. Lastly, duration of hospital stay, hospitalization costs and odds of non-home discharge and 30-day readmissions were greater in patients with PAD and CLI compared with non-PAD. PAD severity was associated with worse clinical outcomes in patients with ACS, including in-hospital mortality and resource utilization.

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.

Analysis of in-hospital deaths in patients with critical limb ischemia necessitating invasive treatments: based on a Japanese nationwide database.

Critical limb ischemia (CLI) is associated with systemic cardiovascular and non-cardiovascular diseases. Treatments primarily targeting limb-related outcomes may not improve overall life prognosis. We aimed to describe in-hospital mortality and the underlying etiologies in Japanese patients with CLI. We analyzed the Diagnosis Procedure Combination (DPC) database from approximately 1200 Japanese acute-care hospitals between April 2018 and March 2020. The definition of patients with CLI was based on the diagnostic codes listed as the most resource-intensive diagnosis and information regarding invasive procedures (endovascular treatment, bypass, or amputation). The DPC database provides information on whether in-hospital death was caused by the most resource-intensive diagnosis. Among 15,228 distinct patients with CLI, we identified 18,970 records, including 5,378 amputations. In-hospital death occurred in 1238 (6.5%) patients. Among them, 811 (65.5%) were due to causes unrelated to CLI. In patients who underwent amputation (n = 5378), causes unrelated to CLI accounted for 70.0% of in-hospital deaths, whereas among patients who did not undergo amputation (n = 13,592), this proportion was 60.1%. When compared to patients who died due to causes related to CLI, the prevalence of male patients was higher (62.6% vs 52.7%, p = 0.001), and amputation was more frequently performed (58.0% vs 47.1%, p < 0.001) in those who died due to causes unrelated to CLI. The majority of in-hospital deaths among patients with CLI necessitating endovascular treatment, bypass, or amputation were attributable to factors unrelated to the primary condition of CLI. Managing systemic cardiovascular and non-cardiovascular diseases beyond the affected limb is crucial to improve the prognosis of these patients.

Emerging trends in nationwide mortality, limb loss, and resource utilization for critical limb ischemia in young adults.

BACKGROUND/OBJECTIVES: Recent trends indicate a rise in the incidence of critical limb ischemia (CLI) among younger adults. This study examines trends in CLI hospitalization and outcomes among young adults with peripheral arterial disease (PAD) in the United States. METHODS: Adult hospitalizations (18-40 years) for PAD/CLI were analyzed from the 2016-2020 nationwide inpatient sample database using ICD-10 codes. Rates were reported per 1000 PAD or 100,000 cardiovascular disease admissions. Outcomes included trends in mortality, major amputations, revascularization, length of hospital stay (LOS), and hospital costs (THC). We used the Jonckheere-Terpstra tests for trend analysis and adjusted costs to the 2020 dollar using the consumer price index. RESULTS: Approximately 63,045 PAD and 20,455 CLI admissions were analyzed. The mean age of the CLI cohort was 32.7 ± 3 years. The majority (12,907; 63.1 %) were female and white (11,843; 57.9 %). Annual CLI rates showed an uptrend with 3265 hospitalizations (227 per 1000 PAD hospitalizations, 22.7 %) in 2016 to 4474 (252 per 1000 PAD hospitalizations, 25.2 %) in 2020 (Ptrend<0.001), along with an increase in PAD admissions from 14,405 (188 per 100,000, 0.19 %) in 2016 to 17,745 (232 per 100,000, 0.23 %%) in 2020 (Ptrend<0.0001). Annual in-hospital mortality increased from 570 (2.8 %) in 2016 to 803 (3.9 %) in 2020 (Ptrend = 0.001) while amputations increased from 1084 (33.2 %) in 2016 to 1995 (44.6 %) in 2020 (Ptrend<0.001). Mean LOS increased from 5.1 (SD 2.7) days in 2016 to 6.5 (SD 0.9) days in 2020 (Ptrend = 0.002). The mean THC for CLI increased from $50,873 to $69,262 in 2020 (Ptrend<0.001). The endovascular revascularization rates decreased from 11.5 % (525 cases) in 2016 to 10.7 % (635 cases) in 2020 (Ptrend = 0.025). Surgical revascularization rates also increased from 4.9 % (225 cases) in 2016 to 10.4 % (600 cases) in 2020 (Ptrend = 0.041). CONCLUSION: Hospitalization and outcomes for CLI worsened among young adults during the study period. There is an urgent need to enhance surveillance for risk factors of PAD in this age group.

Utilization of coronary computed tomography angiography and computed tomography-derived fractional flow reserve in a critical limb-threatening ischemia cohort.

Objective: Patients with peripheral arterial disease (PAD) have a significant risk of myocardial infarction and death secondary to concomitant coronary artery disease (CAD). This is particularly true in patients with critical limb-threatening ischemia (CLTI) who exceed a 20% mortality rate at 6 months despite standard treatment with risk factor modification. Although systematic preoperative coronary testing is not recommended for patients with PAD without cardiac symptoms, the clinical manifestations of CAD are often muted in patients with CLTI due to poor mobility and activity intolerance. Thus, the true incidence and impact of "silent" CAD in a CLTI cohort is unknown. This study aims to determine the prevalence of ischemia-producing coronary artery stenosis in a CLTI cohort using coronary computed tomography angiography (cCTA) and computed tomography (CT)-derived fractional flow reserve (FFRCT), a noninvasive imaging modality that has shown significant correlation to cardiac catheterization in the detection of clinically relevant coronary ischemia. Methods: Patients presenting with newly diagnosed CLTI at our institution from May 2020 to April 2021 were screened for underlying CAD. Included subjects had no known history of CAD, no cardiac symptoms, and no anginal equivalent complaints at presentation. Patients underwent cCTA and FFRCT evaluation and were classified by the anatomic location and severity of CAD. Significant coronary ischemia was defined as FFRCT ≤0.80 distal to a >30% coronary stenosis, and severe coronary ischemia was documented at FFRCT ≤0.75, consistent with established guidelines. Results: A total of 170 patients with CLTI were screened; 65 patients (38.2%) had no coronary symptoms and met all inclusion/exclusion criteria. Twenty-four patients (31.2%) completed cCTA and FFRCT evaluation. Forty-one patients have yet to complete testing secondary to socioeconomic factors (insurance denial, transportation inaccessibility, testing availability, etc). The mean age of included subjects was 65.4 ± 7.0 years, and 15 (62.5%) were male. Patients presented with ischemic rest pain (n = 7; 29.1%), minor tissue loss (n = 14; 58.3%) or major tissue loss (n = 3; 12.5%). Significant (≥50%) coronary artery stenosis was noted on cCTA in 19 of 24 patients (79%). Significant left main coronary artery stenosis was identified in two patients (10%). When analyzed with FFRCT, 17 patients (71%) had hemodynamically significant coronary ischemia (FFRCT ≤0.8), and 54% (n = 13) had lesion-specific severe coronary ischemia (FFRCT ≤0.75). The mean FFRCT in patients with coronary ischemia was 0.70 ± 0.07. Multi-vessel disease pattern was present in 53% (n = 9) of patients with significant coronary stenosis. Conclusions: The use of cCTA-derived fractional flow reserve demonstrates a significant percentage of patients with CLTI have silent (asymptomatic) coronary ischemia. More than one-half of these patients have lesion-specific severe ischemia, which may be associated with increased mortality when treated solely with risk factor modification. cCTA and FFRCT diagnosis of significant coronary ischemia has the potential to improve cardiac care, perioperative morbidity, and long-term survival curves of patients with CLTI. Systemic improvements in access to care will be needed to allow for broad application of these imaging assessments should they prove universally valuable. Additional study is required to determine the benefit of selective coronary revascularization in patients with CLTI.

Tips and Tricks for Simple and Complex Below-the-Ankle Punctures.

CLINICAL IMPACT: When the standard endovascular crossing maneuvers have failed during CLTI recanalization procedures and the distal below-the-knee or proximal below-the-ankle retrograde access is not possible due to chronic occlusion of the vessels, mastering the more distal and complex retrograde BTA punctures may be advantageous.There are scanty reports regarding the retrograde puncture of the mid and forefoot vessels. The aim of this article is to review different tips and tricks related to these techniques to help operators to apply them in specific scenarios to eventually improve procedural success rate.

Subcutaneous injection of lidocaine around ischemic ankle provides safe and effective foot analgesia in patients with critical limb ischemia.

OBJECTIVE: It is often difficult to alleviate foot pain associated with critical limb ischemia (CLI) using common analgesics. Neuraxial block is contraindicated in anticoagulant therapy. This study was designed to determine the response to subcutaneous injection of lidocaine around the network of peripheral nerves around the ankle in patients with CLI pain on anticoagulants and antiplatelets. METHODS: Sixteen patients with CLI pain in the foot were enrolled in this double-blind placebo-controlled crossover study. Patients were randomized to receive either 2% lidocaine or saline via catheters inserted into the subcutaneous area around the ankle. After recurrence of pain, the patients were crossed over to receive the alternative treatment. Pain was assessed with a numerical rating scale (NRS) before and 15 min after injection. Patients used a descriptive scale to grade pain control and were asked to determine the duration of analgesia in each arm of the study. RESULTS: No serious complications including protracted bleeding occurred. Lidocaine significantly decreased the NRS on movement from 10 (6, 10) [median (range)] to 2 (0, 10) (p < .001), and the differences in the Δ change in NRS between lidocaine and placebo were significant (p = .009). Of the 16 patients, 14 patients were very satisfied after lidocaine but only one described the same after saline. The effect of lidocaine and placebo lasted 11 (0, 28) and 1 (0, 22) h, respectively. CONCLUSION: Subcutaneous injection of lidocaine around the ischemic ankle affectively alleviated pain in patients with CLI without serious adverse effects under anticoagulant therapy.

Trends in Lower Extremity Artery Disease Repair Incidence, Comorbidity, and Mortality: A Danish Nationwide Cohort Study, 1996-2018.

Background: The prevalence of occlusive lower extremity artery disease (LEAD) is rising worldwide while European epidemiology data are scarce. We report incidence and mortality of LEAD repair in Denmark from 1996 through 2018, stratified on open aorto-iliac, open peripheral, and endovascular repair. Methods: A nationwide cohort study of prospective data from population-based Danish registers covering 1996 to 2018. Comorbidity was assessed by Charlson's Comorbidity Index (CCI). Incidence rate (IR) ratios and mortality rate ratios (MRR) were estimated by multivariable Poisson and Cox regression, respectively. Results: We identified 41,438 unique patients undergoing 46,236 incident first-time LEAD repairs by either aorto-iliac- (n=5213), peripheral surgery (n=18,665) or percutaneous transluminal angioplasty (PTA, n=22,358). From 1996 to 2018, the age- and sex-standardized IR for primary revascularization declined from 71.8 to 50.2 per 100,000 person-years (IRR, 0.70; 95% CI, 0.66-0.75). Following a 2.5-fold IR increase of PTA from 1996 to 2010, all three repair techniques showed a declining trend after 2010. The declining IR was driven by decreasing LEAD repair due to claudication, and by persons aged below 80 years, while the IR increased in persons aged above 80 years (p interaction<0.001). LEAD repair was more frequent in men (IRRfemale vs male, 0.78; 95% CI, 0.77-0.80), which was consistent over calendar time (p interaction=0.41). Crude mortality decreased following open/surgical repair, and increased following PTA, but all three techniques trended towards lower adjusted mortality comparing the start and the end of the study period (MRRaorto-iliac, 0.71; 95% CI, 0.54-0.93 vs MRRperipheral, 0.76; 95% CI, 0.69-0.83 vs MRRPTA, 0.96; 95% CI, 0.86-1.07). Increasing age and CCI, male sex, smoking, and care dependency associated with increased mortality. Conclusion: The incidence rate of LEAD repair decreased in Denmark from 1996 to 2018, especially in persons younger than 80 years, and primarily due to reduced revascularization for claudication. Adjusted mortality rates decreased following open surgery, but seemed unaltered following PTA.

Novel Glycomimetics Protect against Glycated Low-Density Lipoprotein-Induced Vascular Calcification In Vitro via Attenuation of the RAGE/ERK/CREB Pathway.

Heparan sulphate (HS) can act as a co-receptor on the cell surface and alterations in this process underpin many pathological conditions. We have previously described the usefulness of mimics of HS (glycomimetics) in protection against ß-glycerophosphate-induced vascular calcification and in the restoration of the functional capacity of diabetic endothelial colony-forming cells in vitro. This study aims to investigate whether our novel glycomimetic compounds can attenuate glycated low-density lipoprotein (g-LDL)-induced calcification by inhibiting RAGE signalling within the context of critical limb ischemia (CLI). We used an established osteogenic in vitro vascular smooth muscle cell (VSMC) model. Osteoprotegerin (OPG), sclerostin and glycation levels were all significantly increased in CLI serum compared to healthy controls, while the vascular calcification marker osteocalcin (OCN) was down-regulated in CLI patients vs. controls. Incubation with both CLI serum and g-LDL (10 µg/mL) significantly increased VSMC calcification vs. controls after 21 days, with CLI serum-induced calcification apparent after only 10 days. Glycomimetics (C2 and C3) significantly inhibited g-LDL and CLI serum-induced mineralisation, as shown by a reduction in alizarin red (AR) staining and alkaline phosphatase (ALP) activity. Furthermore, secretion of the osteogenic marker OCN was significantly reduced in VSMCs incubated with CLI serum in the presence of glycomimetics. Phosphorylation of cyclic AMP response element-binding protein (CREB) was significantly increased in g-LDL-treated cells vs. untreated controls, which was attenuated with glycomimetics. Blocking CREB activation with a pharmacological inhibitor 666-15 replicated the protective effects of glycomimetics, evidenced by elevated AR staining. In silico molecular docking simulations revealed the binding affinity of the glycomimetics C2 and C3 with the V domain of RAGE. In conclusion, these findings demonstrate that novel glycomimetics, C2 and C3 have potent anti-calcification properties in vitro, inhibiting both g-LDL and CLI serum-induced VSMC mineralisation via the inhibition of LDLR, RAGE, CREB and subsequent expression of the downstream osteogenic markers, ALP and OCN.

Transplantation of Human Embryonic Stem Cell-Derived Pericyte-Like Cells Transduced with Basic Fibroblast Growth Factor Promotes Angiogenic Recovery in Mice with Severe Chronic Hindlimb Ischemia.

Critical limb ischemia (CLI) is a state of severe peripheral artery disease, with no effective treatment. Cell therapy has been investigated as a therapeutic tool for CLI, and pericytes are promising therapeutic candidates based on their angiogenic properties. We firstly generated highly proliferative and immunosuppressive pericyte-like cells from embryonic stem (ES) cells. In order to enhance the angiogenic potential, we transduced the basic fibroblast growth factor (bFGF) gene into the pericyte-like cells and found a significant enhancement of angiogenesis in a Matrigel plug assay. Furthermore, we evaluated the bFGF-expressing pericyte-like cells in the previously established chronic hindlimb ischemia model in which bone marrow-derived MSCs were not effective. As a result, bFGF-expressing pericyte-like cells significantly improved blood flow in both laser Doppler perfusion imaging (LDPI) and dynamic contrast-enhanced MRI (DCE-MRI). These findings suggest that bFGF-expressing pericyte-like cells differentiated from ES cells may be a therapeutic candidate for CLI.