Therapy For Critical Limb Ischemia Research Articles

Contemporary Endovascular Outcomes for Critical Limb Ischemia Are Still Failing to Meet Society for Vascular Surgery Objective Performance Goals.

The Society for Vascular Surgery (SVS) created Objective Performance Goals (OPGs) for critical limb ischemia (CLI) in 2009. It was previously shown that endovascular therapy for CLI was not meeting these benchmarks. The OPG for all peripheral interventions is <8% for major adverse cardiac events (MACE), <8% for major adverse limb events (MALE), and <3% for major amputation. The goal of this study is to evaluate if outcomes have improved for CLI in recent years, specifically 2015-2018. The Targeted Vascular Module from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) was queried to identify patients who underwent endovascular intervention for critical limb ischemia from 2011-2018. Cohorts were divided into 2011-2014 and 2015-2018. Primary 30-day outcomes were MACE, MALE, and major amputation. Univariate analyses were performed using the Fisher's exact test and the Wilcoxon rank-sum test. Multivariate analysis comparing groups was performed using inverse probability weights and trend over time analysis was performed using logistic regression with year of intervention as a continuous variable. From 2011 to 2018, 7,168 patients underwent an endovascular intervention for CLI. 28% were classified as "OPG high anatomic risk," and 17% were classified as "OPG high clinical risk." The 2015-2018 cohort vs. the 2011-14 cohort experienced MACE in 3.3% vs. 2.7% (p = .23), MALE in 9.1% vs. 8.9% (p = 0.83), and amputation in 4.0% vs. 4.2% (p = 0.71). When only high anatomic risk patients were considered (n = 1988), MACE was experienced in 2.4% vs. 2.2% (p = 0.87), MALE by 9.5% vs. 10.6% (p = 0.47) and amputation by 5.1% vs. 6.0% (p = 0.40). When only high clinical risk patients were considered (n = 1224), MACE was experienced in 5.2% vs. 3.9% (p = 0.33), MALE by 8.0% vs. 7.4% (p = 0.74) and amputation by 3.9% vs. 3.7% (p = 0.88). Comparing 2015-2018 to the reference 2011-2014, MALE adjusted odds ratio (AOR) = 0.99, 95% CI [0.83-1.18], MACE AOR = 1.19 95% CI [0.88-1.60], and major amputation AOR = 0.91 95% CI [0.70-1.17]. There were no decreases in the trend over time for MALE (AOR per year 0.97, CI [.94-1.02], major amputation (AOR per year: 0.97, CI [0.91-1.03], nor for MACE (AOR per year: 1.05, CI [.98-1.13]). Outcomes following endovascular interventions for CLI continue to underperform when compared to OPG benchmarks for MALE and amputations. There is no decrease over time for these target outcomes. Target MACE events remain acceptable despite the increasing clinical complexity of patients being treated.

Double VEGF/HGF Gene Therapy in Critical Limb Ischemia Complicated by Diabetes Mellitus

Critical leg ischemia (CLI) complicated by diabetes mellitus (DM), which is a very common and dangerous disease, represents the ultimate stage of peripheral arterial disease. Patients are treated with antiplatelet drugs, statins and limb revascularization, but a significant number of patients are not candidate for revascularization. Literature shows that in such cases, gene therapy could be a perfect therapeutic option. The aim of our study was to evaluate efficacy of double vascular endothelial growth factor/hepatocyte growth factor (VEGF/HGF) gene therapy in patients with CLI complicated by DM. We observed that 90 days after administration, serum level of VEGF and ankle-brachial index increased significantly (p < 0.001) and rest pain decreased significantly compared with the control group (p < 0.002). Moreover considerable improvement in vascularization was observed in computed tomography angiography (P = 0.04). Based on the results of this study, we suggest that the therapy with pIRES/VEGF165/HGF bicistronic plasmid administration is a safe and effective method of treatment of patients with both CLI and DM.Graphical abstract

Progress of Gene Therapy in Cardiovascular Disease.

Gene therapy has been extensively studied in peripheral and cardiac ischemia, heart and vein graft failure, and dyslipidemia, but most clinical trials failed to show their efficacies despite good outcomes in preclinical studies. So far, 2 gene therapies for dyslipidemia and one for critical limb ischemia in peripheral artery disease have been approved. In critical limb ischemia, gene therapy using proangiogenic factors has emerged as a novel therapeutic modality for promoting angiogenesis. Initial researches mainly focused on vascular endothelial growth factor, fibroblast growth factor, or hepatocyte growth factor. After the favorable results of basic research, several phase I and II clinical trials of these proangiogenic factors have shown promising results. However, only a phase III clinical trial of the intramuscular injection of hepatocyte growth factor plasmid DNA has shown successful outcomes, and it was recently approved in Japan for treating patients with critical limb ischemia who have ulcers and for whom no alternative therapeutic options are available. DNA vaccine is another promising modality of gene therapy. An antitumor vaccine suppressing angiogenesis through the inhibition of proangiogenic factors and an antihypertensive vaccine inhibiting the renin-angiotensin system are representative DNA vaccines. The advantage of DNA vaccine is its long-term effectiveness with a few vaccinations; however, the benefits and risks, such as adverse T-cell reaction against self-antigen or long-term side effects, of DNA vaccines should be carefully evaluated. In this review, we discuss the recent advances in proangiogenic gene therapy for critical limb ischemia and DNA vaccine for hypertension.

Contemporary Endovascular Outcomes for Critical Limb Ischemia Are Still Failing to Meet Society for Vascular Surgery Objective Performance Goals

The Society for Vascular Surgery created objective performance goals for critical limb ischemia (CLI) in 2009. It has previously been shown that endovascular therapy for CLI was not meeting these benchmarks. The objective performance goal for all peripheral interventions is <8% for major adverse cardiac events (MACE), <8% for major adverse limb event (MALE), and <3% for major amputation. The goal of this study is to evaluate if outcomes have improved for CLI in recent years.

Injectable Therapeutic Organoids Using Sacrificial Hydrogels

SummaryOrganoids are becoming widespread in drug-screening technologies but have been used sparingly for cell therapy as current approaches for producing self-organized cell clusters lack scalability or reproducibility in size and cellular organization. We introduce a method of using hydrogels as sacrificial scaffolds, which allow cells to form self-organized clusters followed by gentle release, resulting in highly reproducible multicellular structures on a large scale. We demonstrated this strategy for endothelial cells and mesenchymal stem cells to self-organize into blood-vessel units, which were injected into mice, and rapidly formed perfusing vasculature. Moreover, in a mouse model of peripheral artery disease, intramuscular injections of blood-vessel units resulted in rapid restoration of vascular perfusion within seven days. As cell therapy transforms into a new class of therapeutic modality, this simple method—by making use of the dynamic nature of hydrogels—could offer high yields of self-organized multicellular aggregates with reproducible sizes and cellular architectures.

Identification of the initial molecular changes in response to circulating angiogenic cells-mediated therapy in critical limb ischemia

BackgroundCritical limb ischemia (CLI) constitutes the most aggressive form of peripheral arterial occlusive disease, characterized by the blockade of arteries supplying blood to the lower extremities, significantly diminishing oxygen and nutrient supply. CLI patients usually undergo amputation of fingers, feet, or extremities, with a high risk of mortality due to associated comorbidities.Circulating angiogenic cells (CACs), also known as early endothelial progenitor cells, constitute promising candidates for cell therapy in CLI due to their assigned vascular regenerative properties. Preclinical and clinical assays with CACs have shown promising results. A better understanding of how these cells participate in vascular regeneration would significantly help to potentiate their role in revascularization.Herein, we analyzed the initial molecular mechanisms triggered by human CACs after being administered to a murine model of CLI, in order to understand how these cells promote angiogenesis within the ischemic tissues.MethodsBalb-c nude mice (n:24) were distributed in four different groups: healthy controls (C, n:4), shams (SH, n:4), and ischemic mice (after femoral ligation) that received either 50 μl physiological serum (SC, n:8) or 5 × 105 human CACs (SE, n:8). Ischemic mice were sacrificed on days 2 and 4 (n:4/group/day), and immunohistochemistry assays and qPCR amplification of Alu-human-specific sequences were carried out for cell detection and vascular density measurements. Additionally, a label-free MS-based quantitative approach was performed to identify protein changes related.ResultsAdministration of CACs induced in the ischemic tissues an increase in the number of blood vessels as well as the diameter size compared to ischemic, non-treated mice, although the number of CACs decreased within time. The initial protein changes taking place in response to ischemia and more importantly, right after administration of CACs to CLI mice, are shown.ConclusionsOur results indicate that CACs migrate to the injured area; moreover, they trigger protein changes correlated with cell migration, cell death, angiogenesis, and arteriogenesis in the host. These changes indicate that CACs promote from the beginning an increase in the number of vessels as well as the development of an appropriate vascular network.Graphical abstract

3:45 PM Abstract No. 47 MicroStent: initial single-center experience at a vascular center of excellence

(1) Brief overview on the treatments used in critical limb ischemia (CLI) arteries below the knee (BTK) and the current treatment landscape limitations. (2) Guide the reader on the composition of the MicroStent (Micro Medical Solutions, Wilmington, MA) (MS), dedicated for below-the-knee vessels in CLI. (3) Discuss our single-center experience via retrospective analysis and case examples Based on the angiographosome concept, vascular specialists have aimed to revascularize BTK vessels to improve in line flow to aid wound healing and promote limb salvage in Rutherford class (RC) 4-6 patients. Traditional methods spanning from POBA and bare-metal stenting to newer paclitaxel impregnated devices and atherectomy have been the mainstay to restore vessel patency and flow. However, there has been no dedicated peripheral stent for vessels BTK prior to recent advancements. Off label use of coronary stents, such as the 4-mm Resolute Onyx (Medtronic, Dublin, Ireland) have been used to salvage perfusion BTK. MS aims to create an ‘instructions for use’ (IFU) BTK stent for CLI therapy. Here, we share our experience with MS, exploring parameters beyond initial feasibility trials. Single center retrospective analysis in RC 4-6 CLI patients revascularized with MS. The first phase of the study included 8 patients treated from April–November 2018. Ultrasound was obtained for primary patency and hemodynamically significant stenosis with standardized protocol performed by a single technician on prescheduled follow-up visits at 15 days, 30 days, 3 months, 6 months and 1 year. Our analysis examined (1) primary patency, (2) secondary patency (defined as 1 reintervention at target lesion), (3) change of 1 or more RC, (4) wound healing, (5) major amputation and cardiovascular events, and (6) death. The second phase of the study is under enrollment with further analysis to be performed with larger sample size prior to publication. Exploring the safety and efficacy of novel devices for tibiopedal disease is imperative to develop IFU and treatment algorithms in this complex disease. Here, we share our early experience with MS in BTK arteries and what impact it may have to further the fight against amputation and CLI mortality.

Cell therapy of critical limb ischemia: A review of preclinical and clinical research in China

Critical limb ischemia (CLI) is the advanced stage of peripheral artery diseases and is characterized by limb pain. Current available treatments for CLI include pharmacological agents, bypass surgery, and endovascular therapy. When these conventional therapies fail, some patients may eventually suffer from amputation because of long-term blood flow insufficiency to the affected extremity. Novel therapeutic approaches are emergently needed. At present, proangiogenic gene/protein therapies and stem cell-based proangiogenic therapies have been proposed, and the promising results have been reported. Gene-modified stem cells and pretreated stem cells have been evaluated in the animal models. Proper bioscaffolds are also used to increase the survival and engraftment of delivered stem cells. Here, we address the current situation of stem cell research for CLI in China.

Increasing the Therapeutic Potential of Stem Cell Therapies for Critical Limb Ischemia.

Peripheral Arterial Disease (PAD) is a progressive, atherosclerotic disease that at its end stage, Critical Limb Ischemia (CLI), results in severely diminished limb perfusion and causes leg pain at rest, non-healing ulcers, and tissue gangrene. Many patients with CLI fail current medical and surgical therapies and thus are deemed “no option” and require limb amputation. Novel therapies to attempt limb salvage in these “no option” patients are needed. Stem cell therapy is one therapeutic angiogenic avenue that has been tested over the last 20 years. To date, clinical trials have shown promise but with only modest improvement and none demonstrated a significant decrease in amputation rates in those treated with stem cell therapy. Thus, recent investigations into improving stem cell therapy have been the focus of our laboratory and many others. This review aims to describe recent advances in increasing the therapeutic potential of stem cell therapies for CLI.

Limb Preservation Using Edetate Disodium-based Chelation in Patients with Diabetes and Critical Limb Ischemia: An Open-label Pilot Study.

BackgroundIn 2015, there were 30.3 million patients with diabetes in the US, including 25.2% of people ages 65 or older and 108,000 hospitalizations for non-traumatic amputations. Severe diabetic limb disease includes critical limb ischemia (CLI ) due to an infrapopliteal disease with foot pain and ischemic ulcerations including gangrene. Environmentally acquired toxic metals, such as lead and cadmium, have been associated with cardiovascular disease. Thus, we designed the present unblinded pilot study to determine whether there was a signal of benefit for edetate disodium-based infusions in patients with critical limb ischemia.MethodsThis was an open-label pilot study in 10 patients with diabetes and critical limb ischemia. Each patient received up to 50 edetate disodium-based infusions and was assessed for safety, clinical efficacy, metal excretion, and quality of life. The primary endpoint was to assess the effect of edetate disodium-based therapy plus vitamins in patients with diabetes and infra-popliteal peripheral artery disease presenting with severe CLI and determine if there were improvements in vascular flow parameters.ResultsWe enrolled 10 (60% male) predominantly Caucasian (90%) subjects. The mean age was 75.3 (8.0) years. Smoking was reported by 30%. There were 70% with coronary artery disease (30% had prior coronary artery bypass grafting) and 50% had a prior lower-extremity amputation, three having previous minor amputations and two major amputations. There were no major adverse cardiovascular events during the infusion phase through the one-year follow-up. Patients completing 40 infusions demonstrated complete wound healing and improvement in the quality of life.ConclusionPatients with diabetes and CLI treated with a regimen of edetate disodium-based infusions demonstrated a potential signal of benefit and preliminary evidence of safety. The Trial to Assess Chelation Therapy in Critical Limb Ischemia (TACT3a), a randomized double-blind, placebo-controlled clinical trial now in progress, will further test these findings.

Ultrasound Surveillance after Endovascular Therapy in Critical Limb Ischemia has Better Results Than Clinical and Haemodynamic Assesment Alone

Introduction - Endovascular treatment (EVT) has replaced open repair as first option in critical limb ischemia (CLI) during last years in the majority of centres. However, evidence in its surveillance is sparse, and has not yet been established. The aim of this study was to evaluate duplex ultrasound (DUS) surveillance after EVT for CLI, and compare it with clinical and haemodynamic assessment (CHA) alone.

Endovascular management of Critical Limb Ischaemia: Study of 100 Cases

Background: Critical limb ischemia (CLI) is the most severe form of Peripheral Artery Disease (PAD) and represents approximately 1% of the total number of patients with PAD. CLI is associated with a higher risk of limb loss in the absence of revascularization. Objectives of the study are to find out the modality of treatment in CLI, different types of endovascular therapy in CLI and their outcome.&#x0D; Methods: A retrospective study evaluated 100 patients with CLI reported to cardiovascular surgery department in Combined Military Hospital (CMH), Dhaka between July 2016 to June 2018. Patients with disabling claudication or rest pain and tissue loss are included in the study. All patients were evaluated by peripheral angiogram and revascularisation of limbs was done by endovascular procedure in 79 patients, by surgical intervention in 12 patients.&#x0D; Results: Forty-four patients (44%) presented with rest pain and disabling claudication, 56 patients (56%) presented with tissue loss. Revascularization of limbs was done in 91 patients (93%). No intervention could be done in 9 patients (9%). Endovascular interventions were done in 79 patients (87%). Twelve patients (13%) underwent surgical bypass. All patients with rest pain remains asymptomatic in 6 months follow up; 2 patients developed reocclusion within 1 year. No major amputation in patients with only rest pain.&#x0D; Conclusion: Revascularization is the main modality of treatment in CLI. Most of the patient can be treated by endovascular percuteneous procedure. Early intervention in CLI patient without tissue loss carries excellent outcome.&#x0D; Cardiovasc. j. 2019; 12(1): 40-44

Acute kidney injury in patients undergoing endovascular therapy for critical limb ischemia.

Similar to coronary angiography and interventions, patients undergoing percutaneous treatment of lower extremity peripheral arterial disease are also at risk of acute kidney injury (AKI). The incidence, risk factors associations, need for dialysis and inhospital mortality related to AKI in patients with critical limb ischemia (CLI) following endovascular therapy is poorly defined. The purpose of this study was to analyze data from the National Inpatient Sample (NIS) to determine the aforementioned outcomes in patients with CLI. Using the full NIS admission dataset from 2003 through 2012, ICD-9 codes relevant to comorbid conditions, procedure codes, composite codes for AKI, and inhospital mortality were analyzed using multivariate models. A total of 273,624 patients were included with a mean age of 70.0 ± 27.4 years, 46.0% were female, 57.2% had diabetes, 43.4% had coronary artery disease (CAD), and 29.2% had chronic kidney disease (CKD). The overall rate of AKI was 10.4%, and there was a temporal rise over the analysis period in AKI incidence (p < .001). Age, diabetes, CKD, and heart failure were all associated with AKI (p < .0001). The inhospital mortality rate in the patients with AKI declined over time but was higher than in patients without AKI (6.0% vs. 1.4%), p < .0001. The mortality rate was substantially higher in patients with AKI requiring dialysis as compared to AKI not requiring dialysis (13.4% vs. 5.6%), p < .0001. AKI is associated with age, CKD, and heart failure. The incidence of AKI following endovascular therapy for CLI is rising and independently associated with inhospital mortality.

Trial to Assess Chelation Therapy in Critical Limb Ischemia

Trial to Assess Chelation Therapy in Critical Limb Ischemia

Cost-Effective, Safe, and Personalized Cell Therapy for Critical Limb Ischemia in Type 2 Diabetes Mellitus.

Cell therapy is a progressively growing field that is rapidly moving from preclinical model development to clinical application. Outcomes obtained from clinical trials reveal the therapeutic potential of stem cell-based therapy to deal with unmet medical treatment needs for several disorders with no therapeutic options. Among adult stem cells, mesenchymal stem cells (MSCs) are the leading cell type used in advanced therapies for the treatment of autoimmune, inflammatory and vascular diseases. To date, the safety and feasibility of autologous MSC-based therapy has been established; however, their indiscriminate use has resulted in mixed outcomes in preclinical and clinical studies. While MSCs derived from diverse tissues share common properties depending on the type of clinical application, they markedly differ within clinical trials in terms of efficacy, resulting in many unanswered questions regarding the application of MSCs. Additionally, our experience in clinical trials related to critical limb ischemia pathology (CLI) shows that the therapeutic efficacy of these cells in different animal models has only been partially reproduced in humans through clinical trials. Therefore, it is crucial to develop new research to identify pitfalls, to optimize procedures and to clarify the repair mechanisms used by these cells, as well as to be able to offer a next generation of stem cell that can be routinely used in a cost-effective and safe manner in stem cell-based therapies targeting CLI.

Cell therapy of critical limb ischemia-problems and prospects.

Cell therapy is proposed for indirect revascularization for the patient's incurable by endovascular or surgical revascularization. The therapy with stem cells (SCs) or progenitor cells is assumed to be more efficient as compared with protein or gene therapy not only because of their direct vasculogenic properties, but also thanks to their paracrine effect via secretion of manifold biologically active substances. This review gives an overview of the potential of SC-based therapy for critical limb ischemia (CLI), putative mechanism underlying cell therapy, and comparison of cell therapy to angiogenesis gene therapy in CLI treatment. Human trial data and meta-analysis, as well as some problems of clinical trials and considerations for future SC-based therapy in CLI are also discussed.

Critical limb ischemia: Current and novel therapeutic strategies.

Critical limb ischemia (CLI) is the advanced stage of peripheral artery disease spectrum and is defined by limb pain or impending limb loss because of compromised blood flow to the affected extremity. Current conventional therapies for CLI include amputation, bypass surgery, endovascular therapy, and pharmacological approaches. Although these conventional therapeutic strategies still remain as the mainstay of treatments for CLI, novel and promising therapeutic approaches such as proangiogenic gene/protein therapies and stem cell-based therapies have emerged to overcome, at least partially, the limitations and disadvantages of current conventional therapeutic approaches. Such novel CLI treatment options may become even more effective when other complementary approaches such as utilizing proper bioscaffolds are used to increase the survival and engraftment of delivered genes and stem cells. Therefore, herein, we address the benefits and disadvantages of current therapeutic strategies for CLI treatment and summarize the novel and promising therapeutic approaches for CLI treatment. Our analyses also suggest that these novel CLI therapeutic strategies show considerable advantages to be used when current conventional methods have failed for CLI treatment.

Noninvasive monitoring of the development and treatment response of ischemic hindlimb by targeting matrix metalloproteinase-2 (MMP-2).

Critical limb ischemia (CLI) is a common cause of high vascular morbidity and mortality. Monitoring the development and treatment response of hindlimb ischemia (HI) in an animal model enables a better understanding of the pathological mechanisms underlying CLI, and evaluation of the efficacy of novel therapeutic approaches. Matrix metalloproteinase (MMP) activity is essential for remodeling of ischemic tissue including extracellular matrix degradation and angiogenesis. Herein, a mouse HI model is established and subjected to noninvasive optical imaging with a novel and ultra-sensitive MMP activatable probe, termed MMP-P12, for analyzing the development and treatment response of HI. Our results show that angiogenesis development during HI was well correlated with MMP-2 activity alteration as examined by western blot, histological staining and MMP-P12 fluorescence signal recovery. Moreover, vascular endothelial growth factor (VEGF) mediated HI treatment was also monitored by MMP-P12. Up-regulated MMP-2 expression and an enhancement of angiogenesis were observed after VEGF treatment, which peaked at 7 days after the treatment. Overall, our results showed that MMP-2 plays an important role in the monitoring of angiogenesis during HI development and therapy. Application of MMP-P12 to visualize MMP-2 activity alteration can serve as a promising noninvasive optical imaging strategy to monitor angiogenesis and its response to therapy in CLI.

On the Cutting Edge: Wound Care for the Endovascular Specialist.

Clinical outcomes in patients with critical limb ischemia (CLI) depend not only on endovascular restoration of macrovascular blood flow but also on aggressive periprocedural wound care. Education about this area of CLI therapy is essential not only to maximize the benefits of endovascular therapy but also to facilitate participation in the multidisciplinary care crucial to attaining limb salvage. In this article, we review the advances in wound care products and therapies that have granted the wound care specialist the ability to heal previously nonhealing wounds. We provide a primer on the basic science behind wound healing and the pathogenesis of ischemic wounds, familiarize the reader with methods of tissue viability assessment, and provide an overview of wound debridement techniques, dressings, hyperbaric therapy, and tissue offloading devices. Lastly, we explore emerging technology on the horizons of wound care.

Abstract 16598: Carnosine Synthetase Overexpression in Skeletal Muscle Promotes Functional Recovery of Ischemic Limb

Carnosine synthetase (ATPGD1) is an ATP grasp enzyme that catalyzes formation of histidyl dipeptides such as carnosine (β-alanine-histidine) and anserine (β-alanine-methyl histidine). These dipeptides are food constituents found in a high concentration in the skeletal muscle (10-20 mM) that have the abilities to chelate metals, scavenge lipid peroxidation products and buffer intracellular pH. These dipeptides are regarded as protective against injury and stress. Despite this knowledge, whether carnosine regulates angiogenesis is unknown. To assess this potential, a model of hindlimb ischemia (HLI) was surgically induced by femoral artery and vein ligation in the C57BL/6J (wild type, WT) mice provided drinking water without or with carnosine (1g/L) for 21 days post-surgery. C57BL/6J WT mice subjected to HLI and supplemented with carnosine had increased skeletal muscle expression of the dipeptide/histidine transporter (PHT1), carnosine transport, improved blood flow recovery, re-vascularization and regeneration of myocytes in the ischemic limb compared with mice without carnosine. To support that elevated skeletal muscle carnosine was beneficial in HLI, transgenic mice overexpressing ATPGD1 in the skeletal muscle were constructed. Transgenic (α-HSA-ATPGD1TG) mice had ~2-2.5-fold increase in carnosine (WT: 2.71±0.54 vs 7.40±0.54 nmoles/mg protein α-HSA-ATPGD1TG; p &lt;0.05) and anserine levels (WT: 3.65±1.12 vs 8.04±0.23 nmoles/mg protein α-HSA-ATPGD1TG p &lt;0.05) in the skeletal muscle than WT mice. At 2 and 3 weeks post-HLI surgery, α-HSA-ATPGD1TG mice had significantly improved blood flow recovery compared with the WT mice (2 weeks: α-HSA-ATPGD1TG: 59±3% vs 45±3% WT; p &lt;0.05; 3 weeks: α-HSA-ATPGD1TG: 65±4% vs 46±2% WT; p &lt;0.05). Because faster recovery of blood flow in the carnosine-supplemented mice was accompanied with increased expression of hypoxia inducible factor (HIF-1α) and vascular endothelial factor (VEGF) in the ischemic limb, we further investigated the mechanistic connection. Skeletal muscle myoblasts C2C12 cells pretreated with octyl-D-carnosine and subjected to 1 h of hypoxia, replacing oxygen with 95% N 2 and 5% CO 2 , had enhanced HIF-1α translocation, VEGF mRNA and secretion compared with untreated hypoxic and normoxic cells. Collectively, our results demonstrate that carnosine improves ischemia-stimulated angiogenesis potentially by stabilizing HIF1-α and promoting VEGF formation suggesting that carnosine may be a useful therapy in critical limb ischemia.