Compared to Intermittant Claudication Critical Limb Ischemia Is Associated with Elevated Levels of Cytokines

Association between aortic calcification and cytokine levels in patients with peripheral artery disease

Aortic calcification-a marker of advanced atherosclerosis in large arteries-associates with cardiovascular mortality and morbidity. Little is known about the soluble inflamJarmatory profiles involved in large artery atherosclerosis. We investigated the correlation between aortic calcification in the abdominal aorta and cytokine levels in a cohort of peripheral artery disease patients. Aortic calcification index was measured from computed tomography exams and circulating cytokine levels were analyzed from blood serum samples of 156 consecutive patients prior to invasive treatment of peripheral artery disease. The study included 156 patients (mean age 70.7 years, 64 (41.0%) women). The mean ankle-brachial index (ABI) was 0.64 and the mean aortic calcification index (ACI) was 52.3. ACI was associated with cytokines cutaneous T-cell-attracting chemokine CTACK (β 23.08, SE 5.22, p < 0.001) and monokine induced by gamma-interferon MIG (β 9.40, SE 2.82, p 0.001) in univariate linear regression. After adjustment with cardiovascular risk factors, CTACK and MIG were independently associated with ACI, β 17.9 (SE 5.22, p < 0.001) for CTACK and β 6.80 (SE 3.33, p 0.043) for MIG. CTACK was significantly higher in the patients representing the highest ACI tertile (highest vs. middle, 7.53 vs. 7.34 Tukeys HSD p-value 0.023 and highest vs. lowest tertile 7.53 vs. 7.29, Tukeys HSD p-value 0.002). MIG was significantly higher in the highest tertile versus lowest (7.65 vs. 7.30, Tukeys HSD p-value 0.027). Cytokines CTACK and MIG are associated with higher ACI, suggesting that CTACK and MIG reflect atherosclerotic disease burden of the aorta. This might further suggest the possible association with other cardiovascular morbidities.

Higher Levels of Cytokines in Patients with Chronic Limb-Threatening Ischemia

BACKGROUND

Inflammation is a key element in the initiation and progression of peripheral arterial disease (PAD). Understanding the impact of inflammatory molecules, as cytokines in PAD could help us to improve the prognosis of these patients. The main goal of this study was to compare the serum level of cytokines between patients with claudication to those with chronic limb-threatening ischemia (CLTI). The second objective was to evaluate the relationship between the levels of cytokines and death or amputation rate.

METHODS

An observational, single-center, and prospective study was conducted from January 2018 to July 2022. The study was approved by the ethical commission of the Local Hospital (75/2017). Patients with PAD, suggested by the clinical history and objective examination and confirmed with ankle-brachial index, attending vascular surgery consultations of the first author were included. The following exclusion criteria were applied: i) bedridden individuals or subjects who refused to participate in the protocol; ii) diseases responsible for body composition changes or proinflammatory state; iii) recent diet change, iv) active malignancy, v) autoimmune disease, vi) active infection, vii) chronic renal failure (glomerular filtration rate <30 mL/min/1.73 m2), or viii) heart failure in the past 3 months. This cohort was observed at admission, 3, 6, and 12 months. A panel of 27 cytokines was determined with ELISA, at baseline.

RESULTS

We included 119 subjects (mean age: 67.58 ± 9.60 years old; 79.80% males), 65 patients with claudication and 54 with CLTI. From the 27 cytokines analyzed, patients with CLTI, when compared to those with claudication, had a higher serum level of 11 cytokines: IL1ra, IL-6, IL-8, IL12 p70, G-CSF, IP-10, MCP-1, MIP-1α, PDGF-β, RANTES, and TNF-α. From the group of patients with CLTI those who underwent a major amputation had a higher serum level of FGF-basic [median = 49.04; interquartile range = 37.03-52.49; versus median = 33.04; interquartile range = 28.60-38.98; P = 0.001].

CONCLUSIONS

Patients with CLTI have higher serum level of inflammatory cytokines, which may have role in the prognosis of these patients.

The Association between Major Adverse Cardiovascular Events and Peripheral Artery Disease Burden

OBJECTIVE

The aim of the present study was to investigate the possible relationship between the segmental burden of lower limb atherosclerosis and Major Adverse Cardiovascular Events (MACEs).

METHODS

All the consecutive symptomatic peripheral artery disease (PAD) patients admitted for digital subtraction angiography (DSA) at Turku University Hospital department of Vascular Surgery between 1 January 2009 and 30 July 2011 were retrospectively analyzed. Angiography due to symptomatic PAD was used as the index date for the inclusion in the study. The segmental burden of atherosclerosis based on DSA was divided into three categories according to the highest disease burden of the defined artery segment: aorto-iliac, femoropopliteal, or tibial segments. The major association for the study was MACEs (defined as a cerebrovascular event, heart failure (HF) and myocardial infarction requiring hospital admission). Demographic data and MACEs were obtained from the hospital electronic medical records system.

RESULTS

The lower limb atherosclerosis burden of tibial vessels was related to an increased probability for HF (OR 3.9; 95%CI 2.4-6.5) and for MACEs overall (OR 2.3; 95%CI 1.4-3.6). The probability of both HF and MACEs overall rose with the increasing severity of the atherosclerosis burden. Moreover, the more severe the tibial vessel atherosclerosis, the higher the risk of HF and MACEs. The most extensive tibial atherosclerosis patients had an OR 4.5; 95%CI 2.6-8.0 for HF and an OR 3.1; and 95%CI 1.7-5.6 for MACEs overall. The femoropopliteal disease burden was also associated with an increased risk of HF (OR 2.3; 95%CI 1.6-3.2) and MACE (OR 1.9; 95%CI 1.3-2.7). However, the increasing extent of atherosclerosis of the femoropopliteal segment solely increased the risk of MACEs.

CONCLUSIONS

PAD patients with severe tibial atherosclerosis are likely to present with MACEs. The risk is further enhanced as the extent of tibial vessel atherosclerosis is increased. An association between MACE and severe atherosclerosis on the aortoiliac segment was not detected. However, when the femoropopliteal segment was the most affected artery segment, the risk of MACEs was increased.

Inflammatory Cells in Adipose Tissue and Skeletal Muscle of Patients with Peripheral Arterial Disease or Chronic Venous Disease: A Prospective, Observational, and Histological Study

The main goal of this study was to assess whether the presence of peripheral arterial disease (PAD) correlates with increased inflammatory cell infiltration. An observational, single-centre, and prospective study was conducted from January 2018 to July 2022. Clinical characteristics and anthropometric measures were registered. Consecutive PAD patients with surgical indications for a common femoral artery approach and patients with varicose veins with an indication for surgical ligation of the saphenofemoral junction were included. In both groups, samples of sartorius skeletal muscle, subcutaneous adipose tissue (SAT), and perivascular adipose tissue (PVAT) were collected from the femoral region. We analysed the characteristics of adipocytes and the presence of haemorrhage and inflammatory cells in the samples of PVAT and SAT via haematoxylin-eosin staining. We found that patients with PAD had significantly more inflammatory cells in PVAT [16 (43.24%) vs. 0 (0%) p = 0.008]. Analysing SAT histology, we observed that patients with PAD had significantly more CD45+ leucocytes upon immunohistochemical staining [32 (72.73%) vs. 3 (27.27%) p = 0.005]. Upon analysing skeletal muscle histology with haematoxylin-eosin staining, we evaluated skeletal fibre preservation, as well as the presence of trauma, haemorrhage, and inflammatory cells. We registered a significantly higher number of inflammatory cells in patients with PAD [well-preserved skeletal fibres: PAD = 26 (63.41%) vs. varicose veins = 3 (37.50%) p = 0.173; trauma: PAD = 4 (9.76%) vs. varicose veins = 2 (25.00%) p = 0.229; haemorrhage: PAD = 6 (14.63%) vs. varicose veins = 0 (0%) p = 0.248; inflammatory cells: PAD = 18 (43.90%) vs. varicose veins = 0 (0%) p = 0.018]. Patients with PAD had a higher number of inflammatory cells in skeletal muscle and adipose tissue (PVAT and SAT) when compared with those with varicose veins, emphasizing the role of inflammation in this group of patients.

Early Outcomes of Interwoven Nitinol Wire Stent Placement versus Endarterectomy for the Treatment of Atherosclerotic Disease of the Common Femoral Artery

PURPOSE

To compare the clinical outcomes of common femoral artery (CFA) atherosclerotic disease treated with either surgical endarterectomy or an interwoven nitinol wire stent system.

MATERIALS AND METHODS

A retrospective review was conducted of all patients with chronic, de novo atherosclerotic CFA disease treated with surgical endarterectomy (CFAE) or stent placement between July 2019 and March 2022. Outcome measures assessed up to 12 months after procedure included clinical improvement, primary restenosis, target vessel revascularization (TVR), major adverse limb events (MALEs), and all-cause mortality.

RESULTS

Thirty-nine stents were deployed in 33 patients, and 56 CFAEs were performed in 55 patients. No differences were noted in the rate of primary patency (95.5% vs 94.4%, P = .618), TVR (2.9% vs 1.8%, P = .777), MALE (5.1% vs 5.4%, P = .949), and all-cause mortality (14.1% vs 3.6%, P = .076) between the stent and CFAE groups up to 12 months after procedure. There was greater improvement in median clinical severity in the stent group than in the CFAE group (Rutherford score change of 3.0 vs 1.5, P = .013). The median length of stay was less for the stent group (3 vs 7 days, P = .002), and there was a lower likelihood of severe or disabling adverse events in the stent group (0 vs 9 cases, P = .010).

CONCLUSIONS

Patients treated with an interwoven nitinol wire stent had patency rates comparable to those treated with CFAE while having a lower incidence of severe adverse events and a shorter length of hospital stay than those who underwent CFAE.

Inflammation Is a Histological Characteristic of Skeletal Muscle in Chronic Limb Threatening Ischemia

BACKGROUND

The loss of skeletal muscle is a prognostic factor in several diseases including in patients with chronic limb threatening ischemia (CLTI). Patients with CLTI also have a lower skeletal mass and area when compared to those with claudication. However, there are no currently available data regarding the histological characteristics of core muscles in patients with CLTI. This study aims to determine the differences in core skeletal muscles between patients with claudication and those with CLTI. The second aim is to evaluate the differences in myokines, which are molecules secreted by skeletal muscle, between patients with claudication and those with CLTI.

METHODS

An observational, prospective study was conducted from January 2018 to July 2022 involving consecutive patients with peripheral arterial disease (PAD). The clinical characteristics were registered. In PAD patients with surgical indication for common femoral artery approach, samples of sartorius skeletal muscle (and not from the limb muscles directly involved in the ischemic process) were collected. The samples were submitted to histological characterization on hematoxylin-eosin and to immunohistochemical analysis to detect CD45+ leukocytes and CD163+ macrophages. The extent of the inflammatory cells (leukocytes and macrophages) was semiquantitatively assessed using a 0-to-4 grade scale as follows: absent (0†), mild (†), moderate (††), severe (†††), and very severe (††††). Serum levels of myokines: irisin, myostatin, IL-8, and lL-6 were determined with multiplex bead-based immunoassay.

RESULTS

119 patients (mean age: 67.58 ± 9.60 years old, 79.80% males) 64 with claudication and 54 with CLTI were enrolled in the study. No differences were registered between patients with claudication and those with CLTI on age, gender, cardiovascular risk factors, and medication, except on smoking habits. There was a significantly higher prevalence of smokers and a higher smoking load in the claudication group. Samples of sartorius skeletal muscle from 40 patients (14 with claudication and 26 with CLTI) were submitted to histological analysis. No differences were found in skeletal muscle fibers preservation, trauma, or hemorrhage (on hematoxylin-eosin staining). However, in the immunohistochemistry study, we found more inflammatory cells CD45+ leukocytes in patients with CLTI when compared to those with claudication [CD45+ ≥ moderate (††): claudication (n = 14): 4; 28.57%; CLTI (n = 25): 16; 64.00%; P = 0.034]. Patients with CLTI also had higher tissue levels of CD163+ macrophages, but this difference was not significant [CD163+ ≥ moderate (††): claudication (n = 13): 7; 53.85%; CLTI (n = 27): 21; 77.78%; P = 0.122]. The serum levels of the myokines, irisin, and myostatin were below the lower limit of detection, in the majority of patients, so no valid results were obtained. However, patients with CLTI had a higher serum level of Interleukin (IL)-6 and IL-8.

CONCLUSIONS

CLTI patients exhibit increased quantities of leukocytes in their sartorius muscle, as well as elevated serum levels of myokines IL-8 and IL-6. Inflamed skeletal muscle can contribute to the loss of muscle mass and account for the lower density of skeletal muscle observed in CLTI. Additionally, inflamed skeletal muscle may contribute to the development of systemic inflammation through the secretion of pro-inflammatory cytokines into the systemic circulation. Halting the inflammatory process could eventually improve the prognosis of CLTI patients.

The effect of omega-3 polyunsaturated fatty acid intake on blood levels of omega-3s in people with chronic atherosclerotic disease: a systematic review

CONTEXT

Atherosclerosis is a systemic pro-inflammatory and pro-oxidative disease, accounting for approximately a third of deaths globally. It has been proposed that omega-3s, through their antioxidant and anti-inflammatory properties, mitigate atherosclerotic disease progression. However, due to the systemic pro-inflammatory and pro-oxidative state of atherosclerosis, it is proposed that patients with atherosclerotic disease may have higher omega-3 requirements than the average requirement, due to increased nutrient utilization in anti-inflammatory and anti-oxidant processes.

OBJECTIVE

The aim of this review was to determine what dose and duration of omega-3 supplementation is required to reach a therapeutic blood level of omega-3s (eicosapentaenoic acid ≥150 µg/mL or omega-3 index ≥8%) in people with chronic atherosclerotic disease.

DATA SOURCES

This systematic review comprehensively searched MEDLINE, Emcare, Scopus, and CINAHL using key search terms for atherosclerotic disease, omega-3, supplementation, and blood levels of omega-3s.

DATA EXTRACTION

Two reviewers independently screened 529 randomized controlled trials (RCTs) supplementing omega-3s in patients with chronic atherosclerotic disease.

DATA ANALYSIS

In total, 25 journal articles from 17 original RCTs were included and assessed quantitatively. Supplementation at 1.8 g to 3.4 g per day for a 3-month-6-month duration, and at 4.4 g and above for as little as 1 month-6 months were identified as the most effective dosage ranges for increasing blood levels of omega-3s to therapeutic levels in people with atherosclerotic disease.

CONCLUSIONS

Consideration should be given to routine omega-3 supplementation and to increasing the omega-3 dietary recommendations and upper limits of daily intake to improve clinical outcomes and reduce the risk of cardiac mortality in this population.

New Biomarkers (Endocan, Interleukin-17, and Thrombospondin-4) for the Diagnosis, Assessment of Severity, and Follow-Up of Peripheral Arterial Disease

The present study evaluated the use of endocan, interleukin-17 (IL-17), and thrombospondin-4 (TSP-4) blood levels as potential biomarkers for the diagnosis and follow-up of peripheral arterial disease (PAD). Patients with PAD (Rutherford categories I, II, and III) who were admitted between March 2020 and March 2022 for cardiovascular surgery or outpatient clinic follow-up were included. The patients (n = 60) were divided into 2 groups: medical treatment (n = 30) and surgical treatment (n = 30). In addition, a control group (n = 30) was created for comparison. Endocan, IL-17, and TSP-4 blood levels were measured at the time of diagnosis and at the first month after treatment. Endocan and IL-17 values were found to be significantly higher in both groups that underwent medical (259.7 ± 46 pg/mL, 63.7 ± 16.6 pg/mL) and surgical (290.3 ± 84.5 pg/mL, 66.4 ± 19.6 pg/mL) treatment than the control group (187.4 ± 34.5 pg/mL, 56.5 ± 7.2 pg/mL P < .001). Tsp-4 value was found to be significantly higher only in the surgical treatment group (15 ± 4.3 ng/mL) than the control group (12.9 ± 1.4 ng/mL P < .05). The decreases in endocan, IL-17, and TSP-4 levels at the first month of treatment in both groups were also significant (P < .001). A combination of classical and these new biomarkers could be included in PAD screening, early diagnosis, severity determination, and follow-up protocols in order to provide effective assessment in clinical practice.

Inflammation and Loss of Skeletal Muscle Mass in Chronic Limb Threatening Ischemia

BACKGROUND

Lower extremity peripheral arterial disease (PAD) is an atherosclerotic disease of the lower extremities. Atherosclerosis, inflammation, and sarcopenia are independently associated and potentiate each other. Inflammation is deeply involved in the formation and progression of atherosclerosis and is also involved in the pathophysiology of sarcopenia. Sarcopenia is defined as low muscle mass, with low muscle strength. This study aims to determine the differences in skeletal muscle characteristics and in inflammatory parameters between patients with claudication and with chronic limb threatening ischemia (CLTI).

METHODS

An observational, prospective study in patients with PAD was conducted from January 2018 to December 2020. The clinical characteristics and the cardiovascular risk factors were prospectively registered. The inflammatory parameters determined were: positive acute phase proteins (C-reactive Protein- CRP- and fibrinogen) and negative acute phase proteins albumin, total cholesterol and high-density lipoprotein (HDL). The skeletal muscle area and density were quantified with a computed topography (CT) scan. The strength was determined with a Jamar® hydraulic hand dynamometer.

RESULTS

A total of 116 patients (mean age: 67.65 ± 9.53 years-old) 64% with claudication and 46% with CLTI were enrolled in the study. No differences were registered between patients with claudication and CLTI on age, cardiovascular risk factors (hypertension, dyslipidemia, diabetes mellitus, and smoking habits) and medication. There was a higher prevalence of men in the claudication group (88.89% vs. 71.70%, P = 0.019). Analyzing the inflammatory parameters, we noted that patients with CLTI had increased serum levels of positive acute phase proteins: CRP (37.53 ± 46.61 mg/L vs. 9.18 ± 26.12 mg/L, P = 0.000), and fibrinogen (466.18 ± 208.07 mg/dL vs. 317.37 ± 79.42 mg/dL, P = 0.000). CLTI patients had decreased negative acute phase proteins: albumin (3.53 ± 0.85 g/dL vs. 3.91 ± 0.72 g/dL, P = 0.001), total cholesterol (145.41 ± 38.59 mg/dL vs. 161.84 ± 34.94 mg/dL, P = 0.013) and HDL (38.70 ± 12.19 mg/dL vs. 51.31 ± 15.85 mg/dL, P = 0.000). We noted that patients with CLTI had lower skeletal muscle area and mass (14,349.77 ± 3,036.60 mm² vs. 15,690.56 ± 3,183.97 mm²P = 0.013; 10.11 ± 17.03HU vs. 18.02 ± 13.63HU P = 0.013). After adjusting for the variable sex, the association between skeletal muscle density and CLTI persisted (r (97) = -0.232, P = 0.021). The groups did not differ in strength (patients with claudication: 25.39 ± 8.23 Kgf vs. CLTI: 25.17 ± 11.95 Kgf P = 0.910).

CONCLUSIONS

CLTI patients have decreased skeletal muscle mass and a systemic inflammation status. Recognizing the deleterious triad of atherosclerosis, inflammation and loss of skeletal mass patients with CLTI is an opportunity to improve medical therapy and to perform a timely intervention to stop this vicious cycle.

Plasma Gut Microbe-Derived Metabolites Associated with Peripheral Artery Disease and Major Adverse Cardiac Events

Cardiovascular diseases are associated with gut dysbiosis, but the role of microbe-derived metabolites as biomarkers or modulators of cardiovascular disease are not well understood. This is a targeted metabolomics study to investigate the association of nine microbe-derived metabolites with lower extremity peripheral artery disease (PAD), a form of atherosclerosis, and major adverse cardiac events (MACE). The study cohort consists of individuals with intermittent claudication and ankle-brachial index (ABI) < 0.9 (N = 119) and controls without clinically-apparent atherosclerosis (N = 37). The primary endpoint was MACE, a composite endpoint of myocardial infarction, coronary revascularization, stroke, transient ischemic attack, or cardiac-related death. Plasma metabolite concentrations differed significantly between the PAD and control groups. After adjustment for traditional atherosclerosis risk factors, kynurenine, hippuric acid, indole-3-propionic acid (IPA), and indole-3-aldehyde (I3A) concentrations were negatively associated with PAD, whereas indoxyl sulfate and 3-hydroxyanthranilic acid were positively associated. Hippuric acid, IPA, and I3A correlated with ABI, a surrogate for atherosclerotic disease burden. Those in the highest I3A concentration quartile had significantly improved freedom from MACE during follow-up compared to those in the lowest quartile. This study identifies specific indole- and phenyl-derived species impacted by gut microbial metabolic pathways that could represent novel microbiome-related biomarkers of PAD.

Standardized Whole Blood Assay and Bead-Based Cytokine Profiling Reveal Commonalities and Diversity of the Response to Bacteria and TLR Ligands in Cattle

Recent developments in multiplex technologies enable the determination of a large nu\mber of soluble proteins such as cytokines in various biological samples. More than a one-by-one determination of the concentration of immune mediators, they permit the establishment of secretion profiles for a more accurate description of conditions related to infectious diseases or vaccination. Cytokine profiling has recently been made available for bovine species with the development of a Luminex^® technology-based 15-plex assay. Independently from the manufacturer, we evaluated the bovine cytokine/chemokine multiplex assay for limits of detection, recovery rate, and reproducibility. Furthermore, we assessed cytokine secretion in blood samples from 107 cows upon stimulation with heat-killed bacteria and TLR2/4 ligands compared to a null condition. Secretion patterns were analyzed either using the absolute concentration of cytokines or using their relative concentration with respect to the overall secretion level induced by each stimulus. Using Partial Least Square-Discriminant Analysis, we show that the 15-cytokine profile is different under Escherichia coli, Staphylococcus aureus, and Streptococcus uberis conditions, and that IFN-γ, IL-1β, and TNF-α contribute the most to differentiate these conditions. LPS and E. coli induced largely overlapping biological responses, but S. aureus and S. uberis were associated with distinct cytokine profiles than their respective TLR ligands. Finally, results based on adjusted or absolute cytokine levels yielded similar discriminative power, but led to different stimuli-related signatures.

Subunits of C1Q Are Associated With the Progression of Intermittent Claudication to Chronic Limb-Threatening Ischemia

Background

The pathophysiological mechanisms of intermittent claudication (IC) progression to chronic limb-threatening ischemia (CLTI) are still vague and which of patients with IC will become CLTI are unknown. This study aimed to investigate the key molecules and pathways mediating IC progression to CLTI by a quantitative bioinformatic analysis of a public RNA-sequencing database of patients with peripheral artery disease (PAD) to screen biomarkers discriminating IC and CLTI.

Methods

The GSE120642 dataset was downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between IC and CLTI tissues were analyzed using the “edgeR” packages of R. The Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed to explore the functions of DEGs. Protein–protein interaction (PPI) networks were established by the Search Tool for the Retrieval of Interacting Genes (STRING) database and visualized by Cytoscape software. Hub genes were selected by plugin cytoHubba. Gene set enrichment analysis was performed and the receiver operating characteristic curves were used to evaluate the predictive values of hub genes.

Results

A total of 137 upregulated and 21 downregulated DEGs were identified. Functional enrichment clustering analysis revealed a significant association between DEGs and the complement and coagulation cascade pathways. The PPI network was constructed with 155 nodes and 105 interactions. The most significantly enriched pathway was complement activation. C1QB, C1QA, C1QC, C4A, and C1R were identified and validated as hub genes due to the high degree of connectivity. The area under the curve values for the five hub genes were greater than 0.95, indicating high accuracy for discriminating IC and CLTI.

Conclusion

The complement activation pathway is associated with IC progression to CLTI. C1QB, C1QA, C1QC, C4A, and C1R might serve as potential early biomarkers of CLTI.

Oroxylin a Attenuates Limb Ischemia by Promoting Angiogenesis via Modulation of Endothelial Cell Migration

Oroxylin A (OA) has been shown to simultaneously increase coronary flow and provide a strong anti-inflammatory effect. In this study, we described the angiogenic properties of OA. OA treatment accelerated perfusion recovery, reduced tissue injury, and promoted angiogenesis after hindlimb ischemia (HLI). In addition, OA regulated the secretion of multiple cytokines, including vascular endothelial growth factor A (VEGFA), angiopoietin-2 (ANG-2), fibroblast growth factor-basic (FGF-2), and platelet derived growth factor BB (PDGF-BB). Specifically, those multiple cytokines were involved in cell migration, cell population proliferation, and angiogenesis. These effects were observed at 3, 7, and 14 days after HLI. In skeletal muscle cells, OA promoted the release of VEGFA and ANG-2. After OA treatment, the conditioned medium derived from skeletal muscle cells was found to significantly induce endothelial cell (EC) proliferation. OA also induced EC migration by activating the Ras homolog gene family member A (RhoA)/Rho-associated coiled-coil kinase 2 (ROCK-II) signaling pathway and the T-box20 (TBX20)/prokineticin 2 (PROK2) signaling pathway. In addition, OA was able to downregulate the number of macrophages and neutrophils, along with the secretion of interleukin-1β, at 3 days after HLI. These results expanded current knowledge about the beneficial effects of OA in angiogenesis and blood flow recovery. This research could open new directions for the development of novel therapeutic intervention for patients with peripheral artery disease (PAD).

Regenerative Effects of Hypoxia Primed Flowable Placental Formulation in Muscle and Dermal Injury

The placental tissue, due to its angiogenic, anti-inflammatory, antioxidative, antimicrobial, and anti-fibrotic properties, has become a compelling source towards a solution for several indications in regenerative medicine. However, methods to enhance and capture the therapeutic properties with formulations that can further the applications of viable placental tissue have not been explored. In this study, we investigated the regenerative effects of a hypoxia primed flowable placental formulation (FPF), composed of amnion/chorion and umbilical tissue, in two in vivo injury models. Laser Doppler data from rodent ischemia hindlimbs treated with FPF revealed significant tissue perfusion improvements compared to control ischemic hindlimbs. To further corroborate FPF's effects, we used a rodent ischemic bipedicle skin flap wound model. FPF treatment significantly increased the rate of wound closure and the quality of wound healing. FPF-treated wounds displayed reduced inflammation and an increase in angiogenesis. Furthermore, quantitative PCR and next-generation sequencing analysis confirmed these changes in the FPF-treated group at both the gene and transcriptional level. The observed modulation in miRNAs was associated with angiogenesis, regulation of inflammatory microenvironment, cell migration and apoptosis, reactive oxygen species generation, and restoring epithelial barrier function, all processes involved in impaired tissue healing. Taken together, these data validate the tissue regenerative properties of the flowable placental formulation configuration tested.

Anxiety and Depression Scores in Patients Subjected to Arterial Revascularization for Critical Limb Ischemia

OBJECTIVES

This study aims to examine the changes in anxiety and depression scores in 138 patients with critical limb ischemia (rest pain or gangrene) who had no previous psychiatric history, at 30 days and 6 months after surgical revascularization.

METHODS

Patients were submitted to a questionnaire-based evaluation using the Beck Anxiety and Depression Inventories before surgery (no more than three days before surgery) ("Pre-Op"), 30 days after surgical revascularization ("Early PO") and at least 6 months after surgical revascularization ("Late PO"). The cut-off scores for depression were (1) < 10, no depression or minimal depression; (2) 10‒18, mild to moderate depression; (3) 19‒29, moderate to severe depression; and (4) 30‒63, severe depression. The cut-off scores for anxiety were (1) < 8, no anxiety or minimal anxiety; (2) 8‒15, mild anxiety; (3) 16‒25, moderate anxiety; and (4) 26‒63, severe anxiety.

RESULTS

No perioperative mortality was observed 30 days after surgical revascularization. Thirty-nine (28.2%) patients underwent major (above-ankle) amputation within 30 days. Mean anxiety and depression scores, respectively, declined from 12.48 ± 9.74 (mean ± SD) and 16.92 ± 12.48 preoperatively to 4.89 ± 7.04 and 6.52 ± 9.36 postoperatively (P<0.001, both). Anxiety and depression scores were not significantly affected by preoperative comorbidities (systemic arterial hypertension, diabetes mellitus, previous stroke, and smoking), affected arterial territory (aortoiliac, femoropopliteal, or infrapopliteal), or surgical technique (open surgery vs endovascular therapy). Only patients undergoing amputation within 30 days showed no improvement in depressive symptoms.

CONCLUSIONS

Patients with critical limb ischemia have a high incidence of anxiety and depressive symptoms, which improve considerably after successful surgical revascularization. Major amputation was associated with a lack of improvement in depression scores. A formal psychiatric evaluation may be beneficial in patients who show no improvement in depressive symptoms.

Critical limb ischemia patients clinically improving with medical treatment have lower neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios

OBJECTIVES

Inflammation is a component in the pathogenesis of critical limb ischemia. We aimed to assess how inflammation affects response to treatment in patients treated for critical limb ischemia using neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocytes ratios (PLR) as markers of inflammation.

METHODS

Patients in a single tertiary cardiovascular center with critical limb ischemia unsuitable for surgical or interventional revascularization were retrospectively identified. Data were collected on medical history for risk factors, previous surgical or endovascular revascularization, and outcome. A standard regimen of low molecular weight heparin, aspirin, statins, iloprost infusions, and a standard pain medication protocol were applied to each patient per hospital protocol. Patients with improvement in ischemic pain and healed ulcers made up the responders group and cases with no worsening pain or ulcer size or progression to minor or major amputations made up the non-responders group. Responders and Non-responders were compared for risk factors including pretreatment NLR and PLR.

RESULTS

268 included patients who were not candidates for surgical or endovascular revascularization were identified. Responders had significantly lower pretreatment NLR (4.48 vs 8.47, p < 0.001) and PLR (162.19 vs 225.43, p = 0.001) values. After controlling for associated risk factors NLR ≥ 4.63 (p < 0.001) and PLR ≥ 151.24 (p = 0.016) were independently associated with no response to treatment.

CONCLUSIONS

Neutrophil-to-lymphocyte ratio and platelet-to-lymphocytes ratio are markers of inflammation that are reduced in patients improving with medical treatment suggesting a decreased state of inflammation before treatment in responding patients.

Cytokine Profile in Experimental Models of Critical Limb Ischemia in Rats

We studied the effect of intramuscular administration of a cellular product (mesenchymal stem cells, conditioned media, and erythropoietin) on cytokine levels in blood serum, conditioned media of bone marrow mononuclears, and calf muscles in Wistar rats with hind limb ischemia. It is shown that the cellular product reduces the proinflammatory background at the early stages of the experiment and increases the content proangiogenic factors.

A Pro-Inflammatory Biomarker-Profile Predicts Amputation-Free Survival in Patients with Severe Limb Ischemia

Patients with Severe Limb Ischemia (SLI) have a high risk of amputation and mortality. Here, we investigated a panel of serum biomarkers with the aim of identifying biomarkers for major events and mechanisms that contribute to disease progression in established SLI. A panel of biomarkers including GROα, HGF, SCF, SCGFβ, SDF1α, TRAIL, IL-6, IL-8, FGFβ, GCSF, GMCSF, IP10, MCP1, PDGFbb, RANTES, TNFα, VEGF, sICAM, sVCAM, TM, and E-selectin was measured in serum samples from a subset (n = 108) of the JUVENTAS cohort. The primary outcome was major events, defined as major amputation or death. The inflammatory biomarkers IL-6, IL-8, GROα and IP-10 were significantly elevated in patients who reached a major endpoint. Results were validated in a secondary cohort (n = 146). Cox regression showed that adjusted hazard ratios were 1.40 (95% CI: 1.15-1.70, p = 0.0007) and 1.48 (95% CI 1.16-1.87, p = 0.001) for IL-6 and IP-10 in a fully adjusted model containing both biomarkers. A prediction model using IL-6 and IP-10 showed predictive accuracy with an AUC of ~ 78% in both discovery and validation cohorts, which is higher than previously published models. We conclude that inflammatory biomarkers predict major events in patients with SLI and allow the creation of biomarker-based risk-prediction models.

Nutritional Considerations for Peripheral Arterial Disease: A Narrative Review

Those with peripheral arterial disease (PAD) require important considerations with respect to food and nutrition, owing to advanced age, poor diet behaviours and immobility associated with the disease process and co-morbid state. These considerations, coupled with the economic effectiveness of medical nutrition therapy, mandate that dietetic care plays a vital role in the management of PAD. Despite this, optimising dietetic care in PAD remains poorly understood. This narrative review considers the role of medical nutrition therapy in every stage of the PAD process, ranging from the onset and initiation of disease to well established and advanced disease. In each case, the potential benefits of traditional and novel medical nutrition therapy are discussed.

Review of the Current Basic Science Strategies to Treat Critical Limb Ischemia

Critical limb ischemia (CLI) is a highly morbid disease with many patients considered poor surgical candidates. The lack of treatment options for CLI has driven interest in developing molecular therapies within recent years. Through these translational medicine studies in CLI, much has been learned about the pathophysiology of the disease. Here, we present an overview of the macrovascular and microvascular changes that lead to the development of CLI, including impairment of angiogenesis, vasculogenesis, and arteriogenesis. We summarize the randomized clinical controlled trials that have used molecular therapies in CLI, and discuss the novel imaging modalities being developed to assess the efficacy of these therapies.

Prognostic Factors in Patients Treated with Drug-Coated Balloon Angioplasty for Symptomatic Peripheral Artery Disease

Purpose

Aim of this study is to report real-life experience on the treatment of peripheral artery disease (PAD) with a specific drug-coated balloon (DCB), and to evaluate potential prognostic factors for outcomes.

Materials and Methods

This is a retrospective study reporting outcomes in patients with PAD who were treated with the Lutonix DCB during a four-year period. Major outcomes included: all-cause mortality, amputation, clinical improvement, wound healing and target lesion revascularization (TLR). Mean follow-up was 24.2±2.3 months.

Results

Overall, 149 patients (mean age: 68.6±8.3 years; 113 males) were treated, either for intermittent claudication (IC) (n=86) or critical limb ischemia (CLI) (n=63). More than half the target lesions (n=206 in total) were located in the superficial femoral artery and 18.0% were below-the-knee lesions. CLI patients presented more frequently with infrapopliteal (P=0.002) or multilevel disease (P=0.0004). Overall, all-cause mortality during follow-up was 10.7%, amputation-free survival was 81.2% and TLR-free survival was 96.6%. CLI patients showed higher all-cause mortality (P=0.007) and total amputation (P=0.0001) rates as well as lower clinical improvement (P=0.0002), compared to IC patients. Coronary artery disease (CAD), gangrene and infrapopliteal disease were found to be predictors for death whereas CLI and gangrene were found to be predictors for amputation, during follow-up.

Conclusion

PAD treatment with Lutonix DCBs seems to be an efficient and safe endovascular strategy yielding promising results. However, CAD, gangrene, CLI and infrapopliteal lesions were found to be independent predictors for adverse outcomes. Larger series are needed to identify additional prognostic factors.

Novel biomarkers for cardiovascular risk

Cardiovascular disease refers to different diseases involving the heart and/or the arteries and/or the veins. Cardiovascular disease, overall considered, is a notable source of morbidity and mortality worldwide. Therefore, several research studies are dedicated to explore, by means of biomarkers, the possiblity to calculate the cardiovascular risk both for the onset and for the complications of the related clinical manifestations such as coronary artery disease, carotid artery stenosis, peripheral artery disease, arterial aneurysm, chronic venous disease and venous thromboembolism. This review discusses the most updated information in the area of the novel biomarkers related to omics, imaging techniques and clinical data, that may help physicians in order to improve the knowledge and the management of the cardiovascular risk.

Nationally Representative Readmission Factors Associated with Endovascular versus Open Repair of Abdominal Aortic Aneurysm

BACKGROUND

Hospital readmissions are tied to financial penalties and thus significantly influence health-care policy. Many current studies on readmissions lack national representation by not tracking readmissions across hospitals. The recently released Nationwide Readmission Database is one of the most comprehensive national sources of readmission data available, making it an invaluable resource to understand this critically important health policy issue.

METHODS

The Nationwide Readmission Database for 2013 and 2014 was queried for adult patients with abdominal aortic aneurysm (441.4) undergoing endovascular (39.71) or open (38.44) repair. Outcomes examined were overall/initial admission mortality and overall/30-day readmissions. Multivariate logistic regression for these outcomes was also performed on multiple readmission factors.

RESULTS

Fifty-three thousand four hundred seventeen patients underwent abdominal aortic aneurysm repair (47,431 endovascular aortic repair [EVAR] versus 5,986 open surgical repair [OSR]). Significant differences were found for EVAR versus OSR on overall readmissions, initial admission cost, readmission costs, length of stay, days to readmission, and overall/initial admission mortality. Multivariate logistic regression analysis found that length of stay > 30, Charlson Comorbidity Index > 1, discharge disposition, and female sex were all significant predictors of 30-day readmission. Repair type was significantly associated with 30-day readmissions; however, it was not a significant factor for overall readmissions.

CONCLUSION

There are significant differences in costs, prognosis, and readmission rates for EVAR versus OSR. Given that these differences are being used to create "acceptable" readmission rates, disbursement quotas among hospitals, and subsequent penalties for providers outside the expected rates, it is only prudent to obtain the most accurate information to guide those policies.

LEVEL OF EVIDENCE

Care management/epidemiological, level IV.

Nationally Representative Readmission Factors in Patients with Claudication and Critical Limb Ischemia

BACKGROUND

Hospital readmissions are associated not only with increased mortality, morbidity, and costs but also, with current health-care reform, tied to significant financial and administrative penalties. Some studies show that patients undergoing vascular surgery may have higher than average readmission rates. The recently released Nationwide Readmission Database (NRD) is the most comprehensive national source of readmission data, gathering discharge information from 22 geographically dispersed states, accounting for 51.2% of the total U.S. resident population and 49.3% of all U.S. hospitalizations. The aim of this study is to use the power of the NRD and obtain nationally representative readmission information for patients admitted with claudication or critical limb ischemia (CLI) who underwent revascularization procedures.

METHODS

The NRD was queried for all patients admitted for claudication (International Classification of Diseases Ninth Revision [ICD-9] 440.21) or CLI (ICD-9 440.22-440.24) and who underwent percutaneous transluminal angioplasty, peripheral bypass, or aortofemoral bypass. Patient demographics, comorbidities, length of stay (LOS), mortality, readmission rates, and associated costs were collected. Univariable and multivariable logistic regression analysis was implemented on claudication and CLI groups on all outcomes of interest. The most common readmission diagnosis codes and diagnosis groups were also identified.

RESULTS

A total of 92,769 patients were admitted for peripheral vascular disease (33,055 with claudication and 59,714 with CLI). The 30-day readmission/any readmission rate was 8.97%/21.49% and 19.26%/40.36%, for claudication and CLI, respectively. Significant differences were found for claudication and CLI, respectively, on initial cost of admission ($18,548 vs. $29,148, P < 0.001), readmission costs ($14,726 vs. $17,681 P < 0.001), LOS (4 days vs. 9 days, P < 0.001), days to readmission (73 days vs. 59 days, P < 0.001), mortality during initial admission (256 vs. 1,363, P < 0.001), and mortality during any admission (538 vs. 3,838, P < 0.001). Univariate and multivariate logistic regression analysis found that claudication, CLI, angioplasty, peripheral bypass, aortofemoral bypass, female sex, age >65, Charlson Comorbidity Index, LOS, and primary expected payer status were all significant predictors of 30-day and overall readmissions at varying degrees. The 5 most common disease readmission groups found were other vascular procedures (12.6%), amputation of lower limb except toes (6.3%), sepsis (5.4%), heart failure (4.9%) and postoperative or other device infections (4.8%). Of the abovementioned groups, the 4 most common diagnoses included "other postoperative infections," sepsis, atherosclerosis of native arteries with gangrene, and "other complications due to other vascular device, implant, or graft."

CONCLUSIONS

Our results demonstrate that there is a significant difference in readmission rates, cost, and morbidity between patients admitted for claudication and CLI. Furthermore, based on regression analysis, there are multiple other clear risk factors associated with worse clinical and economic outcomes. Further study is needed to predict which patients will require increased vigilance during their hospital stay to prevent readmissions and worse outcomes.

LEVEL OF EVIDENCE

Care management/epidemiological, level IV.

Correlation between increasing tissue ischemia and circulating levels of angiogenic growth factors in peripheral artery disease

INTRODUCTION

The aim of the present study was to assess the circulating levels of vascular endothelial growth factor (VEGF) and other suggested therapeutic growth factors with the degree of ischemia in patients with different clinical manifestations of peripheral arterial disease (PAD) according to the Rutherford grades.

METHODS

The study cohort consists of 226 consecutive patients admitted to a Department of Vascular Surgery for elective invasive procedures. PAD patients were grouped according to the Rutherford grades after a clinical assessment. Ankle-brachial pressure indices (ABI) and absolute toe pressure (TP) values were measured. Serum levels of circulating VEGF, hepatocyte growth factor (HGF), basic fibroblast growth factor (bFGF), and platelet derived growth factor (PDGF) were measured from serum and analysed against Rutherford grades and peripheral hemodynamic measurements.

RESULTS

The levels of VEGF (P = 0.009) and HGF (P < 0.001) increased significantly as the ischaemic burden became more severe according to the Rutherford grades. PDGF behaved in opposite manner and declined along increasing Rutherford grades (P = 0.004). A significant, inverse correlations between Rutherford grades was detected as follows; VEGF (Pearson's correlation = 0.183, P = 0.004), HGF (Pearson's correlation = 0.253, P < 0.001), bFGF (Pearson's correlation = 0.169, P = 0.008) and PDGF (Pearson's correlation = 0.296, P < 0.001). In addition, VEGF had a clear direct negative correlation with ABI (Pearson's correlation -0.19, P = 0.009) and TP (Pearson's correlation -0.20, P = 0.005) measurements.

CONCLUSIONS

Our present observations show that the circulating levels of VEGF and other suggested therapeutic growth factors are significantly increased along with increasing ischemia. These findings present a new perspective to anticipated positive effects of gene therapies utilizing VEGF, HGF, and bFGF, because the levels of these growth factors are endogenously high in end-stage PAD.

Clinical factors influencing mortality risk in hospital-acquired sepsis

BACKGROUND

Identification of factors that confer an increased risk of mortality in hospital-acquired sepsis (HAS) is necessary to help prevent, and improve the outcome of, this condition.

AIM

To evaluate the clinical characteristics and factors associated with mortality in patients with HAS.

METHODS

Retrospective study of patients with HAS in a major Spanish Hospital from 2011 to 2015. Data from adults receiving any of the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes associated with sepsis were collected. Those fulfilling the SEPSIS-2 definition with no evidence of infection during the first 48 h following hospitalization were included (N = 196). Multivariate analysis was employed to identify the risk factors of mortality.

FINDINGS

HAS patients were found to have many of the risk factors associated with cardiovascular disease (male sex, ageing, antecedent of cardiac disease, arterial hypertension, dyslipidaemia, smoking habit) and cancer. Vascular disease or chronic kidney disease were associated with 28-day mortality. Time from hospital admission to sepsis diagnosis, and the presence of organ failure were risk factors for 28-day and hospital mortality. Experiencing more than one episode of sepsis increased the risk of hospital mortality. 'Sepsis code' for the early identification of sepsis was protective against hospital mortality.

CONCLUSION

This study identifies several major factors associated with mortality in patients suffering from HAS. Implementation of surveillance programmes for the early identification and treatment of sepsis translate into a clear benefit.