Impact of COVID-19 pandemic on patients affected by peripheral arterial disease: an Italian single-center study.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) has evolved into a global pandemic, affecting a wide range of medical and surgical specialties. During COVID-19, we assisted in the reallocation of medical resources and services, as well as social distancing measures, and many patients with chronic diseases and comorbidities may have experienced difficulties in obtaining the correct medical care. The aim of the study was to investigate the impact of the COVID-19 pandemic on major adverse cardiovascular events (MACE) and major adverse limb events (MALE) in patients with peripheral arterial disease (PAD) and chronic limb-threatening ischemia (CLTI), compared to previous years. PATIENTS AND METHODS: We evaluated 1,335 hospital admissions of 877 patients with PAD admitted to Policlinico A. Gemelli Hospital between January 2017 and February 2020 and 368 hospital admissions of 272 patients with PAD admitted to the Policlinico A. Gemelli Hospital between March 2020 and March 2021. Data on demographic characteristics, comorbidities, symptoms, physical and radiological findings, laboratory tests, and routine visits before or after discharge were collected from electronic medical records. RESULTS: Emergency room (ER) admissions among PAD patients during COVID-19 were higher than before the pandemic [190 (51.63%) vs. 579 (43.37%), p = 0.01]. A MACE was found in 78 (5.84%) pre-pandemic hospitalizations and 126 (34.24%) pandemic hospitalizations (p < 0.01). A MALE was identified in 942 (70.56%) pre-pandemic hospitalizations and 331 (89.95%) pandemic hospitalizations (p < 0.01). Amputation rates during the pandemic were higher than before the pandemic [80 (21.74%) vs. 191 (14.31%), p < 0.01]. The number of in-hospital deaths did not differ between the pandemic and pre-pandemic periods [11 (2.99%) vs. 51 (3.82%), p = 0.55]. CONCLUSIONS: In patients with PAD and CLTI, the number of MACE, MALE, and amputations was higher during the COVID-19 period compared to the three years before the pandemic.

Identification of early predictors of clinical outcomes of COVID-19 outbreak in an Italian single center using a machine-learning approach.

OBJECTIVE: SARS-CoV-2 disease (COVID-19) has become a pandemic disease, determining a public health emergency. The use of artificial intelligence in identifying easily available biomarkers capable of predicting the risk for severe disease may be helpful in guiding clinical decisions. The aim of the study was to investigate the ability of interleukin (IL)-6, troponin I, and D-dimer to identify patients with COVID-19 at risk for intensive care unit (ICU)-admission and death by using a machine-learning predictive model. PATIENTS AND METHODS: Data on demographic characteristics, underlying comorbidities, symptoms, physical and radiological findings, and laboratory tests have been retrospectively collected from electronic medical records of patients admitted to Policlinico A. Gemelli Foundation from March 1, 2020, to September 15, 2020, by using artificial intelligence techniques. RESULTS: From an initial cohort of 425 patients, 146 met the inclusion criteria and were enrolled in the study. The in-hospital mortality rate was 15%, and the ICU admission rate was 41%. Patients who died had higher troponin I (p-value<0.01) and IL-6 values (p-value=0.04), compared to those who survived. Patients admitted to ICU had higher levels of troponin I (p-value<0.01) and IL-6 (p-value<0.01), compared to those not admitted to ICU. Threshold values to predict in-hospital mortality and ICU admission have been identified. IL-6 levels higher than 15.133 ng/L have been associated with a 22.91% risk of in-hospital mortality, and IL-6 levels higher than 25.65 ng/L have been associated with a 56.16% risk of ICU admission. Troponin I levels higher than 12 ng/L have been associated with a 26.76% risk of in-hospital mortality and troponin I levels higher than 12 ng/L have been associated with a 52.11% risk of ICU admission. CONCLUSIONS: Levels of IL-6 and troponin I are associated with poor COVID-19 outcomes. Cut-off values capable of predicting in-hospital mortality and ICU admission have been identified. Building a predictive model using a machine-learning approach may be helpful in supporting clinical decisions in a more precise and personalized way.

Effects of aging and life-long moderate calorie restriction on IL-15 signaling in the rat white adipose tissue.

OBJECTIVE: Phosphorylation of insulin receptor substrate (IRS) 1 by tumor necrosis factor alpha (TNF-α) has been implicated as a factor contributing to insulin resistance. Administration of IL-15 reduces adipose tissue deposition in young rats and stimulates secretion of adiponectin, an insulin sensitizing hormone that inhibits the production and activity of TNF-α. We aimed at investigating the effects of age life-long moderate calorie restriction (CR) on IL-15 and TNF-α signaling in rat white adipose tissue (WAT). MATERIALS AND METHODS: Thirty-six 8-month-old, 18-month-old, and 29-month-old male Fischer344´Brown Norway F1 rats (6 per group) were either fed ad libitum (AL) or calorie restricted by 40%. The serum levels of IL-15 and IL-15 receptor α-chain (IL-15Rα) were increased by CR controls regardless of age. An opposite pattern was detected in WAT. In addition, CR reduced gene expression of TNF-α and cytosolic IRS1 serine phosphorylation in WAT, independently from age. RESULTS: IL-15 signaling in WAT is increased over the course of aging in AL rats compared with CR rodents. Protein levels of IL-15Rα are greater in WAT of AL than in CR rats independently from age. This adaptation was paralleled by increased IRS1 phosphorylation through TNF-α-mediated insulin resistance. Adiponectin decreased at old age in AL rats, while no changes were evident in CR rats across age groups. CONCLUSIONS: IL-15 signaling could therefore represent a potential target for interventions to counteract metabolic alterations and the deterioration of body composition during aging.

RANK/RANKL/OPG pathway: genetic association with history of ischemic stroke in Italian population.

OBJECTIVE: RANKL is a member of the TNF superfamily that stimulates chemokine release, monocyte/macrophage matrix migration and matrix metalloproteinase activity and plays an important role in atherosclerosis. In our study, we have evaluated whether RANKL gene polymorphisms are involved in ischemic stroke in Italian subjects. PATIENTS AND METHODS: In a retrospective study we have included 487 patients (242 males, 245 females) with history of ischemic stroke and 543 control subjects without history of ischemic stroke (277 males, 276 females). The rs9533156, and rs2277438 gene polymorphisms of the RANKL gene were analyzed by PCR and restriction fragment length polymorphism. RESULTS: We found that the rs9533156 gene polymorphism of the RANKL gene was significantly (55.0% versus 36.5%, p < 0.0001) and independently (adjusted OR 6.28 [2.34-4.21]) associated with history of ischemic stroke. No statistically significant difference was found between the two groups in our population for the rs2277438 gene polymorphism (p = 439). Furthermore, we have confirmed that rs 3134069, rs 2073617 and rs 2073618 polymorphisms of the OPG gene were significantly and independently associated with cerebrovascular disorders. CONCLUSIONS: The present study identifies, for the first time, the genetic variant of RANKL as an independent risk factor for ischemic stroke.

Fibroblast growth factor 23 serum level in type 2 diabetic italian subjects with peripheral arterial disease and critical limb ischemia.

OBJECTIVE: Fibroblast growth factor 23 (FGF23) was demonstrated to be involved in the occurrence and development of cardiovascular disease (CVD). The aim of this study was to investigate the potential role of FGF23 on presence and severity of peripheral arterial disease (PAD) in type 2 diabetic patients. PATIENTS AND METHODS: In this study, we analyzed FGF23 serum levels in 413 type 2 diabetic patients with PAD and in 598 diabetic controls without lower limbs atherosclerosis. RESULTS: We found that FGF23 median serum levels were significantly higher in patients than in diabetic controls (69.3 (58.8-75.1) pg/mL in PAD and 42.98 (37.1-49.8) pg/mL in subjects without PAD (p < 0.001) and were significantly and independently associated with critical limb ischemia (CLI) [OR, 7.69 (2.64-16.31); p = 0.001]. CONCLUSIONS: We have found, for the first time, that FGF23 could be associated with presence and severity of PAD in Italian patients with type 2 diabetes.

The role of high-mobility group box protein 1 in collagen antibody-induced arthritis is dependent on vascular endothelial growth factor.

High-mobility group box 1 (HMGB1) has been implicated in angiogenesis and rheumatoid arthritis (RA). The aim of this study was to define more clearly the role of HMGB1 in the synovial angiogenesis and pathogenesis of an immune model of arthritis. BALB/c mice were injected with monoclonal anti-collagen antibody cocktail followed by lipopolysaccharide to induce arthritis. HMGB1 and vascular endothelial growth factor (VEGF) were over-expressed in the areas of the synovium where more inflammation and neoangiogenesis were present. The selective blockade of HMGB1 or VEGF resulted alternatively in a lower severity of arthritis evaluated by the arthritis index. Furthermore, exogenous HMGB1 administration caused a worsening of arthritis, associated with VEGF up-regulation and increased synovial angiogenesis. The selective inhibition of VEGF also resulted in no induction of arthritis in mice receiving exogenous HMGB1. Cytokine enzyme-linked immunosorbent assay (ELISA) analyses performed on peripheral blood and synovial fluid demonstrated a significant reduction of interleukin (IL)-1ß, IL-6 and tumour necrosis factor (TNF)-α in mice where HMGB1 and VEGF pathways were blocked. Interestingly, the selective blockade of HMGB1 and VEGF resulted in an increase of the peripheral IL-17A concentration. The development of arthritis mediated by HMGB1 and the synovial angiogenesis can be blocked by inhibiting the VEGF activity. The proinflammatory and proangiogenic cytokine IL-17A was increased when HMGB1 is inhibited, but the synovial angiogenesis was nevertheless reduced in this model of arthritis. Taken together, these findings shed new light on the role of this nuclear protein in the pathogenesis of arthritis in an RA-like model.

Peroxisome proliferator-activated receptors and angiogenesis.

The peroxisome proliferator-activated receptors (PPARs) are a group of three nuclear receptor isoforms, PPARalpha, PPARgamma and PPARdelta, encoded by different genes, and they form a subfamily of the nuclear receptor superfamily. The clinical interest in PPARs originates with fibrates and thiazolidinediones, which, respectively, act on PPARalpha and PPARgamma and are used to ameliorate hyperlipidaemia and hyperglycaemia in subjects with type 2 diabetes mellitus (T2DM). PPARs play a central role in these patients due to their ability to regulate the expression of numerous genes involved in glycaemic control, lipid metabolism, vascular tone and inflammation. Abnormal angiogenesis is implicated in several of the long-term complications of diabetes mellitus, characterized by vasculopathy associated with aberrant growth of new blood vessels. This pathological process plays a crucial role in diabetic retinopathy, nephropathy and neuropathy, impaired wound healing and impaired coronary collateral vessel development. In recent years, there has been increasing appreciation of the fact that PPARs might be involved in the molecular mechanisms that regulate angiogenesis through the action of growth factors and cytokines that stimulate migration, proliferation and survival of endothelial cells. During the last few years direct comparative analyses have been performed, using selective PPARs agonists, to clarify the angiogenic properties of the different members of the PPAR family. Lately, the findings provide new information to order to understand the biological, clinical and therapeutic effects of PPARs, and the role of these nuclear receptors in angiogenesis, with potentially important implications for the management of subjects affected by T2DM.

Pro-inflammatory genetic profiles in subjects with peripheral arterial occlusive disease and critical limb ischemia.

OBJECTIVES: Single nucleotide polymorphisms in genes encoding inflammatory molecules may determine genetic profiles associated with increased risk of development and progression of cardiovascular diseases. In this study, we evaluated distribution and reciprocal interaction of a set of functionally important polymorphisms of genes encoding prototypical inflammatory molecules in subjects with peripheral arterial occlusive disease (PAOD) and critical limb ischemia (CLI). We also investigated whether synergistic interactions between these pro-inflammatory gene polymorphisms influence the risk of PAOD and CLI. DESIGN, SUBJECTS AND METHODS: In a genetic association study that included 157 PAOD patients and 206 controls, the following gene polymorphisms were analysed: C-reactive protein (CRP) 1059 G/C, interleukin-6 (IL-6)-174 G/C, macrophage migration inhibitory factor (MIF)-173 G/C, monocyte chemoattractant protein (MCP-1) - 2518 A/G, E-selectin (E-Sel) Ser128Arg, intercellular adhesion molecule-1 (ICAM-1) 469 E/K, matrix metalloproteinase (MMP)-1 -1607 1G/2G, MMP-3-1171 5A/6A and MMP-9-1563 C/T. RESULTS: We found that IL-6, E-sel, ICAM-1, MCP-1, MMP-1 and MMP-3 gene polymorphisms were significantly and independently associated with PAOD. We also found that these pro-inflammatory polymorphisms determine genetic profiles that are associated with different levels of risk for PAOD and CLI, depending on the number of high-risk genotypes concomitantly carried by a given individual. CONCLUSIONS: Pro-inflammatory genetic profiles are significantly more common in subjects with PAOD. Synergistic effects between pro-inflammatory genotypes might be potential markers for the presence and severity of atherosclerotic disorders.